Effect of the KRAS G12C inhibitor MK-1084 on circulating tumor DNA levels in participants with KRAS G12-mutated tumors
Presenter: Carlos Rojas, MD Session: Biomarkers Predictive of Therapeutic Benefit 1 Time: 4/19/2026 2:00:00 PM → 4/19/2026 5:00:00 PM
Authors
Carlos Rojas 1 , Matteo Simonelli 2 , Adrian Sacher 3 , Mehmet Ali Sendur 4 , Rafal Dziadziuszko 5 , Joon Oh Park 6 , Victor Moreno Garcia 7 , Jair Bar 8 , Yun Fan 9 , Mustafa Erman 10 , Shun Lu 11 , Jenny H. Lee 12 , Rosalyn A. Juergens 13 , Bangwei Cao 14 , Cai Chen 15 , Razvan Cristescu 15 , Thomas Jemielita 15 , Yewon Sofia Choi 15 , Mark D. Ayers 15 , Iwona Lugowska 16 1 Bradford Hill Clinical Cancer Research Center, Santiago, Chile, 2 IRCCS Humanitas Research Hospital, Rozzano MI and Humanitas University, Pieve Emanuele MI, Italy, 3 Princess Margaret Cancer Centre and University of Toronto, Toronto, ON, Canada, 4 Ankara Yıldırım Beyazıt University and Ankara Bilkent City Hospital, Ankara, Turkey, 5 Medical University of Gdánsk, Gdánsk, Poland, 6 Associate Professor, Dept. of Hem./Onc., Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea, Republic of, 7 START Madrid, Madrid, Spain, 8 Jusidman Cancer Center, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel, 9 Zhejiang Cancer Hospital, Hangzhou, China, 10 Hacettepe University Cancer Institute, Ankara, Turkey, 11 Shanghai Chest Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China, 12 Chris O’Brien Lifehouse Research Institute, Camperdown, Australia, 13 Hamilton Health Sciences-Juravinski Cancer Centre, Hamilton, ON, Canada, 14 Beijing Friendship Hospital, Capital Medical University, Beijing, China, 15 Merck & Co., Inc., Rahway, NJ, 16 Maria Sklodowska-Curie National Research Institute and Oncology Centre, Warsaw, Poland
Abstract
Background: Preliminary data from the phase 1 KANDLELIT-001 trial (NCT05067283) showed a manageable safety profile and preliminary antitumor activity for MK-1084, a next-generation, selective KRAS G12C-GDP covalent inhibitor, in participants (pts) with previously treated, KRAS G12C-mutant solid tumors. Here, we examine the effect of MK-1084 monotherapy on KRAS G12C variant allele frequency (VAF) and maximum somatic allele frequency (MSAF) ctDNA levels in pts with advanced KRAS G12C-mutant solid tumors during the monotherapy dose escalation phase of KANDLELIT-001. Methods: KANDLELIT-001 enrolled pts with any KRAS G12C-mutated advanced solid tumor to receive MK-1084 alone or in various combination therapies. Pts with any advanced solid tumor and ≥1 prior systemic therapy received MK-1084 monotherapy PO QD or BID in Arm 1 (total daily dose, 25-800 mg). Serial blood samples collected from pts enrolled in Arm 1 were evaluated for changes in ctDNA KRAS-G12C VAF and MSAF levels at baseline, and before beginning cycle 1 and cycle 3 using the Guardant Health OMNI panel. Differences in ctDNA levels were assessed using descriptive statistics. Results: In Arm 1, 22 of 23 pts were evaluable for changes in ctDNA levels. Median KRAS G12C VAF and MSAF ctDNA levels decreased ≥90% each from 14% to 0.9% and from 25% to 2%, respectively, from cycle 1 (pre-dose, day 0) to cycle 3 (day 42 on treatment); 6 (26%) pts achieved complete clearance of KRAS G12C VAF ctDNA. Greater reductions in tumor size were observed in pts who achieved complete clearance of KRAS G12C ctDNA. Larger reductions in ctDNA levels were seen in pts with a complete or partial response (responders) vs those with no response. Co-occurring mutations in PI3KCA, KEAP1, and KRAS G12D, Q61H, and BRAF were detected at baseline. Conclusions: In a cohort of 23 patients with KRAS G12C mutations receiving MK-1084 monotherapy, tumor response was associated with reductions in KRAS G12C VAF and MSAF ctDNA levels. This potentially reflects the molecular activity and therapeutic effect of MK-1084 in KRAS G12C-mutated tumors. The small sample size of this analysis limits interpretation of these findings.
Disclosure
C. Rojas, MSD ), Other, Invited Speaker. AstraZeneca Other, Invited Speaker, Advisory Board. BMS Other, Invited Speaker, Advisory Board. Knight Other, Invited Speaker. Pfizer Other, Invited Speaker, Advisory Board. Roche Other, Advisory Board. Sanofi Other, Advisory Board. Bradford Hill g., Board of Directors, non-salaried role). M. Simonelli, MSD ). GSK Other, Consulting, Advisory Board. Pfizer Travel, Other, Advisory Board. Sanofi Travel, Other, Advisory Board. Roche Travel, Other, Advisory Board. Incyte Other, Advisory Board. Servier Other, Advisory Board. BMS/Celgene Other, Advisory Board. A. Sacher, MSD ), Travel, Other, Advisory Committee. Amgen Travel, Other, Consultant, Advisory Committee. Iovance Other, Consultant. CRISPR Therapeutics Other, Consultant. Pfizer Other, Consultant. GSK Other, Consultant. Spectrum Other, Consultant. Lilly Other, Consultant. BridgeBio Other, Consultant. Hotspot Therapeutics Other, Consultant. Genentech-Roche Travel, Other, Advisory role. M. A. Sendur, MSD ), Other, consultant. Roche ), Other, consultant. AstraZeneca ), Other, consultant. Pfizer ), Other, consultant. Novartis ), Other, consultant. Astellas ), Other, consultant. BMS ), Other, consultant. Eli Lilly ), Other, consultant. Gilead ), Other, consultant. Takeda ), Other, consultant. Janssen Other, consultant. R. Dziadziuszko, MSD ), Other, Advisory Board. Roche Other, Advisory Board. AstraZeneca Other, Advisory Board. Pfizer Other, Advisory Board. Novartis Other, Advisory Board. BMS Other, Advisory Board. Amgen Other, Advisory Board. J. Park, MSD ). Servier Other, Advisory Board. MediRama Other, Advisory Board. Adicet Bio Other, Advisory Board. AstraZeneca Other, Advisory Board. Merck Serono Other, Advisory Board. ImmuneOncia Other, Advisory Board. Arcus biosciences Other, Advisory Board. Servier Travel. BMS/Celgene Travel. V. Moreno Garcia, MSD ). BMS Other, Advisory Board. Janssen Other, Advisory Board. Roche Other, Advisory Board. Basilea Other, Advisory Board. Bayer Other, Advisory Board. AstraZeneca Other, Advisory Board. START Employment. Abbvie ). AceaBio ). Adaptimmune ). ADC Therapeutics ). Boehringer ). Boston ). Celgene ). Daichii Sankyo, Tesaro, Transgene, Turning Point Therapeutics, Upshersmith ). Debiopharm, Regeneron, Rigontec, Roche, Sanofi, Sierra Oncol, Synthon, Taiho, Takeda ). Eisai, Nektar, Novartis, Odonate Ther, PFizer, Pharma Mar, Principia, PsiOxus, Puma ). e-Therapeutics, Exelisis, Forma Ther, Genmab, GSK, Harpoon, Hutchinson ). Immutep, Incyte, Inovio, Iovance, Janssen, Kyowa Kirin, Lilly, Loxo, MedSir, Menarini, Merus, Millennium, Nanobiotix ). J. Bar, MSD ), Other, Advisory Role. Abbvie ), Other, Advisory Role. Amgen Other, Advisory Role. AstraZeneca ), Other, Advisory Role. Bayer Other, Advisory Role. Beigene Other, Advisory Role. Janssen Other, Advisory Role. Merck Serono Other, Advisory Role. Medison Other, Advisory Role, Speaker/Writing engagement. Roche ), Other, Advisory Role. Takeda Other, Advisory Role. BMS Other, Speaker/Writing engagement. Pfizer Other, Speaker/Writing engagement. Immunai ). OncoHost ). Y. Fan, MSD ). M. Erman, MSD ). S. Lu, MSD ). J. H. Lee, MSD ), Other, Advisory Board, Speaker. AstraZeneca Other, Speaker. Pfizer Other, Conference support. Novartis Other, Conference support. Gilead ). Merus ). Exelixis ). R. Juergens, Merck & Co., Inc., Rahway, NJ, USA ). B. Cao, MSD ). C. Chen, Merck & Co., Inc., Rahway, NJ, USA Employment, Stock, Stock Option. R. Cristescu, Merck & Co., Inc.., Rahway, NJ, USA Employment, Stock, Stock Option. T. Jemielita, Merck & Co., Inc., Rahway, NJ, USA Employment, Stock, Stock Option. Y. S. Choi, Merck & Co., Inc., Rahway, NJ, USA Employment, Stock, Stock Option. M. D. Ayers, Merck & Co., Inc., Rahway, NJ, USA Employment, Stock, Stock Option. I. Lugowska, MSD ), Other, medical writing support. Agenus ). Roche ), Other, consultant. European Society of Medical Oncology Other, consultant. BMS Other, consultant. Janssen Other, consultant. AstraZeneca Other, consultant. Amgen Other, consultant. RyVu Other, consultant. Incyte Other, consultant. Siropa Other, consultant. Mennarini Other, consultant. Celon Other, consultant. Pfizer Other, consultant. Rhizen Other, consultant. Morgan Stanley Capital International (MSCI) Other, consultant. Organization of European Cancer Institutes (OECI) Other, consultant. Clininote Other, consultant.
Cited in
Control: 1433 · Presentation Id: 9717 · Meeting 21436