BMS-986504 in patients (pts) with advanced solid tumors with homozygous <i>MTAP</i> deletion ( <i>MTAP</i> -del): Clinical update and first report of pharmacokinetics (PK) and pharmacodynamic (PD) analyses from CA240-0007.

3011 Background: BMS-986504 selectively binds to the PRMT5-MTA complex, which represents a synthetic lethal target in MTAP -del cancer cells, while sparing MTAP– wild-type cells. In the first-in-human phase 1/2 CA240-0007 study in advanced, unresectable or metastatic solid tumors with homozygous MTAP -del, BMS-986504 was found to be well tolerated and demonstrated antitumor activity in multiple tumors. Here, we report clinical results and the first PK and PD analyses of BMS-986504 from the dose escalation and expansion phases of CA240-0007. Methods: Pts with measurable/evaluable disease and no available treatment (Tx) with curative intent were enrolled; 7 doses were evaluated (50 to 800 mg) in dose escalation. Objective response rate (ORR), disease control rate (DCR), duration of response (DOR), time to response (TTR), safety, PK, PD, including plasma SDMA were assessed. Results: As of 2 Dec 24, 152 heavily pretreated pts were enrolled across all doses: NSCLC (n = 34), PDAC (n = 41), cholangiocarcinoma (n = 12), and mesothelioma (n = 12) were the most common tumor types. With a median f/u of 9.0 mo (95% CI 7.6–9.9), continued durable antitumor activity and deepening tumor regression were seen across tumor types and doses (ORR = 23%, DCR = 70%, median DOR = 10.5 mo, TTR = 4.6 mo). No new safety signals were identified. Most Tx-related adverse events (TRAEs) were grade (Gr) 1 or 2; 13% had Gr ≥ 3 TRAEs (Gr 3 = 12%, Gr 4 = &lt; 1%, Gr 5 = 0). Doses from 50 to 600 mg QD were assessed for PK/PD. The AUC (0-24) after multiple doses was approximately dose proportional at 200 to 600 mg, and the terminal t 1/2 after a single dose was approximately 24 h (table). There were dose-dependent reductions in predicted plasma SDMA, with the 400 and 600 mg doses approaching the plateau. Conclusions: With longer f/u, BMS-986504 continued to show increasingly durable antitumor activity. BMS-986504 demonstrated a favorable PK/PD profile, supporting QD dosing at 400 and 600 mg. These results support further investigation of BMS-986504 at 400 and 600 mg QD as a potential first-in-class synthetic lethal Tx option in pts with advanced solid tumors with MTAP -del. Clinical trial information: NCT05245500 . PK and PD. 50 mg QD 100 mg QD 200 mg QD 400 mg QD 600 mg QD PK after multiple doses t max a (min–max), h 2.0 (2.0–4.0)n = 3 2.0 (1.0–2.0)n = 3 2.0 (0.5–6.0)n = 8 2.0 (0.5–4.0)n = 10 2.0 (1.0–6.0)n = 10 C max , b ng/mL 107n = 3 377n = 3 685n = 8 1240n = 10 2110n = 10 AUC (0-24) , b h∙ng/mL 948 n = 3 3060 n = 3 7150 n = 7 11,800n = 10 26,700n = 9 AUC (0-24) , b,c h∙ng/mL/mg 19.0n = 3 30.6n = 3 35.8n = 7 29.5n = 10 44.6n = 9 Terminal t 1/2 after single dose, d h 21.7 n = 1 80.7 n = 1 21.5 n = 14 21.7 n = 14 24.1 n = 1 PD Translational exposure targets (C avgss ), X 0.08 0.21 0.5 1.1 1.7 Predicted plasma SDMA reduction, a % (90% PI) 30.0 (23.2–37.8)</jats