Background: Tinengotinib is a spectrum-selective multi-kinase inhibitor that targets cell proliferation, angiogenesis, and immune-oncology pathways by inhibiting Aurora kinases A/B, Janus kinases (JAK), and receptor tyrosine kinases (FGFRs, VEGFRs). It has been reported that the activation of JAK/STAT and fibroblast growth factor receptor (FGFR) signaling drives prostate tumor plasticity. Here we present the preliminary safety and efficacy data of tinengotinib in patients with mCRPC from three early phase clinical trials conducted in the US and China. Methods: Eligible mCRPC patients who have no available standard therapeutic treatment options were enrolled to the three studies. Tinengotinib was given as monotherapy at 8 mg QD, 10 mg QD and 12 mg QD. Efficacy tumor assessments were based on RECIST v1.1 for measurable disease and Prostate Cancer Working Group 3 criteria for non-measurable (bone) disease. PSA50 response was also evaluated. CTCAE v5.0 was used for safety assessments. Results: As of 28AUG2023, 30 patients with mCRPC were treated at dose levels of 8 mg QD (n=1), 10 mg QD (n=19) and 12 mg QD (n=10). Median age was 67 years (range 52-82) with ECOG performance status of 1 in 93% of patients. All patients had at least 2 prior therapies including 77% prior docetaxel, 87% prior abiraterone, and 30% prior enzalutamide. The median follow-up time is 5.4 months. Twenty-two (22) patients were efficacy evaluable, of which 13 were evaluable per RECIST v1.1. Fourteen (14) patients were PSA evaluable. The median radiographic progression-free survival (rPFS) was 5.6 months (95% CI, 3.3-7.3). Overall response rate (ORR) was 46% (6/13) and the disease control rate (DCR) was 85% (11/13). Median duration of response (DoR) was 3.0 months. The PSA50 response rate was 50% (7/14). Treatment-related adverse events (TRAEs) occurred in 28 patients (93%). The most common TRAEs (≥20%) included blood thyroid stimulating hormone increase (43%), anemia (37%), hypertension (27%), aspartate aminotransferase increase (23%), electrocardiogram QT prolongation (20%) and white blood cell count decrease (20%). Conclusions: Tinengotinib safety profile was tolerable and manageable. The preliminary efficacy data showed promising clinical benefit of tinengotinib monotherapy in patients with heavily pretreated mCRPC. Further study of tinengotinib in this disease is warranted. Clinical trial information: NCT03654547, NCT04742959, NCT05253053.