Biogen (NSDQ:BIIB) and Eisai yesterday released six months of detailed results from a clinical study of its BAN2401 experimental drug for treating Alzheimers, but criticisms quickly emerged casting doubt on the results and sending shares in both companies down.
Researchers working with Eisai and Biogen released trial results showing that high doses of the drug resulted in a statistically significant 30% reduction in the rate of decline when compared to the control group at 18 months, as defined by a custom set of measurements developed by the team.
Investigators also noted a 47% reduction in the rate of decline at 18 months as defined by a standard Alzheimer’s Disease Assessment Scale-cognitive subscale, or ADAS-Cog, according to a Biogen press release.
But critics, skeptical of the results, began to pick through the data and saw what they claimed as possible flaws with the design, according to an Endpoints report.
During a call with Biogen execs, questions arose about the decision by European regulators to move APOe4 carriers out of the high dose arm of the study due to a threat of brain swelling, which they are prone to, while keeping the same individuals in the control group, according to the report.
Carriers of APOe4 are at higher risk of the disease, and often experience a faster progression, according to the report. Critics suggested that moving them out of the high-dose arm, but keeping them in the control group, may have been done to help the high dose arm hit statistical significance, Endpoints reports.
Biogen chief medical officer Al Sandrock did not exclude the possibility that the move may have affected the results, and suggested that a subgroup analysis would be performed to examine the possibility, according to the report.
Shares in Biogen have fallen 9.5% so far today, at $347.42 a while shares of Esai have dropped 9.3%, at $91.75 as of 11:52 a.m. EDT.
Earlier this month, reports emerged that Biogen head Michel Vounatsos is considering entering the medical device market as a possible opportunity to differentiate the pharmaceutical player.