Novel Erdafitinib Delivery System Safe, Well-Tolerated for NMIBC

Treatment options are limited for patients with non-muscle invasive bladder cancer (NMIBC) that recurs after intravesical chemotherapy or bacillus Calmette-Guérin (BCG) therapy. At the European Society for Medical Oncology Congress 2023, Dr. Antoni Vilaseca presented the first safety and efficacy results from the ongoing TAR-210 trial, which is examining a novel intravesical drug delivery system in patients with NMIBC with select FGFR alterations.

The TAR-210 delivery system provides a local and continuous release of erdafitinib within the bladder while limiting systemic toxicities. The open-label, multicenter, phase 1 trial is evaluating the safety, pharmacokinetics (PK), and efficacy of TAR-210.

FGFR alterations were identified in the tumor tissue or urine cell-free DNA of patients involved in 1 the study’s 2 cohorts. Cohort 1 included patients who had recurrent, BCG-experienced, high-risk NMIBC (high-grade Ta/T1; papillary only) who refused or were ineligible for radical cystectomy. Cohort 3 included patients with recurrent, intermediate-risk NMIBC (Ta/T1) with a history of only low-grade papillary disease.

Before treatment was administered, patients in cohort 1 must have had all visible disease resected, while patients in cohort 3 needed the presence of visible tumors. Two different erdafitinib release rates administered by TAR-210 were evaluated. Response is assessed every 3 months with continued treatment for up to 1 year if patients are recurrence-free (RF) in cohort 1 or in complete response (CR) in cohort 3.

As of August 2023, a total of 16 patients in cohort 1 and 27 patients in cohort 3 have been treated. One or more response assessments have been administered to 11 patients in cohort 1 and 15 patients in cohort 3. The most common treatment-related adverse events (AEs) were grade 1 or 2 lower urinary tract AEs.

No dose-limiting toxicities or deaths occurred; 2 patients discontinued treatment due to AEs of low-grade urinary symptoms. One patient experienced serious AEs of pyelonephritis and sepsis. PK showed sustained erdafitinib concentrations in urine with very low plasma exposure.

The TAR-210 delivery system appears safe and well-tolerated with low-grade urinary system AEs and high CR rates and RF survival in patients with NMIBC with FGFR alterations. These results justify further studies of targeted treatments of erdafitinib through the use of a novel intravesical delivery system in early-stage bladder cancer.