Sensei Biotherapeutics (Nasdaq: SNSE) Q1 loss reflects Faeth acquisition impact

Rhea-AI Filing Summary

Sensei Biotherapeutics reported a sharply higher net loss for the first quarter of 2026 driven by its acquisition of Faeth Therapeutics and related accounting charges, while also ending the period with a significantly stronger cash position.

For the quarter ended March 31, 2026, net loss was $170.2 million, or $131.45 per share, compared with a net loss of $6.9 million, or $5.45 per share, a year earlier. Results included $133.0 million of acquired in‑process research and development expense tied to Faeth assets that had no alternative future use at the acquisition date.

Cash, cash equivalents and marketable securities rose to $202.8 million as of March 31, 2026, from $21.2 million at December 31, 2025, supported by a $200 million private placement completed in February. R&D expenses increased to $18.0 million and G&A to $19.7 million, reflecting ongoing integration of Faeth and one‑time acquisition costs.

Following the Faeth deal, Sensei’s lead program is PIKTOR, an oral multi‑node inhibitor of the PI3K/AKT/mTOR pathway in development for advanced endometrial and HR+/HER2‑ advanced breast cancers, with topline Phase 2 endometrial data expected in the second half of 2026.

Positive

• Cash strengthened: Cash, cash equivalents and marketable securities increased to $202.8 million as of March 31, 2026, from $21.2 million at December 31, 2025, supported by a $200 million private placement.

Negative

• Large loss and equity deficit: Net loss jumped to $170.2 million, driven by $133.0 million of acquired in‑process R&D, and total stockholders’ equity shifted from $18.6 million to a $137.3 million deficit, alongside $328.5 million of Series B redeemable convertible preferred stock.

Insights

Biotech equity analyst

Large non‑cash R&D charge and new capital reshape Sensei’s financial profile.

Sensei Biotherapeutics transformed its business in early 2026 by acquiring Faeth Therapeutics and raising $200 million in a private placement, while designating PIKTOR as its lead oncology asset targeting the PI3K/AKT/mTOR pathway.

The quarter’s $170.2 million net loss for the period ended March 31, 2026 is dominated by an acquired in‑process R&D charge of $133.0 million. This reflects the fair value of Faeth’s R&D assets with no alternative future use, a common but lumpy feature of biotech M&A accounting.

On the balance sheet, cash and marketable securities climbed to $202.8 million, while a new Series B redeemable convertible preferred stock line of $328.476 million contributed to a stockholders’ deficit. Future filings may clarify how this capital structure and cash runway support upcoming PIKTOR milestones, including Phase 2 endometrial cancer data expected in the second half of 2026.

8-K Event Classification

2 items: 2.02, 9.01

2 items

Item 2.02 Results of Operations and Financial Condition Financial

Disclosure of earnings results, typically an earnings press release or preliminary financials.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Key Figures

Net loss: $170.2 million Net loss per share: $131.45 per basic and diluted share Acquired in-process R&D expense: $133.0 million +5 more

8 metrics

Net loss $170.2 million Quarter ended March 31, 2026

Net loss per share $131.45 per basic and diluted share Quarter ended March 31, 2026

Acquired in-process R&D expense $133.0 million Quarter ended March 31, 2026

Cash, cash equivalents and marketable securities $202.8 million As of March 31, 2026

R&D expenses $18.0 million Quarter ended March 31, 2026 vs. $3.7 million in 2025

G&A expenses $19.7 million Quarter ended March 31, 2026 vs. $3.5 million in 2025

Series B redeemable convertible preferred stock $328.476 million Balance as of March 31, 2026

Total stockholders’ (deficit) equity -$137.286 million As of March 31, 2026

Key Terms

Acquired in-process research and development, multi-node inhibition, PI3K/AKT/mTOR pathway, HR+/HER2- advanced breast cancer, +2 more

6 terms

Acquired in-process research and development financial

"Acquired In-Process Research and Development (Acquired IPR&D) Expenses: Acquired IPR&D expenses were $133.0 million for the quarter"

Acquired in-process research and development is the unfinished scientific work and product programs a company buys from another firm as part of a deal — think of it as buying an unfinished prototype and the team working on it. Investors care because the buyer is paying for future potential that may never materialize; that payment often shows up as a large one-time cost and signals higher risk and reward tied to future products rather than current sales.

multi-node inhibition medical

"focused on improving outcomes for cancer patients through multi-node inhibition of critical oncogenic pathways"

PI3K/AKT/mTOR pathway medical

"designed to inhibit multiple nodes of the PI3K/AKT/mTOR pathway through PI3K-alpha and dual mTORC1/2 targeting"

A chain of proteins inside cells that passes signals controlling cell growth, survival and energy use; think of it like a thermostat and wiring that tells a cell when to grow, divide or conserve resources. It matters to investors because drugs or tests that alter this pathway are central to many cancer and metabolic disease treatments, influencing the value and risk of biotech pipelines, trial outcomes and future sales potential.

HR+/HER2- advanced breast cancer medical

"Phase 1b/2 trial of PIKTOR in HR+/HER2- advanced breast cancer"

Series B redeemable convertible preferred stock financial

"Series B redeemable convertible preferred stock. | | | 328,476 | | | | — |"

Phase 1/2 trial medical

"Sensei is also completing a Phase 1/2 trial of solnerstotug"

A phase 1/2 trial combines the earliest human safety testing with an initial look at whether a treatment works, typically starting by checking tolerability and side effects and then expanding to measure early signs of benefit and the best dose. For investors, results from these trials are an early indicator of a drug’s clinical promise and regulatory path: positive data can materially increase a company’s value and reduce development risk, while negative data can sharply lower expectations.

Earnings Snapshot

Net loss: $170.2 million

Q1 2026

Net loss $170.2 million

Net loss per share $131.45

Cash, cash equivalents and marketable securities $202.8 million

R&D expenses $18.0 million

G&A expenses $19.7 million

Understanding 8-K Material Events →

false 0001829802 0001829802 2026-05-15 2026-05-15

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): May 15, 2026

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 2.02 Results of Operations and Financial Condition.

On May 15, 2026, Sensei Biotherapeutics, Inc. issued a press release announcing its financial results for the quarter ended March 31, 2026. A copy of the press release is attached hereto as Exhibit 99.1.

The information in this Item 2.02 and the exhibit 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 of Sensei Biotherapeutics, Inc., dated May 15, 2026
104		The cover page from this Current Report on Form 8-K, formatted in Inline XBRL

2

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: May 15, 2026						/s/ Christopher W. Gerry
						Christopher W. Gerry
						General Counsel and Secretary

3

Exhibit 99.1

Sensei Biotherapeutics Reports First Quarter 2026 Financial Results and Provides Corporate Update

First patient dosed in Phase 1b/2 trial of PIKTOR in HR+/HER2- advanced breast cancer

Topline Phase 2 data in patients with advanced endometrial cancer expected in second half 2026

BOSTON, Mass., May 15, 2026 – Sensei Biotherapeutics, Inc. (Nasdaq: SNSE) today reported financial results for the first quarter ended March 31, 2026, and provided a corporate update.

“The first quarter of 2026 was transformational for the Company, with the acquisition of Faeth Therapeutics and the concurrent $200 million private placement in February, supported by a group of leading life sciences investors,” said Christopher Gerry, President & General Counsel of Sensei Biotherapeutics. “This acquisition and injection of new capital will allow us to advance PIKTOR, a differentiated multi-node pathway inhibitor, through key clinical milestones.”

“New data across the industry continues to support the significant potential of multi-node inhibition of the PI3K/AKT/mTOR pathway,” said Anand Parikh, Chief Operating Officer of Sensei Biotherapeutics. “We believe PIKTOR is differentiated as an orally administered multi-node therapy specifically targeting PI3K-alpha, mTORC1 and mTORC2, with the potential to treat a variety of solid tumors. With our Phase 2 trial in advanced endometrial cancer expected to read out by the end of the year and the recent initiation of our Phase 1b/2 trial in advanced breast cancer, we are making great strides towards delivering the next generation of solid tumor therapies.”

Clinical Program Highlights

Acquired through the Faeth transaction, PIKTOR is now Sensei’s lead program. The investigational, proprietary, all-oral combination of serabelisib and sapanisertib is designed to inhibit multiple nodes of the PI3K/AKT/mTOR pathway through PI3K-alpha and dual mTORC1/2 targeting.

• In April 2026, the first patient was dosed in the Phase 1b/2 trial evaluating PIKTOR for the treatment of HR+/HER2- advanced breast cancer (Study FTH-PIK-101). Interim data from the trial is expected in 2027.

• The Phase 2 trial evaluating PIKTOR in advanced endometrial cancer (Study FTH-PIK-201) is on track to report topline data in the second half of 2026.

First Quarter 2026 Financial Results

Cash Position: Cash, cash equivalents and marketable securities were $202.8 million as of March 31, 2026, as compared to $21.2 million as of December 31, 2025.

Research and Development (R&D) Expenses: R&D expenses were $18.0 million for the quarter ended March 31, 2026, compared with $3.7 million for the quarter ended March 31, 2025. The increase in R&D expenses was primarily attributable to the inclusion of Faeth R&D operations as well as one-time costs associated with the Faeth acquisition, partially offset by a reduction in the SNS-101 clinical trial costs.

General and Administrative (G&A) Expenses: G&A expenses were $19.7 million for the quarter ended March 31, 2026, compared to $3.5 million for the quarter ended March 31, 2025. The increase in G&A expense was primarily attributable to one-time costs associated with the Faeth acquisition.

Acquired In-Process Research and Development (Acquired IPR&D) Expenses: Acquired IPR&D expenses were $133.0 million for the quarter ended March 31, 2026. This represents the fair value of IPR&D assets obtained in connection with asset acquisition where the acquired IPR&D has no alternative future use as of the acquisition date.

Net Loss: Net loss was $170.2 million, or $131.45 per basic and diluted share, for the quarter ended March 31, 2026, compared with a net loss of $6.9 million, or $5.45 per basic and diluted share, for the quarter ended March 31, 2025.

Weighted-average common shares outstanding, basic and diluted, were 1,295,052 for the quarter ended March 31, 2026, compared with 1,259,531 for the quarter ended March 31, 2025.

Condensed Statements of Operations

(Unaudited, in thousands except share and per share data)

		For the Three Months Ended March 31,
		2026				2025
Operating expenses:
Research and development		$	17,957			$	3,725
General and administrative			19,713				3,549
Acquired in-process research and development			132,957				—
Total operating expenses			170,627				7,274
Loss from operations			(170,627	)			(7,274	)
Total other income			391				410
Net loss			(170,236	)			(6,864	)
Net loss per share, basic and diluted		$	(131.45	)		$	(5.45	)
Weighted-average common shares outstanding, basic and diluted			1,295,052				1,259,531

Selected Condensed Balance Sheet Data

(Unaudited, in thousands)

		March 31, 2026				December 31, 2025
Cash and cash equivalents		$	152,325			$	8,668
Marketable securities			50,468				12,516
Total assets			205,381				22,902
Total liabilities			14,191				4,310
Series B redeemable convertible preferred stock.			328,476				—
Total stockholders’ (deficit) equity			(137,286	)			18,592

About Sensei Biotherapeutics

Sensei Biotherapeutics, Inc. (Nasdaq: SNSE) is a clinical-stage biotechnology company focused on improving outcomes for cancer patients through multi-node inhibition of critical oncogenic pathways. Following the acquisition of Faeth Therapeutics, Sensei’s lead program is PIKTOR, an investigational multi-node inhibitor of the PI3K/AKT/mTOR pathway in development for endometrial and breast cancer. Sensei is also completing a Phase 1/2 trial of solnerstotug, its V-domain Ig suppressor of T cell activation (VISTA) inhibitor, in patients with advanced solid tumors. Sensei intends to use its website as a means of disclosing material non-public information and for complying with its disclosure obligations under Regulation FD. For more information, please visit www.senseibio.com and follow the company on X @SenseiBio and LinkedIn.

Cautionary Note Regarding Forward-Looking Statements

Certain statements in this press release, other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of the safe harbor provisions under the United States Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to, express or implied statements relating to the company’s expectations, hopes, beliefs, intentions or strategies regarding the future including, without limitation, statements regarding: the expected benefits or opportunities following the acquisition of Faeth Therapeutics; expectations regarding or plans for the company’s pipeline, including the Phase 2 trial evaluating PIKTOR in advanced endometrial cancer and the expected timing for topline data, the Phase 1b/2 trial evaluating PIKTOR in HR+/HER2- advanced breast cancer and the expected timing for interim data, the completion of the remaining portion of the Phase 1/2 trial of solnerstotug and other research and development programs and the expected timing for key milestones; the potential benefits of PIKTOR, including its potential to treat a variety of solid tumors; expectations regarding the use of proceeds from the private placement and cash runway expectations therefrom, including such proceeds funding the company through key clinical milestones. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words “opportunity,” “potential,” “milestones,” “pipeline,” “can,” “goal,” “aim,” “strategy,” “target,” “seek,” “anticipate,” “achieve,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “intends,” “may,” “might,” “plan,” “possible,” “predict,” “project,” “should,” “will,” “would” and similar expressions (including the negatives of these terms or variations of them) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. These forward-looking statements are based on current expectations and beliefs concerning future developments and their potential effects. There can be no assurance that future developments affecting the company will be those that have been anticipated. These forward-looking statements involve a number of risks, uncertainties (some of which are beyond the company’s control) or other assumptions that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. These risks and uncertainties include, but are not limited to those uncertainties and factors described under the heading “Risk Factors” and “Summary of Risk Factors” in the company’s Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission (the “SEC”) on May 14, 2026, as well as discussions of potential risks, uncertainties, and other important factors included in other filings by the company from time to time, as well as risk factors associated with companies, such as Faeth, that operate in the biotechnology industry. Should one or more of these risks or uncertainties materialize, or should any of the company’s assumptions prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements. Nothing in this press release should be regarded as a representation by any person that the forward-looking statements set forth herein will be achieved or that any of the contemplated results of such forward-looking statements will be achieved. You should not place undue reliance on forward-looking statements in this press release, which speak only as of the date they are made and are qualified in their entirety by reference to the cautionary statements herein. The company does not undertake or accept any duty to release publicly any updates or revisions to any forward-looking statements. This press release does not purport to summarize all of the conditions, risks and other attributes of an investment in the company.

Investor Contact:

Stephanie Ascher, Precision AQ

Stephanie.ascher@precisionaq.com

Media Contact:

Patrick Schmidt, Consort Partners

senseibio@consortpartners.com

FAQ

What were Sensei Biotherapeutics (SNSE) Q1 2026 financial results?

Sensei Biotherapeutics reported a Q1 2026 net loss of $170.2 million, or $131.45 per share. The loss was largely driven by a $133.0 million acquired in‑process R&D expense related to the Faeth Therapeutics acquisition.

How much cash does Sensei Biotherapeutics (SNSE) have after Q1 2026?

As of March 31, 2026, Sensei held $202.8 million in cash, cash equivalents and marketable securities. This compares with $21.2 million at December 31, 2025, reflecting the impact of a $200 million private placement completed in February.

What drove the increase in Sensei Biotherapeutics (SNSE) expenses in Q1 2026?

Research and development expenses rose to $18.0 million and G&A to $19.7 million for Q1 2026. The company attributes these increases mainly to integrating Faeth Therapeutics’ operations and one‑time costs associated with completing the Faeth acquisition.

What is PIKTOR in Sensei Biotherapeutics’ (SNSE) pipeline?

PIKTOR is Sensei’s lead program, acquired with Faeth Therapeutics. It is an all‑oral combination targeting the PI3K/AKT/mTOR pathway and is being developed for advanced endometrial cancer and HR+/HER2‑ advanced breast cancer.

When will Sensei Biotherapeutics (SNSE) report key clinical data for PIKTOR?

Sensei expects topline Phase 2 data for PIKTOR in advanced endometrial cancer in the second half of 2026. Interim data from the Phase 1b/2 trial in HR+/HER2‑ advanced breast cancer are also anticipated, according to the company’s stated timeline.

How did the Faeth Therapeutics acquisition affect Sensei Biotherapeutics’ (SNSE) balance sheet?

The Faeth transaction contributed to a $133.0 million acquired in‑process R&D expense and the recognition of $328.476 million in Series B redeemable convertible preferred stock. Total stockholders’ equity moved from $18.6 million to a $137.3 million deficit as of March 31, 2026.

Filing Exhibits & Attachments

4 documents

Press Releases

• EX-99.1 EX-99.1 30.8 KB

Other Documents

• EX-101 XBRL TAXONOMY EXTENSION SCHEMA 3.1 KB
• EX-101 XBRL TAXONOMY EXTENSION LABEL LINKBASE 18.3 KB
• EX-101 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE 11.4 KB