CytomX Therapeutics Announces Proposed Public Offering of Common Stock and Pre-Funded Warrants

Rhea-AI Summary

CytomX Therapeutics (NASDAQ:CTMX) has commenced an underwritten public offering of $250.0 million of common stock and, for certain investors, pre-funded warrants, with a 30-day underwriter option to purchase up to an additional $37.5 million. The offering is subject to market and other conditions and may not be completed.

According to the company, net proceeds are expected to fund continued development of Varseta-M and other pipeline programs, with any remaining proceeds for capital expenditures, working capital and general corporate purposes. A shelf registration filed March 16, 2026, became effective upon filing.

Positive

• Planned gross raise of $250.0M
• Underwriter option of $37.5M available for additional shares
• Net proceeds designated for Varseta-M development
• Shelf registration effective on March 16, 2026

Negative

• Potential shareholder dilution from the $250.0M offering
• Additional dilution risk if underwriters exercise $37.5M option
• No assurance the offering will be completed as announced

News Market Reaction – CTMX

-19.26% 28.1x vol

75 alerts

-19.26% Session close to close

+67.7% Peak in 4 hr 41 min

$1.39B Market Cap

28.1x Rel. Volume

In the Mar 17 session, CTMX declined 19.26%, reflecting a significant negative market reaction. Argus tracked a peak move of +67.7% during that session. Our momentum scanner triggered 75 alerts that day, indicating high trading interest and price volatility. Trading volume was exceptionally heavy at 28.1x the daily average, suggesting significant selling pressure.

Data tracked by StockTitan Argus on the day of publication.

Market Context

The stock dropped -19.3% in the session following this news. A negative reaction despite prior stren...

Analysis

The stock dropped -19.3% in the session following this news. A negative reaction despite prior strength would fit a pattern where financing risk becomes more prominent after large runs. CytomX entered this offering with a 68.59% gain, heavy volume of 80.66M shares, and an existing $137.1M cash balance. The proposed $250M raise plus a $37.5M option, layered on top of a $100M 2025 deal, could later have raised concerns over dilution and deal pricing.

Key Figures

Proposed offering size: $250.0 million Underwriter option: $37.5 million Current share price: $4.68 +5 more

8 metrics

Proposed offering size $250.0 million Underwritten public offering of common stock and pre-funded warrants

Underwriter option $37.5 million 30-day option for additional common stock at the offering price

Current share price $4.68 CTMX last sale price referenced in S-3ASR prospectus

1-day move 68.59% Price change over the last 24 hours pre-offering news

Trading volume 80,660,733 shares Today’s volume versus 20-day average of 6,747,938 shares

Year-end cash $137.1 million Cash, cash equivalents and investments as of 12/31/2025

Prior offering size $100 million Gross proceeds target from May 12, 2025 underwritten offering

Shares in prior deal 76,923,076 shares at $1.30 Common stock sold in May 12, 2025 underwritten offering

Previous Offering Reports

1 past event · Latest: May 12 (Neutral)

Same Type Pattern 1 events

Date	Event	Sentiment	24h Move	Catalyst
May 12	Equity offering	Neutral	+129.4%	Underwritten offering of common stock priced to raise about $100M.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Pattern Detected

For this company, prior equity offerings have coincided with strong positive price reactions rather than typical pressure.

Recent Company History

Recent news for CytomX has centered on advancing Varseta-M and CX-801 while shoring up finances. On May 12, 2025, the company priced a $100 million underwritten offering at $1.30, which saw a 129.43% next-day move. The current proposed $250 million offering, plus an additional $37.5 million option, comes after positive Phase 1 data and filings on March 16, 2026. Together, these events show a pattern of financing around key clinical milestones.

Key Terms

underwritten public offering, pre-funded warrants, shelf registration statement, prospectus supplement, +2 more

6 terms

underwritten public offering financial

"it has commenced an underwritten public offering of $250.0 million of shares"

An underwritten public offering is when a company sells new shares of its stock to the public with the help of a financial firm, called an underwriter. The underwriter agrees to buy all the shares upfront, reducing the company's risk, and then sells them to investors. This process helps companies raise money quickly and confidently from a wide range of buyers.

pre-funded warrants financial

"in lieu of common stock to certain investors, pre-funded warrants"

Pre-funded warrants are financial instruments that give investors the right to purchase a company's stock at a set price, but with most or all of the purchase price paid upfront. They function like a coupon or gift card for stock, allowing investors to buy shares later at a fixed price, which can be beneficial if they want to avoid future price increases. This makes them important for investors seeking flexibility and certainty in their investment plans.

shelf registration statement regulatory

"A shelf registration statement relating to these securities was filed"

A shelf registration statement is a document a company files with regulators that allows it to sell shares or bonds quickly when it’s a good time to raise money. It’s like having a pre-approved plan ready so the company can act fast without going through lengthy paperwork each time they want to sell, making fundraising more flexible.

prospectus supplement regulatory

"Copies of the preliminary prospectus supplement and the accompanying prospectus"

A prospectus supplement is an additional document provided alongside a company's main offering details, offering updated or extra information about a specific financial product being sold. It helps investors understand the latest terms, risks, and details of the investment, similar to how an update or revision clarifies or expands on original instructions, ensuring they have current and complete information before making a decision.

bookrunning managers financial

"Jefferies, Piper Sandler, Cantor and Barclays are acting as joint bookrunning managers"

Lead banks that organize and manage a new stock or bond offering, coordinating other banks, setting the initial sale price, collecting investor orders and deciding how many shares each buyer receives. Think of them as the project manager and ticket-seller for a public offering — their pricing, allocations and ability to sell the issue directly affect how successful the offering is and how the security performs for investors afterward.

Form S-3 regulatory

"filed a shelf registration on Form S-3 to register securities for sale"

Form S-3 is a legal document companies use to register their stock sales with the government, making it easier and faster for them to raise money by selling shares to investors. It’s like having a pre-approved shopping list that lets a company quickly sell new shares when they need funds, without going through a lengthy approval process each time.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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SOUTH SAN FRANCISCO, Calif., March 16, 2026 (GLOBE NEWSWIRE) -- CytomX Therapeutics, Inc. (Nasdaq:CTMX), a leader in the field of masked, conditionally activated biologics, today announced that it has commenced an underwritten public offering of $250.0 million of shares of common stock and, in lieu of common stock to certain investors, pre-funded warrants. In addition, CytomX expects to grant the underwriters a 30-day option to purchase up to an additional $37.5 million of shares of common stock at the public offering price, less underwriting discounts and commissions. The offering is subject to market and other conditions, and there can be no assurance as to whether or when the offering may be completed, or as to the actual size or terms of the offering. All of the shares of common stock and pre-funded warrants are to be offered by CytomX.

CytomX expects to use the net proceeds from this offering for the continued development of Varseta-M and other pipeline programs. CytomX expects to use any remaining net proceeds from this offering for capital expenditures, working capital and other general corporate purposes.

Jefferies, Piper Sandler, Cantor and Barclays are acting as joint bookrunning managers for the offering. Wedbush PacGrow is acting as co-manager for the offering.

A shelf registration statement relating to these securities was filed with the U.S. Securities and Exchange Commission (“SEC”) on March 16, 2026, and automatically became effective upon filing. Copies of the preliminary prospectus supplement and the accompanying prospectus relating to the offering may be obtained, when available, for free from: Jefferies LLC, Attention: Equity Syndicate Prospectus Department, 520 Madison Avenue, New York, NY 10022, by telephone at (877) 821-7388, or by email at prospectus_department@jefferies.com; Piper Sandler & Co., Attention: Prospectus Department, 350 North 5th Street, Suite 1000, Minneapolis, Minnesota 55401, or by telephone at (800) 747-3924, or by email at prospectus@psc.com; Cantor Fitzgerald & Co., Attention: Capital Markets, 110 East 59th Street, 6th Floor, New York, NY 10022, or by email at prospectus@cantor.com; or Barclays Capital Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, or by telephone at (888) 603-5847, or by email at Barclaysprospectus@broadridge.com.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of, these securities in any state or jurisdiction in which such offer, solicitation, or sale would be unlawful prior to registration or qualification of these securities under the securities laws of any such state or jurisdiction.

About CytomX Therapeutics

CytomX is a clinical-stage, oncology-focused biopharmaceutical company focused on developing novel conditionally activated, masked PROBODY® therapeutics designed to be localized to the tumor microenvironment. By pioneering a novel pipeline of localized biologics, powered by its PROBODY therapeutic platform, CytomX’s vision is to create safer, more effective therapies for the treatment of cancer. CytomX’s robust and differentiated pipeline comprises therapeutic candidates across multiple treatment modalities including antibody-drug conjugates (“ADCs”), cytokines and T-cell engagers. CytomX’s clinical-stage pipeline includes varsetatug masetecan (Varseta-M; CX-2051) and CX-801. Varseta-M is a masked, conditionally activated ADC armed with a topoisomerase-1 inhibitor payload and directed toward epithelial cell adhesion molecule (EpCAM). EpCAM is a highly expressed tumor antigen that has previously been undruggable due to expression on normal tissues. Varseta-M is designed to open a therapeutic window for this high potential target and is initially being developed for the treatment of metastatic colorectal cancer. Varseta-M was discovered in collaboration with ImmunoGen, now part of AbbVie. CX-801 is a masked interferon alpha-2b PROBODY® cytokine with broad potential applicability in traditionally immuno-oncology sensitive as well as insensitive (cold) tumors. CX-801 is initially being developed for the treatment of metastatic melanoma. CytomX has established strategic collaborations with multiple leaders in oncology, including Amgen, Bristol Myers Squibb, Regeneron and Moderna.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Certain statements contained in this press release, including those relating to the anticipated size and terms of the proposed offering and the planned use of proceeds, are forward-looking statements that involve a number of risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. These risks and uncertainties include, but are not limited to, risks and uncertainties associated with the company’s ability to complete the offering on the anticipated terms, or at all, general economic conditions and other risks identified from time to time in the reports the company files with the SEC, including its Annual Report on Form 10-K for the year ended December 31, 2025, filed on March 16, 2026, and the prospectus supplement and accompanying prospectus related to the offering to be filed with the SEC, which are available at www.sec.gov. The forward-looking statements in this press release speak only as of the date hereof, and the company undertakes no obligation to update or revise any of the statements. The company’s business is subject to substantial risks and uncertainties, including those referenced above. Investors, potential investors, and others should give careful consideration to these risks and uncertainties.

PROBODY is a U.S. registered trademark of CytomX Therapeutics, Inc. All other trademarks are the properties of their respective owners.

Company Contact:
Chris Ogden
SVP, Chief Financial Officer
cogden@cytomx.com

Investor Contact:
Precision AQ
Stephanie Ascher
Stephanie.Ascher@precisionaq.com

Media Contact:
Precision AQ
Colleen Ketchum
Colleen.ketchum@precisionaq.com

FAQ

What is CytomX (CTMX) offering in the March 16, 2026 public offering?

CytomX is offering $250.0 million of common stock and pre-funded warrants to certain investors. According to the company, there is a 30-day underwriter option to purchase up to an additional $37.5 million of common stock at the public offering price.

How does CytomX (CTMX) plan to use proceeds from the $250M offering?

The company expects to use net proceeds to continue development of Varseta-M and other pipeline programs. According to the company, remaining funds will target capital expenditures, working capital and other general corporate purposes.

What is the dilution risk for CTMX shareholders from the offering?

Shareholders face potential dilution from the issuance of new common stock and pre-funded warrants totaling $250.0M. According to the company, an additional underwriter option could increase issuance by $37.5M, raising further dilution risk if exercised.

When did CytomX file its shelf registration and did it become effective?

CytomX filed a shelf registration with the SEC on March 16, 2026, which became effective upon filing. According to the company, the effective registration clears the way for the proposed offering subject to market conditions.

Who are the lead underwriters managing the CTMX public offering?

Jefferies, Piper Sandler, Cantor and Barclays are acting as joint bookrunning managers for the offering. According to the company, Wedbush PacGrow is acting as co-manager for the offering.