Corbus Pharmaceuticals Unveils Promising Data for Nectin-4 ADC, Challenging Pfizer's Padcev

Corbus Pharmaceuticals has released the first Western clinical data for its antibody-drug conjugate (ADC) targeting Nectin-4, positioning the therapy as a potential rival to Pfizer's Padcev. The results, presented at the 2025 American Society of Clinical Oncology Genitourinary Cancers Symposium, demonstrate efficacy comparable to earlier Chinese trial data and suggest possible advantages over the current market leader.

Phase 1 Trial Results Show Encouraging Response Rates

The phase 1 trial, conducted in the United States and United Kingdom, reported a 27% response rate among 26 evaluable patients across various tumor types. This outcome closely aligns with the 28% response rate observed in the previous Chinese study of 25 participants, indicating consistent performance across different populations.

Notably, the Western trial expanded its scope beyond the Chinese study by including a wider range of tumor types and enrolling patients regardless of their individual Nectin-4 expression levels. Responses were observed even in patients with low H-scores for Nectin-4, suggesting potential broader applicability of the therapy.

Potential Advantages Over Padcev

Corbus believes its ADC may offer several advantages over Pfizer's Padcev, including:

• Longer half-life
• Lower drug antibody ratio
• Potential for reduced dosing frequency and higher doses

These characteristics could translate into improved patient outcomes and a more favorable treatment regimen. Additionally, Corbus reported lower rates of peripheral neuropathy and skin toxicity compared to Padcev studies, potentially offering a better safety profile.

Promising Results in Multiple Cancer Types

While the trial's primary focus was on bladder cancer, where Padcev has shown significant efficacy, Corbus's ADC also demonstrated potential in other cancer types:

• Bladder cancer: 25% response rate (1 out of 4 patients)
• Cervical cancer: 50% response rate, including one complete response (1 out of 2 patients)
• Head and neck cancer: 57% response rate (4 out of 7 patients)

The head and neck cancer results are particularly noteworthy, as the current response rate significantly exceeds Padcev's 24% in this indication. However, the small sample sizes necessitate caution in interpreting these early results.

Market Reaction and Future Outlook

Despite the encouraging data, Corbus's stock experienced a 10% decline in premarket trading following the announcement. This reaction may be partially attributed to the slightly lower response rate in bladder cancer compared to the Chinese trial (25% vs. 44%), although the small sample size limits definitive conclusions.

Corbus is now focusing on optimizing the ADC dose to further enhance its efficacy and safety profile. The company's strategic licensing of the Nectin-4-directed ADC from China's CSPC Pharmaceutical in 2023 for $7.5 million upfront has positioned it to potentially compete in the lucrative ADC market, challenging Pfizer's $43 billion acquisition of Seagen and its flagship product, Padcev.

As Corbus continues to refine its ADC candidate, the pharmaceutical industry will be watching closely to see if this potential Padcev rival can maintain its promising performance in larger, more comprehensive clinical trials.