Welcome to our dedicated page for Sensei Biotherapeutics SEC filings (Ticker: SNSE), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Sensei Biotherapeutics, Inc. filings document a Nasdaq-listed clinical-stage oncology company, its common stock, and its disclosure obligations around pipeline development, operating results, governance, and capital structure. Material-event reports cover financial results, Regulation FD disclosures, board composition and compensation arrangements, and the completed acquisition of Faeth Therapeutics, including acquired-business financial statements and pro forma combined financial information.
Proxy and governance filings describe shareholder voting matters, director and board matters, equity compensation, preferred stock conversion-related disclosures, authorized-share matters, material agreements, and other capital-structure topics. The filing record also reflects clinical and regulatory disclosure categories for PIKTOR and solnerstotug within the company’s oncology development business.
Sensei Biotherapeutics, Inc. reported that entities associated with Millennium Management LLC actively traded its Common Stock over several days in early April 2026. The trades were made by ICS Opportunities II LLC and other trading entities, with voting control and investment discretion held by Millennium Management LLC, Millennium Group Management LLC and Israel A. Englander.
Across these open-market transactions, the reporting entities sold 17,076 shares and purchased 4,215 shares of Common Stock at prices generally between $28.9417 and $35.5472 per share, resulting in a net sale. After the final transaction, Millennium Management LLC beneficially owned 133,986 shares indirectly, as disclosed in column 5. Each reporting person disclaims beneficial ownership beyond any pecuniary interest.
Entities associated with Millennium Management LLC reported active trading in Sensei Biotherapeutics, Inc. common stock over March 31 and April 1, 2026. Across multiple open-market purchases and sales, they were net buyers of 9,439 shares, with 12,180 shares purchased and 2,741 shares sold. Following these transactions, Millennium Management LLC beneficially owned 147,731 shares of Sensei common stock indirectly. The trades were executed by ICS Opportunities II LLC or other trading entities under Millennium’s voting control, and each reporting person disclaims beneficial ownership beyond any pecuniary interest.
Sensei Biotherapeutics, Inc. reported a series of open-market trades in its Common Stock by entities associated with Millennium Management LLC over March 26–30, 2026. The trades were executed by ICS Opportunities II LLC or other trading entities subject to voting control and investment discretion by Millennium Management LLC, Millennium Group Management LLC, and Israel A. Englander.
Across these dates, the entities reported purchases of 30,585 shares and sales of 3,250 shares, resulting in a net purchase of 27,335 shares of Sensei Biotherapeutics Common Stock. Following the transactions on March 30, 2026, Millennium Management LLC is reported as beneficially owning 145,678 shares, with each reporting person disclaiming beneficial ownership beyond any pecuniary interest.
Sensei Biotherapeutics, Inc. insider filings show Millennium-affiliated entities as significant indirect holders of Common Stock. A total of 127,095 shares were reported as indirectly owned, including 126,828 shares held by ICS Opportunities II LLC and 267 shares held by other trading entities under Millennium Management LLC’s voting control. The reporting persons, including Millennium Group Management LLC and Israel A. Englander, disclaim beneficial ownership of these shares except to the extent of any pecuniary interest.
Sensei Biotherapeutics reported a joint Schedule 13G from ICS Opportunities II LLC, Millennium Management LLC, Millennium Group Management LLC and Israel A. Englander disclosing shared beneficial ownership stakes in Common Stock. The reporting persons stated they beneficially owned 84,541 shares (6.7%) as of February 24, 2026, increased to 127,095 shares (10.1%) on March 26, 2026, and were reported as holding 128,761 shares (9.6%) as of May 14, 2026. The filing ties calculations to 1,261,290 shares outstanding (as of November 10, 2025) and 1,341,140 shares outstanding (as of April 13, 2026) cited from company filings.
Sensei Biotherapeutics reports a joint Schedule 13G filing disclosing a 9.9% stake. The filing states that StemPoint Capital LP, StemPoint Capital Management GP LLC and Michelle Ross may be deemed beneficial owners of 132,873 shares of Common Stock. Shares outstanding were 1,340,281 as of March 23, 2026, per the company’s Form 10-K cited in the filing. The Reporting Persons disclose shared voting power of 116,587 and shared dispositive power of 132,873.
Sensei Biotherapeutics files a Schedule 13G reporting passive ownership. Caligan Partners LP and David Johnson report beneficial ownership of 126,002 shares of common stock, representing 9.40% of the class based on 1,340,281 shares outstanding as of March 23, 2026. The filing notes the Reporting Persons also hold Series B Non‑Voting Convertible Preferred Stock convertible into 361,010 shares of common stock under the Certificate of Designation.
The statement is a joint filing by Caligan Partners (as investment manager) and Mr. Johnson (Managing Partner). Voting and dispositive power are reported as shared for 126,002 shares. The filing is presented as passive ownership under Schedule 13G.
Sensei Biotherapeutics transformed its business in the quarter by acquiring Faeth Therapeutics and making PIKTOR, an oral multi-node inhibitor of the PI3K/AKT/mTOR pathway, its lead cancer program. The deal was paired with a $200 million private placement of Series B redeemable convertible preferred stock.
The company reported a net loss of $170.2 million, driven largely by a $133.0 million acquired in-process R&D charge and one-time stock-based compensation and tax gross-up costs tied to the acquisition. Cash, cash equivalents and marketable securities rose to $202.8 million, but management disclosed substantial doubt about its ability to continue as a going concern because holders of the new preferred stock could demand cash settlement if stockholder approval and timely share delivery are not achieved.
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.