Research Article Chemoimmunotherapy Using Pegylated Liposomal Doxorubicin and Interleukin-18 in Recurrent Ovarian Cancer: A Phase I

Recombinant interleukin (IL)-18 (SB-485232) is an immunostimulatory cytokine, with shown antitumor activity in combination with pegylated liposomal doxorubicin (PLD) in preclinical models. This phase I study evaluated the safety, tolerability, and biologic activity of SB-485232 administered in combination with PLD in subjects with recurrent ovarian cancer. The protocol comprised four cycles of PLD (40 mg/m2) on day 1 every 28 days, in combination with SB-485232 at increasing doses (1, 3, 10, 30, and 100 mg/kg) on days 2 and 9 of each cycle, to be administered over five subject cohorts, followed by discretionary PLD monotherapy. Sixteen subjects were enrolled. One subject withdrew due to PLD hypersensitivity. Most subjects (82%) were platinum-resistant or refractory, and had received a median of three or more prior chemotherapy regimens. SB-485232 up to 100 mg/kg with PLDhad an acceptable safety profile. Common drug-related adverse events were grade 1 or 2 (no grade 4 or 5 adverse events). Concomitant PLD administration did not attenuate the biologic activity of IL-18, with maximal SB-485232 biologic activity already observed at 3 mg/kg. Ten of 16 enrolled subjects (63%) completed treatment, whereasfive (31%) subjects progressed on treatment. A 6%partial objective response rate and a 38 % stable disease ratewere observed.We provide pilot data suggesting that SB-485232 at the 3mg/kg dose level in combinationwith PLD is safe and biologically active. This combination warrants further study in a phase II trial. Cancer Immunol Res; 1(3); 168–78. 2013 AACR