Singapore, 12 July 2022: A novel therapy to treat rare gastrointestinal stromal tumours (GIST) has been accepted for evaluation by Singapore’s Health Sciences Authority.
The proposed indication for the therapy known as QINLOCK (ripretinib) in Singapore is “for the treatment of adult patients with advanced gastrointestinal stromal tumours (GIST) who have received treatment with three or more kinase inhibitors, including imatinib”.
Dr. Richard Quek, a Singapore-based senior consultant in medical oncology welcomed the evaluation of QINLOCK, saying any new therapy options for rare GIST cancers “can only be good for patients”.
“I would like patients to know that there is a new treatment, even in the advanced setting, that has been shown to prolong the period of disease control and progression-free survival,” Dr Quek said.
“There is still clearly a need to discover new therapies. Despite new treatment options available, advanced GIST is still considered incurable.”
QINLOCK is an oral medication used to treat GIST in people who have received at least three prior treatments. It belongs to a drug class called tyrosine kinase inhibitors and works by blocking specific tumour proliferation pathways.2
A pivotal Phase 3 clinical trial of QINLOCK – the INVICTUS study – demonstrated that QINLOCK was able to significantly reduce the risk of disease progression by 85% (hazard ratio of 0.15, p<0.0001) with a median progression-free survival of 6.3 months in patients administered QINLOCK, compared to 1.0 month in the placebo arm.1 QINLOCK was associated with clinically meaningful overall survival of 15.1 months vs 6.6 months and reduced the risk of death by 64% (hazard ratio of 0.36). The objective response rate by Blinded Independent Central Review was 9.4% with QINLOCK vs 0.0% with placebo (p=0.0504)1
In addition, in a long-term follow up analysis of the INVICTUS trial, patients in the QINLOCK arm demonstrated a median overall survival of 18.2 months compared to 6.3 months in the placebo arm and reduced the risk of death by 58% (hazard ratio of 0.41).3
ST Chief Executive Officer Carlo Montagner said the HSA submission follows ST’s success achieving regulatory and reimbursement approval in Australia.
“We look forward to progressing QINLOCK through the appropriate regulatory pathway in Singapore,” as authorised by the HSA, Mr Montagner said.
“Until then, we are committed to ensuring all eligible patients in our region have access at the earliest opportunity via pre-approval access programs where permitted.”
Pending approval in Singapore, eligible GIST patients are being provided an early opportunity to access QINLOCK via an Early Patient Access Program, as per HSA guidelines.
QINLOCK will be commercialised in Singapore under an exclusive agreement from US based Deciphera Pharmaceuticals.
Gastrointestinal stromal tumor (GIST) is a cancer affecting the digestive tract or nearby structures within the abdomen, most often presenting in the stomach or small intestine. GIST growth usually begins in the connective tissue in the wall of the affected organ and grows outwards. The common location of GISTs are in the stomach (50 to 60%) and small intestines (30 to 40%) but can occur in any site in the digestive system. Other possible GIST sites are the oesophagus, rectum, and colon. GIST cases are rare and estimated to cause between 0.1% and 3% of GI cancer. The risk of GIST diagnosis increases with age, with GIST incidence peaking among people in their fifties and sixties.4
QINLOCK is a switch-control tyrosine kinase inhibitor that was engineered to broadly inhibit KIT and PDGFRA mutated kinases by using a dual mechanism of action that regulates the kinase switch pocket and activation loop to lock the kinase in the inactive state, preventing downstream signalling and cell proliferation. This dual mechanism of action provides broad inhibition of KIT and PDGFRA kinase activity, including wild type and multiple primary and secondary mutations. Ripretinib also inhibits other kinases in vitro, such as PDGFRB, TIE2, VEGFR2, and BRAF.2
Headquartered in Singapore, Specialised Therapeutics (ST) is an international biopharmaceutical company providing new specialist therapies and technologies to patients throughout Southeast Asia, as well as in Australia and New Zealand. ST and its regional affiliates collaborate with leading global pharmaceutical and diagnostic companies to bring novel, innovative and life-changing healthcare solutions to patients affected by a range of diseases. Its mission is to provide therapies where there is an unmet need. The company’s broad therapeutic portfolio currently includes novel agents in oncology, haematology, neurology, ophthalmology and supportive care. Additional information can be found at www.stbiopharma.com
INVICTUS is a Phase 3 randomised, double-blind, placebo-controlled, international, multicenter clinical study evaluating the safety, tolerability, and efficacy of QINLOCK compared to placebo in patients with advanced GIST whose previous therapies have included at least imatinib, sunitinib, and regorafenib. Patients were randomized 2:1 to either 150 mg of QINLOCK once daily (n=85) or placebo (n=44). The primary efficacy endpoint was progression-free survival (PFS) as determined by independent radiologic review using modified Response Evaluation Criteria in Solid Tumors (RECIST). The median PFS in the study was 6.3 months compared to 1.0 month in the placebo arm and significantly reduced the risk of disease progression or death by 85% (hazard ratio of 0.15, p<0.0001).1 Secondary endpoints as determined by independent radiologic review using modified RECIST included Objective Response Rate (ORR) and Overall Survival (OS). QINLOCK demonstrated an ORR of 9.4% compared with 0% for placebo (p =0.0504), which was not statistically significant.1 QINLOCK demonstrated a median overall survival of 15.1 months compared to 6.6 months in the placebo arm and reduced the risk of death by 64% (hazard ratio of 0.36).1 In a long-term follow up of 19 months after the primary analysis, QINLOCK also demonstrated a median OS of 18.2 months compared to 6.3 months in the placebo arm and reduced the risk of death by 58% (hazard ratio of 0.41).3 The most common (>2%) grade 3 or 4 treatment related adverse events in the QINLOCK group included lipase increase (5%), hypertension (4%), fatigue (2%), and hypophosphataemia (2%); and in the placebo group, anaemia (7%), fatigue (2%), diarrhoea (2%), decreased appetite (2%), dehydration (2%), hyperkalaemia (2%), acute kidney injury (2%), and pulmonary oedema (2%).1
Emma Power, Corporate Affairs and Communications Manager, Specialised Therapeutics Asia +65 3158 9940 or +61 419 149 525 or firstname.lastname@example.org