At the 3.6 mg/kg dose of CRB-701, objective response rates reached 47.6% in head and neck squamous cell carcinoma, 37.5% in cervical cancer, and 55.6% in metastatic urothelial cancer, based on unconfirmed best overall response per RECIST 1.1. Across the 167-patient Phase 1/2, grade 3 treatment-related events occurred in 18%, with no grade 4 or 5 events reported; discontinuations attributed to the drug were 6%. Peripheral neuropathy was observed in 8.4% of patients, all grade 1–2, while keratitis occurred in 32.3%. Responses were seen irrespective of Nectin-4 expression, HPV status, or PD(L)-1 status.
Corbus presented updated dose-optimization data for its next-generation Nectin-4 ADC at ESMO25 from an all-comer, multicenter U.S./EU study that enrolled heavily pretreated patients (median three prior lines). Eighty-four patients treated at 2.7 or 3.6 mg/kg were response-evaluable in the prespecified tumor cohorts, with additional patients from dose escalation. The company plans to meet the FDA this year and says registrational studies will begin by mid-2026. CRB-701 holds Fast Track designations in HNSCC and cervical cancer.
Strategically, Corbus is aiming to extend Nectin-4 beyond urothelial cancer into settings where the mechanism is biologically plausible but not yet clinically validated, while differentiating on tolerability. Using a site-specific linker and a homogeneous DAR2 MMAE payload, the company appears to be trading potency density for a potentially cleaner safety profile. The neuropathy signal looks lighter than class expectations for MMAE ADCs, a practical advantage for patients already sensitized by platinum and taxanes. The counterweight is ocular toxicity: a 32% keratitis rate is notable and will need proactive management to avoid the operational burdens that have hampered other ADCs with corneal events.
For sites and CROs, the all-comer design reduces screening friction and may accelerate accrual in community networks, but it shifts complexity to safety oversight. Expect requirements for baseline and on-treatment ophthalmology assessments, prophylactic eye care algorithms, and closer coordination with outside specialists. Lower neuropathy may reduce dose holds and infusion chair churn, but keratitis management will introduce new visit cadence and data capture demands. Vendors with ophthalmic monitoring capabilities could see near-term pull-through if Corbus bakes those workflows into protocols.
For sponsors watching the regulatory path, ORR magnitude at 3.6 mg/kg is competitive in post-IO HNSCC and cervical settings where options are thin, but durability remains the gating variable. Several responses at cutoff were unconfirmed, and duration-of-response and time-to-progression data will likely determine whether the FDA entertains a single-arm, ORR-based approach or pushes for randomized evidence against docetaxel or cetuximab in HNSCC and against chemotherapy in cervical cancer. In urothelial cancer, where enfortumab vedotin now anchors combinations earlier in the pathway, prior exposure to Nectin-4-directed MMAE will be a critical stratifier; the registrational plan will need to address cross-resistance risk explicitly.
Key watch items over the next two quarters include dose selection trade-offs between 2.7 and 3.6 mg/kg, given the apparent ORR advantage and mixed DCR signals, maturity of response confirmation and durability, and a clearly articulated ocular toxicity mitigation package acceptable to investigators and regulators. Clarity on cohort definitions, comparator choices, and any planned IO combinations will signal how aggressively Corbus intends to pursue accelerated versus full approval. Manufacturing control for a site-specific ADC and a reliable ophthalmology network build-out are the operational linchpins if the program moves at the cadence implied for mid-2026 registrational starts.
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.
