Last week, biopharmaceutical company Deciphera Pharmaceuticals announced results from its Phase 1 clinical trial on QINLOCK (ripretinib). The study, published in the Journal of Clinical Oncology, tested QINLOCK as a potential treatment for patients with gastrointestinal stromal tumors (GIST). According to both researchers and Deciphera CMO Dr. Matthew L. Sherman, MD, these promising results supplement those discovered in the Phase 3 INTRIGUE trial.
Study Results
In the most recent study, researchers gave 150mg QINLOCK daily to 142 patients with GIST. While it was relatively safe and well-tolerated, there were some adverse reactions, including anemia, hypertension, and abdominal discomfort.
QINLOCK (ripretinib) is a switch-control tyrosine kinase inhibitor. It works by inhibiting KIT and PDGFR mutations, particularly those involved in GIST and systemic mastocytosis (SM). Currently, QINLOCK is FDA-approved for the treatment of previously treated patients with advanced GIST. Additionally, it is approved in Canada and Australia for the same patients.
The recent study results were consistent with prior findings, including those in the Phase 3 INVICTUS trial.
INVICTUS
During the randomized, double-blind, and placebo-controlled INVICTUS trial, researchers analyzed the efficacy, safety, and tolerability of QINLOCK in previously treated patients with GIST. One requirement for trial enrollment was prior treatment with at least 3 kinase inhibitors. For those receiving a placebo, median progression-free survival was only 1 month. For those receiving QINLOCK, progression-free survival rate grew to 6.3 months. Additionally, QINLOCK reduced death risk.
The trial involved 85 participants. While the drug was found to be relatively well-tolerated, there were some adverse reactions. These included:
- Poor wound healing
- Nausea and vomiting
- Palmar-plantar erythrodysesthesia syndrome
- Hypertension (high blood pressure)
- Cardiac failure
- Abdominal pain
- Constipation or diarrhea
- Appetite loss
- Muscle pain
- Increased lipase
- Cutaneous squamous cell carcinoma (cuSCC) or melanoma
- Fatigue
Gastrointestinal Stromal Tumors (GIST)
A gastrointestinal stromal tumor (GIST) develops in the gastrointestinal (digestive) tract. Usually, this tumor is found in the stomach or small intestine, but can also appear in the rectum, esophagus, or colon. It is rare that GIST is inherited. Rather, these tumors usually develop from KIT or PDGFR gene mutations. Around 80% of diagnoses involve KIT mutations. There are up to 6,000 new cases in the U.S. each year. Most patients are between 40 and 70 years old. A GIST is a soft-tissue cancer, meaning it begins in soft tissue. While some tumors are benign, others are cancerous and will spread to the bone, lungs, and liver. Currently, the five-year survival ranges from 48% for those with later stages of GIST to 90% for those caught by early detection.
Symptoms include:
- Bloody stool
- Abdominal pain and swelling
- An abdominal mass
- Nausea and vomiting
- Anemia
- Unintended weight loss
- Appetite loss
- Fatigue
- Muscle weakness
- Vomiting blood
- Difficulty swallowing
Learn more about GIST.
