Sensei Biotherapeutics, Inc. SEC Filings

Sensei Biotherapeutics, Inc. has registered 24,868,028 shares of Common Stock for resale by selling stockholders under a shelf prospectus dated April 28, 2026. The registered shares consist of Merger Conversion Shares, Private Placement Conversion Shares and Warrant Conversion Shares related to the February 2026 Acquisition of Faeth Therapeutics and a concurrent private placement.

The company will not receive proceeds from Resale Shares; proceeds go to the selling stockholders. The registration covers shares issuable on conversion of Series B Non-Voting Convertible Preferred Stock and certain warrant conversions and is subject to stockholder approvals required by Nasdaq listing rules.

Sensei Biotherapeutics calls a virtual 2026 annual meeting to vote on key actions tied to its completed acquisition of Faeth Therapeutics and a large PIPE financing. Stockholders are asked to approve conversion of all outstanding Series B Non-Voting Convertible Preferred Stock into common shares and to increase authorized common stock from 12.5 million to 300 million shares. The Series B Preferred, issued in the Faeth deal and a concurrent 2026 private placement, is convertible into common stock at a 1,000:1 ratio and, together with assumed options and warrants, leaves Faeth holders and PIPE investors with the vast majority of economic ownership on an as-converted basis. If Proposals 3 and 4 and a related Nasdaq Listing Application are approved, the company expects to change its name to Faeth Therapeutics, Inc. and its Nasdaq ticker to FTH. Risk factors emphasize that failure to secure these approvals could force cash settlement of the Series B Preferred at fair value and materially strain the company’s financial position.

Sensei Biotherapeutics, Inc. outlines a contingent refresh of its board and leadership team tied to stockholder approvals at the June 10, 2026 annual meeting. Three current directors, including Christopher W. Gerry and Thomas Ricks, have tendered resignations effective two business days after the meeting, conditional on approval of specified charter and conversion proposals. Three new directors – Stephen M. Hahn, Saira Ramasastry and Karen Vousden – have been conditionally appointed, with planned roles across the audit, compensation, and nominating and governance committees.

If the required proposals are approved, Chief Operating Officer and director Anand Parikh is expected to become Chief Executive Officer and principal executive officer, while Gerry will remain General Counsel but step down as President and principal executive officer. Brian Stephenson, Ph.D., is anticipated to become Chief Financial Officer and principal financial officer, with Josiah Craver continuing as Senior Vice President of Finance and principal accounting officer.

The company also adopted a Severance and Change in Control Plan for executive officers and key employees. For qualifying terminations outside a change in control period, designated executives may receive 6–12 months of base salary and COBRA coverage; during a defined change in control window, cash severance increases to 12–18 months of salary, plus a 1.0x–1.5x target bonus multiple, COBRA coverage and full vesting of time-based equity awards, subject to a release of claims and the company’s clawback policy.

Sensei Biotherapeutics, Inc. is asking stockholders to vote at its virtual annual meeting on June 10, 2026 on proposals tied to the recently completed acquisition of Faeth Therapeutics and a concurrent private placement. The company issued Series B Non‑Voting Convertible Preferred Stock as merger consideration and sold additional Series B Preferred in a PIPE for approximately $200 million. If approved, each outstanding share of Series B Preferred will convert into 1,000 common shares, subject to beneficial ownership limitations, and the company would seek Nasdaq approval and an authorized share increase to complete the conversions and related governance changes.

Sensei Biotherapeutics, Inc. filed an amended report to add full-year 2025 and 2024 audited financial statements for Faeth Therapeutics and unaudited 2025 pro forma combined financials following Sensei’s acquisition of Faeth. Faeth reported no product revenue and a 2025 net loss of $16.0 million, with cash and restricted cash of $20.4 million.

The auditor drew attention to substantial doubt about Faeth’s ability to continue as a going concern. This risk arises because, after a merger with Sensei and a related $200.0 million PIPE financing in Series B Non-Voting Convertible Preferred Stock, the acquirer may be required to make significant cash payments to Series B holders if it cannot timely deliver common shares upon conversion, which could substantially reduce available cash resources.

Sensei Biotherapeutics’ principal financial and accounting officer, Josiah Craver, received a grant of stock options covering 80,000 shares of common stock on April 10, 2026. The options have an exercise price of $29.89 per share and expire on April 9, 2036.

According to the vesting terms, 25% of the shares subject to the option vest and become exercisable on April 10, 2027, with the remaining shares vesting in 36 equal monthly installments so that the award is fully vested by April 10, 2030, subject to his continuous service with the company.

Sensei Biotherapeutics director Phillip B. Donenberg received a supplemental stock option grant for 23,100 shares of Common Stock. The option has an exercise price of $29.89 per share and expires on April 9, 2036. This award aligns his total initial director option grant with the company’s amended non-employee director compensation policy, which now provides 25,000 options to new directors. The new options vest in 36 equal monthly installments over three years, fully vesting on April 10, 2029, contingent on his continued service as a director.