Abstract 80P
Background
Patients with advanced gastrointestinal stromal tumours (GIST) have limited treatment options once they have developed resistance to standard therapies. We investigated the treatment outcomes in patients prescribed ripretinib, a novel tyrosine kinase inhibitor, as part of the expanded access program (EAP) in the United Kingdom (UK).
Methods
A retrospective review of patients with advanced GIST who commenced EAP ripretinib between January 2020 to October 2021 was completed using The Royal Marsden Hospital database. Survival curves were constructed with the Kaplan-Meier method, and univariate and multivariate Cox regression analyses were performed. All analyses were performed using R Statistical Software (v4.0.3; R Core Team 2020).
Results
In total, 45 patients with advanced GIST were included. Baseline characteristics comprised of: patient sex, age, primary mutation type and tumour site, number and type of metastatic sites, ECOG performance status, as well as information on previous lines of therapy. After a median follow-up of 21.5 (95% CI 19.0–28.2) months, median PFS of ripretinib 150 mg OD was 7.4 (95% CI 5.6–10.0) months. Upon progression, 23 patients received ripretinib 150 mg BD with their median PFS being a further 5.9 (95% CI 3.5–9.2) months. Overall, total PFS and OS on ripretinib were 12.2 (95% CI 7.9–17.6) and 14.0 (95% CI 9.9–NA) months, respectively. In multivariate analysis, the presence of primary KIT exon 11 mutation was consistently associated to better prognosis. Notably, there was no association between number of previous lines of treatment and survival outcomes on ripretinib. The best responses to ripretinib OD and BD dosing were PR (26.7% and 8.7%, respectively) and SD (46.7% and 34.8%, respectively). Toxicity data will also be presented.
Conclusions
Patients with advanced GIST who received ripretinib in the UK within the EAP reported a prolonged clinical and radiological benefit, in line with the recently reported phase III INTRIGUE and INVICTUS clinical trials.
Clinical trial identification
NCT04148092.
Editorial acknowledgement
Legal entity responsible for the study
The Royal Marsden NHS Foundation Trust.
Funding
Has not received any funding.
Disclosure
A. Napolitano: Financial Interests, Personal, Advisory Role: Agenus. R.L. Jones: Financial Interests, Personal, Advisory Role: Immune Design, Merck Serono, Adaptimmune, Daiichi Sankyo, Eisai, Morphotek, TRACON, Deciphera, PharmaMar, Blueprints Medicines, Boehringer Ingelheim. All other authors have declared no conflicts of interest.