ARMO BioSciences Announces Efficacy and Safety Data for Immuno-Oncology Program with Novel Mechanism of Action

Redwood City, CA, June 1, 2015 — ARMO BioSciences, Inc., a clinical-stage biotechnology company, today announced positive clinical data from a Phase 1 clinical trial of AM0010, a PEGylated form of recombinant human interleukin-10 (PEG-rHuIL-10) at the 2015 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, IL.

“We are pleased to present the positive results of our Phase 1 dose escalation study, demonstrating the promise of ARMO’s immuno-oncology agent AM0010 to harness the body’s capability to arm itself against tumor cells,” said Peter Van Vlasselaer, President and CEO of ARMO. “We have now enrolled over 200 patients across 12 indications in the expansion portion of the Phase 1 study. We see sustained stable disease extending longer than a year, and objective responses (CR and PR) in heavily pre-treated patients resulting from treatment with AM0010 as a single agent and in combination with either anti-PD-1 antibodies or standard of care chemotherapy. Importantly, AM0010 induces a comprehensive T cell activation signature in serum cytokines, and increases the quantity and activity of PD1+ CD8+ T-cells in the blood and in the tumors of patients, indicating that AM0010 effectively stimulates the immune system of cancer patients, irrespective of their prior treatment.”

AM0010 Clinical Data

ARMO BioSciences is conducting a Phase 1 open-label dose escalation study with multiple expansion cohorts. The open-label study is designed to evaluate the safety and tolerability of AM0010 in patients with advanced solid and blood borne tumors, both as a monotherapy and in combination with immunotherapy, targeted therapy or chemotherapy. Patients were dosed subcutaneously daily, with objective responses assessed every eight weeks.

Results from the 33-patient dose escalation portion of the Phase 1 study demonstrate that AM0010 was safe and well-tolerated with no autoimmune adverse events. Of the 12 patients treated at the recommended Phase 2 dose, two patients (18%) achieved an objective response, as evaluated by immune-related response criteria. In addition, five patients (45%) achieved disease control. Systemic immune activation, including Th1 cytokines and IL-7, was observed in all enrolled patients. Increased percentages of PD-1+ T cells were observed in the blood of responding patients. Furthermore, immuno-histochemistry shows an increased quantity and activity of PD-1+ CD8+ T cells in the tumors of patients, upon AM0010 treatment. Patients have been treated for over one year with good tolerability and compliance.

About AM0010

Preclinical studies have shown that AM0010, a PEGylated form of recombinant human interleukin-10 (PEG-rHuIL-10), directly activates tumor specific CD8+ killer T lymphocytes. In preclinical models of solid and blood born tumors, these activated CD8+ killer T lymphocytes completely eradicate large tumor masses and significantly reduce metastatic disease while establishing a lasting anti-tumor immune surveillance. ARMO plans to develop this unique molecule for known indications and innovative applications including cancer. ARMO has over 53 issued and pending US and foreign patents and applications covering compositions of matter, methods of use, and methods of manufacturing of AM0010. Additional information about the ongoing Phase 1 study can be obtained at (NCT02009449).

About ARMO BioSciences, Inc.

ARMO BioSciences is focused on developing immunotherapies for the treatment of cancer, fibrosis, hypercholesterolemia/atherosclerosis and inflammatory diseases. ARMO believes that by harnessing the body's own capability to arm itself against dysregulated cells, it may provide safer and more effective drugs for patients suffering from grievous diseases. ARMO's medicines are designed to normalize the underlying biology of disease through immunotherapeutic mechanisms for sustained and durable responses. Founded in 2012, ARMO is backed by investors Kleiner Perkins Caufield & Byers, OrbiMed, DAG Ventures, and NanoDimension.