STM434

STM 434 is a recombinant fusion protein that acts as a soluble ligand trap targeting activin A, a member of the TGF-beta family involved in cell growth, differentiation, and cancer cachexia. By binding to activin A and other ligands of the activin type IIB receptor (ActRIIB), including myostatin, STM 434 prevents their interaction with endogenous receptors and inhibits downstream signaling. This mechanism is intended to block tumor proliferation in cancers where activin A is overexpressed—such as ovarian cancer—and may also impact muscle wasting associated with cancer cachexia. The drug was developed by Atara Biotherapeutics (originator Amgen) and reached phase I clinical trials for advanced ovarian cancer and other solid tumors. Although it showed metabolic effects such as increased lean body mass, no direct antitumor efficacy was observed in early studies[1][2][3][4][5].

Other names

activin type 2B receptor Fc fusion protein STM 434