Mesothelioma Therapy Could Lead to Painful Skin Condition

French researchers say that an adverse effect of the skin associated with pemetrexed (Alimta), the only FDA-approved drug for the treatment of malignant mesothelioma, “must be recognized” due to its potential severity.

The antifolate pemetrexed is approved in combination with cisplatin (another chemotherapy cancer drug). It works by blocking enzymes believed to play a role in the development of mesothelioma tumors, which affect the inside lining of the chest cavity and grow rapidly.

Alimta obtained FDA approval because in clinical trials, MPM patients who were treated with a combination of pemetrexed and cisplatin had a median survival that was roughly three months longer compared to patients treated with just cisplatin.

Rash is among the most common side effects of Alimta, according to the FDA. French researchers, however, have encountered a severe cutaneous side effect associated with pemetrexed that they believe is previously undocumented.

In an article published in Annales de Dermatologie et de Vénéréologie researchers from Perigueux Hospital in Perigueux, France describe two cancer patients taking pemetrexed-cisplatin who developed a severe skin problem in the lower extremities.

Patient one, a 66 year old man, developed painful redness and swelling first in one leg and then in both legs. Patient two, a 70-year old female, presented similar symptoms beginning with her first course of pemetrexed, but symptoms worsened with a second course to the point where the patient had difficulty walking. Both patients showed gradual improvement when pemetrexed therapy was halted.

“This cutaneous adverse effect is unrecognized, resulting in delayed diagnosis,” write the study authors, adding that the problem is often initially confused with a type of bacterial skin infection.

Previous studies indicate that the cutaneous toxicity of pemetrexed is associated with a patient’s folate status, and thus the researchers state that the use of folate and vitamin B12, along with a corticosteroid, could decrease the incidence of the severe skin side effect.

Both the FDA and its European equivalent, the European Medicines agency, recommend that Alimta patients should take folic acid and vitamin B12 during treatment. This would seem to suggest that the patients described by the French researchers were not following this recommendation.

Nevertheless, their study Pemetrexed-induced scleroderma-like changes in the lower legs provides a warning for mesothelioma patients and their doctors about a potentially serious Alimta side effect.

Alimta is a treatment option for MPM patients for whom surgery is not an option. Mesothelioma is diagnosed in about 3,000 U.S. patients each year and associated with asbestos exposure. There is no known cure for mesothelioma, and while mesothelioma drug clinical trials—including the COMMAND Study—are ongoing, pemetrexed is the only cancer drug currently approved to specifically treat malignant mesothelioma.

Know more about mesothelioma and how you can deal with it.