EPI-326 is a selective bispecific antibody that targets and degrades both oncogenic mutant and wild-type EGFR. EPI-326 binds specifically to tumor tissue, induces EGFR endocytosis and lysosomal degradation, clears EGFR protein, and blocks oncogenic signaling. EPI-326 is being investigated for use in the treatment of advanced solid tumors.

EPI-326 specifically binds to EGFR and tumor-enriched degraded receptors, enabling selective enrichment and binding to tumor cells; it induces deep and sustained lysosomal degradation of EGFR in a mutation-independent manner; and effectively blocks downstream oncogenic signaling mediated by EGFR and its heterodimers.[1]

EPI-326 achieved a high complete response rate in EGFR-mutated NSCLC models and remained effective against tumors harboring T790M and C797S resistance mutations. EPI-326 demonstrated significant antitumor activity in both wild-type HNSCC and CRC models. EPI-326 exhibited excellent tolerability in animals, with no traditional EGFR-targeted drug toxicities such as rash or diarrhea, and no dose-limiting toxicity was observed at a dose of 200 mg/kg. [1]