Horinouchi, Hidehito

8524 Background: Teliso-V is a c-Met–directed antibody-drug conjugate comprising telisotuzumab and the microtubule polymerization inhibitor monomethyl auristatin E (MMAE) payload. In the Ph2 LUMINOSITY study (NCT03539536), Teliso-V showed durable responses and manageable safety (Camidge et al, JCO 2024;42:3000-11) resulting in its accelerated approval in locally advanced/metastatic NSQ NSCLC with high c-Met protein OE (3+, ≥50%), as determined by an FDA-approved test. MET amp is a negative prognostic risk factor in advanced NSCLC, frequently associated with recurrent disease. High levels of MET amp and c-Met OE are hallmarks of MET -addicted tumors. Here, we analyzed the effects of MET amp on clinical responses to Teliso-V in LUMINOSITY. Methods: MET amp was evaluated by FISH and ctDNA in baseline samples from 108 NSQ EGFR WT NSCLC pts with c-Met OE (3+, ≥25%). MET amp by FISH was defined as having focal MET amp (MET/CEP7 ≥2.0) with MET gene copy number (GCN) ≥4. MET amp (focal) by ctDNA was defined as having plasma MET GCN ≥4 with no co-amplification in CDK6 and EGFR. c-Met OE by Immunohistochemistry (IHC; SP44) was defined as 3+ tissue staining intensity in ≥25% tumor cells (high c-Met OE: 3+, ≥50%; intermediate [int] c-Met OE: 3+, 25% to 49%). Exploratory analysis of tumor response was assessed in 76 efficacy evaluable pts with c-Met OE and MET amp assay results. Results: MET amp was detected in 34% (37/108) of pts with c-Met OE (3+, ≥25%) and was enriched by c-Met levels: 22% (11/50) in pts with Int c-Met OE (3+, 25% to 49%) and 45% (26/58) in pts with high c-Met OE (3+, ≥50%). The effects of MET amp on tumor response in LUMINOSITY are shown in Table 1. The majority of c-Met OE pts (79%) with PFS ≥10 mo (n=14) had GCN ≥10 and/or c-Met IHC 3+ ≥50%. No new safety signals were reported in pts with c-Met OE and MET amp. Conclusions: MET amp is more common in pts with high c-Met OE in this retrospective subgroup analysis. Tumor activity with Teliso-V was observed regardless of MET amp status. The impact of MET amp in pts with c-Met OE will be further evaluated in ongoing Phase 3 study (NCT04928846). Teliso-V efficacy in NSQ EGFR -WT NSCLC pts with c-Met OE with or without MET amp in LUMINOSITY. Total c-Met OE(3+, ≥25%) Total c-Met OE(3+, ≥25%) Intermediate c-Met OE(3+, ≥25%-49%) Intermediate c-Met OE(3+, ≥25%-49%) High c-Met OE(3+, ≥50%) High c-Met OE(3+, ≥50%) MET amp(N) No (N=53) Yes (N=23) No (N=30) Yes (N=7) No (N=23) Yes (N=16) ORR %(95% CI) 28 (18.0, 41.6) 39 (22.2, 59.2) 23 (11.8, 40.9) 57 (25, 84.2) 35 (18.8, 55.1) 31 (14.2, 55.6) PFS,median, mo(95% CI) 5.26 (3.71, 8.11) 8.02 (4.47, 14.65) 5.32 (2.69, 8.11) 7.52 (4.47, NA) 4.17 (3.25, 8.87) 8.02 (3.06, 25.92) OS,median, mo(95% CI) 14.5 (8.18, 17.38) 13.86 (6.54, 22.24) 14.03 (3.65, 17.02) 9.79 (6.54, NA) 16.26 (5.59, 36.44) 13.86 (3.06, 30.29)

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 Lung adenocarcinoma in never-smokers is a major public health burden, especially among East Asian women. Polygenic risk scores (PRSs) are promising for risk stratification but are primarily developed in European-ancestry populations. We aimed to develop and validate single- and multi-ancestry PRSs for East Asian never-smokers to improve lung adenocarcinoma risk prediction. Methods PRSs were developed using genome-wide association study summary statistics from East Asian (8002 cases; 20 782 controls) and European (2058 cases; 5575 controls) populations. Single-ancestry models included a PRS with 25 single nucleotide variants (PRS-25), PRS clumping and thresholding (CT), and LDpred2; multi-ancestry models included LDpred2 plus European PRS-128, PRS-CSx, and clumping and thresholding, super learning, empirical Bayes (CT-SLEB). Performance was evaluated in independent East Asian data from the Female Lung Cancer Consortium and externally validated in the Nanjing Lung Cancer Cohort. We assessed predictive accuracy via area under the curve operating procedure (AUC), with 10-year and (ages 30-80 years) absolute risks estimates. Results The best multi-ancestry PRS, using East Asian and European data via CT-SLEB, outperformed the best East Asian-only (LDpred2; AUC = 0.629, 95% confidence interval [CI] = 0.618 to 0.641), achieving an AUC of 0.640 (95% CI = 0.629 to 0.653) and odds ratio of 1.71 (95% CI = 1.61 to 1.82) per standard deviation increase. Nanjing Lung Cancer Cohort validation confirmed robust performance (AUC = 0.649, 95% CI = 0.623 to 0.676). The top 20% PRS group had a 3.92-fold higher lung adenocarcinoma risk than the bottom 20%. Further, the top 5% PRS group reached a 6.69% lifetime absolute risk. Notably, this group reached the average population 10-year lung adenocarcinoma risk at age 50 years (0.42%) by age 41 years, 9 years earlier. Conclusions Multi-ancestry PRS approaches enhance lung adenocarcinoma risk stratification in East Asian never-smokers, with consistent external validation, suggesting future clinical utility.

8618 Background: Telisotuzumab vedotin (Teliso-V) is a c-Met–directed antibody-drug conjugate comprising the mAb telisotuzumab and the microtubule polymerization inhibitor monomethyl auristatin E. In the phase 2 LUMINOSITY trial (NCT03539536), Teliso-V monotherapy 1.9 mg/kg showed durable responses and a generally manageable safety profile in patients (pts) with c-Met protein–overexpressing (OE) non-squamous (NSQ) EGFR -wildtype (WT) non-small cell lung cancer (NSCLC). Herein we present an analysis of efficacy outcomes according to prior platinum or prior platinum and immune checkpoint inhibitor (ICI)-based therapies. Methods: Pts (≥18 years) with locally advanced/metastatic c-Met protein–OE NSQ EGFR -WT NSCLC who had ≤2 prior lines of therapy, including ≤1 line of chemotherapy, were treated with 1.9 mg/kg Teliso-V Q2W. c-Met protein overexpression (by immunohistochemistry clinical trial assay for MET [SP44] [Roche]) was defined as ≥25% tumor cells with 3+ staining intensity (high: ≥50% 3+; intermediate [int]: 25 to <50% 3+). The primary endpoint was overall response rate (ORR) by independent central review per RECIST v1.1. Results: As of 21 Feb 2024, 172 pts received ≥1 dose of Teliso-V and 168 pts were included in efficacy analyses (c-Met high, n=84; c-Met int, n=84). In the c-Met OE total population, 97.6% of pts received prior platinum and 78.6% received prior platinum + ICI. Efficacy data for pts with prior platinum and platinum + ICI therapies are shown in the Table. Among the 172 dosed pts, the most common any-grade treatment-related adverse events (TRAEs) were peripheral sensory neuropathy (31%), peripheral edema (16%), and fatigue (14%). The most common grade ≥3 TRAE was peripheral sensory neuropathy (7%). Conclusions: This analysis demonstrated that Teliso-V elicited durable responses in pts with c-Met protein–OE NSQ EGFR -WT NSCLC regardless of whether they had received prior platinum or platinum + ICI therapies; the efficacy outcomes in these subgroups were consistent with those in the overall pt population. Clinical trial information: NCT03539536 . Platinum Platinum + ICI Overall ORR, a n/N (%) [95% CI] c-Met OE total c-Met high c-Met int 48/164 (29.3) [22.4, 36.9]28/81 (34.6) [24.3, 46.0]20/83 (24.1) [15.4, 34.7] 38/132 (28.8) [21.2, 37.3]22/67 (32.8) [21.8, 45.4]16/65 (24.6) [14.8, 36.9] 49/168 (29.2) [22.4, 36.7]29/84 (34.5) [24.5, 45.7]20/84 (23.8) [15.2, 34.3] Median DOR, a mo [95% CI] c-Met OE total c-Met high c-Met int 7.2 [5.5, 11.3]9.0 [3.8, 12.0]7.2 [4.7, 11.5] 7.2 [5.5, 11.0]9.0 [3.8, 11.3]7.2 [5.3, 11.5] 7.2 [5.5, 11.0]7.2 [4.2, 12.0]7.2 [4.7, 11.5] a Per independent central review. DOR, duration of response.

PURPOSE Telisotuzumab vedotin (Teliso-V) is a c-Met–directed antibody-drug conjugate with a monomethyl auristatin E cytotoxic payload. The phase II LUMINOSITY trial (ClinicalTrials.gov identifier: NCT03539536 ) aimed to identify the optimal c-Met protein–overexpressing non–small cell lung cancer (NSCLC) population for treatment with Teliso-V (stage I) and expand the selected group for efficacy evaluation (stage II). Stage II enrolled patients with nonsquamous epidermal growth factor receptor ( EGFR )-wildtype NSCLC. METHODS Eligible patients had locally advanced/metastatic c-Met protein–overexpressing NSCLC and ≤2 previous lines of therapy (including ≤1 line of systemic chemotherapy). c-Met protein overexpression in nonsquamous EGFR -wildtype NSCLC was defined as ≥25% tumor cells with 3+ staining (high [≥50% 3+]; intermediate [≥25%–<50%]). Teliso-V was administered at 1.9 mg/kg once every 2 weeks. The primary end point was overall response rate (ORR) by independent central review. RESULTS In total, 172 patients with nonsquamous EGFR -wildtype NSCLC received Teliso-V in stages I and II. ORR was 28.6% (95% CI, 21.7 to 36.2; c-Met high, 34.6% [95% CI, 24.2 to 46.2]; c-Met intermediate, 22.9% [95% CI, 14.4 to 33.4]). The median duration of response was 8.3 months (95% CI, 5.6 to 11.3; c-Met high, 9.0 [95% CI, 4.2 to 13.0]; c-Met intermediate: 7.2 [95% CI, 5.3 to 11.5]). The median overall survival was 14.5 months (95% CI, 9.9 to 16.6; c-Met high, 14.6 [95% CI, 9.2 to 25.6]; c-Met intermediate, 14.2 [95% CI, 9.6 to 16.6]). The median progression-free survival was 5.7 months (95% CI, 4.6 to 6.9; c-Met high, 5.5 [95% CI, 4.1 to 8.3]; c-Met intermediate: 6.0 [95% CI, 4.5 to 8.1]). Most common any-grade treatment-related adverse events (AEs) were peripheral sensory neuropathy (30%), peripheral edema (16%), and fatigue (14%); the most common grade ≥3 AE was peripheral sensory neuropathy (7%). CONCLUSION Teliso-V was associated with durable responses in c-Met protein–overexpressing nonsquamous EGFR -wildtype NSCLC, especially in those with high c-Met. AEs were generally manageable.