According to an industry report today, AbbVie has called a halt to the Phase 2 trial of its anti-tau antibody ABBV-8E12 for progressive supranuclear palsy after it failed a futility analysis. AbbVie announced the termination during a quarterly earnings call. No other details were immediately available.
"While I and others were hopeful about the PSP trial, individuals in this and other PSP trials are already at a relatively advanced stage of clinical disease by the time they are diagnosed and able to enter these trials, so I am not overly surprised there was not a clear benefit," David Holtzman of Washington University, St. Louis, wrote to Alzforum.
According to David Freundel, a public affairs director at Abbvie, this is also the end for two extension studies evaluating ABBV-8E12 in patients with PSP. Ditto for Abbvie's pre-approval access program (PAA) to this antibody for primary tauopathies. "AbbVie recommends that patients in the ABBV-8E12 PSP studies, and the ABBV-8E12 PAA for primary tauopathies currently on treatment with ABBV-8E12, speak with their physician about the appropriate next steps regarding their treatment," Freundel wrote to Alzforum.
The antibody is also in a Phase 2 trial of 400 people with MCI and early dementia due to Alzheimer’s disease. This trial is continuing without changes. "I think prospects for AD are still good, as the stage of tauopathy in the AD trial is relatively early," Holtzman noted.
Different types of tau fibrils characterize PSP and AD, with the former containing only four-repeat (4R) tau, and the latter a mix of 3R and 4R tau.
ABBV-8E12 and some other anti-tau antibodies currently in trials, including Biogen’s BIIB092, target the N-terminus of tau. These antibodies have high affinity, though some reports indicate that they do not block propagation of misfolded tau in cellular assays. Antibodies against tau’s mid-region, which are in development at several companies, performed better in these assays (Apr 2018 conference news).
Biogen’s shares fell after news of the AbbVie trial termination, but recovered by end of day.—Madolyn Bowman Rogers