Latest Publication on Elto from Sep 2021 suggests pairing eltoprazine with Levadopa and Preladenant as a sort of Parkinson's cocktail. Preladenant is an Adenosine 2A Receptor Antagonist owned by Merck. Others include Vipadenant owned by Celgene, or Tozadenant, owned by Acorda, or istradefylline, owned by Kyowa Kirin in Japan. So that's more of the field of potential partners. Remember, GC may already be talking to Merck via Todos given his focus on supplanting Remsdesivir.

This study is critical because it was this same group of researchers from the National Research Council of Italy (CNR), Neuroscience Institute that put the temporary kibosh on eltoprazine in dyskinesia back in 2016 when they said that when just paired with levedopa, both drugs counteracted each other.

Neuroinflammation and L-dopa-induced abnormal involuntary movements
in 6-hydroxydopamine-lesioned rat model of Parkinson’s disease are
counteracted by combined administration of a 5-HT1A/1B receptor agonist
and A2A receptor antagonist

Pinna, A., Costa, G., Serra, M., Contu, L., & Morelli, M. (2021). Neuroinflammation and L-dopa-induced abnormal involuntary movements in 6-hydroxydopamine-lesioned rat model of Parkinson’s disease are counteracted by combined administration of a 5-HT1A/1B receptor agonist and A2A receptor antagonist. Neuropharmacology, 196, 108693. doi:10.1016/j.neuropharm.2021.108693
10.1016/j.neuropharm.2021.108693

In conclusion, the present findings show that a challenge with L-dopa
induces a reduced neuroinflammatory response in 6-OHDA-lesioned rats
pretreated with an association of A2A antagonists and 5-HT1A/1B agonists, suggesting that this drug association may be a promising therapeutic strategy for preventing both neuroinflammation and dyskinesia.