I just presented the results of the randomised phase II trial MAPS-2 in patients with malignant pleural mesothelioma treated as second or third line treatment, so people escaping the standard first line of treatment by chemotherapy, pemetrexed-based chemotherapy. These patients are really a big problem because we don’t have any treatment to propose so far to these patients and they are really a poor outcome, usually with a median overall survival close to six months and a disease control rate of about 30% or less with the usual treatment.
We were able to show that giving nivolumab or nivolumab plus ipilimumab we increased the first endpoint of the trial, so the disease control rate, at twelve weeks of treatment up to 44% with nivolumab and 50% with nivo plus ipi as well as a response rate increase of up to 8% with nivo and 26% with nivo plus ipi. More importantly this was translated in [?? 1:00] in a benefit of survival because the median overall survival with nivolumab was 10.4 months and with nivo plus ipi we still have more than half the patients still alive so the median overall survival was not reached so far with the nivo plus ipi.
On the safety issue the treatment was well tolerated with only mostly non-severe adverse events even if we had, as expected, slightly more severe adverse events in the combo arms. We had three potential drug-related adverse events in the nivo plus ipi arm.
Can I just ask how large the population is you’re working with again?
We were able to recruit 125 patients, so half with nivo, half with nivo plus ipi.
Three deaths out of 65 is still a significant number of deaths.
Yes, sure, but you have to remember that these patients are old patients, they are in their 70s with comorbidities. The second thing is that there was no treatment so far for these patients so any treatment will be very important and we are very happy to have such a result with checkpoint inhibitors because mesothelioma could be considered not like lung cancer or melanoma, like a cold tumour because you have a low expression of PD-L1, low infiltration of T-cells in the tumour. So it was really not expected to have such a nice result with checkpoint inhibitors in mesothelioma and in routine, as a clinician, for my patients a real new hope of treatment for them.
You mentioned that this was nivo or nivo and ipi, were there any trials of just using anti-CTLA-4 for this?
We know that from a previous trial that anti-CTLA-4 does not work by itself alone. The question is now should we use nivo alone or nivo plus ipilimumab. We don’t have the answer yet because we need more data, for example quality of life and survival, with a longer follow-up. We do now as well as the biomarker studies so perhaps it may help us to select better the candidates for nivo alone or nivo plus ipi.