Alzheon is looking to tap public investors for $81 million to take a beta amyloid Alzheimer’s drug into phase 3. The Nasdaq IPO will equip Alzheon to take its reworking of a once-failed drug into a pivotal clinical trial in a subset of Alzheimer’s patients later this year.
Framingham, Massachusetts-based Alzheon is focused on the development of a molecule designed to inhibit the formation of the beta amyloid plaques that characterize Alzheimer’s and have been the focus of R&D in the field. When Alzheon acquired the rights to the program in 2013, it had been consigned to the scrapheap after failing in phase 3 and dragging then-owner Neurochem down with it.
Alzheon’s bid to rescue tramiprosate from the mountain of failed Alzheimer’s drugs is underpinned by a post-hoc analysis of how the drug fared in a genetic subgroup of patients in the previous clinical trial program. While the drug failed to move the needle in the overall population, Alzheon saw signs of efficacy in patients with two copies of the APOE4 gene. The mutation is associated with a higher risk of Alzheimer’s and greater burden of beta amyloid.
Restricting enrollment in the upcoming phase 3 to the 10% or so of Alzheimer’s patients who are APOE4/4 homozygous is one way that Alzheon thinks it can improve on the results generated by Neurochem. The other relates to the drug itself.
Having identified gastrointestinal metabolism as the likely cause of the patient-to-patient variability in pharmacokinetic performance seen in Neurochem’s trials, Alzheon developed an inactive prodrug form of tramiprosate, ALZ-801. The molecule is metabolized into tramiprosate after passing through the gut and into the liver. Phase 1 data suggest ALZ-801 has more consistent pharmacokinetics.
Rolling the dice on a phase 3 trial based on a post-hoc subgroup analysis has often ended badly for drug developers, particularly in Alzheimer’s. Alzheon’s attempt to buck the trend has garnered it an FDA breakthrough tag for ALZ-801 but the agency has indicated it will only lower the bar so far for the drug. Unless Alzheon’s first phase 3 demonstrates “robust and unquestionable” efficacy, the FDA will ask for a second study to substantiate the findings.