FDA approves nogapendekin alfa inbakicept plus BCG for NMIBC

This approval is based on the results of the phase 2/3 QUILT-3.032 trial (NCT03022825).

The FDA has approved N-803 (Anktiva, nogapendekin alfa inbakicept-pmln), a first-in-class IL-15 receptor agonist immunotherapy, for use in combination with BCG for the treatment of patients with BCG-unresponsive non–muscle-invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) with or without papillary tumors, announced ImmunityBio, the developer of the therapy, in a news release.¹

“Today’s approval of ANKTIVA for patients with NMIBC marks an important milestone in our quest to develop cancer vaccines, and preventative vaccines for patients with genetic predisposition to developing cancer such as in Lynch syndrome,” said Patrick Soon-Shiong MD,Executive Chairman and Global Chief Scientific and Medical Officer at ImmunityBio, in the news release.1 “We believe that by orchestrating the innate and adaptive immune system and driving long-term complete remission, ANKTIVA has the potential to play a key role as the immunotherapy beyond checkpoints in multiple tumor types in the years to come.”

The approval is supported by findings from cohort B of the ongoing QUILT-3.032 trial (NCT03022825), assessing BCG in combination with N-803 in patients with BCG-unresponsive, high-grade Ta/T1 papillary NMIBC. Patients in cohort B received N-803 in combination with BCG maintenance therapy for up to 37 months.

Data from the trial have shown a complete response (CR) of 62% to 73% among the 77 evaluable patients included in the analysis. The duration of CR was longer than 47 months at the time of data cutoff, which exceeded the threshold for meaningful clinical results per a panel of experts at the International Bladder Cancer Group.

Among patients with a CR, 58% demonstrated a duration of response (DOR) of 12 months or longer, and 40% demonstrated a DOR of 24 months or longer. The median DOR has not yet been reached as the DOR data is still ongoing.

“The long duration of complete response ranging over 47 months is a game changer for NMIBC patients and provides further clinical evidence of ANKTIVA’s effectiveness for patients who historically have faced high rates of recurrence and significantly diminished quality of life due to radical surgeries,” said Karim Chamie, MD, associate professor of urology at UCLA and principal investigator for the QUILT 3.032 study, in the news release.¹ “With this approval, ANKTIVA could represent a new standard of care for patients with NMIBC and has the potential to change the way we treat bladder cancer.”

Overall, the phase 2/3, open-label, multicenter study included patients with BCG-unresponsive bladder CIS with or without Ta/T1 papillary tumors who received N-803 plus BCG in cohort A (n = 84) or N-803 monotherapy in cohort C (n = 10). The trial also enrolled patients with BCG-unresponsive high-grade Ta/T1 papillary NMIBC who received N-803 plus BCG in cohort B (n = 77).

The primary end point for the trial is the incidence of CR at 3 and 6-month assessment for cohorts A and C, and the disease-free survival at 12 months for cohort B. Secondary end points for cohort A are durability, cystectomy avoidance, progression-free survival, disease-specific survival, and overall survival.²

Previous data on the QUILT-3.032 trial were published in NEJM Evidence in November 2022.³

In cohort A, 71% (95% CI, 59.6% – 80.3%) of patients achieved a CR with a median follow-up of 23.9 months. The median duration of CR was 26.6 months (95 CI, 9.9 months – not reached). Among those with a CR at 24 months, the probability of avoiding a cystectomy was 89.2%, and the probability of disease-specific survival was 100%, per Kaplan-Meier estimates.

In cohort B (n = 72), the disease-free survival (DFS) rate was 55.4% (95% CI, 42% - 66.8%) at 12 months, with a median DFS of 19.3 months (95% CI, 7.4 months – not reached).

In cohort C, CR was achieved in 20% of patients at 3-month follow-up. Only 1 patient maintained a CR at 6 months. Six patients underwent reinduction. The median follow-up for all patients was 7.9 months at the time of data cutoff.

Regarding safety, 86% of treatment-emergent adverse events (TEAEs) from the combination therapy were grade 1 to 2, with 3 grade 3 immune-related TEAEs.

Additional updates on the ongoing analyses of QUILT-3.032 will be presented by Soon-Shiong at the upcoming American Urological Association Annual Meeting in San Antonio, Texas.

The approval of N-803 comes after a previous FDA decision to decline approval for the combination in May 2023. In their decision, the FDA noted observed deficiencies related to its pre-license inspection of the company’s third-party contract manufacturing organizations.⁴ ImmunityBio resubmitted their biologics license application for the treatment combination in October 2023.⁵

According to ImmunityBio, N-803 is expected to be available in the US by mid-May 2024.

References

1. ImmunityBio announces FDA Approval of ANKTIVA, first-in-class IL-15 receptor agonist for BCG-unresponsive non-muscle invasive bladder cancer. News release. ImmunityBio. April 22, 2024. Accessed April 23, 2024. https://immunitybio.com/immunitybio-announces-fda-approval-of-anktiva-first-in-class-il-15-receptor-agonist-for-bcg-unresponsive-non-muscle-invasive-bladder-cancer/

2. QUILT-3.032: A multicenter clinical trial of intravesical Bacillus Calmette-Guerin (BCG) in combination with ALT-803 (N-803) in patients With BCG unresponsive high grade non-muscle invasive bladder cancer. ClinicalTrials.gov. Last updated April 8, 2024. Accessed April 23, 2024. https://clinicaltrials.gov/study/NCT03022825

3. Chamie K, Chang SS, Kramolowsky E, et al. IL-15 superagonist NAI in BCG-unresponsive non-muscle-invasive bladder cancer. NEJM Evid. 2023;2(1):EVIDoa2200167. doi:10.1056/EVIDoa2200167

4. FDA declines to approve ImmunityBio's bladder cancer therapy, shares slump. News release. ImmunityBio, Inc. May 11, 2023. Accessed January 31, 2024. https://www.reuters.com/business/healthcare-pharmaceuticals/immunitybio-slumps-fda-declines-approve-bladder-cancer-treatment-2023-05-11/

5. FDA accepts ImmunityBio’s BLA resubmission as complete and sets new PDUFA date. News release. ImmunityBio, Inc. October 26, 2023. Accessed April 22, 2024. https://immunitybio.com/fda-accepts-immunitybios-bla-resubmission-as-complete-and-sets-new-pdufa-date/