# Magrolimab

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

## TL;DR

The first 'don't eat me' signal blocker. Gilead paid $4.9B for it; it was stopped in 2024 after trials showed more deaths, not fewer.

## Summary

Magrolimab blocks CD47 so macrophages can phagocytose tumour cells. Early single-arm data with azacitidine in TP53-mutant AML and MDS were striking. ENHANCE (higher-risk MDS) was stopped for futility in 2023; ENHANCE-2 (TP53-mutant AML) and ENHANCE-3 (unfit AML) were halted in 2024 after an increased risk of death in the magrolimab arms; the FDA placed a full clinical hold. Gilead had acquired Forty Seven for $4.9B in 2020.

Lesson: a ubiquitous target (CD47 is on every red cell) plus an immunosuppressed population is a narrow window; single-arm response rates in TP53-mutant disease were not predictive of survival.

## Fields

- Kind: Treatment
- Status: withdrawn
- Last checked: 2026-09-06
- Tags: failure; lesson:toxicity
- Code: Hu5F9-G4, GS-4721
- Modality: Monoclonal antibody (anti-CD47)
- Mechanism: Humanised IgG4 anti-CD47; blocks the CD47-SIRPα 'don't eat me' signal, enabling macrophage phagocytosis.

## Sources

- Gilead discontinues magrolimab in AML (Feb 2024) (page moved; nearest live section): https://www.gilead.com/news-and-press/press-room/press-releases/

## Connected records

- cancers: [Acute myeloid leukaemia](https://onco.cc/cancers/aml/), [Higher-risk myelodysplastic syndromes](https://onco.cc/cancers/mds-higher-risk/), [Myelodysplastic syndromes / neoplasms (MDS)](https://onco.cc/cancers/mds/), [Secondary and therapy-related acute myeloid leukaemia](https://onco.cc/cancers/aml-secondary/)
- technologies: [CD47 and SIRP-alpha blockade](https://onco.cc/technologies/cd47-blockade/), [Monoclonal antibodies](https://onco.cc/technologies/monoclonal-antibody/)
- targets: [CD47](https://onco.cc/targets/cd47/)
- companies: [Gilead Sciences (incl. Kite)](https://onco.cc/companies/gilead/)
- pathways: [CD47 / SIRPα (the 'don't eat me' signal)](https://onco.cc/pathways/cd47-sirpa/), [Myeloid suppression: TAMs, MDSCs & don't-eat-me signals](https://onco.cc/pathways/myeloid-suppression-axis/)
- trials: [Magrolimab + Azacitidine Versus Azacitidine + Placebo in Untreated Participants With Myelodysplastic Syndrome (MDS)](https://onco.cc/trials/nct04313881/), [Study of Magrolimab in Combination With Azacitidine Versus Physician's Choice of Venetoclax in Combination With Azacitidine or Intensive Chemotherapy in Patients With TP53 Mutant Acute Myeloid Leukemia That Have Not Been Treated](https://onco.cc/trials/nct04778397/), [Study of Magrolimab Versus Placebo in Combination With Venetoclax and Azacitidine in Participants With Acute Myeloid Leukemia](https://onco.cc/trials/nct05079230/)
- people: [Irving L. Weissman](https://onco.cc/people/irving-weissman/)
- bottlenecks: [Cold tumours and the immunosuppressive microenvironment](https://onco.cc/bottlenecks/b-tme-immunosuppression/), [Failures are hidden](https://onco.cc/bottlenecks/b-negative-results/)
- ideas: [Automatic offer of shelved cancer assets to non-profits after two years](https://onco.cc/ideas/idea-fund-shelved-asset-escrow/), [Bispecific antibodies that engage macrophages instead of T cells](https://onco.cc/ideas/idea-bio2-myeloid-engager-bispecific/), [Public post-mortem reports when a cancer drug programme is stopped](https://onco.cc/ideas/idea-tr2-termination-reports/)
- terms: [Tumour-associated macrophages (TAMs)](https://onco.cc/terms/tumor-associated-macrophages/)

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