Dive Brief:
- Neurotrope has followed up its modestly positive topline Phase 2 results, with the full data from the completed study presented at the Alzheimer's Association International Conference 2017 in London.
- While the data showed improvements in the primary cognitive endpoint, the Severe Impairment Battery (SIB), for 20 µg bryostatin-1 from week 5, these were only statistically significant in the modified intent-to-treat group at week 5 (p=0.056), or in the completer group at week 5 and week 13 (p=0.016 and p=0.07). The improvement for the 20 µg dose in the secondary functional endpoint, the ADCS-ADL-SIV (Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory Severe Impairment Version), was only seen at week 13.
- The dropout rate was high, with over a third of the 40 µg dose patients out of the study by week 13; perhaps unsurprising as there was no "therapeutic signal" at this dose, and 13% of patients experienced a serious adverse effect, compared with 2% at the lower dose.
Dive Insight:
The costs and numbers are spiraling for Alzheimer's disease. According to the Alzheimer's Association, numbers of patients could reach 13.5 million in the U.S. alone by 2050, with healthcare costs climbing to $1.1 trillion. However, developing a drug for such an astoundingly large market has proven difficult, with approach after approach hitting the buffers. However, at the moment, it doesn't look like Neurotrope has the drug that will turn things around.
Neurotrope's stock tanked by almost 63% last time it announced this Phase 2 data, and it hasn't done much better this time, closing almost 24% down at $5.80, and dipping to $5.56 at one point, pretty nearly the lowest point in the last year.
Suzanne Hendrix, of Pentara Corporation, a leading expert in statistical analysis of Alzheimer's disease clinical trial results, tried to put a positive spin on the results, but it still didn't sound like a celebration. "Although the study was not powered for statistical significance at a = 0.05, the clinical effects in the 20 µg group compared to placebo were consistent in magnitude for cognition and function, and hold up under multiple sensitivity analyses," she said.
This is the first placebo-controlled trial of a protein kinase C epsilon activator in Alzheimer's disease, and is a new mechanism of action compared with many other Alzheimer's disease drugs in development. Additional studies planned include optimal dose and regimen; a larger efficacy study; longer assessment of treatment duration; and a study looking at earlier stage disease. The company also wants to look at biomarkers, and at other routes of administration.
"The persistent improvement seen in the 20 µg group versus the outcomes seen in the 40 µg treatment arm help define an optimal dosing range to potentially sustain clinical benefit with minimal side effects," said Daniel Alkon, president and CSO. "We are well positioned to move forward with our clinical development program."