Interleukin-15 agonist complex earns breakthrough therapy designation

ImmunityBio announced that the FDA has granted Breakthrough Therapy designation for its interleukin-15 (IL-15) agonist complex, N-803, in combination with Bacillus Calmette-Guerin (BCG), for the treatment of patients with BCG-unresponsive nonmuscle-invasive bladder carcinoma in situ.

The cytokine IL-15 plays a crucial role in the immune system by affecting the development, maintenance, and function of the natural killer and T cells. N-803 is a novel IL-15 superagonist complex consisting of an IL-15 mutant (IL-15N72D) bound to an IL-15 receptor α/IgG1 Fc fusion protein. N-803 has improved pharmacokinetic properties, longer persistence in lymphoid tissues, and enhanced anti-tumor activity compared to native, non-complexed IL-15 in vivo.

N-803 is currently being evaluated for adult patients in two clinical NMIBC trials. QUILT 2.005 is investigating use of N-803 in combination with BCG for patients with BCG-naïve NMIBC; QUILT 3.032 is studying N-803 in combination with BCG in patients with BCG-unresponsive NMIBC.