Abstract A027: A phase I open-label, non-randomized study of recombinant compound interferon (rSIFN-co) in patients with advanced solid tumors

Background: Recombinant compound interferon (rSIFN-co) is a new class of interferon derived from altering the spatial structure and configuration of the basic interferon protein. rSIFN-co displayed greater anti-tumor activity in solid tumors compared to interferon α-2b in pre-clinical studies. Methods: Patients with advanced malignancies were enrolled to determine the safety, tolerability, recommended phase II dose (RP2D), pharmacodynamics (PD) and preliminary anti-tumor activities in a 3+3 dose escalation design. Two pre-defined dose levels were planned. rSIFN-co was dosed 3 times a week via subcutaneous injection for 21 days followed by 7 days rest. This was preceded by a lead in phase. PD studies comprised of FDG-PET, pre- and post treatment changes in plasma cytokine profile and tumor repressive/ enhancing genes as well as 2959-oligoadenylate synthetase levels. Results: Results presented are based on preliminary data collected as of Jan. 27, 2015. 22 patients (median age 65.5 years, 14 male and 8 female) have been enrolled with 21 evaluable for safety and 15 amenable to efficacy analysis. 10 hepatocellular carcinoma (HCC), 6 non-small cell lung cancer (NSCLC), 4 colorectal cancer (CRC), 1 melanoma and 1 nasopharyngeal carcinoma patients (pts) were dosed at 2 dose levels. The RP2D was 24μg 3x/week for 21days followed by 7 days rest. No dose limiting toxicities were encountered. Most adverse events (92%) were CTCAE grade 1 and 2. The most frequent grade 1/2 treatment related adverse events (trAEs) were flu-like symptoms (90%), anorexia (33%), fatigue (33%), weight loss (33%), nausea (29%), thrombocytopenia (29%), and diarrhea (24%). Grade 3/4 trAEs were fever (2 pts), leucopenia (2 pts), transaminitis (2 pts), weight loss (1 pt), fatigue (1 pt), afebrile neutropenia (1 pt) and syncope (1 pt). 11 patients had stable disease (SD) and 4 patients had progressive disease (PD). 4 patients (2 HCC, 1 NSCLC and 1 CRC) had prolonged stable disease (>16 weeks). Detailed PD data will be presented for all cohorts. Conclusion: The RP2D was 24μg three times a week for 21days followed by 7 days rest with a lead in phase. Modest activity was seen in heavily pre-treated advanced solid tumor patients. Citation Format: Su Pin Choo, Wai Meng Tai, Maria Macapagal, Aziah Ahmad, Greg Li, Mui Leng Goh, Matthew Ng, Tira Tan, Shao Weng Tan, Wan Teck Lim. A phase I open-label, non-randomized study of recombinant compound interferon (rSIFN-co) in patients with advanced solid tumors. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A027.