Caveats to the study
A letter published in the Journal of Clinical Oncology raises questions about the generalizability of the FOCUS4-N results.
In the letter, Annika Kurreck, MD, and colleagues from Charity-University Medicine Berlin, Germany, highlighted that the trial only included patients without actionable biomarkers, which likely meant the study population had particularly aggressive disease. This possibility is supported by the “dramatically short” PFS reported in FOCUS4-N compared with prior maintenance versus surveillance investigations.
In addition, the letter writers caution that the study was underpowered to detect an overall survival benefit.
“Therefore, it might be hypothesized that FOCUS4-N comprised a cohort of patients with a rather aggressive tumor biology and/or high tumor load, leading to a quick failure of any de-escalation treatment strategy,” Dr. Kurreck and colleagues write.
In a response letter, Dr. Adams and his team countered that there’s no consistent evidence from past trials suggesting that patients with poorer prognostic features are unfit for surveillance. “We believe that it is a common misrepresentation of the evidence that all patients with worse prognostic features need to be maintained on active but toxic combination therapies for longer,” they said.
Instead of a blanket approach, maintenance versus surveillance should be “an assessment guided by the clinician listening to and guiding the patient rather than a molecular or biologically measurable parameter,” they write.
Dr. Adams and colleagues agreed that identifying subgroups of patients who are more likely to benefit from maintenance versus surveillance is required research, which “we plan to undertake.”
The work was funded by Cancer Research UK and the National Institute for Health Research. Many of the investigators had industry ties, including Dr. Adams, who reported various relationships with and payments from Merck, Amgen, and others. Dr. Kasi also had ties to several companies, including Bristol Myers Squibb, Lilly, and AstraZeneca. Dr. Kurreck and the other letter writers had numerous company ties as well, including relationships and payments from Roche, the maker of bevacizumab.
A version of this article first appeared on Medscape.com.