The field is understandably desperate to improve outcomes in this high-risk population of HPV-negative HNSCC.
However, we also have to be cautious in interpreting phase II studies. This sub-100 patient trial led to a truly immense amount of additional work (and money) that ultimately led nowhere.
Sometimes, that will happen, despite the best intentions (as in this case). A few final thoughts:
1. Choose endpoints wisely, and make them meaningful for clinical inference and the follow-up trial. It is atypical to use alive with locoregional control (with a chi-squared test) as a primary endpoint, especially for a systemic drug with a variety of other activities (good or bad).
2. Power the study with sufficient numbers to ask the relevant question. It was quite small, with baseline imbalances in a critical clinical characteristics, with unfortunate, random deaths further compromising interpretation. Smaller trials are cheaper and faster (and the preference for efficiency is understandable), but they can lead to this exact scenario.
3. When transitioning from a phase II to III, don’t change the experimental arm unless there are real data supporting it. I doubt the addition of the 3 extra cycles did anything – the study was bound to be negative – but there was no reason to do it, and patients may have been hurt if it increased the metastatic potential of the tumor.
4. Ensure there are safety guardrails. The interim analysis was performed after 65% of total events. Many trials use 50%, and that would have saved time (and maybe patient enrollment) here. Given the small phase II study, the group should have looked at the results sooner, before enrolling 700 patients.
5. I deeply share the impatience with wanting to improve outcomes, but more caution is needed in interpreting phase II outcomes, especially when there are intrinsic limitations to the study itself.
6. It is an imperative to deploy more creative phase II (and phase III) designs to more quickly and accurately identify novel, successful therapies.