INTRIGUE Phase III study of Qinlock fails to meet primary endpoint in gastrointestinal stromal tumor – Deciphera Pharmaceuticals

Deciphera Pharmaceuticals announced top-line results from the INTRIGUE Phase III clinical study of Qinlock (ripretinib) in patients with gastrointestinal stromal tumor (GIST) previously treated with imatinib. The study did not meet the primary endpoint of improved progression-free survival (PFS) compared with the standard of care.

In the study, 453 patients were randomized 1:1 to either Qinlock 150 mg once daily or sunitinib 50 mg once daily for four weeks followed by two weeks without sunitinib. The study did not achieve the primary efficacy endpoint of progression-free survival (PFS) as determined by independent radiologic review using modified Response Evaluation Criteria in Solid Tumors (RECIST). The statistical analysis plan included a hierarchical testing sequence that included testing patients with a KIT exon 11 primary mutation and then in the all patient intent-to-treat (AP) population. In patients with a KIT exon 11 primary mutation, (n=327), Qinlock demonstrated a median PFS (mPFS) of 8.3 months compared to 7.0 months for the sunitinib arm (Hazard Ratio [HR] 0.88, p=0.360).

Although not formally tested due to the rules of the hierarchical testing sequence, in the AP population Qinlock demonstrated a mPFS of 8.0 months compared to 8.3 months for the sunitinib arm (HR 1.05, nominal p=0.715).