CATEGORY: BRAIN & MENTAL HEALTH
Could one steady pill a day carry early Parkinson’s disease, before levodopa enters the picture? That was the question behind TEMPO-2, and the answer came back yes. Over 27 weeks, 304 adults in the first years of the disease took once-daily tavapadon or a placebo. The combined score of everyday function and movement symptoms improved by 10.3 points on the drug versus 1.2 on placebo, a 9.1-point difference, and 46% of those on tavapadon rated themselves much improved versus 19% on placebo.1 On September 28, the US Food and Drug Administration approved the drug, the first of its class to reach patients.
A Partial Press on a Different Pedal
Levodopa remains the most powerful Parkinson’s medicine, but years of it bring involuntary writhing movements for many, so doctors in early disease often reach for dopamine agonists first. The older agonists lean on the brain’s D2 and D3 receptors and carry baggage of their own, including sleep attacks and compulsive gambling or shopping. Tavapadon works the D1 and D5 receptors instead, and only partway. It’s like a foot resting steadily on a gas pedal at half throttle rather than stamping and lifting all day. The hope was cleaner symptom relief with less of that baggage.1
Dressing, Writing, Walking: What Actually Moved
The trial’s yardstick was a standard rating that adds a clinician’s movement exam to the patient’s own report on tasks like dressing, handwriting and speaking. A 9-point gap on it is a difference you’d notice across a kitchen table. Neither the patients nor the raters knew who had the real tablets; a computer had made the split at the start. The result didn’t come out of nowhere either. In the companion TEMPO-1 trial, 529 adults took fixed doses against placebo, and both doses beat it by roughly 11 to 12 points on the same yardstick.2
What It Costs, and What It Can’t Do
The drug’s main tax fell on the stomach and the head: nausea in 30%, headache in 17%, dizziness in 16%. Nearly a quarter of tavapadon patients quit during the dose-raising weeks, versus 4% on placebo, which says the ramp-up isn’t trivial. Compulsive-behavior problems were rare, about 1%. And the relief is symptomatic. Nothing in these trials shows the disease itself slowing down, a distinction that matters for anyone weighing a new prescription against the standbys.1
Key Takeaways
- In early Parkinson’s, once-daily tavapadon improved daily function and movement scores by about 9 points more than placebo over 27 weeks, and a second trial of 529 adults landed in the same range.
- Side effects clustered in the ramp-up period, when 24% stopped the drug, led by nausea, headache and dizziness.
- Tavapadon treats symptoms. Neither trial shows it slows the underlying disease.
References
- Fernandez HH, Bhatia P, Cloud L, et al. Safety, tolerability, and efficacy of flexible-dose tavapadon for Parkinson’s disease (TEMPO-2): a phase 3, randomised, placebo-controlled, double-blind trial. The Lancet Neurology. 2026;25(8):721–730. link
- Pahwa R, et al. Fixed-dose tavapadon for early Parkinson disease: a randomized clinical trial. JAMA Neurology. 2026;doi:10.1001/jamaneurol.2026.0590. link