- Biogen and Ionis Pharmaceuticals said Monday that one of their experimental drugs for Alzheimer's disease has shown early signs of being safe and effective.
- Results from the first part of a small, placebo-controlled study found the drug, known as BIIB080, to be safe and tolerable, with no serious adverse events seen among any patient who received it. Additionally, patients treated with BIIB080 had reductions in a protein called tau that's been linked to Alzheimer's.
- The study is testing three doses of the drug and researchers have observed dose-dependent decreases in tau levels, according to Biogen and Ionis. Two months after getting the last dose, the average reduction in tau was 30% for the low-dose group, 40% for the medium-dose group and 49% for the high-dose group, each of which were given BIIB080 every four weeks. Tau levels fell 42% among a group receiving a high dose once every 12 weeks.
The update on BIIB080 comes a little more than a month after Biogen suffered a major setback with a different tau-targeting agent.
In June, the company said its drug gosuranemab, which is meant to neutralize certain forms of tau, did not meet the main goal of a mid-stage study that enrolled Alzheimer's patients with mild cognitive impairment. Looking at measures of Alzheimer's progression, patients who received the drug didn't do any better than those given placebo, which led Biogen to halt its development.
Gosuranemab is part of a long list of Alzheimer's drugs to have failed in clinical testing. While some of them have targeted tau, the majority were designed to go after another prominent protein tied to Alzheimer's called amyloid beta. Only one of these drugs, Biogen's recently approved Aduhelm, has been cleared to slow the disease's progression. But whether Aduhelm benefits brain function remains unclear.
That same question lingers over experimental treatments, too, including BIIB080. But Biogen and Ionis executives said they're encouraged by the early data and the drug's seeming effect on tau levels. Unlike other Alzheimer's drugs in development, BIIB080 is what's known as an antisense oligonucleotide, meaning it's designed to block the cellular instructions used to make tau proteins.
"These study results support further investigation of BIIB080 for the treatment of Alzheimer’s disease and suggest that antisense-mediated suppression of tau protein may be a feasible therapeutic approach for other tauopathies," said C. Frank Bennett, chief scientific officer and franchise leader for neurological programs at Ionis, in a statement.
Biogen said the first part of the BIIB080 study is complete, while the second part is ongoing. Part two is an open-label, long-term extension study with a year of treatment followed by a four- or six-month post-treatment period.
Thus far, there have been no deaths, dose-limiting adverse events or discontinuations because of treatment with BIIB080, according to the companies.