14 August 2019 - - US-based biopharmaceutical company Deciphera Pharmaceuticals, Inc. (NASDAQ: DCPH) reported updated data from its ongoing Phase 1 clinical study of ripretinib, a broad-spectrum KIT and PDGFRα inhibitor, in patients with second-line through fourth-line plus gastrointestinal stromal tumors.

Deciphera also announced positive top-line results from its INVICTUS pivotal Phase 3 clinical study supporting a potential new drug application submission to the US Food and Drug Administration for ripretinib for the treatment of patients with advanced GIST who have received prior treatment with imatinib, sunitinib and regorafenib.

In addition to the INVICTUS data, Deciphera will also be submitting in its NDA supportive data from the ongoing Phase 1 clinical study, which will include the updated data from GIST patients at doses of >100mg of ripretinib.

Additional results from the Phase 1 clinical study in these patients are expected to be presented at an upcoming medical meeting.

Gastrointestinal stromal tumor is a cancer affecting the digestive tract or nearby structures within the abdomen, most often presenting in the stomach or small intestine.

GIST is the most common sarcoma of the gastrointestinal tract, with approximately 4,000 to 6,000 new GIST cases each year in the United States and a similar incidence rate in European and other countries. Most cases of GIST are driven by a spectrum of mutations.

The most common primary mutations are in KIT kinase, representing approximately 75% to 80% of cases, or in PDGFRα kinase, representing approximately 5% to 10% of cases.

Current therapies are unable to inhibit the full spectrum of primary and secondary mutations, which drives resistance and disease progression.

Estimates for five-year survival range from 48% to 90%, depending on the stage of the disease at diagnosis.

Ripretinib is an investigational KIT and PDGFRα kinase switch control inhibitor in clinical development for the treatment of KIT and/or PDGFRα-driven cancers, including gastrointestinal stromal tumors, or GIST, systemic mastocytosis, or SM, and other cancers.

Ripretinib was specifically designed to improve the treatment of patients with GIST by inhibiting a broad spectrum of mutations in KIT and PDGFRα. Ripretinib is a KIT and PDGFRα inhibitor that inhibits initiating and secondary KIT mutations in exons 9, 11, 13, 14, 17, and 18, involved in GIST, as well as the primary D816V exon 17 mutation involved in SM.

Ripretinib also inhibits primary PDGFRα mutations in exons 12, 14 and 18, including the exon 18 D842V mutation, involved in a subset of GIST.

In June 2019, the US FDA granted Fast Track Designation to ripretinib for the treatment of patients with advanced GIST who have received prior treatment with imatinib, sunitinib and regorafenib.

Deciphera Pharmaceuticals has an exclusive license agreement with Zai Lab (Shanghai) Co., Ltd. for the development and commercialisation of ripretinib in Greater China (Mainland China, Hong Kong, Macau and Taiwan). Deciphera Pharmaceuticals retains development and commercial rights for ripretinib in the rest of the world.

The INTRIGUE Phase 3 clinical study is an interventional, randomized, global, multicenter, open-label study to evaluate the safety, tolerability and efficacy of ripretinib compared to sunitinib in patients with GIST previously treated with imatinib.

This study was designed to provide evidence of clinical benefit to support regulatory approvals in second-line GIST patients in the United States, Europe and other major markets.

Patients will be randomised 1: 1 to either 150 mg of ripretinib once daily or 50 mg of sunitinib once daily for four weeks followed by two weeks without sunitinib.

The primary efficacy endpoint is median progression-free survival as determined by independent radiologic review using modified Response Evaluation Criteria in Solid Tumors (RECIST).

Secondary endpoints as determined by independent radiologic review using modified RECIST include Objective Response Rate and Overall Survival. See www.clinicaltrials.gov for further information (NCT03673501).

Deciphera Pharmaceuticals is a clinical-stage biopharmaceutical company focused on improving the lives of cancer patients by tackling key mechanisms of drug resistance that limit the rate and/or durability of response to existing cancer therapies.