At the 3.6 mg/kg dose of CRB-701, Corbus reported objective response rates of 47.6% in head and neck squamous cell carcinoma (HNSCC), 37.5% in cervical cancer, and 55.6% in metastatic urothelial carcinoma (mUC). Across 167 treated patients, grade 3 treatment-related adverse events occurred in 18% with no grade 4/5 events; peripheral neuropathy was 8.4% and limited to grade 1–2, and treatment discontinuations attributed to CRB-701 were 6.0%. Keratitis was the most prominent adverse event at 32.3%.
Corbus is presenting Phase 1/2 data for its next-generation Nectin-4 antibody–drug conjugate at ESMO 2025 from an all-comers study run in the U.S. and Europe. Of 167 patients enrolled, 122 were evaluable for efficacy, and 84 in HNSCC, cervical cancer, and mUC contributed to dose-optimization readouts at 2.7 and 3.6 mg/kg. Patients were heavily pretreated (median three prior lines), and enrollment was agnostic to Nectin-4 expression, PD-(L)1 status, and HPV status. Responses were observed irrespective of biomarker strata. The company plans an FDA meeting this year and aims to initiate registrational studies by mid-2026; CRB-701 holds Fast Track designations in HNSCC and cervical cancer.
Strategically, Corbus is positioning CRB-701 as a Nectin-4 ADC with a differentiated tolerability profile versus first-generation MMAE conjugates, leaning on low neuropathy to support chronic dosing and site retention. The signal in HNSCC and cervical cancer targets settings with clear post-IO gaps and fewer direct antigen competitors, while the mUC activity must be read through the lens of an entrenched standard built around enfortumab vedotin combinations. The choice to run an all-comers program and to show responses across biomarker strata suggests Corbus intends to avoid a companion diagnostic, simplifying enrollment and potentially speeding study execution, though it shifts the regulatory burden to demonstrate consistent benefit without enrichment.
For sites, the operational footprint looks manageable but not trivial. Low-grade neuropathy may reduce dose holds relative to other MMAE ADCs, yet the 32% keratitis rate will require ocular baselining, prophylaxis, and coordination with ophthalmology, adding workflow and consult demands. Imaging cadence to confirm responses and manage unconfirmed partial responses will matter for data quality and retention. CROs and sponsors should anticipate single-arm designs in refractory HNSCC and cervical cancer, focused on ORR and duration as the linchpin of any accelerated pathway; randomized cohorts may still be required in geographies or indications where the bar has moved. Vendors supporting AE mitigation, infusion management, and decentralized ophthalmic monitoring could become critical enablers if Corbus scales global studies without biomarker gating.
The next six to nine months will determine the credibility of a mid-2026 registrational start. Dose selection between 2.7 and 3.6 mg/kg needs to reconcile the higher ORR at 3.6 mg/kg with mixed disease control and ocular toxicity. Durability metrics—median duration of response and 6–12 month response persistence—are absent here and will drive regulatory receptivity, especially in single-arm designs. In mUC, Corbus must articulate a clear positioning strategy, either post-enfortumab exposure, in patients intolerant of neuropathy, or via combinations with PD-1 inhibitors. Watch for FDA feedback on pathway and endpoints, ocular safety mitigation plans embedded into protocols, any move toward biomarker cutoffs if heterogeneity emerges with maturity, and manufacturing scale-up for a site-specific DAR2 construct. How Corbus sequences indications—and whether it can sustain enrollment without a CDx while managing ocular AEs—will shape the trajectory from promising signal to registrational reality.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
