Over the last two years, Alector has suffered three setbacks for its neurodegenerative disease pipeline, often forcing the company to downsize.
GSK and Alector are pulling the plug on a Phase 2 study in Alzheimer’s disease after their investigational drug, dubbed nivisnebart, showed no signs of significant efficacy. For Alector, this failure represents the third clinical setback in under two years.
Nivisnebart’s mid-stage miss “represents a third recent development failure from Alector’s first-generation antibody-based neurology platform,” Willaim Blair told investors in a Thursday note. Alector closed Thursday’s trading session down 3.77% at $2.30.
The companies were assessing nivisnebart in the mid-stage PROGRESS-AD trial, which focused on patients with early-stage Alzheimer’s. An independent data board found that continuing the study would be futile and that nivisnebart is unlikely to significantly slow disease progression versus placebo, according to a Wednesday news release.
GSK and Alector did not provide specific data in their press announcement but promised to do so at a future scientific conference. The partners will also work with investigators to inform study participants of the discontinuation and figure out the best next steps for them.
The companies linked up in July 2021 to advance two immuno-neurology assets, one of which was nivisnebart. GSK paid $700 million upfront for the agreement and promised milestone payments up to $1.5 billion. Much of this money, however, will remain unpaid. The second asset under this collaboration, a monoclonal antibody called latozinemab, has also been discontinued.
Latozinemab was being tested in the Phase 3 INFRONT-3 trial of patients with frontotemporal dementia linked to a progranulin gene mutation. Though specific data also remained undisclosed at the time, GSK and Alector announced in October 2025 that latozinemab failed to significantly slow disease progression versus placebo, the trial’s primary outcome.
Latozinemab also missed key secondary endpoints, including magnetic resonance imaging outcomes and fluid biomarker findings. The miss led Alector to downsize by 49%, leaving some 116 employees jobless, BioSpace estimated.
Almost a year earlier, in November 2024, Alector also reported a Phase 2 failure in Alzheimer’s disease. The biotech’s investigational antibody AL002, which it was developing with AbbVie, did not significantly slow clinical progression in patients. This stumble likewise triggered layoffs, with the first affecting 17% of the biotech’s staff and the second, which happened in March 2025, affecting 13%.
Despite this string of failures, William Blair analysts on Wednesday expressed optimism about Alector’s prospects. “We have been energized by Alector’s scientific rationale” for its new Alector Brain Carrier (ABC) platform, which allows candidates to penetrate the blood-brain barrier, they wrote. “We view the company’s next wave of assets . . . as having additional upside.”
On Wednesday, Alector indeed pledged to continue working on the ABC assets for neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease. These are all early-stage, however, with the most mature ones set for investigational new drug applications next year.
