Endometrial Cancer Drug Fails in Late-Stage Clinical Trial

May 5, 2017 | by Sarah Hand, M.Sc.

Canadian biopharmaceutical company, Aeterna Zentaris, has announced that their investigational endometrial cancer drug failed to show a statistically significant increase in overall survival, compared to doxorubicin chemotherapy, in a recent late-stage clinical trial. The Phase III ZoptEC clinical trial tested the safety and efficacy of Zoptrex (zoptarelin doxorubicin) in female patients with recurrent or metastatic endometrial cancer.

“The median overall survival period for patients treated with Zoptrex was 10.9 months compared to 10.8 months for patients treated with doxorubicin,” said Dr. Richard Sachse, Aeterna Zentaris’ Chief Scientific Officer. “This is not a statistically significant, clinically meaningful increase in overall survival and thus the ZoptEC Phase III clinical study did not meet its primary endpoint.

“In addition, Zoptrex generally performed no better than the comparator drug with respect to the secondary efficacy endpoints,” continued Sachse. “For example, the median period of progression-free survival of the patients in the Zoptrex arm of the study was identical to that for patients in the doxorubicin arm. Finally, there was no meaningful difference between the two arms with respect to safety; the number of patients with cardiac disorders was similar – eight in the Zoptrex arm and nine in the doxorubicin arm. Therefore, the results of the study are not supportive to pursue regulatory approval.”

In all, 512 patients were enrolled in the ZoptEC clinical trial, and were randomly assigned to receive intravenous doses or Zoptrex and doxorubicin. Zoptrex combines the well-established chemotherapy agent, doxorubicin, with a synthetic peptide carrier designed to bind to the LHRH receptor and deliver targeted cytotoxic effects to cancer cells.

“We are very disappointed with the outcome of the ZoptEC Phase III clinical study,” said David A. Dodd, the President and Chief Executive Officer of Aeterna Zentaris. “Based on this outcome, we do not anticipate conducting clinical trials of Zoptrex with respect to any other indications.”

It’s estimated that over 60,000 new cases of endometrial cancer will be diagnosed in the US this year, according to the National Cancer Institute. Endometrial cancer is in the top 10 most common types of the disease in the US, and it has a five year survival rate of around 80 percent.

According to Dodd, the company will now shift their focus to the development of Macrilen (macimorelin acetate), an investigational drug designed to treat patients with adult human growth hormone deficiency. The company plans to file for FDA approval for the drug later this year, with the hope of launching the product in early 2018.