Endocannabinoid System & Chronic Low Back Pain: Phase 3 Trial Results on Cannabis Sativa Extracts
Clinical Takeaway
In this phase 3 randomized controlled trial of 820 adults, the full-spectrum cannabis extract VER-01 was evaluated against placebo over 12 weeks for chronic low back pain, with extended follow-up reaching 15 months. The trial used a rigorous withdrawal design to assess durability of effect, addressing a condition where current medications frequently fall short. Results from this study contribute high-quality clinical evidence to the growing body of research on cannabinoid-based treatment for one of the most prevalent and burdensome pain conditions globally.
#2 Full-spectrum extract from Cannabis sativa DKJ127 for chronic low back pain: a phase 3 randomized placebo-controlled trial.
Citation: Karst Matthias et al.. Full-spectrum extract from Cannabis sativa DKJ127 for chronic low back pain: a phase 3 randomized placebo-controlled trial.. Nature medicine. 2025. PMID: 41023483.
Design: 5 Journal: 4 N: 2 Recency: 2 Pop: 2 Human: 1 Risk: -2
- Preclinical only
Methodological Considerations:
- Open-label design — placebo effect not excluded
Abstract: Chronic low back pain (CLBP) affects over half a billion people worldwide. Current pharmacologic treatments offer limited efficacy and carry substantial risks, warranting the development of safe and effective alternatives. This multicenter, randomized, placebo-controlled phase 3 trial evaluated the efficacy and safety of VER-01 in CLBP. It enrolled 820 adults with CLBP (VER-01, n = 394; placebo, n = 426) and included a double-blind 12-week treatment phase (phase A), a 6-month open-label extension (phase B), followed by either a 6-month continuation (phase C) or randomized withdrawal (phase D). The primary endpoint of phase A was a change in mean numeric rating scale (NRS) pain intensity, with a change in total neuropathic pain symptom inventory (NPSI) score as a key secondary endpoint in participants with a neuropathic pain component (PainDETECT > 18). The primary endpoint for phase D was time to treatment failure. The study met its primary endpoint in phase A, with a mean pain reduction of -1.9 NRS points in the VER-01 group (mean difference (MD) versus placebo = -0.6, 95% confidence interval (CI) = -0.9 to -0.3; P < 0.001). Pain further decreased to -2.9 NRS points in phase B, with effects sustained through phase C. The study also met its key secondary endpoint of phase A, with a mean NPSI decrease of -14.4 (standard error, 3.3) points from baseline in the VER-01 arm (MD versus placebo = -7.3, 95% CI = -13.2 to -1.3; P = 0.017). Although phase D did not meet its primary endpoint (hazard ratio = 0.75, 95% CI = 0.44-1.27; P = 0.288), pain increased significantly more with placebo upon withdrawal (MD = 0.5, 95% CI = 0.0-1.0; P = 0.034). In phase A, the incidence of adverse events-mostly mild to moderate and transient-was higher with VER-01 than with placebo (83.3% versus 67.3%; P < 0.001). VER-01 was well-tolerated, with no signs of dependence or withdrawal. VER-01 shows potential as a new, safe and effective treatment for CLBP. ClinicalTrials.gov registration: NCT04
What This Study Teaches Us
A full-spectrum cannabis extract (VER-01) reduced chronic low back pain by roughly 0.6 points on a 10-point scale compared to placebo over 12 weeks, and pain continued to improve over longer follow-up. The effect was modest but statistically significant, and a neuropathic pain subgroup also showed benefit on a symptom inventory score.
Why This Matters Clinically
For clinicians, this is the first large phase 3 RCT data on a defined cannabis product for CLBP, a condition affecting 500 million people globally where current drugs have poor efficacy or carry addiction risk. For patients considering cannabis for back pain, this provides some objective evidence of modest benefit, though the effect size raises questions about clinical meaningfulness versus statistical significance.
Study Snapshot
| Study Design | Multicenter randomized placebo-controlled phase 3 trial with 12-week double-blind phase, 6-month open-label extension, and randomized withdrawal phase |
| Population | 820 adults with chronic low back pain (VER-01 n=394, placebo n=426); demographics not specified in abstract |
| Intervention | VER-01 (full-spectrum Cannabis sativa extract from DKJ127 strain); specific dose and administration route not specified in abstract |
| Primary Outcome | Change in numeric rating scale (NRS) pain intensity (0-10 scale) over 12 weeks |
| Key Result | VER-01 reduced pain by 1.9 NRS points; placebo by 1.3 NRS points; difference of 0.6 points (95% CI 0.3-0.9, P<0.001). Secondary neuropathic pain outcome also met significance (7.3 point NPSI difference, P=0.017) |
Where This Paper Deserves Skepticism
The 0.6 point difference on a 10-point pain scale, while statistically significant with N=820, may not meet the threshold for clinical meaningfulness in individual patients (many trials consider 1-2 points the minimally clinically important difference). The randomized withdrawal phase (phase D) did not reach statistical significance for time to treatment failure, which weakens the claim of durability. The abstract does not specify dosing, strain composition details, CBD/THC ratios, or how many subjects experienced the adverse events mentioned at 83% incidence, limiting interpretation of the safety profile. Generalizability to cannabis consumed in non-pharmaceutical settings remains unclear.
Dr. Caplan’s Take
This is meaningful data. A well-designed phase 3 trial showing efficacy for a defined extract is exactly what we need in cannabis medicine, and the fact that it met both primary and secondary endpoints signals this isn’t noise. That said, I read the 0.6 point NRS difference as clinically modest, and the failure of the withdrawal phase to show robust relapse prevention is worth noting. For patients already using cannabis with good effect on back pain, this validates the approach; for those considering it as a first-line agent, I’d still place it below physical therapy and consider it alongside, not instead of, conventional care.
Clinical Bottom Line
VER-01 showed modest but statistically significant pain reduction in chronic low back pain compared to placebo, with acceptable tolerability, making it a candidate for further clinical consideration. The effect size is small enough that it should not displace established non-pharmacologic treatments, but it may have a role in patients who have failed or cannot tolerate conventional therapies.
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