Zynyz: Withdrawal of the marketing authorisation application

Zynyz was developed as a medicine to treat adults with squamous carcinoma of the anal canal that had spread beyond the original site. It was intended for use when the cancer had got worse during treatment with platinum-based cancer medicines or when this treatment was not suitable.

Zynyz contains the active substance retifanlimab and was to be available as a concentrate to be made up into a solution for infusion (drip) into a vein.

Retifanlimab was designated an ‘orphan medicine’ (a medicine used in rare diseases) on 19 October 2020 for the treatment of anal cancer.

The active substance in Zynyz, retifanlimab, is a monoclonal antibody. This is a protein that has been designed to block a target called PD-1 found on certain cells of the immune system (the body’s natural defences). Some cancers can make a protein that attaches to PD-1 and switches off the immune cells’ ability to attack the cancer. By blocking PD-1, retifanlimab was expected to stop the cancer switching off these immune cells, thereby increasing the immune system’s ability to kill the cancer cells.

The company presented results from a main study involving 94 previously treated patients with squamous carcinoma of the anal canal that had spread beyond the original site and whose cancer had got worse on platinum-based therapy or who could not be given this treatment. The main measure of effectiveness was the number of patients who responded to treatment. The study did not compare Zynyz with any other cancer medicine.

The application was withdrawn after the European Medicines Agency had evaluated the initial information from the company and had prepared questions for the company. The company had not responded to the questions at the time of the withdrawal.

Based on the review of the data, at the time of the withdrawal, the Agency had major concerns and its provisional opinion was that Zynyz could not have been authorised for the treatment of squamous carcinoma of the anal canal.

In terms of the main study, the Agency considered that it was not clear whether the number and duration of the responses seen in the study would lead to meaningful benefits for patients such as improvement in survival or living longer without the disease getting worse.

In addition, the Agency noted that the wording of the indication proposed for Zynyz might allow use in previously untreated patients who cannot be given platinum-based therapy, while this group of people was not represented in the study.

Therefore, at the time of the withdrawal, the Agency’s opinion was that the company had not provided enough data to support the application for conditional marketing authorisation of Zynyz.

In its letter notifying the Agency of the withdrawal of the application, the company stated that they were not able to satisfactorily address the Agency’s concerns at this time.

The company informed the Agency that there are no consequences for patients in clinical trials using Zynyz.

If you are in a clinical trial and need more information about your treatment, speak with your clinical trial doctor.