There is no clear evidence supporting the benefits of second-line active treatments for patients with malignant pleural mesothelioma (MPM) whose first line of treatment failed. This is according to an opinion piece published in JAMA Oncology by cancer specialists in Bristol, England, and Turin, Italy.
According to the authors of the article, “Is There Room for Second-Line Treatment of Pleural Malignant Mesothelioma?” clinical research is vital, and well-designed clinical trials are strongly needed to better treat MPM patients.
The expected course of progression of MPM is usually bad, and although some early case studies have shown that additional chemotherapy after the failure of the first-line treatment can be beneficial in some patients, doctors do not agree on the benefits of such second-line treatments.
There is some weak evidence suggesting that treating MPM patients with second-line chemotherapy agents may be beneficial. However, clinical trials testing this approach were usually small scale, had a selection bias, and were heterogeneous in terms of drug administration. The results obtained from such trials were mediocre and, according to the authors, their external validity cannot be considered useful for clinical practice.
Interestingly, the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology seems to support the use of second-line chemotherapy options, including the chemotherapy drugs Alimta (pemetrexed), if it’s not administered as a first-line therapy; Navelbine (vinorelbine); or Gemzar (gemcitabine). The European Society of Medical Oncology, however, recommends that patients who are in good clinical condition at disease progression after first-line treatment should be enrolled in clinical trials.
According to Dr. Alfredo Addeo at the Bristol Cancer Centre and the co-authors of the article, “patients should be encouraged to participate in trials, but clinical trials should be better designed.”
They suggest that the trials should be randomized, and include a control arm. They also suggest that patients enrolled in the trials should be well balanced according to their existing prognostic scores (or estimated course of the disease) and should be classified based on the duration of disease control obtained with first-line treatment.
They conclude by noting a clinical trial currently testing immunotherapy as a second-line treatment, (NCT02588131), but warn it does not have the proposed features.