Study: QINLOCK as a Treatment for Gastrointestinal Stromal Tumors

According to an article from BioTech 365, data from the Phase 3 INVICTUS trial and Phase 1 dose-escalation study, which evaluated QINLOCK as a treatment for gastrointestinal stromal tumors, was released at the ESMO Virtual Congress 2020. The results are positive, and researchers are very excited by the potential that QINLOCK has.

About Gastrointestinal Stromal Tumors (GIST)

GISTs are a type of tumor that form in the gastrointestinal tract, typically in the stomach or small intestine. These tumors are soft tissue sarcomas, and they can be benign or malignant. If they are cancerous, then they have the potential to spread throughout the body. Symptoms include vomiting or defecating blood, abdominal pain and swelling, anemia, fatigue, a mass in the abdomen, vomiting, weakness, gastrointestinal bleeding, loss of appetite, problems swallowing, and weight loss. All of these symptoms are the result of mutated genes that cause insterstitial cells of Cajal to grow and multiply until they form a tumor. It is usually the KIT or PDGFR genes that are mutated, but there are other genes that have yet to be identified. Treatment consists of surgery and targeted drug therapy.


QINLOCK was created by Deciphera Pharmaceuticals, and it is switch-control tyrosine kinase inhibitor that is intended to inhibit the mutated genes that cause the tumors. It does so through the use of a dual mechanism that moderates the kinase switch pocket and activation loop.

It has already been approved by the FDA for patients over the age of 18 with advanced GIST who have already been treated with three or more kinase inhibitors. It is also approved in Canada and Australia. Deciphera is working with Zai Lab in China to make QINLOCK available there as well.

About the Studies

The first study, titled INVICTUS Phase 3, is a placebo-controlled, double-blind, randomized, multicenter, and international trial that is intended to evaluate the efficacy, tolerability, and safety of QINLOCK in comparison to a placebo. 129 patients enrolled into the study, all of whom had already been treated with imatinib, sunitinib, and regorafenib.

Data showed that QINLOCK improved progression-free survival and overall survival, along with being well tolerated and maintaining its safety profile. Results include:

  • Progression-free survival of 6.3 months vs. 1.0 month in the placebo group
  • Overall-survival was 15.1 months vs. 6.6 months in the placebo group
  • Objective response rate of 11.8% vs. 0% in the placebo group

The second study, which is a Phase 1 dose-escalation trial, is evaluating QINLOCK in patients with second-line through fourth-line GIST. Participants were able to raise their doses to 150 mg either once or twice a day. Those who received this dosage experienced clinically meaningful benefits.

Medical professionals and patients are very excited by these results, and they are hopeful that further trials will continue to produce positive data.

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