Phase Ib/II study of ALT-803 in combination with gemcitabine and nab-paclitaxel in patients with advanced pancreatic cancer.

Abstract

TPS510 Background: IL-15 is one of the most promising new candidates in cancer immunotherapy. Similar to IL-2, IL-15 stimulates natural killer (NK) and CD8+ T cells, however IL-15 may be a more effective and safer therapy as it does not trigger regulatory T cells or induce capillary leak syndrome. Preclinical data also show that IL-15 is effective in eradicating murine pancreatic cancers. However, the use of rhIL-15 in the clinic however has been limited by its short half-life (30 minutes) and cytokine related adverse effects, such as fever and hypotension. Compared with IL-15, ALT-803, a novel IL-15 superagonist complex (IL-15N72D:IL-15RαSu/Fc), has a prolonged serum half-life and is capable of potently inducing NK and CD8+ T cell proliferation in vivo. Pancreatic cancer remains one of the most common causes of cancer death and novel therapies are needed. This study represents the first clinical experience of ALT-803 in the treatment of pancreatic cancer. Methods: This is a Phase Ib/II, multi-institution study of ALT-803 in combination with gemcitabine and nab-paclitaxel in patients with advanced pancreatic cancer. The study involves a phase Ib dose escalation phase to determine the MTD using a standard 3+3 design. Patients will receive gemcitabine 1,000 mg/m2 and nab-paclitaxel 125 mg/m2 D1, 8, 15 and ALT-803 at assigned dose on D2, 9, 16 of a 28d cycle. Primary endpoints are safety and tolerability. Phase II will be a two-stage expansion phase using a Simon two-stage design with a primary endpoint of survival at 8.5 months. Secondary endpoints include response rate, progression free survival, and overall survival. Response will be assessed q8 weeks by RECIST v1.1. Major inclusion criteria include: locally advanced (Phase Ib only) or metastatic pancreatic adenocarcinoma, adequate organ function, PS ECOG 0-2, and 0 or 1 (Phase Ib only) line of prior therapy for advanced pancreatic cancer. Prior nab-paclitaxel is not allowed Current enrollment: Enrollment to the first dose level is ongoing. Complete accrual of phase Ib is expected within nine months. Clinical trial information: NCT02559674.