Abstract
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.
Original language | English |
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Pages (from-to) | 3705-3715 |
Number of pages | 11 |
Journal | Journal of Clinical Oncology |
Volume | 39 |
Issue number | 33 |
Early online date | 18 Sept 2021 |
DOIs | |
Publication status | Published - Nov 2021 |
Bibliographical note
Funding Information:FOCUS4-C was cofunded by the MRC/NIHR Efficacy and Mechanism Evaluation (EME) program and CRUK with funding commencing in April 2013. Drug supply and distribution of adavosertib and an educational grant were provided by AstraZeneca Ltd. The MRC Clinical Trials Unit at UCL receives core funding from the Medical Research Council within UKRI (Budget: MC_UU_12023/20).
Publisher Copyright:
© 2021 by American Society of Clinical Oncology
ASJC Scopus subject areas
- Oncology
- Cancer Research