The primary objective of this study is to evaluate the safety and tolerability of JAB-2485 monotherapy to determine the maximum tolerated dose (MTD) and recommended Phase 2 dose (RP2D) during Dose Escalation phase when administered in participants with advanced solid tumors; then to further evaluate preliminary antitumor activity of JAB-2485 monotherapy at the RP2D during Dose Expansion phase in patients with advanced solid tumors such as ER+ breast cancer, triple negative breast cancer (TNBC), AT-rich interaction domain 1A (ARID1A) mutant solid tumors and small cell lung cancer (SCLC).

Inclusion Criteria:

Must have Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
Must be able to provide an archived tumor sample
Must have histologically or cytologically confirmed metastatic or locally advanced solid tumor

Dose Expansion phase cohorts must meet specific expression or gene mutation where indicated
Must have at least 1 measurable lesion per RECIST v1.1
Must have adequate organ functions
Must be able to swallow and retain orally administered medication

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05490472