# Crossbow Therapeutics, Inc.

> Crossbow Therapeutics is a Cambridge, Massachusetts biotechnology company building a new class of cancer immunotherapies. Its T-Bolt platform engineers TCR-mimetic antibodies - T-cell engagers that recognize tiny peptide fragments displayed on a cancer cell's surface (peptide-HLA complexes), opening up intracellular proteins that conventional antibodies cannot reach. The lead program, CBX-250, is a first-in-class T-cell engager in a Phase 1 trial for relapsed or refractory myeloid malignancies. Backed by more than $157M in venture funding, Crossbow aims to expand the universe of targetable cancer antigens.

- **Founded:** 2021
- **Headquarters:** Cambridge, Massachusetts, United States
- **Founders:** Daniel J. Powell Jr. (Scientific Co-Founder (University of Pennsylvania)), Geraldine Paulus (Co-Founder, SVP & Head of Corporate Development), Patrick A. Baeuerle (Co-Founder & Scientific Advisor), Todd Foley (Co-Founder (MPM BioImpact))
- **Team size:** ~44 employees
- **Products:** T-Bolt platform (TCRm technology engine), CBX-250, CBX-663
- **Notable:** Launched publicly in 2023 with an $80M Series A., Dosed first patient in the Phase 1 CROSSCHECK-001 trial of CBX-250 in September 2025., Raised $77M Series B in March 2026, bringing total funding above $157M.

## Products & services

- **T-Bolt platform (TCRm technology engine)** — A discovery and engineering engine that produces TCR-mimetic antibodies - 'T-Bolt' molecules - which bind tumor-specific peptide-HLA complexes with high accuracy and potency, allowing the immune system to attack intracellular targets displayed on the cell surface.
- **CBX-250** — Lead program. A first-in-class T-cell engager targeting a peptide-HLA complex specific to myeloid cancer cells. In the Phase 1 CROSSCHECK-001 trial for relapsed or refractory myeloid malignancies including AML, CML, MDS and CMML. Initial clinical data expected by end of 2026.
- **CBX-663** — Second program. A first-in-class T-cell engager targeting a telomerase reverse transcriptase (TERT)-derived peptide-HLA complex, addressing both hematologic and solid tumors. IND filing and Phase 1 start planned for Q3 2026.

## Achievements

- Launched publicly in 2023 with an $80M Series A.
- Dosed first patient in the Phase 1 CROSSCHECK-001 trial of CBX-250 in September 2025.
- Raised $77M Series B in March 2026, bringing total funding above $157M.
- Built a pipeline of two first-in-class T-cell engagers (CBX-250, CBX-663) from a single platform.
- Attracted strategic pharma investors including Pfizer Ventures and Eli Lilly.

## Latest updates

- **2026-03** — Closed $77M Series B co-led by Taiho Ventures and Arkin Bio Capital to advance CBX-250 and the broader T-Bolt pipeline.
- **2025-09** — Dosed first patient in the Phase 1 CROSSCHECK-001 trial of lead candidate CBX-250 for myeloid malignancies.
- **2026-06** — CBX-663 (TERT-directed T-cell engager) IND filing and Phase 1 initiation planned for Q3 2026; initial CBX-250 clinical data expected by year end.

## Links

- Website: https://crossbowtx.com
- LinkedIn: https://www.linkedin.com/company/crossbow-therapeutics-inc

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Profile page: https://yespress.io/crossbow-therapeutics-inc
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Last updated: 2026-06-09