FDA Approves New Bladder Cancer Drug

The US Food and Drug Administration (FDA) has approved the first-in-class interleukin (IL)-15 superagonist nogapendekin alfa inbakicept-pmln (Anktiva), plus bacillus Calmette-Guérin (BCG), for the treatment of certain non–muscle-invasive bladder cancers that fail to respond to BCG alone.

Specifically, the agent is approved to treat patients with BCG-unresponsive non–muscle-invasive bladder cancer carcinoma in situ with or without Ta or T1 papillary disease. 

The FDA declined an initial approval for the combination in May 2023 because of deficiencies the agency observed during its prelicense inspection of third-party manufacturing organizations. In October 2023, ImmunityBio resubmitted the Biologics License Application, which was accepted.

The new therapy represents addresses "an unmet need" in this high-risk bladder cancer population, the company stated in a press release announcing the initial study findings. Typically, patients with intermediate or high-risk disease undergo bladder tumor resection followed by treatment with BCG, but the cancer recurs in up to 50% of patients, including those who experience a complete response, explained ImmunityBio, which acquired Altor BioScience. 

Approval was based on findings from the single arm, phase 2/3 open-label QUILT-3.032 study, which included 77 patients with BCG-unresponsive, high-risk disease following transurethral resection. All had Eastern Cooperative Oncology Group performance status of 0-2. 

Patients received nogapendekin alfa inbakicept-pmln induction via intravesical instillation with BCG followed by maintenance therapy for up to 37 months. 

According to the FDA's press release, 62% of patients had a complete response, defined as a negative cystoscopy and urine cytology; 58% of those with a complete response had a duration of response lasting at least 12 months and 40% had a duration of response lasting 24 months or longer.

The safety of the combination was evaluated in a cohort of 88 patients. Serious adverse reactions occurred in 16% of patients. The most common treatment-emergent adverse effects included dysuria, pollakiuria, and hematuria, which are associated with intravesical BCG; 86% of these events were grade 1 or 2. Overall, 7% of patients discontinued the combination owing to adverse reactions.

The recommended dose is 400 mcg administered intravesically with BCG once a week for 6 weeks as induction therapy, with an option for a second induction course if patients don't achieve a complete response at 3 months. The recommended maintenance therapy dose is 400 mcg with BCG once a week for 3 weeks at months 4, 7, 10, 13, and 19. Patients who achieve a complete response at 25 months and beyond may receive maintenance instillations with BCG once a week for 3 weeks at months 25, 31, and 37. The maximum treatment duration is 37 months.

The FDA recommends discontinuing treatment if disease persists after second induction or owing to disease recurrence, progression, or unacceptable toxicity. 

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on Twitter: @SW_MedReporter.