Cinrebafusp alfa is a high-affinity CD137/HER2 bispecific antibody-like protein capable of specifically binding to recombinant human HER2 (Kd = 0.3 nM) and human monomeric CD137 (4-1BB, Kd = 5 nM). Cinrebafusp alfa is designed to target HER2-positive tumors by delivering activated 4-1BB to these sites, thereby mediating T-cell co-stimulatory signaling to exert an antitumor effect. It is indicated for the treatment of HER2-positive solid tumors.

MCF-7 cells (HER2 positive):7.4 nmol/L (EC50), CD137:5 nM (Kd), HER2:0.3 nM (Kd)

Cinrebafusp alfa can bind to HER2-positive MCF-7 cells and CHO cells overexpressing human 4-1BB, with corresponding EC₅₀ values of 7.4 nmol/L and 6.2 nmol/L, respectively, as determined by flow cytometry (FACS) [1].

In humanized mice bearing HER2‑positive SK‑OV‑3 tumors, intravenous administration of Cinrebafusp alfa at 0.2–10 mg/kg once weekly for 20 consecutive days inhibits tumor growth and increases tumor‑infiltrating lymphocyte levels in a dose‑dependent manner. Pharmacokinetic studies show that the terminal elimination half‑life of Cinrebafusp alfa is >14 days in male CD‑1 mice (10 mg/kg, single intravenous dose) and approximately 4 days in male cynomolgus monkeys (3 mg/kg, single intravenous injection) [1].

Human

Monoclonal, Bispecific

Unconjugated