Werner helicase inhibitor for advanced microsatellite instability solid tumors: a phase 1 trial.

RO7589831 demonstrates a manageable safety profile and a 74.2% disease control rate in patients with MSI solid tumors in a phase 1 trial.

• Why it matters: Effective treatments for MSI cancers are limited, and targeting Werner syndrome helicase (WRN) offers a potential synthetic lethal approach; understanding safety and activity is crucial for development.
• What they did: The phase 1 trial evaluated escalating doses of RO7589831 in 88 patients with MSI or deficient mismatch repair tumors, assessing safety, tolerability, and preliminary efficacy, including response rates and survival metrics.
• The result: RO7589831 was generally well tolerated, with common adverse events being mostly grade 1-2; seven patients achieved partial responses, and median progression-free and overall survival were 6.7 and 17.6 months, respectively, supporting further testing.