Investors are returning to Ark Therapeutics after the firm asked regulators in Europe to take another look at its recently-rejected brain cancer drug Cerepro.

Just before Christmas, Ark’s stock halved in value after it emerged that the European Committee for Medicinal Products for Human Use advised the European Medicines Agency to reject the gene-based therapy for operable malignant glioma at this time, on fears over treatment bias. However the firm’s shares have risen again after it filed a formal request to the EMEA for re-examination of its marketing authorisation application for Cerepro

The rationale to adopt a negative decision was based on the CHMP’s concerns that some patients given the drug in late-stage trials may, for whatever reason, have been made to wait longer before receiving re-intervention from doctors than those who were not, leaving them at a greater risk of their cancer progressing. “As time to re-intervention is the main efficacy measure in the primary endpoint, the assessors determined that they could not recommend approval based on the data presented by Ark so far,” the company explained at the time.

Now chief executive Nigel Parker says that “in the last two weeks we have assessed the full range of evidence from the Phase III study”. As such, “We are confident that we have the necessary data to address the main underlying objection concerning the re-intervention decision in the Cerepro trial”, he added.

Mr Parker went on to say that “Ark has successfully pioneered the adenovirus platform to an approvable standard and we are now dealing with a final clinical issue, through the standard EMEA regulatory process”. He concluded by saying that “The body of evidence is substantial and robust and we are thus comfortable to file for re-examination.

The company expects to receive a final decision from the EMEA early in the second quarter of this year.