Inhibition of WEE1 Is Effective in TP53 - and RAS -Mutant Metastatic Colorectal Cancer: A Randomized Trial (FOCUS4-C) Comparing Adavosertib (AZD1775) With Active Monitoring.

Purpose: Outcomes in RAS -mutant metastatic colorectal cancer (mCRC) remain poor and patients have limited therapeutic options. Adavosertib is the first small-molecule inhibitor of WEE1 kinase. We hypothesized that aberrations in DNA replication seen in mCRC with both RAS and TP53 mutations would sensitize tumors to WEE1 inhibition.
Methods: Patients with newly diagnosed mCRC were registered into FOCUS4 and tested for TP53 and RAS mutations. Those with both mutations who were stable or responding after 16 weeks of chemotherapy were randomly assigned 2:1 between adavosertib and active monitoring (AM). Adavosertib (250 mg or 300 mg) was taken orally once on days 1-5 and days 8-12 of a 3-week cycle. The primary outcome was progression-free survival (PFS), with a target hazard ratio (HR) of 0.5 and 80% power with a one-sided 0.025 significance level.
Results: FOCUS4-C was conducted between April 2017 and Mar 2020 during which time 718 patients were registered; 247 (34%) were RAS/TP53 -mutant. Sixty-nine patients were randomly assigned from 25 UK hospitals (adavosertib = 44; AM = 25). Adavosertib was associated with a PFS improvement over AM (median 3.61 v 1.87 months; HR = 0.35; 95% CI, 0.18 to 0.68; P = .0022). Overall survival (OS) was not improved with adavosertib versus AM (median 14.0 v 12.8 months; HR = 0.92; 95% CI, 0.44 to 1.94; P = .93). In prespecified subgroup analysis, adavosertib activity was greater in left-sided tumors (HR = 0.24; 95% CI, 0.11 to 0.51), versus right-sided (HR = 1.02; 95% CI, 0.41 to 2.56; interaction P = .043). Adavosertib was well-tolerated; grade 3 toxicities were diarrhea (9%), nausea (5%), and neutropenia (7%).
Conclusion: In this phase II randomized trial, adavosertib improved PFS compared with AM and demonstrates potential as a well-tolerated therapy for RAS/TP53 -mutant mCRC. Further testing is required in this sizable population of unmet need.
Competing Interests: Jenny F. SeligmannHonoraria: Pierre Fabre, Merck Serono, ServierConsulting or Advisory Role: Pierre Fabre, Roche Molecular DiagnosticsTravel, Accommodations, Expenses: Bristol Myers Squibb/Medarex Louise C. BrownResearch Funding: AstraZeneca Richard A. AdamsHonoraria: Merck Serono, Servier, AmgenConsulting or Advisory Role: Merck Serono, Amgen, Servier, BayerSpeakers' Bureau: Merck Serono, AstraZeneca, Merck Sharp & DohmeTravel, Accommodations, Expenses: Servier, Amgen, Merck Serono, AstraZeneca Janet GrahamHonoraria: Merck Serono, Bristol Myers Squibb, Nucana, BayerConsulting or Advisory Role: Merck KGaATravel, Accommodations, Expenses: Nucana Philip QuirkeHonoraria: RocheConsulting or Advisory Role: Roche, Adlai Nortye, Avacta Life Sciences, Amgen, BayerResearch Funding: Roche, GeneFirst, ONIPatents, Royalties, Other Intellectual Property: Roche has filed a patent jointly with my University; I may receive income but none to dateTravel, Accommodations, Expenses: Roche, Bayer, Amgen Rachel ButlerSpeakers' Bureau: Bayer, Pfizer, Roche, AstraZeneca, MSD, Illumina, Lilly, Novartis, Amgen, Boehringer Ingelheim Michael BraunHonoraria: Servier, Amgen, Pierre FabreTravel, Accommodations, Expenses: Servier Fiona CollinsonResearch Funding: Bristol Myers Squibb Rob JonesHonoraria: Astellas Pharma, Janssen, AstraZeneca, MSD Oncology, Bristol Myers Squibb, Pfizer, Novartis, Ipsen, Seattle Genetics, Sanofi, Bayer, Roche/Genentech, EUSA Pharma, Pharmacyclics, Clovis Oncology, Merck Serono, EisaiConsulting or Advisory Role: Clovis OncologyResearch Funding: Roche, Astellas Pharma, AstraZeneca, Pfizer, Novartis, Exelixis, Clovis Oncology, BayerTravel, Accommodations, Expenses: Ipsen, Bayer, Janssen, Astellas Pharma, MSD Ewan BrownResearch Funding: MSD Oncology Timothy C. HumphreyResearch Funding: Debiopharm Group Mahesh ParmarResearch Funding: AstraZeneca, Astellas Pharma, Janssen, Clovis Oncology Richard KaplanResearch Funding: AstraZeneca Richard WilsonHonoraria: Servier, Amgen, Bristol Myers SquibbConsulting or Advisory Role: Amgen, CV6 Therapeutics, Pierre Fabre, Amphista Therapeutics, NucanaTravel, Accommodations, Expenses: Amgen, Pierre Fabre Matthew SeymourResearch Funding: Amgen, AstraZeneca Timothy S. MaughanConsulting or Advisory Role: AstraZeneca, Vertex, Pierre FabreResearch Funding: AstraZeneca, PsiOxus Therapeutics, Merck KgAA, Almac DiagnosticsNo other potential conflicts of interest were reported.