1966P - Treatment with BLU-667, a potent and selective RET inhibitor, provides rapid clearance of ctDNA in patients with RET-altered non-small cell lung cancer (NSCLC) and thyroid cancer

BLU667, an investigational agent, is a potent and selective inhibitor of oncogenic rearranged during transfection (RET) alterations and predicted resistance mutations. Up to 90% of advanced medullary thyroid cancer (MTC) is characterized by single nucleotide variants and short insertions/deletions in the RET gene. In NSCLC, 1-2% of patients (pts) harbor rearrangements resulting in RET fusions. In the first-in-human ARROW study (NCT03037385), BLU-667 has demonstrated significant clinical activity in RET-altered NSCLC and MTC and has been well tolerated. Previous data has shown that early declines in circulating tumor DNA (ctDNA) may predict for treatment outcome. We investigated the change in ctDNA levels from baseline following treatment with BLU-667 and whether early changes in ctDNA during treatment were associated with clinical responses and outcomes.Blood was collected at baseline and prespecified time points during treatment. Plasma from 111 pts with locally documented RET-altered MTC and NSCLC were profiled with the Personal Genome Diagnostics PlasmaSELECT™ R64 sequencing panel.RET fusions were detected at baseline in 45/63 (71%) pts with NSCLC and RET mutations in 35/48 (73%) pts with MTC. Baseline ctDNA mutant allele fraction (MAF; MTC) or unique fusion reads (NSCLC) correlated with the sum of target lesions (p<0.01). BLU-667 led to rapid RET ctDNA declines in almost all pts and across all doses (60-600mg QD, 100-200mg BID). Eighty-one percent of pts with NSCLC and detectable ctDNA at baseline had undetectable RET ctDNA after 8 weeks of treatment. Clearance of RET fusions in NSCLC was observed for multiple fusion partners including CCDC6 and KIF5B. Forty-one percent of pts with MTC harboring somatic RET mutations also had undetectable RET ctDNA after 8 weeks. The correlation between changes in ctDNA levels and clinical outcomes are currently not mature and will be reported at the meeting.Treatment with BLU-667 led to a robust and rapid decline in ctDNA in almost all patients regardless of treatment dose or tumor diagnosis and in NSCLC irrespective of fusion partner studied.NCT03037385.Blueprint Medicines Corporation.Blueprint Medicines Corporation.G. Curigliano: Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Seattle Genetics; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Novartis; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Lilly; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: BMS; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Pfizer. V. Subbiah: Advisory / Consultancy: MedImmune; Research grant / Funding (institution): Novartis (Inst), GlaxoSmithKline (Inst), NanoCarrier (Inst), Northwest Biotherapeutics (Inst), Genentech (Inst), Roche (Inst), Berg Pharma (Inst), Bayer AG (Inst), Incyte (Inst), Fujifilm (Inst), PharmaMar (Inst), D3 Oncology Solutions (Inst), Pfizer (Ins; Travel / Accommodation / Expenses: PharmaMar, Bayer AG. J.F. Gainor: Honoraria (self): Merck, Incyte, ARIAD Pharmaceuticals, Novartis, Pfizer; Advisory / Consultancy: Genentech, Bristol-Myers Squibb, Theravance, Loxo, Takeda, Array BioPharma, Amgen, Merck, Agios, Regeneron, Oncorus, Jounce Therapeutics; Research grant / Funding (institution): Merck (Inst), Novartis (Inst), Genentech (Inst), Bristol-Myers Squibb (Inst), Adaptimmune (Inst), AstraZeneca (Inst), ARIAD Pharmaceuticals (Inst), Jounce Therapeutics (Inst), Blueprint Medicines (Inst), Moderna Therapeutics (Inst), Tesaro (Inst), Alexo T. D.H. Lee: Honoraria (self): AstraZeneca, Boehringer-Ingelheim, Bristol-Myers Squibb, CJ Healthcare, Eli Lilly, Janssen, Merck, MSD, Mundipharma, Novartis, Ono, Pfizer, Roche, Samyang Biopharm and ST Cube; Advisory / Consultancy: Ministry of Food and Drug Safety, Korea, Health Insurance Review and Assessment Service, Korea, National Evidence-based Collaborating Agency, Korea, and National Cancer Control Planning Board, Korea. M.H. Taylor: Honoraria (self), Advisory / Consultancy: BMS, Eisai Inc, Array Biopharma, Bayer, LOXO, Blueprint, Arqule, Novartis; Speaker Bureau / Expert testimony: BMS, Eisai Inc; Research grant / Funding (institution): BioAtla; Travel / Accommodation / Expenses: BMS, Eisai Inc, Array Biopharma, Bayer, Loxo, Blueprint. V. Zhu: Honoraria (self), Speaker Bureau / Expert testimony: AstraZeneca, Roche-Foundation Medicine, Roche/Genentech, Takeda; Advisory / Consultancy, Shareholder / Stockholder / Stock options: TP Therapeutics. R.C. Doebele: Honoraria (self): Pfizer, AstraZeneca, ARIAD Pharmaceuticals, Guardant Health, Takeda Pharmaceuticals, Spectrum Pharmaceuticals, Trovagene; Advisory / Consultancy: Pfizer, OncoMed Pharmaceuticals, Trovagene, Ignyta, GreenPeptide, AstraZeneca; Research grant / Funding (institution): Ignyta (Inst); Travel / Accommodation / Expenses: Ignyta, ARIAD Pharmaceuticals, Guardant Health; Shareholder / Stockholder / Stock options: Rain Therapeutics; Licensing / Royalties: Other Intellectual Property: Licensing fees from Abbott Molecular for patent PCT/US2013/057495, licensing fees from Ignyta for biologic materials (Inst). G. Lopes: Advisory / Consultancy: Pfizer; Research grant / Funding (self): AstraZeneca; Research grant / Funding (institution): Merck Sharp & Dohme (Inst); EMD Serono (Inst), AstraZeneca (Inst), AstraZeneca, Blueprint Medicines (Inst), Tesaro (Inst), Bavarian Nordic (Inst), Novartis (Inst), G1 Therapeutics (Inst). E. Garralda: Research grant / Funding (self), Research grant / Funding (institution): Novartis; Travel / Accommodation / Expenses: BMS, Menarini, Glycotope; Licensing / Royalties: MSD. S.M. Gadgeel: Advisory / Consultancy: Pfizer, Genentech, ARIAD Pharmaceuticals, AstraZeneca, Bristol-Myers Squibb, AbbVie; Speaker Bureau / Expert testimony: AstraZeneca; Research grant / Funding (self), Research grant / Funding (institution): Merck; Research grant / Funding (institution): Pfizer (Inst), Merck, Genentech (Inst), Blueprint Medicines (Inst), ARIAD Pharmaceuticals (Inst), Takeda (Inst); Travel / Accommodation / Expenses: ARIAD Pharmaceuticals, Takeda. C.D. Turner: Full / Part-time employment: Blueprint Medicines Corporation. M. Palmer: Full / Part-time employment: Blueprint Medicines Corporation. S. Miller: Full / Part-time employment: Blueprint Medicines Corporation. All other authors have declared no conflicts of interest

ESMO recommendations on the standard methods to detect RET fusions and mutations in daily practice and clinical research

International audienceAberrant activation of RET is a critical driver of growth and proliferation in diverse solid tumours. Multikinase inhibitors (MKIs) showing anti-RET activities have been tested in RET-altered tumours with variable results. The low target specificity with consequent increase in side-effects and off-target toxicities resulting in dose reduction and drug discontinuation are some of the major issues with MKIs. To overcome these issues, new selective RET inhibitors such as pralsetinib (BLU-667) and selpercatinib (LOXO-292) have been developed in clinical trials, with selpercatinib recently approved by the Food and Drug Administration (FDA). The results of these trials showed marked and durable antitumour activity and manageable toxicity profiles in patients with RET-altered tumours. The European Society for Medical Oncology (ESMO) Translational Research and Precision Medicine Working Group (TR and PM WG) launched a collaborative project to review the available methods for the detection of RET gene alterations, their potential applications and strategies for the implementation of a rational approach for the detection of RET fusion genes and mutations in human malignancies. We present here recommendations for the routine clinical detection of targetable RET rearrangements and mutations

Safety of First-line Nivolumab Plus Ipilimumab in Patients With Metastatic Non-Small Cell Lung Cancer: A Pooled Analysis of CheckMate 227, CheckMate 568, and CheckMate 817.

We characterized first-line nivolumab plus ipilimumab (NIVO+IPI) safety in a large patient population with metastatic non-small cell lung cancer (NSCLC) and efficacy outcomes after NIVO+IPI discontinuation due to treatment-related adverse events (TRAEs). We pooled data from three first-line NIVO+IPI studies (NIVO, 3 mg/kg or 240 mg every 2 weeks; IPI, 1 mg/kg every 6 weeks) in metastatic NSCLC (CheckMate 227 Part 1, CheckMate 817 cohort A, CheckMate 568 Part 1). Safety endpoints included TRAEs and immune-mediated adverse events (IMAEs) in the pooled population and patients aged ≥75 years. In the pooled population (N=1255), any-grade TRAEs occurred in 78% of patients, grade 3/4 TRAEs in 34%, and discontinuations of any regimen component due to TRAEs in 21%. The most frequent TRAE and IMAE were diarrhea (20%; grade 3/4, 2%) and rash (17%; grade 3/4, 3%), respectively. The most common grade 3/4 IMAEs were hepatitis (5%) and diarrhea/colitis and pneumonitis (4% each). Pneumonitis was the most common cause of treatment-related death (5/16). Safety in patients aged ≥75 years (n=174) was generally similar to the overall population, but discontinuations of any regimen component due to TRAEs were more common (29%). In patients discontinuing NIVO+IPI due to TRAEs (n=225), 3-year overall survival was 50% (95% CI: 42.6-56.0), and 42% (31.2-52.4) of 130 responders remained in response 2 years after discontinuation. First-line NIVO+IPI was well tolerated in this large population with metastatic NSCLC and in patients aged ≥75 years. Discontinuations due to TRAEs did not reduce long-term survival