medwireNews: The adenovirus vector-based gene therapy nadofaragene firadenovec elicits durable responses in people with non-muscle-invasive bladder cancer (NMIBC) unresponsive to Bacillus Calmette-Guérin (BCG), shows a phase 3 trial.
The intravesical therapy “delivers the human IFNα2b gene resulting in IFNα2b expression,” and its use led to promising outcomes in a prior phase 2 trial, explained study author Stephen Boorjian (Mayo Clinic, Rochester, Minnesota, USA) at the 2020 Genitourinary Cancers Symposium in San Francisco, California, USA.
The current study included 157 patients, 151 of whom were BCG unresponsive. Of these, 103 had carcinoma in situ (CIS) with or without Ta or T1 papillary disease, while the remaining 48 participants had Ta or T1 disease alone. Nadofaragene firadenovec was administered at a dose of 3x1011 vp/mL once every 3 months for up to four doses in the first 12 months.
The primary endpoint of complete response at any timepoint in the CIS patients was achieved by just over half (53.4%) of the 103 evaluable participants, in all cases by 3 months after treatment initiation.
The presenter noted that responses were durable, with nearly half (45.5%) of the responding patients remaining free of high-grade recurrence at 12 months.
Among the 48 patients with papillary disease who were eligible for the efficacy analyses, the complete response rate was 72.9%, with again all responses achieved by 3 months, and 60.0% of responders remained high-grade recurrence-free at the 12-month mark.
The treatment was well tolerated, with an “acceptable safety profile,” said Boorjian. Treatment-related adverse events (AEs) of grade 3–5 occurred in 3.8% of the total 157 participants, with 0.6% experiencing serious AEs and 1.9% discontinuing the drug due to a treatment-emergent AE.
The most common treatment-related AEs of any grade were leakage at the catheter site, fatigue, bladder spasm, and micturition urgency, observed in 24.8%, 19.7%, 15.9%, and 15.3% of patients, respectively.
Taken together, “[t]hese data represent a potentially significant management advancement for a historically difficult-to-treat disease state,” concluded Boorjian.
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2020 Genitourinary Cancers Symposium; San Francisco, California, USA: 13–15 February