Standardized cannabis extract safely relieves chronic back pain

A new large-scale clinical trial has found that a standardized, full-spectrum cannabis extract can effectively and safely reduce chronic low back pain. The study, published in Nature Medicine, showed that the treatment, known as VER-01, provided meaningful pain relief and improved physical function and sleep quality without signs of causing dependence or withdrawal.

Chronic low back pain is a leading cause of disability worldwide, affecting over half a billion people and diminishing their quality of life. Current drug treatments offer limited help and come with significant risks. Nonsteroidal anti-inflammatory drugs are not suited for long-term use because of potential gastrointestinal and cardiovascular side effects. Opioids are frequently prescribed but carry a high risk of abuse, dependence, and overdose, which has fueled a global health crisis.

Researchers led by Matthias Karst of Hannover Medical School in Germany recognized an urgent need for new, non-addictive pain relievers. They focused on cannabis-based medicines, which have generated public interest but often lack high-quality scientific evidence. To address this gap, the team designed a rigorous, large-scale trial to test a chemically well-defined and consistent cannabis extract.

The research was a complex, multi-phase trial conducted at 66 sites in Germany and Austria. In the first phase, 820 adults with chronic low back pain were randomly assigned to receive either the oral cannabis extract VER-01 or a placebo for 12 weeks. This phase was double-blind, meaning neither the participants nor the investigators knew who was receiving the active treatment. The primary goal was to measure the change in average pain intensity, which participants rated on a 0-to-10 scale. For a subgroup of participants whose pain had a nerve-related component, the researchers also assessed changes in neuropathic pain symptoms using a specific questionnaire.

After the initial 12 weeks, the study found that VER-01 was significantly more effective than the placebo at reducing pain. The group receiving the cannabis extract reported an average pain reduction of 1.9 points on the 10-point scale, compared to a 1.4-point reduction in the placebo group. The difference between the two groups was statistically significant. The treatment was especially effective for participants who started with severe pain and for those who had nerve-related pain. The study also met its secondary goal, showing a significant decrease in neuropathic pain symptoms for those taking VER-01 compared to placebo.

The benefits extended beyond simple pain reduction. Participants taking the active treatment reported significant improvements in their sleep quality and physical function. A higher percentage of people in the VER-01 group achieved at least a 30% reduction in their pain, a level considered clinically meaningful. They also used about half as much rescue medication, like ibuprofen, as the participants in the placebo group. Overall, these improvements translated into a better quality of life and a more positive global impression of their condition.

Following the 12-week controlled phase, the trial entered a long-term open-label extension, where participants could continue taking VER-01 for an additional six to twelve months. During this period, the pain relief was not only sustained but continued to improve. Participants did not show signs of needing higher doses over time to achieve the same effect, suggesting a lack of tolerance development.

A final phase of the study involved a randomized withdrawal. Some participants who had benefited from the treatment were unknowingly switched from VER-01 to a placebo to see if their pain would return. The primary measurement for this phase, which was the time it took for the treatment to be considered a failure, did not show a statistically significant difference between the groups. The study authors suggest this may be due to the limited number of participants in this part of the trial. A secondary analysis did show, however, that participants who were switched to the placebo experienced a significant increase in their pain compared to those who continued taking VER-01.

Regarding safety, adverse events were more common in the VER-01 group than in the placebo group. The most frequent side effects were dizziness, headache, fatigue, nausea, and dry mouth. Most of these events were mild to moderate in intensity and tended to occur during the first few weeks of treatment before subsiding. While more participants on VER-01 discontinued the study due to side effects, the rate of serious adverse events was similar between the two groups. A central finding of the safety analysis was the complete absence of signs related to drug abuse, dependence, or withdrawal symptoms, even after treatment was stopped abruptly.

Jan Vollert, a lecturer in neuroscience at the University of Exeter, told the Science Media Centre: “This is an excellent study. We have long argued that studies on cannabis or cannabis-based substances need to provide high level of evidence: this is it. It is only one trial, and we will need further studies to confirm the findings, but this is a good signal that the compound could help patients.”

Vollert also emphasized the importance of using a specific, controlled product. “This is in no way comparable to smoking cannabis…this study does not make a case for smoking cannabis, as smoking cannabis and taking VER-01 are probably as similar as eating hazelnuts and eating Nutella: they might share a similar basis, but they just are not comparable.”

David Nutt, the head of the Centre for Neuropsychopharmacology at Imperial College London, also weighed in. “This is an elegant study using a placebo design with later cross over from placebo to active that confirms what we at DrugScience and other have been saying for some time based on our T21 initiative and Multi-Criteria Decision Analysis – that whole plant extract cannabis-based products have a role in chronic pain treatment.”

The researchers acknowledge some limitations of their work. The study did not directly compare VER-01 to other pain medications like opioids, though a follow-up study on that topic is planned. Cognitive function was not formally assessed, which could be included in future investigations of cannabinoid treatments. The lack of a statistically significant result in the withdrawal phase suggests that future studies of this kind may require a larger sample size to confirm the maintenance of effect. The findings position VER-01 as a promising therapeutic option that could play an important part in the future of pain management.

The study, “Full-spectrum extract from Cannabis sativa DKJ127 for chronic low back pain: a phase 3 randomized placebo-controlled trial,” was authored by Matthias Karst, Winfried Meissner, Sabine Sator, Jens Keßler, Volker Schoder, and Winfried Häuser.