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ASCO 2024 – IDRx shoots for an early-line gist

Last year IDRx mounted a challenge against Deciphera’s Qinlock in gastrointestinal stromal tumours, and today at ASCO the company showed that the response rate with its rival KIT inhibitor, IDRX-42, had improved in more patients. Since the previous update Ono Pharmaceutical has swooped for Deciphera, showing that other groups see promise here. So far this has been limited to genetically defined populations and late-line disease, but privately held IDRx is hoping to go earlier. The phase 1 Strategist dose-ranging trial, which enrolled patients with a median of four prior lines of therapy, showed a confirmed ORR of 18% with IDRX-42 – which looks good stacked against a 9% response rate with Quinlock in its late-line Invictus study. And there was also a confirmed ORR of 29% among 14 second-line patients receiving IDRX-42. IDRx sees the relevant comparator here as Sutent, which when used as control in the failed second-line Intrigue study of Qinlock produced a response rate of 18%. The company is now moving into dose expansion with a 300mg IDRX-42 daily dose; this portion of the study will also include a front-line cohort, a spokesperson told ApexOnco.


Evolving Strategist data with IDRX-42 in GIST

VenueCTOS Nov 2023ASCO 2024 abstract May 2024ASCO 2024 presentation Jun 2024
Cutoff date5 Oct 20232 Jan 202428 Apr 2024
Median prior therapies444
ORR14% (4/28)12% confirmed ORR (5/39); 23% confirmed + unconfirmed ORR (9/39)18% confirmed ORR (12/66); 23% confirmed + unconfirmed ORR (15/66)
Treatment-related discontinuations022

Source: ASCO.


Molecular Drug Targets