AUA 2024: First Safety and Efficacy Results of the TAR-210 Erdafitinib Intravesical Delivery System in Patients with Non–muscle-Invasive Bladder Cancer with Select FGFR Alterations

(UroToday.com) The 2024 American Urological Association (AUA) annual meeting held in San Antonio, TX between was host to the Bladder Cancer Non-invasive podium session. Dr. Antoni Vilaseca presented presented the first safety and efficacy results of the TAR-210 erdafitinib intravesical delivery system in patients with non–muscle-invasive bladder cancer (NMIBC) with select Fibroblast Growth Factor Receptor (FGFR) alterations.

Dr Vilaseca began his presentation by highlighting that treatment options remain limited for patients with NMIBC that recurs after intravesical chemotherapy or Bacillus Calmette-Guérin (BCG). In patients with NMIBC, FGFR alterations are prevalent and present in 50 – 80% of patients. These alterations promote cancer progression, tumor neoangiogenesis, and targeted treatment resistance, and may also function as oncogenic drivers.1,2

Erdafitinib is a pan-FGFR tyrosine kinase inhibitor approved in the United States for the treatment of locally advanced or metastatic urothelial carcinoma in adults with susceptible FGFR3/2 alterations who have progression after platinum-based chemotherapy.3

TAR-210 is a novel intravesical drug delivery system designed to provide local, continuous release of targeted therapy, including Erdafitinib within the bladder while limiting systemic toxicities. This delivery system is inserted into the bladder through a dedicated urinary placement catheter and removed via cystoscopy. The investigators presented the first safety and efficacy results of this open-label, multicenter phase 1 study (NCT05316155) evaluating TAR-210 in patients with NMIBC whose tumors harbor select FGFRalt.

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This study included 2 cohorts:

  • Cohort 1; High-risk NMIBC (HG Ta/T1, no CIS, papillary only), BCG-experienced/unresponsive and not undergoing radical cystectomy. All patients in this cohort had a TURBT with complete resection of all visible disease prior to treatment.
  • Cohort 3: Intermediate-risk NMIBC (LG Ta/T1 disease) and visible target lesions prior to treatment (chemoablation design)

The study was also divided into two parts:

  • Part 1 was a dose escalation phase with two different erdafitinib release rates being evaluated.
  • Part 2 was the dose expansion phase for patients in Cohorts 1 and 3. Response was assessed every 3 months with continued treatment for up to 1 year if recurrence-free (Cohort 1) or until complete response (Cohort 3). Of note, the first response assessment was at 3 months.

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Today, data from 21 patients in Cohort 1 and 43 patients in Cohort 3 who have been treated with TAR-210 were presented. All tumors in both cohorts were recurrent tumors after intravesical chemotherapy and BCG. The baseline characteristics are shown in Table 1 below:

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In cohort 1, 90% of patients were recurrence free at 12 months, the median RFS was not estimable, and the median duration of follow-up was 8.9 months.

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In cohort 3 only 321 patients were evsaluable for response, 90% achieved a complete response (CR) rate, with 28/31 achieving a CR at week 12. At time of data analysis, 84% (24/28) CR were ongoing.

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TAR-210 provided sustained erdafitinib release in urine over 90 days with very low plasma concentrations:

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The most common treatment-related adverse events were grade 1/2 lower urinary tract adverse events. There were no dose-limiting toxicities. Two patients discontinued treatment due to adverse events of low-grade urinary symptoms, and one patient had serious adverse events of pyelonephritis and sepsis (unrelated to TAR-210). No deaths were reported and from a safety standpoint, there were no dose-limiting toxicities.

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Dr. Vilaseca wrapped up his talk with the following conclusions:

  • TAR-210, an innovative intravesical drug delivery system, offers localized and sustained release of erdafitinib within the bladder for up to 90 days while minimizing systemic exposure.
  • TAR-210 demonstrates promising clinical efficacy in individuals with BCG-experienced high-risk NMIBC with FGFR alterations (Cohort 1) with an impressive 12-month RFS rate of 90%.
  • In the intermediate-risk NMIBC (Cohort 3), 90% of patients achieved a complete response at week 12, and 86% had ongoing complete responses at time of clinical cut-off.
  • Incidences of TAR-210-related adverse events of grade ≥2 and discontinuations were rare, primarily limited to grade 1 urinary system adverse events.
  • These encouraging initial findings provide a strong basis for advancing TAR-210 to phase 3 trials such as the MoonRISE which has already been initiated.

Presented by: Antoni Vilaseca, MD, FEBU. Urologist at Hospital Clinic de Barcelona, Associate Medical Professor at the Universitat de Barcelona, Barcelona, Spain.

Written by: Julian Chavarriaga, MD – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @chavarriagaj on Twitter during the 2024 American Urological Association (AUA) Annual Meeting, San Antonio, TX, Fri, May 3 – Mon, May 6, 2024. 

References:

  1. Hernandez S, Lopez-Knowles E, Lloreta J, et al. Prospective study of FGFR3 mutations as a prognostic factor in nonmuscle invasive urothelial bladder carcinomas. J Clin Oncol. 2006;24(22):3664-71.
  2. Knowles MA, Hurst CD. Molecular biology of bladder cancer: new insights into pathogenesis and clinical diversity. Nat Rev Cancer. 2015;15(1):25-41
  3. Loriot Y, Matsubara N, Park S. H, Huddart RA, Burgess EF, Houede N. Erdafitinib or chemotherapy in advanced or metastatic urothelial carcinoma. New England Journal of Medicine. 2023; 389(21), 1961-1971.