FDA approves nivolumab and ipilimumab for unresectable malignant pleural mesothelioma

Summary: The Food and Drug Administration (FDA) has approved the combination of nivolumab (Opdivo) and ipilimumab (Yervoy) as first-line treatment for adult patients with unresectable malignant pleural mesothelioma, a type of lung cancer caused by exposure to asbestos. These two drugs are “immunotherapies”, which means that they enhance the ability of the patient’s own immune system to recognize and kill cancer cells.

Dr. Dan’s Takeaway: The approval of this drug combination represents an important step in the treatment of pleural mesothelioma, as it immediately becomes the new standard of care for the non-epitheloid subtype of the disease (see below). On average, patients survived for four months longer on the combination as opposed to standard chemotherapy (18.1 months vs. 14.1 months), but patients with non-epitheloid mesothelioma survived for almost 8 months longer (16.5 months vs. 8.8 months). Side effects occurred at similar rates in the two groups, but the rate of discontinuation of immunotherapy due to severe side effects was higher (15% vs. 7%).

What do you mean by ‘non-epitheloid’ mesothelioma?

Mesothelioma can be classified into three distinct types based on the way the cancer cells look under a microscope: epithelial, sarcomatoid, and biphasic (mix of epithelial and sarcomatoid). It is important to know the cell type because epithelial mesothelioma responds better to standard chemotherapy, while non-epitheloid is more resistant to chemo and has a worse prognosis. The approval of Opdivo + Yervoy suggests a new approach to mesothelioma treatment based on cell type:

Epithelial mesothelioma = Standard chemo (pemetrexed + Cisplatin or carboplatin) followed by immunotherapy (Opdivo + Yervoy) if no response

Sarcomatoid mesothelioma = Immunotherapy (Opdivo + Yervoy)

Biphasic (both types of cell) = Immunotherapy and/or chemo depending on the ratio of the two cell types (for instance: a cancer that is 75% sarcomatoid and 25% epithelial would likely be treated with immunotherapy first to kill the sarcomatoid type than chemo second to kill the epithelial cells)



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Chief Medical Officer