Eiger writes off ubenimex in PAH after total flop in phase 2

Eiger BioPharmaceuticals is ready to stop development of ubenimex in pulmonary arterial hypertension (PAH). The biotech indicated ubenimex is for the chop in PAH after a phase 2 trial in the indication failed to find a hint of efficacy. 

Investigators enrolled 61 PAH patients in the trial and randomized them to receive either ubenimex, a dual-inhibitor of aminopeptidase and leukotriene A4 hydrolase, or placebo for 24 weeks.

Ubenimex failed to improve pulmonary vascular resistance, resulting in the trial missing its primary endpoint. The drug also failed to drive improvements in the six-minute walk test, a key secondary endpoint. And, to complete the inventory of failures, the poor performance of ubenimex was seen in both the overall population and key subgroups.

Eiger is still analyzing biomarkers and other aspects of the data. But its release to disclose the data is free from the straw-clutching statements made by some of its peers. As it stands, Eiger will scrap development of ubenimex in PAH.

The PAH setback won’t derail ubenimex completely, though. Eiger is also trialling the drug in patients with lymphedema of the lower limb, a use case it thinks is backed up by mechanistic evidence. Data from a phase 2 trial that could validate Eiger’s belief in the mechanism are due in the second half of 2018.

Eiger has other data drops coming up, too, and crucially its financial runway extends out beyond some of its upcoming milestones. The biotech raised $19.5 million last year to secure its financial future through to the middle of 2019.

The upshot is that, while its margin for error is shrinking, Eiger has a crack at weathering the PAH failure.

“Eiger has a deep pipeline of products focused on rare diseases that was built to reduce risk against a single binary event,” Eiger CEO David Cory said in a statement.

Analysts at Jefferies said in a note to clients this morning: “While the phase 2 LIBERTY failure is disappointing, we note that HDV and PBH programs are more de-risked with clinical data in these settings and near-term catalysts.

“We would buy, especially into weakness, and continue to view EIGR as a compelling 2018 story with 1) Feb 2018 EOP2 meeting for HDV, which should help de-risk path to registration; 2) 3Q18 data for exendin 9-39 in PBH; and 3) 3Q18 data for ubenimex in lymphedema. With multiple shots on goal, we view EIGR as diversified/robust enough to overcome PAH failure.”

The biotech was down around 43% midmorning on the news.