Paul Baas, MD, PhD

INVITED DISCUSSANT Paul Baas, MD, PhD, of The Netherlands Cancer Institute, called the MAPS2 trial an “excellent example of how studies in mesothelioma should be run.” 

As Dr. Baas pointed out, both arms performed well as second- and third-line treatment, with median progression-free survival with nivolumab (Opdivo) alone reaching 4 months and “becoming even better” at 5.6 months with nivolumab plus ipilimumab (Yervoy). The fact that median overall survival was not reached with the combination is “quite impressive from the point of view of what we have had in the past,” he commented. “And 13.6 months’ survival with nivolumab alone is also quite a good achievement.” 

According to Dr. Baas, toxicity was understandably higher with the combination, “but it did not translate into harmful toxicities such as colitis. He suggested that the three deaths in the combination arm may reflect the learning curve for managing toxicities; as with the evolution of the study, serious toxicities diminished. 

Better than Standard Therapies 

CERTAINLY, THE CHECKPOINT INHIBITORS have already proved they are better than standard therapies, he concluded. Pembrolizumab (Keytruda) has also been studied in relapsed mesothelioma, producing disease control rates of up to 80%. “I don’t think there’s a real difference between nivolumab and pembrolizumab,” said Dr. Baas. 

“We saw 4-month progression-free survival with nivolumab alone, whereas we see less than 2 months with vinorelbine or gemcitabine, the drugs we use often when faced with the hopeless situation of patients with recurrence,” he revealed. “That time is over. We must consider offering our patients the best treatment available.” ■

DISCLOSURE: Dr. Bass reported no conflicts of interest.