A feud between the richest nonprofit group targeting Parkinson’s disease and a Georgetown University researcher is pushing back clinical trials of nilotinib, a treatment that could reverse symptoms of the disorder.

Charles Piller of STAT News writes that the Michael J. Fox Foundation and Georgetown neurology researcher Charbel Moussa, MD, PhD, were to collaborate on the trial, set to begin in October. Now, the foundation will wait another year before starting its own trial after what Piller calls a “bitter falling out” with Moussa.

“Some people think they are the owners of the conversation, the owners of the scientific debate, the owners of Parkinson’s research,” Moussa said.

The foundation denies Moussa’s characterization, saying it acted in good faith to reach an agreement with Georgetown.

Moussa had led a small 12-patient trial of nilotinib in 2015, with patients described “substantial relief” from Parkinson’s symptoms such as shuffling gait and cognitive decline. The Fox Foundation then approached Moussa about funding a larger study, but Moussa already had separate funding and approval for a larger trial from the federal government and the university.

While he still wanted the foundation involved to underwrite the costs of additional test locations, Moussa says the group started demanding changes in the study design which would delay the trial. The last straw the foundation’s senior vice president, Brian Fiske, dismissing the project to nilotinib’s maker, Novartis, which Moussa feels was an attempted sabotage.

“Whether they [Novartis] will continue to review your proposal is of course up to Novartis, but we made it clear that this was submitted without our knowledge or commitment to support,” Fiske wrote to Moussa in a June 17 email provided to STAT by Moussa.

For more on where both trials go from here—and how scientists and large foundations continue to battle for control of clinical research—click on the link below: