Cancer Drug Raises Dopamine Levels, Eases Parkinson’s Symptoms in Early Study in Patients
A small Phase 1 clinical trial from the Georgetown University Medical Center (GUMC) suggests that the approved cancer drug Tasigna (nilotinib)can treat both motor and cognitive problems in patients with Parkinson’s disease or Lewy body dementia.
The study, “Nilotinib Effects in Parkinson’s disease and Dementia with Lewy bodies,” published in the Journal of Parkinson’s Disease, provided evidence that the treatment increased dopamine levels in the patients’ brains, and reduced the levels of factors indicating that dopamine-producing neurons are dying.
Findings also suggested that levels of the protein α-synuclein were decreased following treatment, but the effects were too small to establish if this was due to the therapy.
“These results need to be viewed with caution,” Charbel Moussa, a senior study author and the scientific and clinical research director of the GUMC Translational Neurotherpeutics Program, said in a news release. By this, Moussa meant that since the study was very small and the drug was not compared to placebo, its results are not conclusive and randomized trials are needed to establish if the drug really helps Parkinson’s patients.
Researchers initially enrolled 12 patients, but one withdrew due to severe adverse effects experienced four weeks after starting treatment (a heart attack), and two others were hospitalized to treat a urinary tract infection and pneumonia, respectively. Researchers said more investigations are needed to conclude if the events could have been caused by the nilotinib treatment.
Among the remaining 11 patients, who had moderately advanced Parkinson’s disease and mild to severe cognitive impairment, the drug appeared safe. Although it was used at lower doses than for patients with leukemia (150 or 300 mg once daily), Tasigna seemed to improve symptoms over the 24 weeks of treatment.
“Patients progressively improved in motor and cognitive functions as long as they were on the drug — despite the decreased use of dopamine replacement therapies in those participants with Parkinson’s and dementia with Lewy bodies,” said Fernando Pagan, medical director of the GUMC Translational Neurotherpeutics Program and director of the Movement Disorders Program at MedStar Georgetown University Hospital, and the study’s lead author.
Earlier laboratory studies, performed by Moussa, demonstrated that Tasigna turns on the enzymatic machinery clearing out the accumulation of toxic proteins inside nerve cells.
“Our hope is to clarify the benefits of nilotinib to patients in a much larger and well-controlled study. This was a very promising start,” said Moussa. “If these data hold out in further studies, nilotinib would be the most important treatment for Parkinsonism since the discovery of Levodopa almost 50 years ago,” and potentially one of the first treatments for Lewy body dementia.
Phase 2 placebo-controlled studies are being planned involving patients with Parkinson’s and Alzheimer’s. Tasigna, produced by Novartis, is approved in the U.S. as a treatment of certain forms of chronic myeloid leukemia in newly diagnosed adult patients.