Werewolf (NASDAQ: HOWL) to combine with Ambros in stock merger
Rhea-AI Filing Summary
Werewolf Therapeutics, Inc. (HOWL) entered into a definitive all‑stock merger agreement to combine with Ambros Therapeutics, with Ambros becoming a wholly owned subsidiary and the combined company expected to operate as Ambros Therapeutics and trade on Nasdaq as “AMBX.” Ambros stockholders will receive Werewolf common stock or pre‑funded warrants based on an exchange ratio reflecting an implied $500.0 million valuation for Ambros and $47.5 million for Werewolf.
On a fully diluted, treasury‑stock basis, pre‑merger Werewolf holders (excluding PIPE participants) are expected to own 6.8% of the combined company, pre‑merger Ambros stockholders 71.7%, and PIPE investors 21.5%, subject to adjustments including Werewolf net cash. Concurrently, Werewolf agreed to a $150.0 million private placement of common stock and PIPE pre‑funded warrants, with proceeds expected to fund Ambros’s pivotal CRPS‑RISE Phase 3 trial of neridronate and a planned NDA submission, providing cash runway into the first half of 2029. Existing Werewolf holders will receive one non‑transferable contingent value right per share tied to potential monetization of Werewolf’s legacy INDUKINE assets.
Positive
- $150.0 million oversubscribed PIPE financing provides substantial capital, with Ambros expecting the combined company to be fully funded through pivotal CRPS‑RISE Phase 3 topline data in 2028, a planned NDA submission, and cash runway into the first half of 2029.
- Ambros’s lead asset neridronate targets CRPS‑1, a severely debilitating orphan disease with ~65,000 newly diagnosed U.S. patients annually and currently no FDA‑approved therapies, creating a large unmet‑need market.
- Pro forma ownership concentrates 71.7% of the combined company with Ambros holders and 21.5% with new institutional PIPE investors, aligning control and capital with the neridronate program that will define the combined company’s strategy.
Negative
- Pre‑merger Werewolf stockholders (excluding PIPE participants) are expected to own only 6.8% of the combined company on a fully diluted basis, indicating significant dilution and a change of control away from existing HOWL holders.
- Ambros may owe Werewolf a termination fee of $20.0 million and Werewolf may owe Ambros $1.9 million in certain deal‑failure scenarios, introducing additional financial risk if the transaction is not completed.
- Closing is contingent on numerous conditions, including at least $100.0 million of PIPE cash proceeds, effectiveness of the Form S‑4, shareholder approvals, Nasdaq listing conditions, and Werewolf Final Net Cash being greater than $0.
Filing Explained
The merger and $150.0 million financing remain unclosed; issuance and the ownership shift await approvals, an effective S-4 and financing conditions.
The
The release calls the PIPE “secured commitments,” but the agreement makes its closing conditional and requires Werewolf to receive at least
Pre-funded warrants are near-full-price instruments with nominal exercise prices that convert to shares on exercise; here, the merger and PIPE warrants carry a
Support agreements cover approximately
8-K Event Classification
Key Figures
Key Terms
Pre-Funded Warrants financial
Contingent Value Rights Agreement financial
Beneficial Ownership Limitation financial
Reverse Stock Split Proposal financial
Orphan Drug designations medical
triple-blind, placebo-controlled medical
FAQ
What did Werewolf Therapeutics (HOWL) announce regarding Ambros Therapeutics?
How will ownership of the combined Werewolf (HOWL) and Ambros company be split?
What is the size and structure of Werewolf’s (HOWL) concurrent PIPE financing?
What are the implied valuations for Werewolf (HOWL) and Ambros in this merger?
What contingent value rights (CVRs) will Werewolf (HOWL) stockholders receive?
How long is the combined Werewolf–Ambros company expected to be funded?
What key regulatory designations does neridronate have in CRPS‑1?
AI-generated analysis. How Rhea-AI works. Not financial advice.
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM
CURRENT REPORT
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| Item 1.01 | Entry into a Material Definitive Agreement |
Merger Agreement
On August 21, 2026, Werewolf Therapeutics, Inc., a Delaware corporation (“Werewolf”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) by and among Ambros Therapeutics, Inc., a Delaware corporation (“Ambros”), Werewolf, and Wave Atlantis Merger Sub, Inc., a Delaware corporation and a direct, wholly owned subsidiary of Werewolf (“Merger Sub”).
Pursuant to the Merger Agreement, and upon the terms and subject to the satisfaction of the conditions described therein, Merger Sub will be merged with and into Ambros, with Ambros surviving as a wholly owned subsidiary of Werewolf (the “Merger” and, together with the other transactions contemplated by the Merger Agreement, the “Contemplated Transactions”). The Merger is intended to qualify as a tax-free reorganization for U.S. federal income tax purposes.
Subject to the terms and conditions of the Merger Agreement, (i) immediately prior to the effective time of the Merger (the “Effective Time”), the then-outstanding shares of Ambros preferred stock, par value $0.00001 per share, will be converted into shares of Ambros common stock, par value $0.00001 per share (“Ambros Common Stock”) and (ii) at the Effective Time, each then-outstanding share of Ambros Common Stock (excluding shares held by stockholders who have exercised and perfected appraisal rights for such shares) will be converted into the right to receive a number of shares of Werewolf common stock, par value $0.0001 per share (“Werewolf Common Stock”), calculated in accordance with the exchange ratio as set forth in the Merger Agreement and subject to any election pursuant to the terms of the Merger Agreement to receive pre-funded warrants to acquire Werewolf Common Stock with an exercise price of $0.0001 per share (“Merger Pre-Funded Warrants”) in lieu of any shares of Werewolf Common Stock in excess of the Beneficial Ownership Limitation (as defined in the Merger Agreement). In addition, at the Effective Time, each then-outstanding option to purchase shares of Ambros Common Stock will be assumed by Werewolf and converted into an option to acquire Werewolf Common Stock, with the number of underlying shares and exercise price adjusted in accordance with the exchange ratio as set forth in the Merger Agreement.
At the closing of the Merger (the “Closing” and such date, the “Closing Date”), on a pro forma basis and based upon the number of shares of Werewolf Common Stock and Merger Pre-Funded Warrants and pre-funded warrants to purchase shares of Werewolf Common Stock with an exercise price of $0.001 per share expected to be issued in connection with the Concurrent PIPE Financing (as defined below) (“PIPE Pre-Funded Warrants” and, together with the Merger Pre-Funded Warrants, the “Pre-Funded Warrants”), pre-merger equityholders of Werewolf, other than those participating in the private placement, are expected to own approximately 6.8% of the combined company, pre-merger Ambros stockholders are expected to own approximately 71.7% of the combined company and Investors (as defined below) participating in the private placement are expected to own approximately 21.5% of the combined company, in each case, calculated on a fully diluted basis, using the treasury stock method, and subject to certain assumptions, including (i) an implied valuation for Werewolf of $47.5 million, (ii) a valuation for Ambros of $500.0 million, and (iii) the relative capitalization of Werewolf and Ambros. The percentage of the combined company that each party’s equity holders will own following the Closing is subject to certain adjustments as described in the Merger Agreement.
The Merger Agreement contains representations and warranties of the parties regarding their respective businesses. The Merger Agreement also contains certain covenants made by each of Werewolf and Ambros, including non-solicitation restrictions binding each party and its representatives (subject to certain exceptions as further described in the Merger Agreement) and restrictions on the operation of each party’s business between the date of the Merger Agreement and the Closing.
In connection with the Merger, Werewolf, in cooperation with Ambros, will prepare and file with the Securities and Exchange Commission (the “SEC”) a registration statement on Form S-4 (the “Form S-4”), which will contain a proxy statement to be used by Werewolf to solicit approval of the applicable stockholder matters at a special meeting of Werewolf stockholders (the “Werewolf Stockholder Meeting”). Promptly after the Form S-4 is declared effective, Ambros will, in cooperation with Werewolf, solicit an action by written consent from the requisite Ambros stockholders to approve the Merger Agreement and Contemplated Transactions. At the Werewolf
Stockholder Meeting, Werewolf stockholders will be asked to approve, among other matters, (i) the issuance of Werewolf Common Stock in the Merger and the resulting change of control for purposes of The Nasdaq Stock Market (“Nasdaq”) rules, (ii) if required, the issuance of securities in the Concurrent PIPE Financing pursuant to Nasdaq Listing Rule 5635(d) (clauses (i) and (ii), the “Nasdaq Proposals”), and (iii) amendments to Werewolf’s certificate of incorporation (including a name change (the “Name Change Proposal”), a reverse stock split (the “Reverse Stock Split Proposal” and, together with the Nasdaq Proposals and the Name Change Proposal, the “Werewolf Stockholder Matters”) and an increase in authorized Werewolf Common Stock), and (iv) the equity plan proposals described in the Merger Agreement. Werewolf’s obligation to call, give notice of and hold the Werewolf Stockholder Meeting is not limited or otherwise affected by the commencement, disclosure, announcement or submission of any Superior Offer, any Acquisition Proposal or Acquisition Inquiry (each as defined in the Merger Agreement), or certain specified events relating to a change in the recommendation of the Werewolf board of directors.
The Closing is subject to certain closing conditions, including: (i) the approval by the requisite Ambros stockholders of the adoption and approval of the Merger Agreement and the Contemplated Transactions; (ii) the approval by the requisite Werewolf stockholders of the Werewolf Stockholder Matters; (iii) the existing shares of Werewolf Common Stock having been continually listed on Nasdaq and the approval of the listing of the shares of Werewolf Common Stock and the shares of Werewolf Common Stock underlying the Pre-Funded Warrants on Nasdaq; (iv) the Securities Purchase Agreement (as defined below) being in full force and effect with cash proceeds of not less than $100.0 million (less applicable expenses) having been received by Werewolf; (v) the effectiveness of the Form S-4; and (vi) Final Werewolf Net Cash (as defined in the Merger Agreement) being greater than $0. The Closing is also subject to other specified customary closing conditions of each party, including the accuracy of each party’s representations and warranties, subject to applicable materiality qualifications, compliance by each party with its covenants under the Merger Agreement in all material respects, respectively, delivery of certain customary closing documents by each of Werewolf and Ambros, and no Werewolf material adverse effect or Ambros material adverse effect having occurred since the date of the Merger Agreement that is continuing, respectively.
Either party may be required to pay a termination fee in the event of termination of the Merger Agreement in certain circumstances. A termination fee of $20.0 million may become payable by Ambros to Werewolf if the Merger Agreement is terminated by (a) Werewolf following certain specified events relating to a change in the recommendation of the Ambros board of directors or certain other actions by Ambros relating to an acquisition proposal, (b) by Ambros concurrently with Ambros’s entry into a definitive agreement with respect to a Superior Offer (as defined in the Merger Agreement), subject to certain requirements set forth in the Merger Agreement, or (c) in certain circumstances following termination of the Merger Agreement if an acquisition proposal with respect to Ambros had been made prior to such termination and Ambros enters into or consummates an Acquisition Transaction (as defined in the Merger Agreement) within 12 months following such termination. A termination fee of $1.9 million may become payable by Werewolf to Ambros if the Merger Agreement is terminated by (a) Ambros following certain specified events relating to a change in the recommendation of the Werewolf board of directors or certain other actions by Werewolf relating to an acquisition proposal or (b) in certain circumstances following termination of the Merger Agreement if an acquisition proposal with respect to Werewolf had been made prior to such termination and Werewolf enters into or consummates an Acquisition Transaction within 12 months following such termination.
Support Agreements
Concurrently with the execution of the Merger Agreement, the executive officers and directors of Werewolf holding approximately 1.4% of the outstanding Werewolf Common Stock entered into support agreements (the “Werewolf Support Agreements”) in favor of Ambros, providing among other things, that such officers and directors will vote all of their eligible shares of Werewolf capital stock in favor of, among other things the Werewolf Stockholder Matters.
Concurrently with the execution of the Merger Agreement, certain officers and directors and certain other stockholders of Ambros holding approximately 71.3% of the outstanding Ambros Common Stock (on an as-converted basis) entered into support agreements (the “Ambros Support Agreements” and, together with the Werewolf Support Agreements, the “Support Agreements”) in favor of Werewolf, providing among other things, that such officers, directors and stockholders will vote all of their shares of Ambros capital stock, among other things, in favor of approving the Merger Agreement and Contemplated Transactions.
Lock-Up Agreements
Concurrently with the execution of the Merger Agreement, certain executive officers, directors and certain other stockholders of Ambros entered into lock-up agreements (the “Ambros Lock-Up Agreements”), pursuant to which, subject to specified exceptions, such persons accepted certain restrictions on transfers of the shares of Werewolf Common Stock, Merger Pre-Funded Warrants, and any other securities convertible into or exercisable or exchangeable for Werewolf Common Stock, in each case, received in connection with the Merger for the 180-day period following the Effective Time.
Pre-Funded Warrants
Each PIPE Pre-Funded Warrant and each Merger Pre-Funded Warrant has an exercise price of $0.001 per share of Werewolf Common Stock. The Pre-Funded Warrants will be exercisable at any time and from time to time on or after the Effective Time until exercised in full. A holder (together with its affiliates and other attribution parties) may not exercise any portion of a Pre-Funded Warrant to the extent that, immediately after giving effect to such exercise, the holder would own more than a specified percentage of the outstanding common stock of the combined company (9.99%), which percentage may be increased at the holder’s option (not to exceed 19.99%) upon 61 days’ notice, subject to the terms of the Pre-Funded Warrants.
The foregoing descriptions of the Merger Agreement, the form of PIPE Pre-Funded Warrant, the form of Merger Pre-Funded Warrant, the form of Werewolf Support Agreement, the form of Ambros Support Agreement, and the form of Ambros Lock-Up Agreement, (collectively, the “Agreements”), do not purport to be complete and are qualified in their entirety by reference to those Agreements, which are filed as Exhibits 2.1, 4.1, 4.2, 10.1, 10.2, and 10.3, respectively, to this Current Report on Form 8-K and are incorporated herein by reference. In particular, the assertions embodied in the representations and warranties contained in the Merger Agreement are qualified by information in confidential disclosure schedules provided by each of Werewolf and Ambros in connection with the signing of the Merger Agreement. These confidential disclosure schedules contain information that modifies, qualifies and creates exceptions to the representations and warranties and certain covenants set forth in the Merger Agreement. Moreover, certain representations and warranties in the Agreements were used for the purpose of allocating risk between the parties thereto rather than establishing matters as facts. Accordingly, the representations and warranties may not describe the actual state of affairs at the date they were made or at any other time, and investors should not rely on them as statements of fact.
Werewolf Contingent Value Rights Agreement
In connection with the Merger and immediately prior to the Effective Time, Werewolf is expected to enter into a Contingent Value Rights Agreement (the “CVR Agreement”), with a nationally recognized rights agent agreed to between Werewolf and Ambros (“Rights Agent”) pursuant to which Werewolf will distribute to each holder of Werewolf Common Stock of record as of the close of business on the last business day prior to the Effective Time one non-transferable contingent value right (each, a “CVR”) for each outstanding share of Werewolf Common Stock held by such stockholder as of such date. Each CVR represents the right to receive contingent cash payments (any such cash payments, “CVR Payment Amounts”) in respect of certain of Werewolf’s legacy assets, consisting of Werewolf’s conditionally activated INDUKINE programs, WTX-124 and WTX-330 (together, the “Legacy Assets”), pursuant to the terms and conditions of the CVR Agreement.
The CVR Payment Amounts, if any, will become payable to the Rights Agent for subsequent distribution to the CVR holders in accordance with the terms of the CVR Agreement. In the event that no such proceeds are received during the CVR Term (as defined in the CVR Agreement), holders of the CVRs will not receive any payment pursuant to the CVR Agreement. There can be no assurance that the CVR holders will receive any payments with respect to the CVR Agreement.
The CVRs will not be evidenced by a certificate or any other instrument and will not be registered with the SEC. The CVRs will not have any voting or dividend rights. The CVRs are solely contractual rights and will not constitute equity or ownership interests in Werewolf, or any of its respective affiliates, and Werewolf has agreed to cooperate, including by making changes to the CVR Agreement, as necessary to ensure that the CVRs are not subject to registration under the Securities Act of 1933, as amended (the “Securities Act”), the Exchange Act of 1934, as amended (the “Exchange Act”), or applicable state securities or “blue sky” laws. The CVRs are not transferable except in limited circumstances specified in the CVR Agreement.
The foregoing description of the CVR Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the CVR Agreement, which is attached hereto as Exhibit 10.6 and incorporated herein by reference.
Concurrent PIPE Financing
Concurrently with entering into the Merger Agreement, Werewolf entered into a securities purchase agreement (the “Securities Purchase Agreement”) with certain qualified institutional buyers or accredited investors (the “Investors”). Pursuant to the Securities Purchase Agreement, and subject to the terms and conditions therein, Werewolf agreed to sell, and the Investors agreed to purchase, immediately prior to the Closing of the Merger, shares of Werewolf Common Stock (the “Shares”) and, in the case of certain Investors, in lieu of shares of Werewolf Common Stock, PIPE Pre-Funded Warrants (together with the Shares, the “Securities”) for an aggregate purchase price of $150.0 million (the “Concurrent PIPE Financing”). The closing of the Concurrent PIPE Financing is anticipated to occur immediately prior to the Closing of the Merger, subject to the satisfaction of customary closing conditions.
The purchase price per Share of Werewolf Common Stock will be determined prior to Closing, and will equal the aggregate gross proceeds of the Concurrent PIPE Financing divided by the number of shares of Werewolf Common Stock allocated to the Investors pursuant to the framework in the Merger Agreement. Werewolf is obligated to notify the Investors of the purchase price at least three business days prior to Closing. The purchase price per share of Werewolf Common Stock underlying each PIPE Pre-Funded Warrant will be equal to the purchase price of one share of Werewolf Common Stock, less the $0.001 exercise price.
The PIPE Pre-Funded Warrants will be exercisable at any time and from time to time on or after the Effective Time until exercised in full. A holder (together with its affiliates and other attribution parties) may not exercise any portion of a PIPE Pre-Funded Warrant to the extent that, immediately after giving effect to such exercise, the holder would own more than a specified percentage of the outstanding common stock of the combined company (ranging from 4.99% to 9.99%, as applicable), which percentage may be increased or decreased at the holder’s option (not to exceed 19.99%) upon 61 days’ notice, subject to the terms of the PIPE Pre-Funded Warrants.
The Securities Purchase Agreement contains customary representations and warranties of Werewolf and the Investors, and certain customary conditions to closing.
Werewolf has also agreed to enter into a registration rights agreement (the “Registration Rights Agreement”) with the Investors at the closing of the Concurrent PIPE Financing. Pursuant to the Registration Rights Agreement, the combined company will prepare and file a resale registration statement with the SEC within 45 calendar days following the Closing Date. The combined company will use its reasonable best efforts to cause such registration statement to become effective at the earliest possible date but no later than the earlier of the 75th calendar day following the initial filing date of the registration statement if the SEC notifies the combined company that it will review the registration statement and the third business day after the date the combined company is notified that the SEC will not review the registration statement.
The combined company will also agree to, among other things, indemnify the Investors, their members, shareholders, directors, officers, partners, employees, managers, agents, representatives and advisors under the Registration Rights Agreement from certain liabilities and pay all fees and expenses (excluding underwriting discounts and selling commissions and all similar fees and commissions relating to an Investor’s disposition of its Registrable Securities (as defined in the Registration Rights Agreement)) incident to the combined company’s obligations under the Registration Rights Agreement.
Werewolf and Ambros engaged Leerink Partners LLC, Piper Sandler & Co., Cantor Fitzgerald & Co., Wells Fargo Securities, LLC and LifeSci Capital LLC as placement agents for the Concurrent PIPE Financing, and agreed to pay customary placement fees and reimburse certain expenses of the placement agents.
The foregoing descriptions of the Securities Purchase Agreement, the PIPE Pre-Funded Warrants and Registration Rights Agreement do not purport to be complete and are qualified in their entirety by reference to the form of Securities Purchase Agreement, the form of PIPE Pre-Funded Warrant and the form of Registration Rights Agreement, which are filed as Exhibits 10.4, 4.1 and 10.5, respectively, to this Current Report on Form 8-K and are incorporated herein by reference.
| Item 3.02 | Unregistered Sales of Equity Securities |
To the extent required by this Item, the information included in Item 1.01 of this Current Report on Form 8-K is incorporated herein by reference.
The offering and sale of the Shares and the PIPE Pre-Funded Warrants in the Concurrent PIPE Financing will be made in reliance on the exemption from registration under Section 4(a)(2) of the Securities Act. The Investors represented that they are qualified institutional buyers or accredited investors, as such term is defined in Rule 501(a) of Regulation D under the Securities Act, and that they are acquiring the securities for investment purposes only and not with a view to any resale, distribution or other disposition of the securities in violation of the U.S. federal securities laws.
The securities to be issued in the Concurrent PIPE Financing will not be registered under the Securities Act or any state securities laws upon issuance and may not be offered or sold in the United States absent registration under the Securities Act or an applicable exemption from the registration requirements. The offering and sale of the securities in the Concurrent PIPE Financing did not involve a public offering.
Neither this Current Report on Form 8-K nor any of the exhibits attached hereto is an offer to sell or the solicitation of an offer to buy any securities of Werewolf or Ambros.
| Item 7.01 | Regulation FD Disclosure |
On August 21, 2026, Werewolf and Ambros issued a press release announcing the execution of the Merger Agreement and the Securities Purchase Agreement. A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K. In addition, Werewolf and Ambros made available a presentation to be used with investors to discuss the proposed Merger. A copy of the corporate presentation is attached hereto as Exhibit 99.2 to this Current Report on Form 8-K.
The information in Item 7.01 of this Current Report on Form 8-K, including the information in the press release attached as Exhibit 99.1 and the corporate presentation attached as Exhibit 99.2 to this Current Report on Form 8-K is furnished pursuant to Item 7.01 of Form 8-K and shall not be deemed “filed” for the purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section. Furthermore, the information in Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.1 and Exhibit 99.2 to this Current Report on Form 8-K, shall not be deemed to be incorporated by reference in the filings of Werewolf under the Securities Act.
Use of Website to Distribute Material Non-Public Information
Werewolf’s Investor Relations website is https://investors.werewolftx.com/. Werewolf uses its Investor Relations website as a means of disclosing material non-public information and for the purpose of complying with its disclosure obligations under Regulation FD. Therefore, Werewolf encourages investors, the media and others interested in Werewolf to review the information it posts on its Investor Relations website.
Important Additional Information and Where to Find It
In connection with the proposed transaction between Werewolf and Ambros, Werewolf will file relevant materials with the SEC, including the Form S-4, which will include a proxy statement relating to the proposed transaction, and a prospectus, of Werewolf (the “Proxy Statement/Prospectus”). This Current Report on Form 8-K and the exhibits filed or furnished herewith are not a substitute for the Proxy Statement/Prospectus or any other document which Werewolf may file with the SEC or send to stockholders of Werewolf or Ambros in connection with the proposed transaction. The Proxy Statement/Prospectus will be mailed to stockholders of Werewolf. INVESTORS AND SECURITYHOLDERS OF WEREWOLF ARE URGED TO READ THE REGISTRATION STATEMENT AND THE PROXY STATEMENT/PROSPECTUS AND ALL OTHER DOCUMENTS FILED OR THAT WILL BE FILED WITH THE SEC CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT WEREWOLF, AMBROS AND THE PROPOSED TRANSACTION. Investors and securityholders will be able to obtain free copies of the Form S-4 and the Proxy Statement/Prospectus (when available) and other documents filed with the SEC by Werewolf through the website maintained by the SEC at www.sec.gov. Copies of the documents filed with the SEC by Werewolf will also be available free of charge on Werewolf’s website at https://investors.werewolftx.com/financial-information/sec-filings.
No Offer or Solicitation
This Current Report on Form 8-K and the exhibits filed or furnished herewith are for informational purposes only and not intended to and does not constitute an offer to subscribe for, buy or sell, or the solicitation of an offer to subscribe for, buy or sell, or an invitation to subscribe for, buy or sell, any securities of Werewolf or Ambros, or the solicitation of a proxy, consent, any vote or approval in any jurisdiction pursuant to or in connection with the proposed transaction or otherwise, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in contravention of applicable law. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended, or pursuant to an applicable exemption from the registration requirements thereof, and otherwise in accordance with applicable law.
NEITHER THE SEC NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THE SECURITIES OR DETERMINED IF THIS CURRENT REPORT ON FORM 8-K AND THE EXHIBITS FILED OR FURNISHED HEREWITH ARE TRUTHFUL OR COMPLETE.
Participants in the Solicitation
This communication is not a solicitation of a proxy from any securityholder of Werewolf or Ambros. However, Werewolf and Ambros and each of their respective directors and executive officers may be deemed to be participants in the solicitation of proxies in connection with the proposed transaction. Information about the directors and executive officers of Werewolf may be found in its Annual Report on Form 10-K for the year ended December 31, 2025, which was filed with the SEC on March 27, 2026 and in subsequent documents filed with the SEC. Other information regarding the participants in the proxy solicitations and a description of their direct and indirect interests, by security holdings or otherwise, will be contained in the Proxy Statement/Prospectus relating to the proposed transaction when it is filed with the SEC. Such documents can be obtained free of charge from the sources indicated above.
Cautionary Statements Regarding Forward-Looking Statements
This Current Report on Form 8-K contains “forward-looking statements” within the meaning of the federal securities laws, including Section 27A of the Securities Act, and Section 21E of the Exchange Act. In this context, forward-looking statements often address expected future business and financial performance and often contain words such as “expect,” “anticipate,” “intend,” “plan,” “believe,” “seek,” “will,” “would,” “target,” and similar expressions. Forward-looking statements by their nature address matters that involve risks and uncertainties, many of which are beyond Werewolf’s and Ambros’s control and are not guarantees of future results, including statements about the potential transaction, the structure, timing and completion of the potential transaction, the expected ownership structure of the combined company, the expected listing of the combined company’s common stock on Nasdaq, the Concurrent PIPE Financing, future financial and operating results, potential contingent value right payments, and combined company strategy and operations. These forward-looking statements reflect Werewolf’s and Ambros’s management’s, as applicable, good faith judgment based on facts and factors currently known to them. Werewolf and Ambros caution investors not to place undue reliance on any such forward-looking statements.
These and other forward-looking statements are not guarantees of future results and are subject to risks, uncertainties and assumptions that could cause actual results to differ materially from those expressed in any forward-looking statements. Important factors that could cause actual results to differ materially include, but are not limited to: (i) the satisfaction or waiver of closing conditions to the potential transaction in the anticipated timeframe or at all; (ii) the risk that the Concurrent PIPE Financing may not be completed in a timely manner or at all; (iii) the risk that the potential transaction disrupts current plans and operations or diverts management’s attention from ongoing business operations and makes it more difficult to maintain business and operational relationships; (iv) the risk that the anticipated benefits and synergies of the potential transaction will not be realized or will take longer to realize than expected; (v) the magnitude of transaction costs associated with the potential transaction and the Concurrent PIPE Financing; (vi) the occurrence of any event, change or other circumstance that could give rise to the termination of the Merger Agreement; and (vii) those additional risks and uncertainties set forth more fully under the caption “Risk Factors” in Werewolf’s most recently filed Quarterly Report on Form 10-Q filed with the SEC, and elsewhere in Werewolf’s filings and reports with the SEC. Forward-looking statements necessarily involve assumptions that, if they do not materialize or prove correct, could cause actual results to differ materially from those expressed or implied by such forward-looking statements. Forward-looking statements contained in this Current Report on Form 8-K are made as of the date hereof, and neither Werewolf nor Ambros undertake any duty to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required under applicable law.
| Item 9.01 | Financial Statements and Exhibits |
| Exhibit No. |
Description | |
| 2.1* | Agreement and Plan of Merger, dated as of August 21, 2026, by and among Ambros Therapeutics, Inc., Werewolf Therapeutics, Inc., and Wave Atlantis Merger Sub, Inc. | |
| 4.1 | Form of PIPE Pre-Funded Warrant | |
| 4.2 | Form of Merger Pre-Funded Warrant | |
| 10.1 | Form of Werewolf Stockholder Support Agreement | |
| 10.2 | Form of Ambros Stockholder Support Agreement | |
| 10.3 | Form of Ambros Lock-Up Agreement | |
| 10.4 | Form of Securities Purchase Agreement, dated as of August 21, 2026, by and among Werewolf Therapeutics, Inc. and each of the Investors listed on Exhibit A thereto | |
| 10.5 | Form of Registration Rights Agreement | |
| 10.6 | Form of CVR Agreement | |
| 99.1 | Press Release issued on August 21, 2026 | |
| 99.2 | Corporate Presentation dated August 21, 2026 | |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document). | |
| * | Certain schedules and attachments have been omitted pursuant to Item 601(a)(5) of Regulation S-K. Werewolf agrees to provide, on a supplemental basis, a copy of any omitted schedules and attachments to the SEC or its staff upon request. |
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
| Werewolf Therapeutics, Inc. | ||||||
| Date: August 21, 2026 | By: | /s/ Daniel J. Hicklin | ||||
| Daniel J. Hicklin, Ph.D. | ||||||
| President, Chief Executive Officer and Director | ||||||
Exhibit 99.1
Werewolf Therapeutics and Ambros Therapeutics Announce Merger Agreement and Concurrent Oversubscribed $150 million Private Placement
| • | Proposed merger to create a Nasdaq-listed, late-stage biotechnology company advancing neridronate, a potential first FDA-approved treatment for CRPS-1, a debilitating orphan disease with 65,000 newly diagnosed U.S. patients annually and no currently FDA-approved therapy |
| • | Pivotal CRPS-RISE Phase 3 trial evaluating neridronate remains ongoing, with FDA Breakthrough Therapy, Fast Track and Orphan Drug designations received and alignment with FDA that a single successful pivotal trial could potentially support approval |
| • | Neridronate has been administered to approximately 600,000 patients in Italy across approved indications including CRPS-1 |
| • | Concurrent oversubscribed private placement of $150 million from a syndicate of leading healthcare-dedicated investors expected to fund company operations through CRPS-RISE Phase 3 topline results and planned NDA submission, with cash runway into 1H 2029 |
WALTHAM, Mass. and SAN DIEGO, Calif. – August 21, 2026 – Werewolf Therapeutics, Inc. (Nasdaq: HOWL) and Ambros Therapeutics, Inc., today announced that they entered into a definitive merger agreement to combine the companies in an all-stock transaction. The combined company will focus on advancing Ambros Therapeutics’ neridronate development program in Complex Regional Pain Syndrome Type 1 (“CRPS-1”, formerly known as Reflex Sympathetic Dystrophy). Upon completion of the merger, the combined company will operate as Ambros Therapeutics, headquartered in San Diego, California, and is expected to trade under the Nasdaq ticker symbol “AMBX”.
In connection with the proposed merger, the companies secured commitments for an oversubscribed concurrent private placement of $150 million from a syndicate of leading healthcare-dedicated investors co-led by RA Capital Management and Janus Henderson Investors. The private placement includes participation from Aberdeen Investments, Adage Capital Partners, L.P., ADAR1 Capital Management, Affinity Asset Advisors, LLC, Arkin Bio Capital, Balyasny Asset Management, Patient Square Capital’s platform Enavate Sciences, SilverArc Capital, Sphera Healthcare, and Woodline Partners LP as well as other new and existing investors. The private placement is expected to close concurrently with the proposed merger, at which time Werewolf Therapeutics will issue common stock and pre-funded warrants for aggregate gross proceeds of $150 million. Ambros Therapeutics expects the combined company to be fully funded through topline results from the pivotal CRPS-RISE Phase 3 clinical trial expected in 2028 and a planned New Drug Application (“NDA”) submission to the U.S. Food and Drug Administration (“FDA”) for potential approval of neridronate in patients with CRPS-1, with cash runway into the first half of 2029.
“We are uniquely positioned to be advancing neridronate, a differentiated bisphosphonate with extensive prior clinical experience, in an FDA-aligned single Phase 3 trial supporting potential regulatory approval in patients with CRPS-1, a debilitating orphan disease with no currently FDA-approved therapy,” said Jay Hagan, Chief Executive Officer of Ambros Therapeutics. “With the capital raised through this financing from a leading investor syndicate, we expect to be fully funded through potentially value-generating topline results of our pivotal CRPS-RISE Phase 3 trial and have the resources to advance a potential NDA submission and commercial preparations. Our strengthened foundation resulting from today’s transformative announcement positions us to deliver value on behalf of patients, investors and all other stakeholders.”
“Following a comprehensive review of strategic options, management and the board of directors believe a merger with Ambros Therapeutics is in the best interest of Werewolf Therapeutics’ stockholders. The Ambros management team’s extensive track record, drug development expertise and the potential of neridronate to deliver a meaningful treatment to patients with CRPS-1 is very compelling,” said Daniel J. Hicklin, Ph.D., President and Chief Executive Officer of Werewolf Therapeutics. “Neridronate, which has received the FDA’s Breakthrough Therapy, Fast Track, and Orphan Drug designations, is a differentiated bisphosphonate with the potential to redefine the standard of care for patients with CRPS-1.”
Proceeds from the proposed transaction will be used to advance the clinical development of neridronate, a differentiated bisphosphonate that has demonstrated lasting pain reduction along with improvement in other CRPS-related symptoms.
Neridronate is advancing in the pivotal CRPS-RISE Phase 3 clinical trial (“CRPS-RISE”), a multicenter, randomized, triple-blind, placebo-controlled clinical trial designed to assess the efficacy, safety and tolerability of neridronate in patients with warm CRPS-1. CRPS-RISE leverages a precision medicine approach focused on diagnosed CRPS-1 patients in the warm-phase of the disease with positive triple-phase bone scans (“TPBS”), whose disease biology most closely aligns with neridronate’s proposed mechanism and where prior clinical evidence suggests the treatment effect may be greatest. The primary efficacy endpoint is change in pain intensity from baseline to week 12 as measured on an 11-point Numerical Rating Scale. Key secondary endpoints include other measures of pain reduction and patient reported outcomes. The program includes a registry for long-term outcomes and an
opportunity for CRPS-RISE participants with active disease who completed the study to receive neridronate. Based on interactions with the FDA, Ambros Therapeutics believes that positive results from a single pivotal trial such as CRPS-RISE could support potential U.S. approval. Ambros Therapeutics anticipates reporting topline data from CRPS-RISE in 2028. Along with Orphan Designation, Ambros Therapeutics’ intellectual property portfolio supports the potential for neridronate’s U.S. market exclusivity through 2045.
About the Proposed Merger
Under the terms of the merger agreement, Werewolf Therapeutics will issue to pre-merger Ambros Therapeutics stockholders shares of Werewolf Therapeutics common stock (or pre-funded warrants in lieu thereof) as merger consideration in exchange for the cancellation of shares of capital stock of Ambros Therapeutics, and Ambros Therapeutics will become a wholly owned subsidiary of Werewolf Therapeutics. Stockholders of Ambros Therapeutics will receive newly issued shares of Werewolf Therapeutics common stock (or pre-funded warrants in lieu thereof) pursuant to a formula set forth in the merger agreement. The exchange ratio is based on an implied value of Ambros Therapeutics of $500 million (before giving effect to the concurrent private placement) and an implied value of Werewolf Therapeutics of $47.5 million. Pre-merger Werewolf Therapeutics stockholders (other than those investors participating in the private placement) are expected to own approximately 6.8% of the combined company, pre-merger Ambros Therapeutics stockholders are expected to own approximately 71.7% of the combined company and investors participating in the private placement are expected to own approximately 21.5% of the combined company. The percentage of the combined company that pre-merger Ambros Therapeutics stockholders and pre-merger Werewolf Therapeutics stockholders will own upon the closing of the merger is further subject to adjustment based on the amount of Werewolf Therapeutics’ net cash at the time of closing. In connection with the closing of the proposed transactions, Werewolf Therapeutics stockholders (other than those investors participating in the private placement) will also be issued a contingent value right representing the right to receive certain payments from net proceeds received by the combined company, if any, related to dispositions of Werewolf Therapeutics’ pre-transaction legacy assets.
The merger agreement has been approved by the boards of directors of both companies. The transaction is expected to close by the first quarter of 2027, subject to certain closing conditions, including the approval by the stockholders of each company, the shares of Werewolf Therapeutics common stock issuable in the transaction having been approved for listing on Nasdaq, effectiveness of the registration statement on Form S-4 (the “Form S-4”) and the satisfaction of other customary closing conditions.
Additional information about the transaction will be provided in a Current Report on Form 8-K that will be filed by Werewolf Therapeutics with the Securities and Exchange Commission (the “SEC”) and will be available at www.sec.gov.
Leerink Partners, Piper Sandler, Cantor and Wells Fargo Securities are serving as placement agents for the concurrent private placement. LifeSci Capital is also serving as a placement agent. Cooley LLP is serving as legal counsel to Ambros Therapeutics. Piper Sandler is serving as the exclusive financial advisor, and Sidley Austin LLP is serving as legal counsel, to Werewolf Therapeutics. Latham & Watkins LLP is serving as legal counsel to the placement agents.
Management and Organization
Upon closing of the proposed transaction, the combined company will be led by current members of the Ambros Therapeutics leadership team including:
| • | Joseph (Jay) Hagan, Chief Executive Officer |
| • | Cris Calsada, Chief Financial Officer |
| • | Gail Cawkwell, M.D., Ph.D., Chief Medical Officer |
| • | Christopher Aker, General Counsel |
| • | Kunal Kishnani, SVP of Corporate Development |
Members of Ambros Therapeutics’ existing board of directors will become directors of the combined company.
About Neridronate
Neridronate is a differentiated bisphosphonate that was developed by Abiogen Pharma S.p.A. Neridronate is approved and marketed in Italy for the treatment of Complex Regional Pain Syndrome (“CRPS”); clinical studies have demonstrated lasting pain reduction along with improvements in other CRPS related symptoms. Beyond CRPS, neridronate is also approved in Italy for osteogenesis imperfecta and Paget’s disease and has been administered to approximately 600,000 patients across approved indications. Its well-established safety and tolerability profile and therapeutic benefits make it a potential promising treatment for patients with CRPS-1 worldwide. Recognizing its potential, the FDA has granted neridronate Breakthrough Therapy, Fast Track, and Orphan Drug designations for the treatment of CRPS.
About CRPS-1
CRPS-1 is a severely painful, debilitating orphan disease typically following a limb injury affecting an estimated 65,000 newly diagnosed people in the United States each year. There are currently no FDA-approved medicines available to treat this high unmet need patient population. The condition is characterized by intense pain that can be continuous in the affected limb such as the arm, leg, hand or foot. Patients with CRPS-1 often experience an evolving condition commencing with a “warm” phase that typically predominates in the first year after onset where inflammation and other mechanisms cause the affected limb to become red, swollen, warm, and hypersensitive to pain. In many patients, the disease progresses to a chronic “cold” phase, where the affected limb changes its presentation and patients face ongoing, debilitating pain.
About CRPS-RISE
CRPS-RISE is a Phase 3, multicenter, randomized, triple-blind, placebo-controlled clinical trial designed to assess the efficacy, safety and tolerability of neridronate in patients with warm CRPS-1. The trial will evaluate approximately 270 participants randomized 1:1 to receive either intravenous (“IV”) neridronate or placebo. To be eligible for the trial, participants must have a confirmed CRPS-1 diagnosis per the Budapest Clinical Criteria, a known precipitating event (e.g. fracture, sprain, contusion), CRPS-1 duration of 6 months or less and moderate to severe pain. Additionally, participants must have characteristics that Ambros Therapeutics believes make them more likely responders to neridronate treatment: a positive triple phase bone scan and specific attributes of the warm CRPS-1 subtype. Following an initial screening period of two to six weeks, participants will receive four IV infusions over 10 days of either 100 mg neridronate (400 mg total dose) or placebo followed by a post-treatment period through week 12. The primary efficacy endpoint is change in pain intensity from baseline to week 12 as measured on an 11-point Numerical Rating Scale. Key secondary endpoints include other measures of pain reduction and patient reported outcomes. The program includes a registry for long-term outcomes and an opportunity for CRPS-RISE participants with active disease who completed the study to receive neridronate.
About Ambros Therapeutics
Ambros Therapeutics, headquartered in San Diego, California, is a clinical-stage biotechnology company focused on the development of innovative and transformative medicines for diseases with high unmet medical need. Ambros Therapeutics’ lead investigational program, neridronate, is currently being evaluated in an ongoing pivotal Phase 3 clinical trial for warm CRPS-1. Neridronate has the potential to become the first FDA-approved pharmacological therapy addressing patients with CRPS-1.
About Werewolf Therapeutics
Werewolf Therapeutics is an innovative biopharmaceutical company pioneering the development of therapeutics engineered to stimulate the body’s immune system for the treatment of cancer and other immune-mediated conditions. Werewolf Therapeutics has leveraged its proprietary PREDATOR® platform to design conditionally activated INDUKINE™ molecules that stimulate both adaptive and innate immunity with the goal of addressing the limitations of conventional proinflammatory immune therapies. Werewolf’s INDUKINE molecules are intended to remain inactive in peripheral tissue yet activate selectively in the tumor microenvironment. Werewolf Therapeutics’ most advanced clinical stage product candidates, WTX-124 and WTX-330, are systemically delivered, conditionally activated Interleukin-2 and Interleukin-12 INDUKINE molecules, respectively, for the treatment of solid tumors.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements concerning expectations regarding or plans for the combined company’s pipeline, the synergies or benefits of the proposed transaction, including future financial and operating results, plans, objectives, expectations and intentions, the anticipated timing of closing of the proposed transaction and the concurrent private placement financing, the expected ownership structure of the combined company, the expected listing of the combined company’s common stock on Nasdaq, potential contingent value right payments, the expected executive officers and directors of the combined company, anticipated clinical development activities and related timelines, including the expected timing of clinical data and regulatory submissions, the combined company’s strategy and operations and expectations regarding the use of proceeds from the concurrent private placement financing and cash runway expectations resulting therefrom.
These forward-looking statements relate to Werewolf Therapeutics, Ambros Therapeutics and the combined company (together, “us” or “we”), our business prospects and our results of operations and are subject to certain risks and uncertainties posed by many factors and events that could cause our actual business, prospects and results of operations to differ materially from those anticipated by such forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those described under the heading “Risk Factors” included in Werewolf Therapeutics’ Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2026. The words “aim,” “anticipate,” “approach,” “believe,” “contemplate,” “continue,” “could,” “design,” “designed to,” “engineered,” “estimate,” “expect,” “goal,” “intend,” “may,” “might,” “objective,” “ongoing,” “plan,” “potential,” “predict,” “project,” “promise,” “should,” “target,” “will” or “would,” or the negative of these terms, or other comparable terminology are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release. We undertake no obligation to revise any forward-looking statements in order to reflect events or circumstances that might subsequently arise, except as required by applicable law.
These forward-looking statements are based upon our current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, including, without limitation:
| • | Risks related to the combined company’s ability to correctly estimate its operating and other expenses and its cash runway; |
| • | The ability to retain key personnel; |
| • | Negative effects of the announcement or consummation of the proposed transaction on the market price of our capital stock and our operating results; |
| • | Risks relating to the value of shares of the combined company to be issued in the proposed transaction; |
| • | Risks that the proposed transaction may not be completed on the anticipated timeline or at all, including risks related to the failure or delay in satisfying the conditions to closing, including obtaining the requisite approvals of Werewolf Therapeutics’ and Ambros Therapeutics’ stockholders, effectiveness of the Form S-4 and approval for listing on Nasdaq of the shares to be issued in the proposed transaction; |
| • | Risks that the concurrent private placement financing may not be consummated on the anticipated terms or may not result in the anticipated proceeds; |
| • | Risks that the ownership percentages of the parties’ respective equityholders following the closing may differ from those currently anticipated as a result of adjustments contemplated by the Merger Agreement; |
| • | Risks that the proposed transaction may disrupt current plans and operations, divert management’s attention from ongoing business operations or make it more difficult to maintain business and operational relationships; |
| • | Changes in capital resource requirements; |
| • | Risks related to our inability to obtain sufficient additional capital to continue to advance our product candidates; |
| • | Our and our collaborators’ ability to execute clinical programs for our product candidates; |
| • | Results of clinical trials with our product candidates; |
| • | Risks related to obtaining regulatory approval for neridronate, including the risk that positive results from CRPS-RISE may not be sufficient to support regulatory approval and that the FDA may require additional clinical trials, data or other requirements; |
| • | Risks related to any payments under the contingent value right; and |
| • | Our ability to obtain and maintain intellectual property rights and regulatory exclusivities. |
No Offer or Solicitation
This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities nor a solicitation of a proxy, consent, any vote or approval with respect to the proposed transactions herein or otherwise. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended (the “Securities Act”), or pursuant to an exemption from the registration requirements thereof and otherwise in accordance with applicable law. No public offering of securities will be made in any jurisdiction where such an offering would violate applicable law.
NEITHER THE SEC NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THE SECURITIES OR DETERMINED IF THIS PRESS RELEASE IS TRUTHFUL OR COMPLETE.
The offer and sale in the concurrent private placement financing of the shares of common stock, pre-funded warrants, or any other securities (including the shares of common stock issuable upon exercise of the pre-funded warrants) are not being registered under the Securities Act, or any state securities laws. The shares of common stock, pre-funded warrants, or any other securities (including the shares of common stock issuable upon exercise of the pre-funded warrants) issued in the concurrent private placement financing may not be offered or sold in the United States except pursuant to an exemption from the registration requirements of the Securities Act and any applicable state securities laws.
Important Additional Information About the Proposed Transaction Will Be Filed With The SEC
This press release is not a substitute for the registration statement or for any other document that Werewolf Therapeutics may file with the SEC in connection with the proposed transaction. In connection with the proposed transaction between Werewolf Therapeutics and Ambros Therapeutics, Werewolf Therapeutics will file relevant materials with the SEC, including a registration statement on Form S-4 that will contain a proxy statement/prospectus of Werewolf Therapeutics. WEREWOLF THERAPEUTICS URGES INVESTORS AND STOCKHOLDERS TO READ THE REGISTRATION STATEMENT, PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS THAT MAY BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY IF AND WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT WEREWOLF THERAPEUTICS, AMBROS THERAPEUTICS, THE PROPOSED MERGER AND RELATED MATTERS. Investors and stockholders will be able to obtain free copies of the proxy statement/prospectus and other documents filed by Werewolf Therapeutics with the SEC (when they become available) through the website maintained by the SEC at www.sec.gov. Stockholders are urged to read the proxy statement/prospectus and the other relevant materials when they become available before making any voting or investment decision with respect to the proposed transaction. In addition, investors and stockholders should note that Werewolf Therapeutics communicates with investors and the public using its website (https://investors.werewolftx.com).
Participants in the Solicitation
Werewolf Therapeutics, Ambros Therapeutics and their respective directors and executive officers may be deemed to be participants in the solicitation of proxies from shareholders in connection with the proposed transaction. Information about Werewolf Therapeutics’ directors and executive officers, including a description of their interests in Werewolf Therapeutics, is included in Werewolf Therapeutics’ most recent Annual Report on Form 10-K, subsequent Quarterly Reports on Form 10-Q filed with the SEC, including any information incorporated therein by reference, as filed with the SEC, and other documents that may be filed from time to time with the SEC. Additional information regarding these persons and their interests in the transaction will be included in the proxy statement/prospectus relating to the proposed transaction when it is filed with the SEC. These documents can be obtained free of charge from the sources indicated above.
Ambros Therapeutics Company Contact
Argot Partners
ambros@argotpartners.com
212-600-1902
Werewolf Therapeutics Company Contact
Jonathan Owen
SVP, General Counsel and Secretary
Werewolf Therapeutics
jowen@werewolftx.com
Corporate Presentation August 2026 Exhibit 99.2
This presentation and the accompanying slides (this “Presentation”) have been prepared by Ambros Therapeutics, Inc. (“Ambros”) for informational purposes only, and shall not form the basis for, or be relied on in connection with, any investment decision. This Presentation has been prepared based on information Ambros considers reliable, but no representation or warranty, express or implied, is given by Ambros, its affiliates, directors, officers, employees or advisers or any other person as to the truth, accuracy, completeness, fairness or reasonableness of the contents hereof. This Presentation may not be all-inclusive, does not purport to contain all information required to evaluate a possible investment decision, does not constitute investment, tax or legal advice, and is provided for informational purposes only. Each recipient should consult with its own legal, tax, accounting and investment advisors as to the matters discussed herein and should conduct its own independent investigation and analysis of Ambros. The information contained herein is subject to change, and any liability in respect of its contents or any omission therefrom is expressly excluded. This Presentation contains forward-looking statements. Such statements include, but are not limited to, statements about Ambros, clinical development activities, plans, key clinical milestones and projected timelines for Ambros’ product candidate, plans regarding regulatory filings, expectations regarding the relative benefits of the product candidate versus competitive therapies, and expectations regarding the therapeutic and commercial potential of the product candidate. The words “believe,” “may,” “will,” “estimate,” “plan”, “continue,” “anticipate,” “expect,” “potential” and similar expressions (including the negative thereof) are intended to identify forward-looking statements. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Risks that contribute to the uncertain nature of the forward-looking statements include: clinical trials may not be successful; the U.S. Food and Drug Administration (“FDA”) may not agree with interpretations of the data from clinical trials of the product candidate; delays in the commencement, enrollment, completion or analysis of clinical testing for the product candidate, or in the reporting of data from such clinical testing; significant issues regarding the adequacy of clinical trial designs or the execution of clinical trials may arise, which could result in increased costs and delays, or limit the ability to obtain regulatory approval; the product candidate may not receive regulatory approval or be successfully commercialized; unexpected adverse side effects or inadequate therapeutic efficacy of the product candidate could delay or prevent regulatory approval or commercialization; and Ambros may not be able to obtain additional financing. Additional risks and uncertainties may emerge from time to time, and it is not possible for management to predict all risks and uncertainties. All forward-looking statements contained in this Presentation speak only as of the date on which they were made, and Ambros undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made. This Presentation includes certain preliminary estimated selected unaudited financial results for the quarter ended June 30, 2026. Ambros’ closing procedures for the quarter ended June 30, 2026 are not yet complete, and therefore these results are preliminary and subject to change, and there is a possibility that Ambros’ actual results may differ materially from these preliminary estimates. These estimates are based on the information available to Ambros as of the date of this Presentation. These preliminary estimated results for the quarter ended June 30, 2026 are subject to the completion of Ambros’ financial reporting, including all the customary reviews and approvals, and the completion by Ambros’ independent registered public accounting firm of its review of such financial statements for the quarter ended June 30, 2026. These preliminary estimated results should not be viewed as a substitute for financial statements prepared in accordance with U.S. GAAP. Ambros’ independent registered public accounting firm has not conducted a review of, and does not express an opinion or any other form of assurance with respect to, these preliminary estimated results. It is possible that Ambros or its independent registered public accounting firm may identify items that would require Ambros to make adjustments to the preliminary estimates set forth below as Ambros completes its financial statements and that its actual results may differ materially from these preliminary estimates. Accordingly, undue reliance should not be placed on these preliminary estimates. These preliminary estimates are not necessarily indicative of any future period. This Presentation may contain trademarks, service marks, trade names and copyrights of third parties, which are the property of their respective owners. The absence of the trademarks, service marks, trade names and copyrights referred to in this Presentation may be listed without the TM, SM, © or ® symbols does not constitute a waiver of the applicable owner’s rights therein. This Presentation contains estimates and statistical data made by independent parties and Ambros relating to Ambros’ unaudited pro forma cash, cash equivalents and short-term marketable securities, market size and other industry data; such data involves assumptions and limitations, and no representation is made as to its accuracy. This Presentation also discusses a product candidate under clinical study that has not been approved by the FDA or other regulatory authorities; no representation is made as to its safety or effectiveness, and data from multiple clinical trials should be considered with caution given differences in study design, phase, population, sample size, and other factors. This Presentation does not constitute an offer to sell or the solicitation of an offer to buy any securities nor a solicitation of any vote or approval with respect to the proposed transactions herein or otherwise. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended, and otherwise in accordance with applicable law. Disclaimers
Neridronate has the potential to become the first and only FDA-approved medicine for Complex Regional Pain Syndrome Type 1 (CRPS-1) CRPS-1 Rare Disease Burden Severely painful and debilitating condition following injury Long-lasting disability; may become permanent No FDA-approved medicines; current pharmacological therapies have limited to no efficacy1 Neridronate Highlights Expected Single Phase 3 for Approval Blockbuster Opportunity Differentiated bisphosphonate administered intravenously (IV) Extensive clinical data, including 2 successful Italian Phase 3 trials in CRPS Approved in Italy for CRPS2 FDA granted Breakthrough Therapy, Fast Track, & Orphan Drug Designations Expected FDA alignment on single pivotal Phase 3 study for approval Phase 3 CRPS-RISE study ongoing (initiated in Q1 2026) Projected to be fully funded through Phase 3 topline data ~65,000 newly diagnosed individuals each year in the U.S.3 Large healthcare and patient burden3; first mover advantage via potential U.S. approval No other known clinical-stage therapies in biopharma pipelines Expected US market exclusivity through 2045 Fassio, Pharmacological treatment in adult patients with CRPS-1: a systematic review and meta-analysis of randomized controlled trials. Rheumatology 2022 Italian commercialization rights are not held by Ambros Ambros analysis of incident CRPS-1 patients from the Komodo Healthcare Map claims (n = 189,483); analysis also quantifies disease burden through elevated rates of mobility loss, long‑term disability (SSDI), opioid use disorder, and depression vs. non‑CRPS individuals.
Backed by leading investors and partners: Experienced Leadership Team Keith Katkin Chairman CEO of Urovant CEO of Avanir Pharmaceuticals Board of Directors at Eledon Pharmaceuticals (chairman)*, Emergent BioSolutions*, and Syndax Pharmaceuticals* Jay Hagan President & CEO CEO of Regulus Therapeutics CFO/CBO of Orexigen Therapeutics Managing Director of Amgen Ventures Gail Cawkwell, MD, PhD Chief Medical Officer CMO of Aclaris Therapeutics SVP of Medical Affairs at Intercept Pharmaceuticals CMO of Purdue Pharma VP of Medical Affairs, R&D at Pfizer Cris Calsada Chief Financial Officer CFO of Regulus Therapeutics CFO of SANIFIT Therapeutics COO of Ambrx Biopharma Kunal Kishnani SVP Corporate Development President of Rare Disease at Kriya Therapeutics Founder & CEO of Warden Bio Co-Founder and Head of Operations Genevant * Indicates ongoing roles. All other mentioned roles are former appointments.
CRPS-1 is an orphan disease with ~65,000 newly diagnosed individuals each year in the U.S2 CRPS-1 is a progressive, debilitating orphan disease typically triggered by injury or trauma, such as bone fractures or limb surgeries Considered among the most painful of all known diseases with high unmet need Extremely severe, continuous, disabling limb pain that is disproportionate to initial injury1 Occurs more frequently in women; typical age of onset between 40 to 60 years old but can occur at any age1 Patients with CRPS-1 may experience sleep disturbance and meaningful diminished quality of life and independence1 Associated with significant increases in depression as well as opioid use disorder as compared to U.S. individuals without CRPS-12 No FDA-approved therapies to address the underlying disease biology or progression Common pain meds (e.g., NSAIDs, opioids, gabapentin) have shown limited efficacy3 Expensive and ineffective procedures such as sympathetic nerve blocks, sympathectomies, and spinal cord stimulation are used despite limited efficacy3 Established Budapest Clinical Diagnostic Criteria confirm CRPS-1 diagnosis4 CRPS-1 comprises ~90% of all CRPS cases5 CRPS Type 2 (CRPS-2) is diagnosed with evidence of nerve damage4 Harden et al. Complex Regional Pain Syndrome: Practical Diagnostic and Treatment Guidelines, Pain Med. 2013 Ambros analysis of incident CRPS-1 patients from the Komodo Healthcare Map claims (n = 189,483) Fassio, Pharmacological treatment in adult patients with CRPS-1: a systematic review and meta-analysis of randomized controlled trials. Rheumatology 2022 Harden RN, Bruehl S, Perez RSGM, et al. Validation of proposed diagnostic criteria (the "Budapest Criteria") for CRPS. Pain, 2010 Sandroni. Complex regional pain syndrome type 1: incidence and prevalence in Olmsted County, a population-based study. Pain, 2003
CRPS-1 progresses through stages of increasing severity post-injury ~50% of patients in the U.S. are currently diagnosed within first 6 months of symptom onset1 Stage 1: “Warm” Phase (typically 0-12 months post-injury)2 Burning pain, allodynia, hyperalgesia Increased warmth and redness in the affected limb Swelling, sweating, shiny skin Abnormal nail growth or rapid hair growth on the affected limb Difficulty bending or moving the affected limb due to pain and stiffness Typically associated with positive triple-phase bone scan (TPBS) reading3 Stage 2: “Cold” Phase (typically >12 months post-injury) Severe, persistent pain, vasoconstriction, and limb discoloration (icy, pale, or blue) While symptoms may spontaneously resolve, patients who forgo early treatment during the warm phase face elevated risk of chronicity, recurrence, or irreversible disease progression4 Primary market research with physicians and CRPS experts conducted by Aquest Ambros post-hoc analysis of pooled baseline assessments of warm symptoms against time since CRPS onset across the four Grunenthal and two Abiogen studies (n = 189) Wertli et al. Usefulness of bone scintigraphy for the diagnosis of Complex Regional Pain Syndrome 1: A systematic review and Bayesian meta-analysis." PLoS One 2017. Harvard Medical School, Complex regional pain syndrome (CRPS). March 11, 2026.
Neridronate is a differentiated bisphosphonate approved in Italy for the treatment of several bone disorders including CRPS1 Developed by Abiogen Pharma S.p.A. under the trade name NERIXIA® Approved in Italy for the treatment of Osteogenesis Imperfecta, Paget’s Disease, and CRPS1 We have licensed commercialization rights in the United States, Canada, and Mexico from Abiogen Cumulative estimated patient exposure of 600,000+ to date (all indications) in Italy2 Large therapeutic window allows high exposures associated with demonstrated efficacy in CRPS – without dose-limiting adverse events that we believe limit usage of other bisphosphonates for CRPS Binding characteristics have been described in literature as unique from other bisphosphonates, leading to enhanced safety profile3 Neridronate (6-Amino-1-hydroxyhexane-1, 1-diphosphonic acid monosodium salt hemihydrate) NERIXIA Italian approval label. Italian commercialization rights are not held by Ambros. Neridronate 2025 Periodic Safety Update Report (Internal). Iolascon, G.; Moretti, A. The Rationale for Using Neridronate in Musculoskeletal Disorders: From Metabolic Bone Diseases to Musculoskeletal Pain. Int. J. Mol. Sci. 2022.
Derived from: Varenna M. Bisphosphonates beyond their anti-osteoclastic properties The lesson of complex regional pain syndrome. Rheumatology 2014;53:965-7. Slide represents proposed disease processes and mechanism of action of neridronate. IL-6: Interleukin 6. TNF: Tumor necrosis factor. NGF: Nerve growth factor. Neridronate concentrates at the site of injury during the warm phase of CRPS-1 where it is expected to address key underlying disease drivers Trauma leads to local tissue hypoxia resulting in increased lactic acid and local acidification Hydroxyapatite crystal dissolution Local Osteoporosis Release and activation of monocytes, macrophages and keratinocytes Release of pro-inflammatory mediators (IL-6, TNF, NGF) Local Inflammation: Red, Warm, Swollen, Painful Increased Release of Substance P and CGRP Local Swelling, Pain Decreases lactic acid Decreased osteoblast and osteocyte apoptosis Inhibits farnesyl synthase and GTPase post-translational modifications Inhibits monocyte, macrophage and keratinocyte production and activation Inhibits farnesyl synthase and GTPase post-translational modifications Inhibits local calcium influx Inhibits gliosis associated with neuropathic pain Neridronate activity in CRPS-1
100 mg neridronate or placebo administered intravenously (IV) on days 1, 4, 7, and 10* Primary endpoint of pain intensity assessed by visual analog scale (VAS, range 0-100 mm) at day 40 Open-label placebo cross-over phase after 10-day washout Key inclusion criteria: Confirmed diagnosis of CRPS-1 No longer than 4 months since onset of symptoms Positive TPBS to confirm bone involvement Successful Abiogen Phase 3 study in warm CRPS-1 patients with confirmed bone involvement supported Italian approval of neridronate Neridronate achieved the primary endpoint of ≥50% reduction in pain intensity score vs. placebo (p=0.0003) and reduced pain intensity score vs. placebo‡ (p<0.0001) in Abiogen's NERIAS Phase 3 study Significant improvements observed across secondary endpoints of pain and quality of life (McGill Pain Questionnaire and SF-36), edema, allodynia, hyperalgesia, and pain at motion vs. placebo Responses similar whether treated initially or after day 40+ washout Successful results replicated in Abiogen’s subsequent NAIMES Phase 3 study in CRPS-1 with intramuscular (IM) neridronate in Italy Placebo Cross-over Pain VAS Days Double-blind n= 82 D D D D D D D D D: IV study treatment dosed.IV: Intravenous. IM: Intramuscular. *Varenna M et al. Treatment of complex regional pain syndrome type 1 with neridronate: a randomized, double-blind, placebo-controlled study. Rheumatology (Oxford). 2013 Mar;52(3):534-42 ‡ This is the primary endpoint in CRPS-RISE
NAIMES achieved primary endpoint measured at Day 30: 65.9% of neridronate-treated versus 29.7% on placebo achieved at least a 50% improvement in pain (p=0.0017) Following completion of the double-blind portion of the Phase 3 IM study, placebo participants were treated with 400 mg IV neridronate (4 doses of 100 mg) Benefits on pain reduction, clinical and functional measures were maintained and further improved over 12 months in most patients treated with neridronate administered either IM or IV ≥88% of subjects in both groups were defined as responders (≥50% improvement in pain) at 12 months Durable, potentially disease-modifying effects observed in multiple long-term studies D: IV study treatment dosed.IV: Intravenous. IM: Intramuscular. Varenna M et al. Intramuscular neridronate for the treatment of complex regional pain syndrome type 1: a randomized, double -blind, placebo -controlled study. Ther Adv Musculoskelet Dis. 2021 Jun 11;13:1759720X211014020. G. Adami et al. Long-term effectiveness and predictors of bisphosphonate treatment in type 1 complex regional pain syndrome. Clinical and Experimental Rheumatology 2024; 42: 961 -966 Phase 3 NAIMES Study in CRPS-1 with IM / IV Neridronate (n = 78)1 Real-world longitudinal study conducted by Italian investigators with 400 mg IV neridronate 78% reduction in pain over 12 months, with improvements sustained up to 3+ years; early VAS pain intensity reduction was significantly and strongly associated to lower loss of motion at month 12 >84% of patients achieved resolution of key symptoms such as hyperalgesia and allodynia by month 12 **** DDDD Longitudinal, observational real-world study in CRPS-1 (n=103)2 DDDD Double-blind (to Day 30) Placebo cross-over and open-label (Days 40 to 360) Wash out (Days 30-40)
Neridronate has been generally well-tolerated across all clinical trials and in post-marketing experience The safety profile of neridronate in CRPS is consistent with the safety profiles of other IV bisphosphonates given over a short term despite higher doses used for neridronate in CRPS Acute Phase Reactions (and associated events) were the most commonly reported treatment emergent adverse events in participants receiving neridronate in CRPS clinical trials Osteonecrosis of the jaw (ONJ), a potential risk with high-dose bisphosphonates, has not been observed in neridronate CRPS-1 clinical trials Post-marketing experience with neridronate in Italy indicates a favorable benefit/risk profile for its approved indications (Paget’s disease, osteogenesis imperfecta, and CRPS-1), with an estimated 600,000+ patients receiving treatment since 20021 Neridronate 2025 Periodic Safety Update Report (Internal).
Ongoing pivotal Phase 3 study (CRPS-RISE) builds on successful Abiogen program Key Eligibility CRPS-1 diagnosed per clinical Budapest criteria A known precipitating event (e.g., sprain, fracture, contusion) CRPS duration ≤6 months Moderate-severe pain >4 on 11-point NRS (average weekly) Precision medicine criteria Positive TPBS Warm CRPS-1 subtype, defined as: Moderate to severe edema, or At least mild edema + obvious redness, or At least mild edema + increase in temperature Primary Endpoint Change from baseline to Week 12 in pain intensity (11-point NRS) Key Secondary Endpoints: ≥ 50% reduction in pain intensity at Week 12 Change from baseline in CRPS Severity Score (CSS) at Week 12 Patient Global Impression of Change (PGIC) in CRPS-related health at Week 12 Change from baseline in SF-36: Physical Functioning Domain at Week 12 Screening 2 to ≤6 weeks Clinical program includes registry for long-term outcomes and open-label extension to support study retention and allow for some data on a second course of treatment in some patients after Week 12 Randomize 1:1 N= ~135 IV neridronate 100 mg Days 1, 4, 7, and 10 Followed by off-treatment follow-up N= ~135 IV placebo Days 1, 4, 7, and 10 Followed by off-treatment follow-up ClinicalTrials.gov ID: NCT07210515 WEEK 3 WEEK 6 WEEK 9 WEEK 12 Clinic Study Visit Clinic Study Visit Clinic Study Visit Phone Call NRS: Numerical Rating Scale
Dose selected: short, fixed treatment course Clinically meaningful efficacy demonstrated in prior Abiogen Phase 3 trials Durable, potentially disease-modifying treatment effects Generally well-tolerated across clinical trials Post marketing experience with 600,000+ patients in Italy1 Breakthrough Therapy, Fast Track and Orphan Drug Designations granted by FDA Precision warm-phase patient selection strategy for enrollment in Phase 3 CRPS-RISE study Initiated Phase 3 trial in Q1 2026 following recent FDA feedback Method of use patent issued; U.S. market exclusivity potentially extends to 2045, providing competitive protection in CRPS-1 indication Neridronate Key Highlights Neridronate 2025 Periodic Safety Update Report (Internal).
Neridronate is a potentially first-in-class therapy for CRPS-1 with a large U.S. market opportunity 1 Opportunity to establish standard of care No FDA-approved pharmacological therapies; current options limited, lack efficacy, costly, and complex Potentially disease-modifying mechanism Lowers risk of opioid use disorder, currently at ~15% of patients in the first year1 2 Well-defined population & call points ~65,000 newly diagnosed individuals in the U.S. per year1 Short in-office IV course of treatment We believe the majority of treating physicians are reachable with a focused sales force 3 Strong market research support Payors view CRPS-1 as a high unmet medical need2 ~95% of physicians would prescribe neridronate if approved2 Potential pricing comparable to other rare disease therapies with similarly sized patient populations Ambros analysis of incident CRPS‑1 patients from the Komodo Healthcare Map claims (n = 189,483). Primary market research with physicians and CRPS experts conducted by Aquest.
Initial addressable market considerations ~65,000 newly diagnosed CRPS-1 patients annually in the U.S.1 ~50% CRPS-1 patients currently diagnosed within 6 months2 ~85% Proportion of CRPS-1 patients diagnosed within 6 months with warm-phase features/symptoms3 ~85% Proportion of TPBS positivity rate in CRPS-1 patients with warm-phase features/symptoms diagnosed within 6 months3 We estimate up to ~80% of patients could be diagnosed within 6 months with awareness and education efforts Ambros analysis of incident CRPS‑1 patients from the Komodo Healthcare Map claims (n = 189,483). Primary market research with physicians and CRPS experts conducted by Aquest. Ambros post‑hoc analysis of pooled baseline warm‑phase symptoms across four Grünenthal and two Abiogen studies (n = 189); TPBS positivity per Wüppenhorst N, et al. Clin J Pain 2010 and Wertli MM, et al. PLoS One 2017.
Pain specialists are the primary prescribers, supported by a referral network with hand and foot specialists We plan to establish targeted specialty sales force to reach the majority of U.S. CRPS-1 patients ~65% of CRPS-1 diagnoses come from four specialties1 Key prescribers concentrated in pain (~6,000 U.S. specialists2) and hand/foot (~12,500 U.S. specialists3) Prioritized using claims data on high-frequency CRPS-1 diagnosers (Komodo) Initial focus: high-volume pain clinics, hand/foot specialists, orthopedists (education/awareness), KOLs Ambros analysis of incident CRPS‑1 patients from the Komodo Healthcare Map claims (n = 189,483); diagnosing-specialty distribution. 2026 AMA Physician Professional Data; U.S. Physician Workforce Data Dashboard. Excludes non-practicing pain physicians. 2024 Occupational Outlook Handbook and Patel R et al. Where Are the Hand Surgeons? J Hand Surg Glob Online. 2025 Dec 5. doi: 10.1016/j.jhsg.2025.100898.
Neridronate protected through IP and high barrier to entry U.S. market exclusivity Methods for patient selection patent granted (exp. 2045) Polymorph patent issued (exp. 2039 + PTE) 7 year Orphan exclusivity; potential 6-month pediatric exclusivity Limitations of other bisphosphonates Differentiated from other branded/generic bisphosphonates IV formulation addresses limited bioavailability of oral bisphosphonates Efficacy and safety of other injectable bisphosphonates have not been established in CRPS-1 trials Existing and future treatment options Expensive procedures such as sympathetic nerve blocks, sympathectomies, and spinal cord stimulation are used in patients despite limited efficacy Opioids may help manage acute pain to limited extent, but tolerance, long-term toxicity, and addiction pose serious risks Lack of late-stage (Phase 2 or beyond) CRPS assets in the clinic
Strong Capital Position ~$104M in cash, cash equivalents, and short-term investments as of 6/30/20261 FDA engagement on incorporating interim analysis in CRPS-RISE First Patient Enrolled in Pivotal CRPS-RISE Trial (June 2026) 2028 Pivotal CRPS-RISE Topline Data Readout Neridronate NDA Submission 1H26 2H26 + ~6 months Unaudited and prepared only by the Company's management, subject to change. Anticipated Key Value-Inflection Milestones Expected Through 2028
Neridronate has the potential to become the first and only FDA-approved medicine for Complex Regional Pain Syndrome Type 1 (CRPS-1) CRPS-1 Rare Disease Burden Severely painful and debilitating condition following injury Long-lasting disability; may become permanent No FDA-approved medicines; current pharmacological therapies have limited to no efficacy1 Neridronate Highlights Expected Single Phase 3 for Approval Blockbuster Opportunity Differentiated bisphosphonate administered intravenously (IV) Extensive clinical data, including 2 successful Italian Phase 3 trials in CRPS Approved in Italy for CRPS2 FDA granted Breakthrough Therapy, Fast Track, & Orphan Drug Designations Expected FDA alignment on single pivotal Phase 3 study for approval Phase 3 CRPS-RISE study ongoing (initiated in Q1 2026) Projected to be fully funded through Phase 3 topline data ~65,000 newly diagnosed individuals each year in the U.S.3 Large healthcare and patient burden3; first mover advantage via potential U.S. approval No other known clinical-stage therapies in biopharma pipelines Expected US market exclusivity through 2045 Fassio, Pharmacological treatment in adult patients with CRPS-1: a systematic review and meta-analysis of randomized controlled trials. Rheumatology 2022 Italian commercialization rights are not held by Ambros Ambros analysis of incident CRPS-1 patients from the Komodo Healthcare Map claims (n = 189,483); analysis also quantifies disease burden through elevated rates of mobility loss, long‑term disability (SSDI), opioid use disorder, and depression vs. non‑CRPS individuals.
Appendix
Abiogen NAIMES Phase 3 study with neridronate administered IM **************** Varenna M er al. Intramuscular neridronate for the treatment of complex regional pain syndrome type 1: a randomized, double-blind, placebo-controlled study. Ther Adv Musculoskelet Dis. 2021 Jun 11;13:1759720X211014020. Randomized, double-blind, placebo-controlled study in CRPS-1 (n=78) TPBS confirmed CRPS-1 with symptoms <4 months 25 mg neridronate (n=41) or placebo (n=37) on days 1-16* Primary endpoint of pain intensity assessed by visual analog scale (VAS, range 0-100mm) at day 30 Neridronate significantly reduced VAS pain intensity score vs. placebo (p=0.0003) Significant improvements observed across secondary endpoints of pain and quality of life (McGill Pain Questionnaire) Significant improvements in edema (p=0.03), allodynia (p=0.0004), hyperalgesia (p=0.0023), pain at motion (p=0.0009) vs. placebo Double-blind
Utility of triple-phase bone scan (TPBS) as a “precision medicine” tool in CRPS-1 TPBS is an imaging procedure that uses a radiolabeled bisphosphonate (BP) and specialized camera to assess bone involvement BPs bind to hydroxyapatite, a calcium mineral exposed during the warm phase of CRPS-11 Qualitative comparison vs. patient’s own unaffected limb Increased radiolabeled BP uptake (positive TPBS reading) indicates high bone turnover and exposed bone tissue2 à increases likelihood of response to neridronate by confirming BP penetrance at site of injury1 Positive TPBS readings have been shown to correlate with CRPS-1 disease duration and are typically seen within the first 5-6 months of symptoms (“warm” phase)3 “Cold” CRPS-1 usually correlates with negative TPBS readings, indicating decreased BP uptake3 Wong KK, Piert M. "Dynamic bone imaging with 99mTc-labeled diphosphonates and 18F-NaF: mechanisms and applications." J Nucl Med. 2013;54(4):590-599. PMID 23482667 Varenna M, Crotti C. Bisphosphonates in the treatment of complex regional pain syndrome: is bone the main player at early stage of the disease? Rheumatol Int 2018;38(11):1959-1962. Varenna M. Bisphosphonates beyond their anti-osteoclastic properties. The lesson of complex regional pain syndrome. Rheumatology (Oxford) 2014;53(6):965-967. Wüppenhorst N, et al. Sensitivity and specificity of 3‑phase bone scintigraphy in the diagnosis of CRPS of the upper extremity. Clin J Pain 2010; Wertli MM, et al. Usefulness of bone scintigraphy for the diagnosis of CRPS 1: a systematic review and Bayesian meta‑analysis. PLoS One 2017.
In 2013, Grünenthal licensed rights to neridronate and ran two global Phase 3 clinical trials1 Positive Grünenthal study was driven by subset of participants with CRPS-1 and warm subtype findings at baseline Ambros is building on the successful Abiogen studies in warm phase CRPS-1 Enrolled all CRPS types (1, 2) No TPBS required for inclusion; majority beyond warm phase Terminated trials early due to interim futility analysis and then returned rights to Abiogen Final analysis of trials showed one positive study (p=0.0111) and one negative study (p=0.2522) Protocol Element Grünenthal Abiogen Ambros Positive TPBS No Yes Yes CRPS -1 Subtype 75% 100% 100% Phase of Disease Warm/Cold Early/Warm Early/Warm Symptom Duration < 24 Months < 4 Months < 6 Months Grünenthal GmbH. Phase 3 trials of intravenous neridronic acid in CRPS: KF7013-02 (ClinicalTrials.gov NCT03530345; EudraCT 2016-003833-91) and KF7013-04 (ClinicalTrials.gov NCT03560986; EudraCT 2017-004244-37). Both trials discontinued following a pre-planned interim futility analysis; company clinical study reports. Neridronate clinical trials in other CRPS populations
Baseline pain was similar across all groups in the post-hoc analyses shown on this slide We believe a precision medicine approach that targets the right treatments to the right patients at the right time is warranted This post hoc subgroup analysis across 3 Phase 3 trials suggests that neridronate shows particularly meaningful benefit in CRPS-1 patients with features of the warm subtype: swelling, redness, warmth Summary of Changes in Average Pain Intensity by Baseline Redness/Warmth Subgroup Analysis of Treatment Effects by Baseline Edema Across Certain Clinical Trials Mean Change at 12 Weeks Mean Diff Evidence of greater efficacy with neridronate in warm CRPS-1 subtype Post-hoc analyses across three Phase 3 trials1 Ambros post-hoc analyses across the Grunenthal and Abiogen CRPS studies (Internal).