On 9 December 2024, AbbVie announced positive topline results from its pivotal Phase III TEMPO-2 trial, evaluating tavapadon as a flexible-dose (5mg to 15mg, once daily) monotherapy in early Parkinson's disease (PD). Tavapadon, the first and only D1/D5 partial agonist in the dopamine agonist class, is under investigation as a once-daily treatment for PD.

The TEMPO-2 trial evaluated the efficacy, safety, and tolerability of flexible-dose tavapadon. The trial met its primary endpoint, as patients treated with tavapadon experienced a statistically significant improvement from baseline compared to placebo in the Movement Disorder Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Parts II and III combined score at week 26. Tavapadon also met the key secondary endpoint, demonstrating a statistically significant and clinically meaningful improvement in motor aspects of experiences of daily living (MDS-UPDRS Part II) in the tavapadon group compared to placebo at week 26. The safety profile of tavapadon was consistent with prior clinical trials, with the majority of adverse events reported as mild to moderate in severity.

The positive results align with sentiments shared by key opinion leaders (KOLs) interviewed by leading data and analytics company GlobalData, who expressed largely favourable opinions on tavapadon. KOLs frequently cited its promising efficacy data and unique position as a D1/D5 partial agonist. They also noted tavapadon’s versatility, highlighting its potential use for dyskinesia, as well as both monotherapy in early PD and adjunctive therapy in advanced PD. This builds on positive data from AbbVie’s Phase III adjunctive therapy trial, where patients treated with tavapadon adjunctive to levodopa experienced a clinically meaningful and statistically significant increase of 1.1 hours in total 'ON' time without troublesome dyskinesia compared to those treated with levodopa and placebo.

However, concerns remain regarding tavapadon’s market positioning. As a dopamine agonist, it will face significant competition within the PD treatment landscape. According to GlobalData’s Drugs Database, six dopamine agonists are currently marketed across the seven major pharmaceutical markets (the US, France, Germany, Italy, Spain, the UK, and Japan), many of which are available as generics. Additionally, two more dopamine agonists - AbbVie’s tavapadon and IRLAB Therapeutics' mesdopetam - are in late-stage development (Phases IIb-III). It is yet to be seen if the recent positive efficacy outcomes will be sufficient for AbbVie to differentiate tavapadon from other dopamine agonists already on the market. GlobalData expects tavapadon to enter the market in 2028. While its strong efficacy data is promising, its success will likely depend on its safety profile. KOLs noted that dopamine agonists are no longer preferred adjunctive therapies for PD due to side effects such as hallucinations, delusions, and compulsive behaviour. Nevertheless, tavapadon’s improved safety profile, alongside its efficacy data, may allow it to stand out in the dopamine agonist market.