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Questions & Answers

On 20 July 2017, the Committee for Medicinal Products for Human Use (CHMP) adopted a negative opinion, recommending the refusal of the marketing authorisation for the medicinal product Onzeald, intended for the treatment of advanced breast cancer that has spread to the brain. The company that applied for authorisation is Nektar Therapeutics UK Limited.

The company requested a re-examination of the initial opinion. After considering the grounds for this request, the CHMP re-examined the opinion, and confirmed the refusal of the marketing authorisation on 9 November 2017.

What is 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.

What was Onzeald expected to be used for?

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.

How does Onzeald work?

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.

What did the company present to support its application?

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).

What were the CHMP’s main concerns that led to the refusal?

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.

What consequences does this refusal have for patients in clinical trials?

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.

Name Language First published Last updated
Questions and answers on the refusal of the marketing authorisation for Onzeald (etirinotecan pegol) (English only) 2017-07-21 2017-11-10

Key facts

Product details for Onzeald
INN or common name

etirinotecan pegol

Therapeutic area Breast Neoplasms
Active substance

etirinotecan pegol

Date opinion adopted09/11/2017
Company name

Nektar Therapeutics UK Limited

Application typeInitial authorisation