Benzinga | Sep 18, 2020 07:04AM EDT

Deciphera Pharma Reports Will Present 9-Month Follow-Up Data From Phase 3 INVICTUS Study Of QINLOCK In Patients With Fourth-Line Gastrointestinal Stromal Tumors At European Society For Medical Oncology Meeting Sept. 19-21

Deciphera Pharmaceuticals, Inc. (NASDAQ:DCPH), today announced the presentation of nine month follow-up data from the Company's Phase 3 INVICTUS study of QINLOCK in patients with fourth-line and fourth-line plus gastrointestinal stromal tumors (GIST) and intra-patient dose escalation data from the ongoing Phase 1 study of QINLOCK in patients with second-line through fourth-line plus GIST. The mini-oral presentations, titled "Clinical Benefit with Ripretinib as ?4th Line Treatment in Patients with Advanced Gastrointestinal Stromal Tumors (GIST): Update from the Phase 3 INVICTUS Study" and "Ripretinib Intra-patient Dose Escalation (IPDE) Following Disease Progression Provides Clinically Meaningful Progression-Free Survival (PFS) in Gastrointestinal Stromal Tumor (GIST) in Phase 1 Study", were featured at the ESMO Virtual Congress 2020 being held September 19-21, 2020.

"As the body of data supporting QINLOCK's efficacy and safety grows, we are pleased with QINLOCK's ability to offer clinically meaningful benefit for GIST patients across multiple lines of therapy," said Matthew L. Sherman, MD, Executive Vice President and Chief Medical Officer of Deciphera. "Data presented today demonstrates impressive long-term, follow-up results from our INVICTUS study, which support QINLOCK's efficacy in fourth-line GIST."

INVICTUS Additional Nine Month Follow-up Data

The INVICTUS Phase 3 clinical study is a randomized (2:1), double-blind, placebo-controlled, international, multicenter study to evaluate the safety, tolerability, and efficacy of QINLOCK compared to placebo in 129 patients with advanced GIST whose previous therapies have included at least imatinib, sunitinib, and regorafenib. The Company previously reported results from the randomized portion of the INVICTUS study, in which QINLOCK significantly improved progression-free survival (PFS) and showed a clinically meaningful overall survival (OS) benefit.

As of a March 9, 2020 cutoff date, approximately nine months from the data cutoff date for the primary analysis, QINLOCK continues to provide clinically meaningful benefit with a well-tolerated safety profile in patients with advanced GIST who have received at least three prior tyrosine kinase inhibitors. The median PFS, as measured by blinded independent central review, remained at 6.3 months versus 1.0 month in the placebo arm. The hazard ratio (HR) was 0.16. The median OS as of the data cutoff was not reached in the QINLOCK arm versus 6.3 months in the placebo arm with a HR of 0.42, as compared to the median OS at the May 2019 data cutoff for the primary analysis of 15.1 months in the QINLOCK arm versus 6.6 months in the placebo arm with a HR of 0.36. QINLOCK also demonstrated a confirmed objective response rate of 11.8% versus 0% in the placebo arm compared to rates of 9.4% versus 0% in the placebo arm as of the data cutoff date for the primary analysis.

Safety findings were consistent with the previous primary analysis results, demonstrating that QINLOCK was generally well tolerated.

Phase 1 Intra-patient Dose Escalation

In the ongoing Phase 1 study of QINLOCK in patients with second-line through fourth-line plus GIST, patients were permitted to dose escalate to QINLOCK 150 mg twice-daily, or BID, after disease progression on QINLOCK 150 mg once-daily, or QD. The presentation highlighted that the patients in second-, third- or fourth-line plus GIST who dose escalated to QINLOCK 150 mg BID experienced additional clinically meaningful benefit.

The table below includes the initial PFS, or PFS1, and the subsequent PFS, or PFS2, from the day of dose escalation to second disease progression or death, from this subgroup of patients who were dose escalated to 150 mg BID.

Ripretinib 150 mg BID (n=67)

Line of Therapy 2nd line (n=10) 3rd line (n=17) ?4th line (n= 40)

mPFS, months mPFS1, 11.0 mPFS1, 8.3 mPFS1, 5.5 mPFS2, 5.6 mPFS2, 3.3 mPFS2, 4.6

mPFS2/mPFS1 51% 40% 84%

mPFS=median progression-free survival

Comparison of TEAEs reported in the QINLOCK 150 mg QD and 150 mg BID periods demonstrated that QINLOCK was similarly well-tolerated.