Deciphera announces top-line results from Phase 3 INVICTUS study
Deciphera announced top-line data from the INVICTUS pivotal Phase 3 clinical study of ripretinib, a broad-spectrum KIT and PDGFRa inhibitor, in patients with fourth-line and fourth-line plus gastrointestinal stromal tumors, or GIST. The INVICTUS Phase 3 clinical study is a randomized, double-blind, placebo-controlled, international, multicenter study to evaluate the safety, tolerability and efficacy of ripretinib compared to placebo in 129 patients with advanced GIST whose previous therapies have included at least imatinib, sunitinib, and regorafenib. The INVICTUS study achieved its primary endpoint of improved PFS as determined by blinded independent central radiologic review using modified Response Evaluation Criteria in Solid Tumors, or RECIST, version 1.1. In the INVICTUS study, ripretinib demonstrated a median PFS of 6.3 months compared to one month in the placebo arm and significantly reduced the risk of disease progression or death by 85% compared to placebo. For the key secondary endpoint of objective response rate, or ORR, as determined by blinded independent central radiologic review using modified RECIST version 1.1, ripretinib demonstrated an ORR of 9.4% compared with 0% for placebo, which was not statistically significant. Ripretinib in this study also showed a clinically meaningful improvement over placebo in terms of the secondary endpoint overall survival, or OS. Since statistical significance was not achieved for ORR, the hypothesis testing of OS was not formally performed. According to the pre-specified hierarchical testing procedure of the endpoints, the hypothesis testing of OS cannot be formally conducted unless the test of ORR is statistically significant. The OS data for the placebo arm includes patients taking placebo who, following progression, were crossed-over to ripretinib treatment. Ripretinib was generally well tolerated and the adverse event results in INVICTUS were consistent with data from previously presented Phase 1 study results. Grade 3 or 4 treatment-emergent adverse events, or TEAEs, occurred in 42 patients on the ripretinib arm compared to 19 on the placebo arm. Grade 3 or 4 TEAEs greater than 5% of patients in the ripretinib arm were anemia, abdominal pain and hypertension. Grade 3 or 4 TEAEs greater than 5% of patients in the placebo arm were anemia. Based on the INVICTUS data, the company expects to submit a new drug application, or NDA to the FDA for ripretinib for the treatment of patients with advanced GIST who have received prior treatment with imatinib, sunitinib and regorafenib in Q1 of 2020.