[8-K] Sensei Biotherapeutics, Inc. Reports Material Event

Rhea-AI Filing Summary

Sensei Biotherapeutics (SNSE) furnished an update via Form 8-K. The company shared a press release titled “Sensei Biotherapeutics Reports New Clinical Results Highlighting Durable Progression Free Survival Data for Solnerstotug in PD-(L)1 Resistant Tumors at the ESMO Congress 2025,” and noted a webcast to discuss the clinical trial results. The company also updated its corporate presentation.

Both the press release (Exhibit 99.1) and the corporate presentation (Exhibit 99.2) were provided under Item 7.01 and are being furnished, not filed, and are not incorporated by reference under the Exchange Act or Securities Act.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 17, 2025

Sensei Biotherapeutics, Inc.

(Exact Name of Registrant as Specified in its Charter)

Delaware		001-39980		83-1863385
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(IRS Employer Identification No.)

1405 Research Blvd, Suite 125 Rockville, MD		20850
(Address of Principal Executive Offices)		(Zip Code)

Registrant’s telephone number, including area code: (240) 243-8000

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Securities Exchange Act of 1934:

Title of each class		Trading symbol		Name of each exchange on which registered
Common Stock		SNSE		The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

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 13(a) of the Exchange Act. ☐

Item 7.01 Regulation FD Disclosure.

On October 17, 2025, Sensei Biotherapeutics, Inc. (the “Company”) issued a press release titled “Sensei Biotherapeutics Reports New Clinical Results Highlighting Durable Progression Free Survival Data for Solnerstotug in PD-(L)1 Resistant Tumors at the ESMO Congress 2025”. The press release also included information regarding a webcast to discuss the clinical trial results. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

The Company is also updating its corporate presentation on its website, which the Company will reference during the webcast described above. A copy of the presentation is furnished as Exhibit 99.2 to this Current Report on Form 8-K.

The information in Item 7.01 and the exhibits attached hereto are being furnished and shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall they be deemed incorporated by reference into any filing under the Exchange Act or the Securities Act of 1933, as amended, whether filed before or after the date hereof and regardless of any general incorporation language in such filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number		Exhibit Description
99.1		Press release dated October 17, 2025
99.2		Sensei Biotherapeutics, Inc. corporate presentation dated October 2025
104		The cover page from this Current Report on Form 8-K, formatted in Inline XBRL

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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.

						Sensei Biotherapeutics, Inc.
Date: October 17, 2025						/s/ Christopher W. Gerry
						Christopher W. Gerry
						General Counsel and Secretary

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FAQ

What did Sensei Biotherapeutics (SNSE) announce in this 8-K?

The company furnished a press release on new clinical results for Solnerstotug presented at ESMO 2025 and noted a webcast to discuss the data.

Which exhibits accompany the SNSE 8-K filing?

The filing includes Exhibit 99.1 (press release dated October 17, 2025) and Exhibit 99.2 (corporate presentation dated October 2025).

Are the materials in the SNSE 8-K filed or furnished?

They are furnished under Item 7.01 and are not deemed filed under Section 18, nor incorporated by reference.

What topic does the SNSE press release cover?

It highlights durable progression-free survival data for Solnerstotug in PD-(L)1 resistant tumors at ESMO 2025.

Does the SNSE 8-K mention a webcast?

Yes. It includes information regarding a webcast to discuss the clinical trial results, referenced in Exhibit 99.1.

Where can investors view the updated SNSE corporate presentation?

The company states it updated its corporate presentation on its website; a copy is furnished as Exhibit 99.2.