Yang, James Chih‐Hsin

3014 Background: Macrocyclic next-generation tyrosine kinase inhibitors (TKIs) have transformed outcomes in ALK- and ROS1-positive NSCLC; such creatively designed medicines are similarly needed to improve outcomes in EGFR-mutant NSCLC. Using a novel, mutant-selective macrocyclic structure, BH-30643 was designed for super-potency against driver EGFRm, largely sparing wildtype (WT) EGFR, and with unique invulnerability to resistance from C797S with or without T790M. Here we report emerging first-in-human dose-escalation data from the SOLARA trial (NCT06706076). Methods: Phase 1 dose escalation used a BOIN design with backfill at potentially efficacious doses. Expansion cohorts targeted populations of interest. Patients (pts) had advanced NSCLC with EGFR and/or HER2 mutations detected on local testing (tissue or plasma). Measurable disease was required; asymptomatic untreated brain metastases (BM) were permitted. Objectives included safety, PK, and RECIST response rate (ORR). Plasma NGS was performed at baseline and on treatment. Results: As of 01/05/2026, 72 pts enrolled into dose escalation and backfill across 7 dose levels at a total daily dose of 20mg -160mg, median age 62, 44% Asian, 65% with history of BM, median of 3 prior lines of treatment (range 1-12). EGFR mutations included classical (38 pts), exon20ins (14 pts) and other/atypical (18 pts) or HER2 mutations (2 pts). Plasma exposures at doses of 40mg BID and above achieved > 10x coverage over target EC90 and exceeded exposure levels of most contemporary EGFR TKIs. Common TRAE ( > 10%) were WT EGFR-associated, including diarrhea (38%), rash (28%), fatigue (15%), stomatitis (13%), and were predominantly grade 1. Bilirubin elevation was seen in 26 pts (36%) related to off-target UGT1A1 inhibition (Gilbert’s-like). Grade 3 TRAE were seen in 15 pts (18%), most commonly bilirubin (8/15); DLTs included bilirubin increase and mucositis, occurring at doses ≥ 60mg BID. No pneumonitis was observed. Responses were observed across diverse EGFRm subsets, including in CNS. Including expansion pts, 28 pts enrolled with C797S on their most recent informative molecular testing (6 with concurrent MET+ or KRAS+), with 23 still on therapy. Of 17 with on-treatment scans, partial responses (confirmed or ongoing) were seen in 10 (59%); ORR was comparable with (50%) or without (66%) T790M. Of 9 pts with baseline C797S detected in ctDNA (3 with T790M), 7 had > 99% reduction of C797S VAF on treatment. Conclusions: Leveraging a novel macrocyclic scaffold, BH-30643 is the first TKI monotherapy to demonstrate clinical responses against C797S both with or without T790M. High plasma exposures combined with super-potency, CNS activity, and favorable safety offers potential for deep and durable EGFR inhibition. Enrollment into backfill and expansion cohorts is ongoing to better characterize activity in both TKI-naïve and resistant pts. Clinical trial information: NCT06706076 .

Abstract Background: Savo is an oral, potent and highly selective MET-TKI. In the Phase 2 SAVANNAH study (NCT03778229), savo + osi had a high rate of durable responses in pts with EGFRm advanced NSCLC and high MET OverExp and/or Amp levels. Early clearance of plasma EGFRm may predict outcomes. We report an exploratory analysis of plasma EGFRm clearance and its association with MET tissue biomarker status, ORR and PFS. Methods: Pts with EGFRm advanced NSCLC and MET OverExp and/or Amp with PD on 1L+ osi received savo 300 mg QD, 300 mg BID or 600 mg QD + osi 80 mg QD. MET OverExp/Amp was centrally confirmed (by IHC [Roche], 3+ intensity in ≥50% of tumor cells [MET IHC3+/≥50%]; by FISH [Abbott Molecular], MET gene copy number ≥5 or MET:CEP7 ratio ≥2 [FISH5+], or at higher thresholds of MET IHC3+/≥90% or FISH10+). Baseline (BL) and Wk 3 plasma EGFRm (Ex19del/L858R) were analyzed by ddPCR (Biodesix) as an estimate of tumor burden. MET Amp was not monitored in ctDNA due to low detection sensitivity. Clearance was defined as undetected EGFRm ctDNA at Wk 3, when detected at BL. PFS was investigator-assessed (RECIST 1.1). DCO: Aug 23, 2024. Results: Of 344 pts with evaluable BL ctDNA, 259 (75%) had detected EGFRm ctDNA. Of these, 225 had evaluable ctDNA at Wk 3 (82 [36%] had EGFRm clearance at Wk 3). Confirmed ORR was higher in pts with EGFRm Wk 3 clearance (56/82; 68%) vs non-clearance (38/143; 27%). PFS was longer in pts with vs without EGFRm clearance at Wk 3 (Table). Across all pts evaluable for ctDNA at Wk 3, clearance rates were higher in pts with vs without high MET (69/162 [43%] vs 13/63 [21%]; odds ratio [95% CI] 0.35 [0.16, 0.72]). Similar results were seen in the savo 300 mg QD + osi subgroup. Conclusions: In SAVANNAH, among pts with detected EGFRm ctDNA at BL, clearance at Wk 3 was associated with improved ORR and PFS. Plasma EGFRm clearance at Wk 3 is enriched in pts with MET IHC3+/≥90% or FISH10+ status, consistent with improved efficacy in this biomarker subgroup. Citation Format: Jonathan W. Riess, Filippo de Marinis, Benjamin Levy, Tae Min Kim, Laura Bonanno, Quincy Chu, Marcello Tiseo, Adrian Sacher, Silvia Novello, Christina Baik, Lyudmila Bazhenova, Jacques Cadranel, Giulio Metro, Cheng-Ta Yang, Tsung-Ying Yang, Gee-Chen Chang, Konstantinos Leventakos, Lorenzo Livi, James Chih-Hsin Yang, Lecia V. Sequist, John Argue, Wanning Xu, Aleksandra Markovets, Ryan Hartmaier, Myung-Ju Ahn. SAVANNAH: Clearance of plasma EGFRm in patients with EGFRm MET-overexpressed (OverExp) and/or -amplified (Amp) NSCLC post-osimertinib (osi) treated with savolitinib (savo) + osi [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2):Abstract nr LB416.