OncoC4 Reports Encouraging Phase 1/2 Data for Cesalatamig Monotherapy in Previously Treated Non-Small Cell Lung Cancer at SITC 2026

— 33% investigator-assessed objective response rate and 90% disease control rate at 10 mg/kg every three weeks in patients with PD-(L)1-resistant/refractory NSCLC —

— Preliminary efficacy and safety results support further development of cesalatamig monotherapy —

ROCKVILLE, Md., Nov. 6, 2026 /PRNewswire/ -- OncoC4 Inc., a late clinical-stage biopharmaceutical company developing novel medicines for cancer, neurological and immunological diseases, today reported encouraging Phase 1/2 results for cesalatamig (AI-081), its investigational PD-1/VEGF bispecific antibody, as monotherapy in patients with PD-(L)1-resistant/refractory non-small cell lung cancer (NSCLC). The findings will be presented in a late-breaking oral presentation at the Society for Immunotherapy of Cancer (SITC) 2026 Annual Meeting in Phoenix, Arizona.

Results reported in the SITC abstract were derived from a pooled analysis of the global, multicenter, open-label BiPAVE-001 and BiPAVE-001 CN Phase 1/2 studies. As of July 31, 2026, the safety population included 103 patients with NSCLC who had received at least one dose of cesalatamig monotherapy at 1, 3, 10 or 20 mg/kg Q3W. Of these patients, 77 (75%) had non-squamous histology, 25 (24%) had squamous histology and one had unknown histology. 77% of patients had a baseline ECOG performance status of 1. The median number of prior therapy lines was two, and 42% of patients had received three or more prior lines.  The safety profile was comparable between patients with squamous and non-squamous histology. The cesalatamig monotherapy is well tolerated at all dose levels.

Among 55 efficacy-evaluable patients with PD-(L)1 resistant/refractory NSCLC, cesalatamig monotherapy demonstrated dose-dependent antitumor activity. At 1 mg/kg (10 patients), 3 mg/kg (24 patients) and 10 mg/kg (21 patients) Q3W, investigator-assessed objective response rates (ORR) were 10%, 21% and 33%, respectively; disease control rates (DCR) were 40%, 67% and 90%, respectively.  Responses to cesalatamig monotherapy were observed across PD-L1 expression levels. Exposure-response analyses support selection of 10 mg/kg Q3W as the dose for further development.

"Patients whose NSCLC progresses after immunotherapy and chemotherapy have limited effective treatment options," said Kai He, MD, PhD, principal investigator of the US BiPAVE-001 trial and the presenter of this study. "The responses and disease control observed with cesalatamig monotherapy are encouraging. Together with the manageable safety profile observed in these studies, these findings support further clinical evaluation in this setting."

"These findings strengthen the rationale for advancing cesalatamig monotherapy in previously treated NSCLC," said Yang Liu, PhD, Co-founder, Chief Executive Officer and Chief Scientific Officer of OncoC4. "The clinical results and exposure-response analyses support the selection of 10 mg/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."

Presentation Information

Title: Safety and Efficacy of Cesalatamig, a Novel PD-1/VEGF Bispecific Antibody, as Monotherapy in PD-(L)1–Resistant/Refractory NSCLC: Results from Global, Multicenter, Open-Label Phase 1/2 Studies

Abstract: #1187 (late-breaking oral presentation)
Presenter: Kai He, MD, PhD
Date: November 7, 2026
Meeting: 41st Annual Meeting of the Society for Immunotherapy of Cancer, Phoenix, Arizona
Session: Clinical Oral Abstract Session 2, beginning at 1:45 PM MST

About Cesalatamig

Cesalatamig (AI-081) is an investigational, tetravalent PD-1/VEGF bispecific antibody designed to promote cooperative interactions between PD-1 and VEGF blockade in the tumor microenvironment. It combines high-affinity binding with Fc-silencing modifications intended to avoid depletion of PD-1-positive effector T cells. Cesalatamig is being evaluated as monotherapy and in combination with standard of care in the ongoing BiPAVE-001 clinical program. In September 2026, the U.S. FDA granted cesalatamig Fast Track designation for NSCLC that has progressed after concurrent or sequential PD-(L)1-targeted immunotherapy and platinum-based chemotherapy.

About BiPAVE-001

BiPAVE-001 (NCT06635785) and BiPAVE-001 CN (CTR20253261) are ongoing Phase 1/2 clinical trials evaluating the safety, pharmacokinetics, and efficacy of cesalatamig (AI-081), a bispecific antibody targeting PD-1 and VEGF, in patients with advanced solid tumors. OncoC4 is conducting these studies in the United States and China, respectively. Part A is the first-in-human Phase 1 dose-escalation and dose-expansion portion in patients with advanced solid tumors. Part B is the Phase 2 portion and includes dose-optimization trials evaluating AI-081 as monotherapy or in combination with standard of care in selected indications.

About OncoC4

Headquartered in Rockville, Maryland, OncoC4 is a privately held, late clinical-stage biopharmaceutical company that is actively engaged in the discovery and development of novel biologics for the treatment of cancer, neurological and immunological diseases. OncoC4's pipeline features assets with first-in-class and best-in-class potential targeting both novel and well-validated targets across oncology and immunological diseases. Among them, cesalatamig is a wholly owned and highly differentiated PD-1/VEGF bispecific antibody currently undergoing rapid global clinical development in multiple oncology indications. Tasafustobart (ONC-841) is a first-in-class anti-SIGLEC-10 antibody currently in a Phase 2 trial for oncology indications and a Phase 1 trial for neurodegenerative diseases. In addition, OncoC4 recently initiated a first-in-human trial of ONC-783, a first-in-class T cell engager targeting a novel CD24 epitope selectively expressed across a broad spectrum of human cancers, including solid tumors and hematological malignancies, in the United States. OncoC4 has a strategic collaboration with BioNTech to co-develop gotistobart (BNT316/ONC-392), a tumor microenvironment-selective Treg depletion candidate targeting CTLA-4, in multiple solid tumor indications, including an ongoing pivotal clinical trial in squamous non-small cell lung cancer.

More information: www.oncoc4.com

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SOURCE OncoC4