# IGM Biosciences

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

## TL;DR

IGM Biosciences engineered antibodies of the IgM class, which have ten binding arms instead of two, originally as T-cell engagers for blood cancers and later for autoimmune disease. It ended development and was bought by Concentra Biosciences in 2025.

## Summary

IGM Biosciences was a biotechnology company that focused on developing engineered IgM-based therapeutic antibodies, exploiting the ten binding sites of the IgM format for T-cell engagers and other constructs. By mid-2025 the company had wound down development; on 1 July 2025 it agreed to be acquired by Concentra Biosciences for $1.247 per share in cash plus a contingent value right entitling holders to closing net cash above $82 million and 80% of net proceeds from any disposition of product candidates within a year. The tender offer and merger completed on 14 August 2025 and the Nasdaq listing (IGMS) ended. The company's website (igmbio.com) no longer resolves. Its earlier oncology programmes (including CD20xCD3 IgM T-cell engagers) are not described in the fetched filings.

## Fields

- Kind: Company
- Last checked: 2026-09-10
- HQ: Mountain View, CA
- Type: biotech

## Notes

- Former Nasdaq ticker IGMS. The company had pivoted from oncology to autoimmune disease before winding down; that pivot is not documented in the fetched sources. The July 2025 release is datelined Mountainview while the August 8-K lists a San Mateo address.

## Sources

- Official website: https://www.sec.gov/edgar/browse/?CIK=0001496323
- Concentra acquisition agreement (8-K exhibit 99.1, July 2025): https://www.sec.gov/Archives/edgar/data/1496323/000119312525153576/d82329dex991.htm
- Completion of merger (8-K, August 2025): https://www.sec.gov/Archives/edgar/data/1496323/000119312525180763/d82965d8k.htm
- SEC EDGAR filings: https://www.sec.gov/edgar/browse/?CIK=0001496323

## Connected records

- fronts: [Immunotherapy](https://onco.cc/fronts/immunotherapy/)
- technologies: [Bispecific antibodies](https://onco.cc/technologies/bispecific-antibody/), [T-cell engagers (bispecific)](https://onco.cc/technologies/t-cell-engager/)

---
JSON: https://onco.cc/api/v1/entities/igm-biosciences.json