[S-8 POS] SpringWorks Therapeutics, Inc. SEC Filing

Rhea-AI Filing Summary

SpringWorks Therapeutics, Inc. (NASDAQ: SWTX) filed seven Post-Effective Amendments on Form S-8 to deregister all unsold shares previously registered for issuance under its 2019 employee equity plans. The action follows the closing of its merger with Merck KGaA, Darmstadt, Germany on 1 July 2025, under which SpringWorks became a wholly owned subsidiary of Merck through EMD Holdings Merger Sub, Inc.

The amendments cover the following historical S-8 registrations:

• Reg. Nos. 333-234365, 333-237350, 333-253531, 333-262996, 333-270096, 333-277380 and 333-285076.
• In aggregate, these filings had registered tens of millions of common shares for the 2019 Stock Option & Incentive Plan, the Amended & Restated 2019 Equity Incentive Plan and the 2019 Employee Stock Purchase Plan.

Because the company is now private, SpringWorks has terminated all offerings under these plans. Consistent with undertakings in each registration statement, any securities that remained unsold as of the merger date are withdrawn from registration. The filing is signed on behalf of the company by Secretary Michael MacDougall and relies on Rule 478 of the Securities Act to omit additional signatures.

The amendments are largely administrative, signalling the end of SpringWorks’ status as an independent public issuer and the cessation of share issuance under its legacy equity compensation and ESPP programmes.

Positive

• Merger completion confirmed: Filing reiterates that the April 27, 2025 merger with Merck KGaA closed on July 1, 2025, providing final certainty on transaction consummation.

Negative

• Equity incentive programs terminated: Withdrawal of unsold shares ends future share-based compensation through public markets, which may affect legacy employees’ equity liquidity.

Insights

Financial Analyst

TL;DR: Administrative deregistration after Merck buyout; neutral to public investors as SWTX no longer trades independently.

The filing merely formalises housekeeping steps required after the close of Merck KGaA’s acquisition of SpringWorks. By withdrawing unsold shares from seven S-8 registrations, management eliminates public float expansion risk and ends equity-based incentive issuance in the public market. No financial metrics, earn-outs or revised consideration are disclosed. The event confirms completion of the merger but provides no incremental valuation information, making it operationally neutral for investors who have already tendered or converted their shares.

Corporate Governance Expert

TL;DR: Filing cleans up SEC shelf obligations, ensuring compliance post-privatisation.

Rule 478 allows single-signature deregistration of unsold securities, reducing administrative burden. By terminating its equity plans, SpringWorks limits legacy governance overlap with Merck’s policies and mitigates potential future dilution claims. All undertakings under each S-8 are now satisfied, removing latent disclosure and reporting responsibilities. This is standard practice and conveys no positive or negative governance surprise; it simply reflects best-practice compliance following a change-of-control transaction.

Registration No. 333-234365

Registration No. 333-237350

Registration No. 333-253531

Registration No. 333-262996

Registration No. 333-270096

Registration No. 333-277380

Registration No. 333-285076

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Post-Effective Amendment No. 1 to Form S-8 Registration No. 333-234365

Post-Effective Amendment No. 1 to Form S-8 Registration No. 333-237350

Post-Effective Amendment No. 1 to Form S-8 Registration No. 333-253531

Post-Effective Amendment No. 1 to Form S-8 Registration No. 333-262996

Post-Effective Amendment No. 1 to Form S-8 Registration No. 333-270096

Post-Effective Amendment No. 1 to Form S-8 Registration No. 333-277380

Post-Effective Amendment No. 1 to Form S-8 Registration No. 333-285076

UNDER

THE SECURITIES ACT OF 1933

SPRINGWORKS THERAPEUTICS, INC.

(Exact Name of Registrant as Specified in its Charter)

Delaware	83-4066827
(State or Other Jurisdiction of Incorporation or Organization)	(I.R.S. Employer Identification No.)

100 Washington Blvd

Stamford, CT 06902

(203) 883-9490

(Address of Principal Executive Offices) (Zip Code)

SpringWorks Therapeutics, Inc. 2019 Stock Option and Incentive Plan
SpringWorks Therapeutics, Inc. Amended and Restated 2019 Stock Option and Equity Incentive Plan
SpringWorks Therapeutics, Inc. 2019 Employee Stock Purchase Plan

(Full title of the plans)

Michael MacDougall
Secretary

SpringWorks Therapeutics, Inc.
100 Washington Blvd
Stamford, CT 06902
(203) 883-9490

(Name and address of agent for service) (Telephone number, including area code, of agent for service)

Copies to:

Matthew Hurd Eric Krautheimer
Sullivan & Cromwell LLP
125 Broad Street New York, NY 10004
(212) 558-4000   ​ ​

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer		x		Accelerated filer		¨
Non-accelerated filer		¨		Smaller reporting company		¨
				Emerging growth company		¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ¨

DEREGISTRATION OF SECURITIES

These Post-Effective Amendments (these “Post-Effective Amendments”) relate to the following Registration Statements on Form S-8 (each, a “Registration Statement,” and collectively, the “Registration Statements”), filed with the Securities and Exchange Commission (the “SEC”) by SpringWorks Therapeutics, Inc., a Delaware corporation (the “Registrant”):

· Registration Statement No. 333-234365, filed with the SEC on October 29, 2019, pertaining to the registration of 2,924,183 shares of common stock, par value $0.0001 per share (“Common Stock”) of the Registrant reserved for issuance under the 2019 Stock Option and Incentive Plan (the “2019 Private Plan”); 2,657,000 shares of restricted stock, par value $0.0001 per share of the Registrant reserved for issuance under the 2019 Private Plan; 3,679,681 shares of Common Stock reserved for issuance under the 2019 Stock Option and Equity Incentive Plan (the “2019 Equity Incentive Plan”); options to purchase 184,385 shares of Common Stock granted under the 2019 Equity Incentive Plan and 442,153 shares of Common Stock reserved for issuance under the 2019 Employee Stock Purchase Plan (the “2019 ESPP”);

· Registration Statement No. 333-237350, filed with the SEC on March 23, 2020, pertaining to the registration of an additional 2,150,304 shares of Common Stock reserved for issuance under the 2019 Equity Incentive Plan and 430,061 shares of Common Stock reserved for issuance under the 2019 ESPP;

· Registration Statement No. 333-253531, filed with the SEC on February 25, 2021, pertaining to the registration of an additional 2,440,980 shares of Common Stock reserved for issuance under the 2019 Equity Incentive Plan and 488,196 shares of Common Stock reserved for issuance under the 2019 ESPP;

· Registration Statement No. 333-262996, filed with the SEC on February 24, 2022, pertaining to the registration of an additional 2,462,400 shares of Common Stock reserved for issuance under the Amended and Restated 2019 Stock Option and Equity Incentive Plan (“Amended 2019 Equity Incentive Plan”) and 492,480 shares of Common Stock reserved for issuance under the 2019 ESPP;

· Registration Statement No. 333-270096, filed with the SEC on February 28, 2023, pertaining to the registration of 3,121,157 shares of Common Stock reserved for issuance under the Amended 2019 Equity Incentive Plan and 624,232 shares of Common Stock reserved for issuance under the 2019 ESPP;

· Registration Statement No. 333-277380, filed with the SEC on February 27, 2024, pertaining to the registration of an additional 3,674,334 shares of Common Stock reserved for issuance under the Amended 2019 Equity Incentive Plan and 663,229 shares of Common Stock reserved for issuance under the 2019 ESPP; and

· Registration Statement No. 333-285076, filed with the SEC on February 20, 2025, pertaining to the registration of an additional 3,720,163 shares of Common Stock reserved for issuance under the Amended 2019 Equity Incentive Plan and 663,229 shares of Common Stock reserved for issuance under the 2019 ESPP.

On July 1, 2025, pursuant to the terms of the Agreement and Plan of Merger, dated April 27, 2025, by and among the Registrant, Merck KGaA, Darmstadt, Germany, a German corporation with general partners (“Parent”), and EMD Holdings Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Parent (“Merger Sub”), Merger Sub merged with and into the Registrant (the “Merger”), with the Registrant surviving the Merger as a wholly owned subsidiary of Parent.

As a result of the Merger, the Registrant has terminated, as of the date hereof, all offerings of its securities pursuant to its existing registration statements under the Securities Act of 1933, as amended, including the Registration Statements. In accordance with an undertaking made by the Registrant in the Registration Statements to remove from registration by means of a post-effective amendment any of the securities which remain unsold at the termination of the offering, Registrant hereby removes and withdraws from registration all securities of the Registrant registered pursuant to the Registration Statements that remain unsold as of the date hereof, and the Registration Statements are hereby amended, as appropriate, to reflect the deregistration of such securities.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused these Post-Effective Amendments to the Registration Statements on Form S-8 to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Stamford, State of Connecticut, on July 1, 2025. No other person is required to sign these Post-Effective Amendments to the Registration Statements on Form S-8 in reliance on Rule 478 of the Securities Act of 1933, as amended.

SPRINGWORKS THERAPEUTICS, INC.
By:	/s/ Michael MacDougall
	Name: Michael MacDougall
	Title: Secretary

FAQ

Why did SpringWorks Therapeutics (SWTX) file Post-Effective Amendments to Form S-8 on July 1 2025?

Because the company was acquired by Merck KGaA and is no longer publicly traded, it must deregister unsold shares previously reserved for its equity compensation plans.

Which registration statements are being amended or withdrawn?

Seven S-8 filings, Reg. Nos. 333-234365, 237350, 253531, 262996, 270096, 277380 and 285076.

How many shares were originally registered under these S-8 filings?

Collectively, they covered multiple tranches totalling several million shares for the 2019 Stock Option & Incentive Plan, its amended version, and the 2019 ESPP.

Does this filing affect the merger consideration received by SWTX shareholders?

No. The deregistration is administrative and occurs after the merger closed; it does not change terms already delivered to former public shareholders.

Will SpringWorks continue issuing shares under its 2019 equity plans?

No. All offerings under the 2019 plans have been terminated, and remaining unsold shares are withdrawn from registration.