FOSTER CITY, CA, USA I  November 16, 2016 I Gilead Sciences, Inc. (Nasdaq: GILD) today announced top-line results from two Phase 3 clinical trials (SIMPLIFY 1 and 2) evaluating momelotinib, an investigational inhibitor of Janus kinase (JAK) compared to ruxolitinib or best alternative therapy (BAT) in patients with myelofibrosis. The SIMPLIFY-1 study achieved its pre-specified primary endpoint of non-inferiority to ruxolitinib for splenic response rate at Week 24 (SRR24), defined as the percentage of patients experiencing a ≥ 35 percent reduction in spleen volume (momelotinib: 26.5%; ruxolitinib: 29.0%; 95 percent CI: -11.2% to +5.6%; p=0.011).

Non-inferiority was not achieved for the key secondary endpoint of response rate in total symptom score (TSS). Greater improvements in all three pre-specified anemia-related secondary endpoints (proportion of patients who are transfusion independent, or transfusion dependent and transfusion rate) were observed in patients receiving momelotinib compared to ruxolitinib. However, because the TSS response rate did not meet the non-inferiority test, formal sequential statistical testing was not undertaken for these three additional anemia secondary endpoints.

During 24 weeks of treatment in SIMPLIFY-1, the most frequent adverse events in patients receiving momelotinib were thrombocytopenia, diarrhea, headache, dizziness and nausea; the most frequent adverse events in patients receiving ruxolitinib were anemia, thrombocytopenia, diarrhea, headache and dizziness. Ten percent of patients receiving momelotinib reported peripheral neuropathy (any grade) compared to five percent of ruxolitinib-treated patients. There was no Grade ≥3 peripheral neuropathy in momelotinib-treated patients and one case in ruxolitinib-treated patients during 24 weeks of treatment.

SIMPLIFY-2 did not achieve its primary endpoint of superiority of momelotinib compared to BAT in patients previously treated with ruxolitinib in SRR24 (momelotinib: 6.7%; BAT: 5.8%; 95 percent CI: -8.9% to +10.2%; p=0.90). Eighty-eight percent of patients randomized to the BAT arm continued to receive ruxolitinib; the remainder of patients received chemotherapy, interferon, corticosteroids, other therapies or some combination thereof. Differences in favor of momelotinib were observed for the pre-specified secondary endpoints of TSS and one of the three anemia-related endpoints (transfusion independence), however, formal sequential statistical testing was not undertaken because the primary superiority endpoint was not achieved.

“The results from both the SIMPLIFY-1 and SIMPLIFY-2 studies indicate that momelotinib provides some treatment benefit, including benefit on anemia-related endpoints,” said Norbert Bischofberger, PhD, Executive Vice President of Research and Development and Chief Scientific Officer. “We plan to discuss these results with regulatory authorities to determine the next steps.”

Detailed results from both studies will be submitted for presentation at upcoming scientific conferences.

Momelotinib is an investigational therapy and has not been proven safe or efficacious.

About the SIMPLIFY Studies

The SIMPLIFY studies were randomized, Phase 3 clinical trials designed to evaluate momelotinib among patients with primary myelofibrosis, post-polycythemia vera myelofibrosis or post-essential thrombocythemia myelofibrosis. In SIMPLIFY-1, a double-blind, active-controlled study, 432 myelofibrosis patients who had not previously been treated with a JAK inhibitor were randomized (1:1) to receive momelotinib or ruxolitinib for 24 weeks. In SIMPLIFY-2, 156 patients previously treated with, but not refractory to, ruxolitinib were randomized (2:1) to receive momelotinib or BAT for 24 weeks.

The primary efficacy endpoint of both studies was SRR24, defined as the proportion of patients achieving a ≥ 35 percent reduction in spleen volume at Week 24 as measured by magnetic resonance imaging (MRI) or computerized tomography (CT) scan. Secondary endpoints included response rate in TSS at Week 24 (the proportion of patients achieving ≥ 50 percent reduction in symptoms, as measured by the modified Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score diary), the proportion of patients who are transfusion-independent at Week 24 (defined as no red blood cell transfusion and no hemoglobin level below 8 g/dL in the prior 12 weeks); the proportion who are transfusion-dependent at Week 24 (defined as at least four units of red blood cell transfusion or hemoglobin level below 8 g/dL in the prior eight weeks), and the rate of red blood cell transfusion through Week 24.

About Gilead Sciences

Gilead Sciences is a biopharmaceutical company that discovers, develops and commercializes innovative therapeutics in areas of unmet medical need. The company’s mission is to advance the care of patients suffering from life-threatening diseases. Gilead has operations in more than 30 countries worldwide, with headquarters in Foster City, California.

SOURCE: Gilead Sciences