Fusion Proteins and Fc Conjugates
8 compounds in this family, each with its recorded mechanism, routes of administration, safety notes and references to published literature.
- ALT-801ALT-801 is an investigational bifunctional fusion protein examined for two distinct therapeutic strategies: as a dual agonist of the glucagon‑like peptide‑1 (GLP‑1) and glucagon receptors to treat metabolic liver disease, and as an interleukin‑2 (IL‑2) fused to a soluble T‑cell receptor that targets the p53 peptide/HLA‑A*0201 complex on cancer cells. Preclinical mouse work shows metabolic and histologic benefits in non‑alcoholic steatohepatitis (NASH), while a phase‑I oncology trial evaluated safety and immune activation in patients with advanced malignancies.
- DalanterceptDalantercept (also known as ACE‑041 or ALK1‑Fc) is an investigational fusion protein that combines the extracellular domain of activin receptor‑like kinase‑1 (ALK1) with an Fc fragment. By acting as a soluble “ligand trap” for the vascular growth factors BMP‑9 and BMP‑10, it aims to inhibit abnormal blood‑vessel formation that supports tumor growth. Clinical development has focused on solid tumours such as renal cell carcinoma and ovarian cancer, where it is being evaluated as a novel anti‑angiogenic strategy.
- Eftrenonacog alfaEftrenonacog alfa (Alprolix®) is a recombinant factor IX‑Fc fusion protein approved for prophylactic and on‑demand treatment of bleeding in patients with haemophilia B. By linking human FIX to the Fc domain of IgG1, the molecule achieves an extended circulating half‑life, allowing less frequent intravenous (and in some settings subcutaneous) infusions while maintaining haemostatic protection.
- EvorpaceptEvorpacept (ALX148) is an investigational CD47‑blocking fusion protein that links a high‑affinity SIRPα domain to an inactive IgG Fc. It is being tested intravenously in cancer, most often combined with other agents such as cetuximab, pembrolizumab, rituximab, lenalidomide, or trastuzumab. Early‑phase trials have shown tumor‑growth inhibition in pre‑clinical models and clinical activity in B‑cell non‑Hodgkin lymphoma and solid tumours, but safety concerns, including severe immune‑related events, have limited its development.
- IpafriceptIpafricept (OMP‑54F28) is an investigational recombinant fusion protein that acts as a decoy receptor for Wnt ligands. By binding extracellular Wnt proteins, it blocks activation of the Wnt/β‑catenin signaling pathway, a driver of cancer stem‑cell traits and tumor dedifferentiation. Early‑phase clinical trials have explored its use in solid tumours such as desmoid tumours, germ‑cell cancers, hepatocellular carcinoma, ovarian cancer and pancreatic adenocarcinoma, primarily as a monotherapy or in combination with standard chemotherapy.
- LuspaterceptLuspatercept is a recombinant fusion protein approved for the treatment of anemia in adults with lower‑risk myelodysplastic syndromes (MDS) that have ring sideroblasts and are dependent on red‑cell transfusions. By trapping select ligands of the transforming growth factor‑β (TGF‑β) superfamily, it promotes late‑stage erythroid maturation, reducing transfusion requirements and raising hemoglobin levels.
- PRO-542PRO‑542 (also called CD4‑IgG2 or tetrameric CD4‑IgG2) is an investigational recombinant fusion protein designed to block the first step of HIV‑1 entry. By mimicking the CD4 receptor, it binds the viral envelope glycoprotein gp120, preventing attachment of the virus to host CD4+ cells. It is being studied as a novel entry inhibitor to complement existing antiretroviral regimens, but it has not yet progressed to approved clinical use.
- RomiplostimRomiplostim is a fusion‑protein (peptibody) that activates the thrombopoietin (TPO) receptor to stimulate platelet production. It is approved in many regions for immune thrombocytopenia (ITP) and is being investigated for chemotherapy‑induced thrombocytopenia (CIT) and other marrow‑suppressive conditions. The drug is given by subcutaneous injection and is titrated to raise platelet counts and reduce bleeding or treatment interruptions.