Development partners at MEI, Helsinn dump a high-risk PhIII AML study after concluding it would fail survival goal
Four years after Switzerland’s Helsinn put $25 million of cash on the table for an upfront and near-term milestone to take MEI Pharma’s drug pracinostat into a long-running Phase III trial for acute myeloid leukemia, the partners are walking away from a clinical pileup.
The drug — an HDAC inhibitor — failed to pass muster during a futility analysis, as researchers concluded that pracinostat combined with azacitidine wasn’t going to outperform the control group in the pivotal.
In a short statement, the partners said they planned to continue other studies involving pracinostat following a further review. There were no safety concerns, according to the companies.
Helsinn had offered up to $439 million in additional milestones on their deal, as the 2 companies also pursued a program for high or very high-risk myelodysplastic syndromes. That’s now in Phase II.
“Quite a few observers wouldn’t give the MEI/Helsinn partnership good odds on this,” I noted back in 2016. Mini-biotechs like MEI rarely do well in oncology.
But the FDA issued a breakthrough drug designation and CEO Dan Gold touted a successful, single-arm Phase II study. MEI had noted at the time that the drug achieved a median overall survival rate of 19.2 months and a 42% complete response rate (21 out of 50 patients) in the single arm study, which Gold compared to the successful 10.4-month survival rate and 19.5% CR rate Celgene saw with Vidaza (azacitidine, or AZA-AML-001, in a pivotal study with 488 patients).
MEI saw its stock start to take off in early March, after shares had dropped perilously close to the $1 mark. And in the past few months the stock more than quadrupled in value, helped along by a $100 million upfront deal with Kyowa Kirin on a PI3Kδ drug.
The stock took a 16% hit ahead of the bell on Thursday.