Nogapendekin alfa inbakicept (ANKTIVA®; nogapendekin alfa inbakicept-pmln) is a recombinant interleukin-15 (IL-15) superagonist protein complex being developed by Altor BioScience, LLC, an indirect wholly owned subsidiary of ImmunityBio, Inc., for the treatment of solid and haematological cancers and HIV infection. In April 2024, nogapendekin alfa inbakicept was approved for use with Bacillus Calmette-Guérin (BCG) for the treatment of adult patients with BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) with or without papillary tumours in the USA. This article summarizes the milestones in the development of nogapendekin alfa inbakicept leading to this first approval for the treatment of cancer.