Corbus Pharmaceuticals (NASDAQ:CRBP) said its antibody-drug conjugate, CRB-701, showed promising efficacy and safety data in a Phase I study.

Patients in the study, which took place in China, had Nectin-4-positive urothelial or cervical cancer and did not receive or received treatment. intolerant to standard treatment. Urothelial cancer is the most common type of bladder cancer.

Data are presented for seven doses and two PK cohorts.

The results showed that to date, for urothelial carcinoma, the overall response rate (ORR) was 44% and the disease control rate (DCR) was 78%. For patients with cervical cancer, the results were 43% and 86%, respectively.

All cancer types at doses ≥ 2.7 mg/kg resulted in 40% ORR and 73% DCR.

Corbus noted that CRB-701 was generally well tolerated, with mostly grade 1 or 2 adverse events occurring, with no dose-limiting toxicities or grade 4 or 5 events observed to date. The most frequently reported side effects were anemia and eye treatment-related side effects.

However, two grade 3 corneal disorders were reported in patients who received doses of 2.7 mg/kg and 3.6 mg/kg.

CRB-701 could potentially compete with Pfizer’s (PFE)-owned Seagen and Astellas Pharma’s (OTCPK:ALPMF)(OTCPK:ALPMY) Padcev (enfortumab vedotin), another Nectin-4-led ADC. In May, a report from RBC Capital Markets cited CRB-701’s longer half-life, stronger cell killing and better side-effect profile as potential advantages over Padcev.