Safinamide Associated With Pain Improvement in Patients With Parkinson Disease

Safinamide may significantly improve pain in patients with Parkinson disease (PD), according to study findings published in the Journal of Personalized Medicine.

Affecting up to 50% of patients with PD, pain has been identified as a common nonmotor symptom (NMS) that is frequently under-recognized and inadequately treated. With experiences of pain varying by each patient, identifying what type of pain is present can be vital in finding effective treatment, noted the study authors.

In prior research, dopaminergic therapy and neurotransmitters have been implicated in the management of pain. Moreover, some studies have suggested the possible benefit of safinamide, an oral alpha-aminoamide derivative marketed for the treatment of PD, with the treatment having been associated with improvements in several pain scales, such as the King’s Parkinson’s Disease Pain Scale (KPPS), and in global NMS burden, particularly for sleep, mood, and urinary symptoms.

“We observed very recently an improvement in the global NMS burden in 50 patients with PD from the SAFINONMOTOR study,” added researchers. “In this analysis, a secondary objective of the SAFINONMOTOR study, we evaluated in detail the change in pain throughout the 6-month follow-up in PD patients treated with safinamide.”

Leveraging data from the prospective open-label SAFINONMOTOR study of patients with PD from 5 centers in Spain, efficacy of safinamide on pain was evaluated via change in KPPS score from V1 (baseline) to V4 (6 months), as measured by Wilcoxon’s rank sum test.

In the analysis, 44 patients with PD (mean age [SD], 68.5 [9.12 years]; 58% women; 6.4 [5.1] years from diagnosis) were included between May 2019 and February 2020.

Compared with baseline, a lower KPPS total score was found in 28 patients (65.1%), the same score in 6 patients (13.9%), and a higher score in 6 patients (13.9%). Overall, the KPPS total score was significantly reduced by 43.6% from V1 to V4 (40.04 [36.18] vs 22.60 [21.42]; P < .0001). By domains, improvement was observed in several pain manifestations:

• musculoskeletal (−35.9%; P = .009)
• fluctuation-related (−51.7%; P = .020)
• nocturnal (−46.1%; P = .001)
• discoloration and/or edema/swelling (−50.4%; P = .009)
• radicular pain (−40.1%; P = .048).
  

There were 21 adverse events recorded in 11 participants (22%), 5 being severe, but not related to safinamide.

“In conclusion, safinamide is well tolerated and could improve pain in PD patients,” said the study authors. “Well-designed randomized double-blind trials are necessary to analyze in detail the effect of safinamide on pain. Especially interesting could be the analysis of pain with objective methods and with regards to action mechanism, dopaminergic and/or glutamatergic, in patients receiving safinamide.”

Reference

Garcia DS, Baña RY, Guerra CL, et al. Pain improvement in Parkinson’s disease patients treated with safinamide: results from the SAFINONMOTOR study. J Pers Med. Published online August 16, 2021. doi:10.3390/jpm11080798