Nectin Therapeutics' First-in-Class Anti-CD155 Antibody NTX1088 Shows Promise in Phase 1 Combo Trial at ASCO 2026
Key Insights
NTX1088, a first-in-class anti-CD155 (search) monoclonal antibody, combined with pembrolizumab demonstrated a favorable safety profile with no dose-limiting toxicities in a Phase 1a/1b trial of 91 patients with advanced solid tumors.
Confirmed partial responses were observed across multiple tumor types including gastric, bladder, non-small cell lung cancer (search), head and neck squamous cell carcinoma, and melanoma (search) among 41 evaluable patients.
The heavily pretreated study population had a median of four prior lines of therapy and high rates of prior checkpoint inhibitor exposure, with most responders still on treatment at data cutoff and a maximum treatment duration of 24 months.
Nectin Therapeutics (search) presented encouraging Phase 1a/1b clinical data for NTX1088, a first-in-class monoclonal antibody targeting the poliovirus receptor (PVR; CD155 (search)), in combination with Merck (search)'s anti-PD-1 therapy pembrolizumab (Keytruda), during an oral presentation at the 2026 American Society of Clinical Oncology (ASCO) annual meeting in Chicago.
The data highlight the potential of NTX1088 to address tumor-mediated immune suppression through a novel mechanism. CD155 (search) is a key regulator of the DNAM1 axis and an important driver of immune escape in the tumor microenvironment, representing a distinct target from established checkpoint pathways.
Study Design and Safety Profile
The ongoing Phase 1a/1b, open-label, multicenter, dose-escalation and expansion study (NTX-1088-01; KEYNOTE E92; NCT05378425) evaluated NTX1088 both as monotherapy and in combination with pembrolizumab in patients with advanced solid tumors. A total of 91 patients were treated in the study.
NTX1088 was well tolerated, with no dose-limiting toxicities observed. Based on pharmacokinetics and target occupancy data, a dose of 1,750 mg was selected as the recommended dose for expansion.
Efficacy Signals in a Challenging Population
Preliminary efficacy analysis focused on patients receiving active dose levels of NTX1088 (1,200 and 1,750 mg) in combination with pembrolizumab (200 mg). Among 41 evaluable patients, confirmed partial responses were observed across multiple tumor types, including gastric cancer (search), bladder cancer (search), non-small cell lung cancer (search), squamous cell carcinoma of the head and neck (search), and melanoma (search).
The study population represented a particularly challenging treatment setting, with a median of four prior lines of therapy and high rates of prior immune checkpoint inhibitor exposure. Additional patients achieved stable disease, and most responding patients were ongoing at the data cutoff, with a maximum treatment duration of 24 months.
"These Phase 1 results indicate that NTX1088 in combination with pembrolizumab was well tolerated and demonstrated encouraging preliminary anti-tumor activity in a difficult-to-treat, CPI-pretreated population," said Sarina A. Piha-Paul, M.D., lead Principal Investigator of the NTX-1088-01 study at The University of Texas MD Anderson Cancer Center. "Based on these findings, further clinical evaluation in Phase 2 studies, including in less heavily pretreated and biomarker-enriched cohorts, is warranted."
Next Steps and Company Profile
Nectin Therapeutics (search) is a clinical-stage biotechnology company focused on leveraging insights into Nectin pathways to develop next-generation immuno-oncology therapies and antibody-drug conjugates. The company's pipeline includes novel monoclonal antibodies and ADCs designed to address major escape mechanisms of current immuno-oncology therapies.
The company is venture-backed and privately held, funded by aMoon Fund, Peregrine Ventures, IBF, Integra Holdings, the Myeloma Investment Fund, GIBF, and the Cancer Focus Fund. The NTX-1088-01 study is supported by the European Innovation Council.