Onzeald

Onzeald is a cancer medicine that contains the active substance etirinotecan pegol. It was to be available as a powder to be made into a solution for infusion (drip) into a vein.

Onzeald was expected to be used to treat adults with advanced breast cancer that had spread to the brain and other parts of the body and who have already received other treatments.

The active substance in Onzeald, etirinotecan pegol, consists of irinotecan (a cancer medicine that belongs to the group ‘topoisomerase inhibitors’) that has been ‘pegylated’ (attached to a chemical called polyethylene glycol). Irinotecan blocks topoisomerase I, an enzyme that is involved in copying cell DNA, which is needed to make new cells. By blocking the enzyme, cancer cells are prevented from multiplying and they eventually die.

Irinotecan has been authorised in the EU for a number of years for the treatment of colorectal cancer. Because it is pegylated in etirinotecan pegol, the medicine is removed from the body at a slower rate, allowing the medicine to be given less often.

The company presented the results of one main study involving 852 patients with breast cancer that had spread to other parts of the body who had been treated with at least 2 other cancer medicines. In this study, Onzeald was compared with standard cancer medicines chosen by the treating doctor, and the main measure of effectiveness was overall survival (how long the patients lived).

The CHMP considered that the benefit of Onzeald in the treatment of advanced breast cancer that had spread to the brain and other parts of the body had not been sufficiently demonstrated. The claim of effectiveness relied on data from a subgroup of patients from a main study which, overall, failed to convincingly show the effectiveness of Onzeald. The Committee considered that the data from this subgroup, which were not supported by additional studies, were not sufficient to prove the effectiveness of Onzeald, even when analysed by different methods.

Therefore, the CHMP was of the opinion that the study did not provide enough evidence on the benefits of Onzeald and recommended that the marketing authorisation be refused. The CHMP refusal was confirmed after re-examination.

The company informed the CHMP that patients receiving the medicine in clinical trials will continue to do so as planned. If you are in a clinical trial and need more information about your treatment, contact the doctor who is giving it to you.