Cemiplimab for cutaneous squamous cell carcinoma: no suitable data due to the short duration of follow-up

Cemiplimab is approved for several therapeutic indications. In a benefit assessment, the Institute for Quality and Efficiency in Health Care (IQWiG) investigated whether cemiplimab as monotherapy for the adjuvant treatment of adults with cutaneous squamous cell carcinoma at high risk of recurrence after surgery and radiation offers advantages over the current standard of care; here: watchful waiting. Squamous cell carcinoma is one of the most common malignant skin tumours and accounts for around a quarter of non-melanoma skin cancers.

The study data submitted to the IQWiG by the manufacturer reveal a key problem: The follow-up period of the C-POST study does not adequately cover the high-risk period for the occurrence of a recurrence. However, a follow-up period of at least two years is required. This should also extend beyond the end of treatment to ensure that, once treatment has been discontinued, recurrences are actually prevented rather than merely delayed. The manufacturer did not take this into account; in fact, during the study, it even decided to analyse the data earlier than originally planned. As follow-up was far too short for some of the patients, meaningful interpretation of the data is not possible. It is therefore not possible to carry out an overall assessment of the positive and negative effects of cemiplimab compared with the appropriate comparator therapy across all outcomes – an added benefit is thus not proven.

Volker Vervölgyi, Head of the Oncology Division in IQWiG’s Drug Assessment Department, emphasises: ‘The European Medicines Agency had already criticized the manufacturer’s observation period as being far too short at the time of the marketing authorization and advised it to extend it.’ The manufacturer has decided against this, so we can only reiterate the EMA’s criticism here."