A single‐institution experience with induction and maintenance intravesical docetaxel in the management of non‐muscle‐invasive bladder cancer refractory to bacille Calmette‐Guérin therapy

Abstract

To analyse the durability of response for patients with non-muscle-invasive bladder cancer (NMIBC) refractory to bacille Calmette-Guérin (BCG) therapy and treated with intravesical docetaxel in a combined induction and maintenance regimen. A previous phase I trial showed docetaxel to be safe for intravesical therapy, with no systemic absorption and minimal toxicity after six weekly instillations for patients with BCG-refractory NMIBC. In that trial, docetaxel gave a 56% complete response (CR) rate at 12 weeks, but the durability was only 22%. Thus a second group of patients was treated with a 6-week induction and then given monthly maintenance therapy with intravesical docetaxel. Thirteen patients with BCG-refractory Ta, T1, or Tis transitional cell carcinoma were treated. Induction therapy was administered as six weekly intravesical instillations of 75 mg followed by single-dose monthly maintenance therapy for nine additional instillations in patients who had a CR. The initial response at 12 weeks from the start of induction therapy was evaluated by cystoscopy with biopsy, and urine cytology. The follow-up consisted of quarterly cystoscopy with biopsy and cytology, and periodic imaging. The median follow-up was 13 months; 10 of 13 patients had a CR after induction, and six have remained disease-free during the follow-up. Of those in who the treatment failed, six had transurethral resection of the tumour and one a cystectomy. All 10 initial responders completed at least three instillations of maintenance therapy to date (median nine instillations), of whom six have remained recurrence-free. Monthly maintenance therapy with intravesical docetaxel appears to extend the durability of response to induction treatment for a selected group of patients with BCG-refractory NMIBC, and might decrease the overall risk of recurrence in high-risk NMIBC.