Annovis plans a 500-patient, U.S.-based open-label extension in Parkinson’s disease starting January 2026, dosing once-daily 30 mg buntanetap for 36 months. The study includes two cohorts: prior participants from earlier buntanetap trials and patients at least 12 months post–deep brain stimulation. Skin and plasma biomarkers will be collected alongside clinical measures, with the design positioned to capture treatment durability after interruption and response upon reintroduction.
The core development is an operational build aimed at long-term safety exposure and durability data rather than a new controlled efficacy readout. Annovis is using the OLE to close FDA exposure requirements — targeting roughly 1,500 total treated patients across its programs, including its ongoing pivotal Alzheimer’s study, with at least 100 treated for one year and 300–600 treated for six months at the final 30 mg dose. By integrating former trial participants and an underserved DBS population, the company is broadening the safety dataset and exploring buntanetap’s performance in real-world clinical complexity that is often excluded from pivotal designs.
Strategically, this is a pragmatic bridge move. The OLE gives Annovis a path to assemble the chronic-exposure safety package regulators expect for a long-term neurodegenerative treatment while avoiding the time and cost of another large randomized PD study in the near term. The inclusion of DBS patients signals an intent to characterize buntanetap as an adjunct across the spectrum of PD management. It also creates a narrative around disease modification by observing symptom trajectories off drug and post re-initiation, though such signals from open-label cohorts will be hypothesis-generating at best. The choice reflects a broader tension in neurodegeneration development: the need to satisfy safety and durability expectations without overextending on expensive, hard-to-execute placebo-controlled trials before a clear regulatory path is secured.
For sites, the 36-month horizon and biomarker collection will stress retention planning, visit cadence, and data completeness. Movement disorder centers with established DBS programs become pivotal, given the need to standardize assessments where stimulation settings can alter motor outcomes and confound longitudinal measures like MDS-UPDRS. CROs and vendors should anticipate sustained adherence monitoring, centralized rater calibration, and consistent biospecimen handling — particularly if skin-based biomarkers are used to support a disease-modifying claim. For regulators, the design yields breadth of safety exposure and external validity but limited inferential power on efficacy; any observed motor or cognitive benefits will require triangulation with controlled data. Patients gain continued access, but expectations should be calibrated around the exploratory nature of long-term, open-label findings.
The key watch items are operational and evidentiary. Retention at 12, 24, and 36 months will determine whether exposure targets are met on time. Clarity on endpoints, visit frequency, rater oversight, and handling of DBS-related confounding will indicate how decision-grade the dataset can become. The extent to which Alzheimer’s and PD safety exposures are pooled for NDA purposes will be scrutinized, as will consistency of safety signals across indications. Ultimately, the OLE can secure the chronic-treatment safety runway; what it cannot do is substitute for definitive, controlled PD efficacy. The program’s success will hinge on clean safety, manageable discontinuation rates, and whether the DBS cohort produces interpretable add-on data without diluting the signal.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
