Preclinical activity of NVL-655 in patient-derived models of ALK cancers, including those with lorlatinib-resistant G1202R/L1196M compound mutation

Introduction: Five tyrosine kinase inhibitors (TKIs) have been approved for treatment of ALK-positive non-small cell lung cancer (NSCLC), including first- (crizotinib), second- (ceritinib, alectinib, and brigatinib), and third-(lorlatinib) generation therapies. Durability of response is limited partly by emergence of ALK resistance mutations. The most frequent ALK mutations after relapse on first- and second-generation ALK TKIs are L1196M and G1202R, respectively, together representing 20–40% of resistance cases. ALK G1202R tumors treated with lorlatinib have relapsed by acquiring compound mutations such as G1202R/L1196M and G1202R/T1151M, which confer resistance to all approved ALK TKIs. To address this medical need, we reported the discovery of NVL-655: a brain-penetrant TKI that selectively inhibits ALK and ALK resistance mutants over TRKB. Avoiding TRKB is advantageous as its inhibition has been linked to neurological adverse events and dose-limiting toxicities. Here we demonstrate the preclinical activity of NVL-655 in patient-derived models, including from patients who progressed on prior ALK TKIs. Methods: EML4-ALK fusion cell lines were established from NSCLC patients: MGH026-1, MGH048-1, and MGH064-1 (treatment-naïve); MGH045-1 (L1196M post-crizotinib); MGH953-4 and YU-1077 (G1202R post-alectinib); MGH9037-2 (G1202R post-brigatinib); MGH953-7 (G1202R/ L1196M post-lorlatinib); and MR448re (G1202R/T1151M post-lorlatinib). Murine xenografts were generated from YU-1077 tumors, MR619 cholangiocarcinoma tumors (STRN-ALK G1202R post-alectinib); MGH953-7 tumors; and MR448re cell line. Results: NVL-655 and lorlatinib had similar potency against cancer cell lines derived from treatment-naïve ALK patients (IC50 <5 nM). However, only NVL-655 retained high activity (IC50 ∼1 nM) against ALK G1202R cell lines derived from alectinib- or brigatinib-relapsed patients, showing substantially improved potency compared to second-generation ALK TKIs or lorlatinib (IC50 ∼35 nM–1.5 μM). ALK G1202R/L1196M and ALK G1202R/T1151M cell lines derived from lorlatinib-relapsed patients were indeed resistant to lorlatinib (IC50 >400 nM) but highly sensitive to NVL-655 (IC50 <5 nM). Western blot analysis confirmed on-target engagement and inhibition of pathway signaling. Consistent with in vitro results, NVL-655 induced regression in ALK G1202R, G1202R/L1196M, and G1202R/T1151M xenografts derived from patient tumors. Conclusion: Patient-derived cells and xenografts are among the most disease-relevant preclinical models for evaluating new therapies and drug resistance. NVL-655 showed activity in diverse patient-derived models of ALK-positive cancers, including ones that exhibited clinical resistance to prior-generation ALK TKIs. The broad preclinical activity of NVL-655 suggests potential utility as a best-in-class therapy for ALK-positive cancer patients. Conflict of interest: Advisory Board: ANH is a scientific advisor of Nuvalent. Corporate-sponsored Research: TF, LN, SY, MY, HM, LB, CN, LF, JL, BC, and ANH receive sponsored research funding from Nuvalent. Other Substantive Relationships: AT and HEP are employees and stockholders of Nuvalent.