Evaluating laser photobiomodulation for chemotherapy-induced peripheral neuropathy: a randomised phase II trial

This study aims to evaluate the efficacy and safety of laser photobiomodulation (PBM) for treatment of established chemotherapy-induced peripheral neuropathy (CIPN) in cancer survivors.

We conducted a randomised phase II, non-comparative, sham-controlled, single-blinded clinical trial in 44 cancer survivors reporting CIPN symptoms at least 3 months following completion of neurotoxic chemotherapy. Participants were randomised 2:1 to either PBM laser or sham control delivered twice weekly for 12 sessions. Assessments were conducted at baseline, the end of intervention (6 weeks), and 6 weeks post intervention (12 weeks). Participants completed neuropathy, quality of life and function questionnaires, and a clinical neurological assessment. The primary outcome was proportion of participants with CIPN response, defined as either symptom resolution or reduction of minimally clinically important difference.

In the laser and control groups, CIPN response rates were - 48% and 53% at 6 weeks and 45% and 33% at 12 weeks, respectively. The null hypothesis that the true response rate is 5% in the laser arm was rejected at both 6 and 12 weeks (p < 0.001 for both). Compared to baseline, patient-reported CIPN improved in both laser and control groups after the intervention. At 12 weeks, improvement was sustained in the laser group and approaching baseline in the control group. Clinical signs, quality of life, and function remained stable in both groups. Low-grade "side-effects" were observed in both arms.

PBM may offer clinically meaningful symptom benefit in cancer survivors with established CIPN with improvement potentially continuing beyond completion of the intervention. A larger study is warranted to evaluate this further.