Mesothelioma patients may be disappointed to learn that a trial of a new mesothelioma drug, anetumab ravtansine, was stopped after the drug was proven to be less effective than an existing drug, vinorelbine. The results of Bayer’s Phase II clinical trial showed that the new drug designed to treat recurrent malignant mesothelioma did not slow progression of mesothelioma better than vinorelbine and therefore the trial did not meet its primary endpoint.
One of the reasons the outcome of this trial is so disappointing is because malignant pleural mesothelioma is a difficult disease to treat; patients rarely even respond to the maximum tolerable dose of chemotherapy. Mesothelioma chemotherapy is often an ineffective treatment because it destroys not only cancer cells but also normal, healthy cells. The new drug was designed to avoid this problem by targeting only tumor cells. Anetumab ravtansine is an antibody-drug conjugate which targets tumor cells and delivers a combination of cancer-fighting medication and an antibody that fights mesothelin, a protein that is overproduced by cancer cells.
The trial involved 248 patients with advanced or metastatic pleural mesothelioma whose tumors continued to grow despite having undergone chemotherapy. Some patients received a weekly dose of the existing drug, vinorelbine, while others received the new drug, anetumab ravtansine, once every three weeks. While it did not work as well as intended for mesothelioma, Bayer continues to test anetumab ravtansine in other types of cancer such as triple-negative breast cancer and small cell lung cancer.
A developer of the new drug expressed his discouragement with the performance of the drug, especially in light of its seemingly significant potential during early trials. The results of the study have not yet been released but the company is expected to do so soon. A future post will discuss the details of the study and its implications for those with malignant mesothelioma.
Source: Surviving Mesothelioma, “Antibody-Drug Conjugate Fails to Stop Recurrent Pleural Mesothelioma“, Alex Strauss, July 26, 2017