A multicentre, open-label, follow-on study to assess the long-term maintenance of effect, tolerance and safety of THC/CBD oromucosal spray in the management of neuropathic pain
THC/CBD spray sustainably reduced neuropathic pain intensity and was well tolerated over 38 weeks without a tendency toward dose escalation.
Summary
n=380 patients with peripheral neuropathic nociception (diabetic neuropathy or allodynia), THC/CBD oromucosal spray as add-on, 38-week open-label extension study; pain NRS decreased from mean 6,9 (baseline of the parent studies) to 4,2 (study end); ≥30% pain reduction in >50% of all patients at all measurement time points; sleep quality NRS and EQ-5D improved; no new safety signals with 38-week treatment.
P
PopulationAdults with peripheral neuropathic pain (PNP) associated with diabetes or allodynia, n=380 (from two preceding RCTs)
I
InterventionTHC/CBD oromucosal spray (add-on to existing analgesic therapy) over 38 weeks
O
OutcomePain reduction (NRS) from mean 6,9 points (baseline of the parent studies) to mean 4,2 points at study end; ≥30% pain improvement in at least half of all patients at all time points
Confidence in the evidence
Very lowLowModerateHigh
Moderate
The third of four GRADE levels, the effect estimate is probably reliable.
Peripheral neuropathic pain (PNP) poses a significant clinical challenge. The long-term efficacy of delta-9-tetrahydrocannabinol (THC)/cannabidiol (CBD) oromucosal spray was investigated in this 38-week open-label extension study. In total, 380 patients with PNP associated with diabetes or allodynia entered this study from two parent randomised, controlled trials. Patients received THC/CBD spray for a further 38 weeks in addition to their current analgesic therapy. Neuropathic pain severity was the primary efficacy measure using a pain 0-10 numerical rating scale (NRS). Additional efficacy, safety and tolerability outcomes were also investigated. In total, 234 patients completed the study (62 %). The pain NRS showed a decrease in score over time in patients from a mean of 6.9 points (baseline in the parent studies) to a mean of 4.2 points (end of open-label follow-up). The proportion of patients who reported at least a clinically relevant 30 % improvement in pain continued to increase with time (up to 9 months); at least half of all patients reported a 30 % improvement at all time points. Improvements were observed for all secondary efficacy outcomes, including sleep quality 0-10 NRS scores, neuropathic pain scale scores, subject global impression of change and EQ-5D questionnaire scores. THC/CBD spray was well tolerated for the study duration and patients did not seek to increase their dose with time, with no new safety concerns arising from long-term use. In this previously difficult to manage patient population, THC/CBD spray was beneficial for the majority of patients with PNP associated with diabetes or allodynia.