Dr. Daneshmand on Erdafitinib in NMIBC

Siamak Daneshmand, MD, professor, Urology with Clinical Scholar designation, director, Clinical Research, fellowship director, Urologic Oncology, the University of Southern California, discusses findings from the interim analysis of cohort 3 of the multicohort phase 2 THOR-2 trial (NCT04172675).

Cohort 3 is evaluating erdafitinib (Balversa), a selective pan-FGFR TKI, in 20 patients with recurrent, intermediate-risk non–muscle invasive bladder cancer (NMIBC) with grade 1 or 2 tumors that have FGFR3 or FGFR2 alterations. Patients needed to have less than a 5% risk of progression in the 2 years following enrollment and a risk of recurrence over 50% to be eligible for this cohort. Patients who achieved a partial response (PR) or complete response (CR) within 3 months of starting erdafitinib could continue erdafitinib for up to 2 years, until progressive disease, intolerable toxicity, withdrawal of consent, treatment discontinuation per investigator decision, or trial closure.

Cohort 3 has an exploratory end point of CR rate, with safety as a key secondary end point. At a data cutoff of September 2022, 11 patients have been enrolled and 10 have received erdafitinib. This interim analysis reported findings from the first 8 evaluable patients.

Patients in cohort 3 underwent transurethral resection of their bladder tumors that left a single untouched 5- to 10-mm marker lesion. After their initial marker lesions were photographed, patients in cohort 3 received 6 mg of oral erdafitinib once daily without uptitration in 28-day cycles, Daneshmand says. When assessed at 6 weeks for safety, some patients’ marker lesions showed partial or complete responses, Daneshmand notes.

Patients received erdafitinib for a median duration of 2.9 months. At a median follow-up of 5.7 months from first erdafitinib dose, 7 patients had responded, with 6 achieving CRs, for a CR rate of 75.0%, and 1 achieving a PR, Daneshmand emphasizes. Additional results from all 20 patients in the cohort are still immature, Daneshmand concludes.