Synergistic safety profile could increase sublingual apomorphine competitiveness: GlobalData

Sublingual apomorphine (SL-APO) is a dopamine agonist (DA) marketed by Bial under the brand name Kynmobi in several countries for the on-demand treatment of levodopa wear-off (OFF-episodes) that are not sufficiently controlled by levodopa “add-on” (adjunct) therapies. At the tenth Congress of the European Academy of Neurology (EAN) 2024, Dr Diego Santos García presented a post-hoc analysis of the Phase III, open-label study on SL-APO showing that it was better tolerated by patients on regular DA treatment. These results could suggest a synergistic safety profile between SL-APO and other DAs, increasing its competitiveness, according to GlobalData.

Lorraine Palmer, Pharma Analyst at GlobalData, states, “After an average of five years, most patients who are taking levodopa experience motor complications that include OFF-episodes. These are often managed using adjunct therapies such as catechol-O-methyltransferase (COMT) inhibitors, DAs, and monoamine oxidase B (MAO-B) inhibitors. However, some patients still experience OFF-episodes even with these adjunct therapies, creating a demand for on-demand ‘rescue’ treatment for OFF-episodes.”

The post-hoc analysis separated the trial participants into DA users and non-DA users at baseline, with DA users being prescribed adjunct DA in addition to levodopa. The analysis aimed to assess the impact of concomitant DA use on outcomes with SL-APO. DA users accounted for 60.4 per cent of participants during the dose optimisation phase of the trial (three weeks), and 63.3 per cent during the long-term safety phase.

“The trial concluded that SL-APO was found to be generally well tolerated and efficacious. However, post-hoc analysis shows DA users had a lower incidence of the common treatment-emergent adverse events (TEAEs), including those associated with DA use such as nausea, dizziness, somnolence, vomiting, orthostatic hypotension, and dyskinesia,” he adds 

While SL-APO used to be marketed in the US by Sumitomo Pharma (formerly Sunovion), it was voluntarily withdrawn in 2023 from the US market due to limited utilisation. However, it remains marketed in four European countries (France, Germany, Spain, and the UK) as well as Canada and India.

According to GlobalData’s Parkinson’s disease market forecast and analysis to 2029, SL-APO is set to experience sizable growth in the seven major markets (7MM*), with sales increasing from $1.5 million in 2024 to $4.7 million in 2029, registering a compound annual growth rate (CAGR) of 25.2 per cent during the period. This growth is expected to be driven by sales in France, Germany, Spain, and the UK.

In addition, speaking to GlobalData, key opinion leaders (KOLs) unanimously preferred SL-APO to competing injectable apomorphine, such as Supernus’s Apokyn, due to its easier administration.

concludes “If further studies confirm what the post-hoc analysis indicates, namely, that there is a synergistic safety profile between SL-APO and other DAs, then it would increase SL-APO’s competitiveness in the European market, which might also encourage Sumitomo Pharma to re-enter SL-APO into the US market, ” concludes Palmer.

*7MM- the US, the UK, Germany, Spain, Italy, France, and Japan