1759P - Long-term updated outcomes of a phase II study of ripretinib vs. sunitinib in chinese patients with advanced gastrointestinal stromal tumor

Background

This study (NCT04633122) was a bridging study of the INTRIGUE study to assess the efficacy and safety of ripretinib versus sunitinib as second line (2L) treatment in Chinese GIST patients (pts). In the primary analysis (data cut-off: 20 July 2022), ripretinib demonstrated comparable overall efficacy and favourable safety vs. sunitinib in Chinese pts with advanced GIST. Furthermore, ripretinib provided greater clinically meaningful benefit vs. sunitinib in pts with KIT exon 11 mutation. Here we report an updated analysis of this study.

Methods

This phase II study enrolled adults with GIST who progressed on or had intolerance to imatinib. Pts were randomized 1:1 to ripretinib 150 mg once daily (QD) or sunitinib 50 mg QD (4 weeks on/2 weeks off). Randomization was stratified by KIT mutational status. After the primary analysis, investigators continued to follow-up all pts to collect survival data and information on subsequent treatments.

Results

As of 15 March 2024, 14.8% (16/108) remain on study treatment. Following study treatment discontinuation, 80 pts received third line (3L) treatment. In the ripretinib arm, 82.0% (32/39) of patients received sunitinib as 3L treatment. In the sunitinib arm, the majority received 3L regorafenib (58.5%, 24/41). PFS on any 3L therapy was similar between two arms in the all-patient (AP) intent-to-treat (ITT) population (median, 6.0 vs. 5.0 months; HR 0.83; 95% CI, 0.50-1.37). The mPFS on most common 3L treatment in ripretinib arm vs. sunitinib arm was 7.0 vs. 5.0 months (HR 0.67; 95% CI, 0.37-1.21) in AP ITT. There were 50 overall survival (OS) events (46.3%) in the AP ITT population. The median duration of follow-up was 34.0 months for both arms. The median OS was not reached (NR) in either arm in the AP ITT population. In the KIT exon 11 ITT population, the median OS for ripretinib vs. sunitinib was NR vs. 28.0 months (HR 0.70; 95% CI, 0.34-1.42; nominal P=0.32).

Conclusions

PFS on next line of therapy was comparable between treatment arms, suggesting that 3L treatment efficacy was not adversely affected by receiving ripretinib in the 2L setting. An OS benefit trend was observed from Ripretinib vs. sunitinib in Chinese pts with KIT exon 11 mutation.

Clinical trial identification

NCT04633122.

Editorial acknowledgement

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.