# Five Prime Therapeutics

Source: https://onco.cc/companies/five-prime-therapeutics/  
OnCo record `five-prime-therapeutics` (Company). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Five Prime Therapeutics developed bemarituzumab, an antibody aimed at a protein called FGFR2b that some stomach cancers carry in large amounts. Amgen bought the company in 2021.

## Summary

Five Prime Therapeutics, Inc. (formerly Nasdaq: FPRX), of South San Francisco, was a clinical-stage company developing immuno-oncology and targeted cancer therapies. Its lead asset, bemarituzumab, is an antibody against FGFR2b, which the announcement says is overexpressed in about 30% of people with HER2-negative gastric cancer; the randomised, placebo-controlled phase 2 FIGHT trial in first-line advanced gastric or gastro-oesophageal junction cancer reported improvements in progression-free survival, overall survival and response rate. Amgen agreed on 4 March 2021 to buy Five Prime for USD 38 per share in cash, an equity value of about USD 1.9 billion, and the merger was completed on 16 April 2021.

## Fields

- Kind: Company
- Last checked: 2026-11-03
- Also known as: Five Prime Therapeutics, Inc.; Five Prime; NASDAQ:FPRX
- HQ: South San Francisco, CA
- Type: biotech

## Notes

- Completion on 16 April 2021 is from Five Prime's 8-K of that date. No website or founding year is recorded.

## Sources

- Amgen to acquire Five Prime Therapeutics (8-K exhibit 99.1, 4 March 2021): https://www.sec.gov/Archives/edgar/data/1175505/000119312521068593/d77427dex991.htm
- Form 8-K: completion of the merger (16 April 2021): https://www.sec.gov/Archives/edgar/data/1175505/000119312521118566/d153048d8k.htm

## Connected records

- cancers: [Gastric & gastro-oesophageal junction cancer](https://onco.cc/cancers/gastric/)
- fronts: [Immunotherapy](https://onco.cc/fronts/immunotherapy/), [Targeted Therapy](https://onco.cc/fronts/targeted-therapy/)
- technologies: [Monoclonal antibodies](https://onco.cc/technologies/monoclonal-antibody/)
- targets: [FGFR2](https://onco.cc/targets/fgfr2/)
- drugs: [Bemarituzumab](https://onco.cc/drugs/bemarituzumab/)
- companies: [Amgen](https://onco.cc/companies/amgen/)

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