AC Immune (NASDAQ: ACIU) slashes workforce 30% to fund key programs through Q3 2027

Rhea-AI Filing Summary

AC Immune SA reports the outcome of a strategic review, deciding to concentrate spending on its most important R&D assets. The focus will be on three clinical-stage active immunotherapy programs, including two in collaborations with pharmaceutical partners, and on small molecule programs targeting NLRP3 and Tau.

To support this sharper focus, AC Immune plans to reduce its workforce by around 30%. The company states that these actions are expected to extend its available cash for operations to the end of the third quarter of 2027, giving it more time to advance its key pipeline programs.

Positive

• None.

Negative

• Workforce reduction of around 30% signals significant cost-cutting that may slow or discontinue non-core programs and could indicate a more constrained operating environment for AC Immune.

Insights

Biotech equity analyst

AC Immune cuts 30% of staff to fund core neurology programs through Q3 2027.

AC Immune is concentrating resources on three clinical-stage active immunotherapy programs, two already partnered with major pharmaceutical companies, plus small molecule projects against NLRP3 and Tau. This reflects a clear prioritization of late- and mid-stage assets over broader pipeline breadth.

The company will reduce its workforce by around 30%, a sizable cut that lowers operating expenses but may also slow or halt non-core projects. Management indicates that, after these changes, available cash for operations should last until the end of Q3 2027, which lengthens the development runway for the prioritized programs.

For investors, the trade-off is between a leaner organization with an extended cash horizon and the loss of broader optionality from trimmed programs. Future disclosures in company filings may provide more detail on which projects are reduced and how collaborations on the two partnered immunotherapies evolve.

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR
15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of September 2025

Commission file number: 001-37891

AC IMMUNE SA

(Exact Name of Registrant as Specified in Its Charter)

EPFL Innovation Park
Building B
1015 Lausanne, Switzerland

(Address of Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or
Form 40-F.

Form 20-F ☒     Form 40-F ☐

On September 4, 2025, AC Immune SA (“AC Immune”) issued a press release reporting that, following a strategic review by executive management, AC Immune is sharpening its focused investment on its most important assets. These include its three clinical-stage active immunotherapy programs, two of which are in ongoing pharma collaborations, and its most promising small molecule programs targeting NLRP3 and Tau. As a result, AC Immune will reduce its workforce by around 30% and extend its cash for operations to the end of the third quarter of 2027.

A copy of the press release is attached as Exhibit 99.1 to this Report on Form 6-K.

This Report on Form 6-K shall be deemed to be incorporated by reference into the registration statements on Form F-3 (File Nos. 333-227016, 333-249655 and 333-277940) and Form S-8 (File Nos. 333-213865, 333-216539 and 333-233019) of AC Immune SA and to be a part thereof from the date on which this report is filed, to the extent not superseded by documents or reports subsequently filed or furnished.

SIGNATURE

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, thereunto duly authorized.

	AC IMMUNE SA
	By:	/s/ Andrea Pfeifer
		Name:	Andrea Pfeifer
		Title:	Chief Executive Officer
	By:	/s/ Christopher Roberts
		Name:	Christopher Roberts
		Title:	Chief Financial Officer

Date: September 4, 2025

EXHIBIT INDEX

Exhibit Number	Description
99.1	Press release dated September 4, 2025

FAQ

What strategic changes did AC Immune (ACIU) announce in this 6-K?

AC Immune announced it is sharpening its focus on key R&D assets. The company will prioritize three clinical-stage active immunotherapy programs and promising small molecule candidates targeting NLRP3 and Tau, reallocating resources away from less critical projects.

How much of its workforce is AC Immune (ACIU) cutting?

AC Immune plans to reduce its workforce by around 30%. This sizable staff reduction is intended to lower operating expenses and help redirect funding toward the company’s most important clinical-stage immunotherapy and small molecule programs.

How long will AC Immune’s cash last after these changes?

AC Immune states that, following the strategic review and workforce reduction, its cash for operations is expected to last until the end of the third quarter of 2027, providing a longer runway to advance its prioritized R&D programs.

Which programs is AC Immune (ACIU) prioritizing after its strategic review?

AC Immune is prioritizing three clinical-stage active immunotherapy programs, two in ongoing collaborations with pharmaceutical partners, and its most promising small molecule programs directed at NLRP3 and Tau, focusing spending on these core neurology-related assets.

Does AC Immune mention pharma collaborations in this update?

Yes. AC Immune notes that two of its three prioritized clinical-stage active immunotherapy programs are part of ongoing collaborations with pharmaceutical partners, highlighting external support around some of its lead assets after the strategic review.

What is the purpose of AC Immune’s workforce reduction?

The workforce reduction is meant to align expenses with a sharpened R&D focus. By cutting around 30% of staff, AC Immune aims to extend its operational cash runway and concentrate resources on its most advanced and promising therapeutic programs.