OncoC4 has reported positive findings from Phase I/II trials of its investigational bispecific antibody, cesalatamig (AI-081), as a monotherapy in patients with pre-treated non-small cell lung cancer (NSCLC).
The study evaluated patients with programmed cell death ligand 1 (PD-(L)1)-resistant/refractory NSCLC.
In an efficacy-evaluable group of 55 patients, the antibody showed dose-dependent antitumour activity across three evaluated cohorts administered every three weeks.
Objective response rates (ORR) assessed by investigators were 10% in the 1mg/kg cohort of 10 patients, 21% in the 3mg/kg cohort of 24 patients, and 33% in the 10mg/kg cohort of 21 patients. Disease control rates (DCR) were 40%, 67%, and 90%, respectively.
Responses occurred across different PD-L1 expression levels, and exposure-response analyses supported selecting the 10mg/kg dose for subsequent clinical testing.
OncoC4 co-founder, CEO and chief scientific officer Yang Liu said: “These findings strengthen the rationale for advancing cesalatamig monotherapy in previously treated NSCLC.
“The clinical results and exposure-response analyses support the selection of 10mg/kg every three weeks as the dose for our planned pivotal study and provide a clear path forward for the continued development of cesalatamig in this setting.”
These pooled findings were derived from the open-label, multicentre, global BiPAVE-001 (NCT06635785) and BiPAVE-001 CN (CTR20253261) Phase I/II studies, with data recorded up to 31 July 2026.
The safety dataset comprised 103 NSCLC patients who received at least one monotherapy dose at 1mg, 3mg, 10mg, or 20mg/kg every three weeks.
Cesalatamig monotherapy was well tolerated across all tested dose tiers, and safety profiles were comparable between squamous and non-squamous disease.
Of these participants, 77 (75%) had non-squamous tumours, 25 (24%) had squamous tumours, and one patient had an unknown histology.
A baseline ECOG performance status of 1 was documented in 77% of patients. Participants had received a median of two previous lines of systemic therapy, and 42% had received three or more lines.
Cesalatamig is a tetravalent bispecific antibody targeting PD-1 and vascular endothelial growth factor (VEGF).
OncoC4 is evaluating the antibody in China and the US across Phase I dose-escalation and Phase II dose-optimisation stages in advanced solid tumours, as monotherapy and in combination with standard care.
In September 2026, the US Food and Drug Administration (FDA) granted cesalatamig fast track designation for NSCLC that has progressed following platinum-based chemotherapy and PD-(L)1 immunotherapy.
