Phase II Study Says Combining Agents Better Than One for Mesothelioma Treatment

Could the first immunotherapy for mesothelioma be on the horizon? Early results from an ongoing phase II clinical trial say yes. In the clinical trial known as MAPS-2, researchers showed that, when combined, a monoclonal antibody called Yervoy (ipilimumab) and the cancer medicine Opdivo (nivolumab) slowed the progression of malignant pleural mesothelioma (MPM) after relapse in 50% of patients who received the combination versus 44% who received Opdivo alone.

What this means is, the percentage of patients in which cancer either shrank or did not grow was 44% among the patients who received Opdivo only, and 50% among those who received the combined agents Opdivo and Yervoy. Note that the 12-week disease control rate (DCR) for all treatments previously tested in relapsed MPM was less than 30%.

The largest clinical trial of immune checkpoint inhibitors to date, MAPS-2 enrolled 125 patients with advanced MPM who had received up to two prior treatments, including standard platinum-based chemotherapy. Around 80% of the patients were male, with a median age of 72. Per the American Society of Clinical Oncology (ASCO), patients were randomly assigned to treatment with Opdivo alone or Opdivo with Yervoy “until the cancer worsened.” Seventy percent of patients received at least three cycles of either treatment.

Said ASCO, after a mean follow-up of 10.4 months, of the 125 patients, the median time until the cancer worsened (progression-free survival) was four months with Opdivo alone and 5.6 months with Opdivo and Yervoy. The median overall survival was 10.4 months in the Opdivo group and not reached in the Opdivo with Yervoy group, meaning that more than 50% were still alive at analysis. “Mature quality-of-life data are not yet available,” said ASCO.

When combining treatment options, potential side effects is always a concern. ASCO reported that side effects were “mild” overall, with the most common being skin rash, thyroid problems, and colon inflammation. However, “severe side effects were more common in the nivolumab (Opdivo) plus ipilimumab (Yervoy) group (18% vs. 10%), in which three treatment-related deaths occurred.”

Said lead study author Arnaud Scherpereel, MD, PhD, “mesothelioma cells build a protective tumor microenvironment to shield themselves against the immune system's attacks and even act against anti-tumor immune response, therefore, therapies that shift the tumor microenvironment from a state of immune suppression to one of immune activation may hold promise in MPM."

Fortunately, a number of ongoing clinical trials are exploring Opdivo and other immunotherapy as second- or third-line treatments for MPM. In addition, says ASCO, “several larger clinical trials investigating immune checkpoint inhibitors as initial therapy for MPM are already under way.” If you have been diagnosed with mesothelioma, innovative clinical trials such as MAPS-2 may help extend or even save your life.

If you would like to enroll in a clinical trial, talk to your doctor about options that might be available to you.

Sources

Scherpereel, Arnaud. "Early Research Suggests First Immunotherapy for Mesothelioma on the Horizon." ASCO. American Society of Clinical Oncology (ASCO), 05 June 2017. Web. 01 Aug. 2017.