The Characteristics of Clinical Trials on Cannabis and Cannabinoids: A Review of Trials for Therapeutic or Drug Development Purposes

SpringerLink

“Introduction: Patients and healthcare practitioners are increasingly interested in using cannabis and cannabinoids to address unmet clinical needs. Although we have clinical evidence on the medical use of cannabinoids, a significant portion of the data is not based on randomized clinical trials, which are considered the gold standard in clinical research. We have reviewed the registered clinical trials on cannabis and cannabinoids for therapeutic or drug development purposes to underline the past and current attempts to generate robust clinical evidence and identify existing knowledge gaps.

Methods: We reviewed four clinical trial registries (International Clinical Trials Registry Program [ICTRP], ClinicalTrials.gov, European Clinical Trial Registry [EUCTR], Australian New Zealand Clinical Trial Registry [ANZCTR]) to identify clinical trials on cannabinoids (phyto- or synthetic) or cannabis-based medications between January 1, 2000, and December 31, 2021. All interventional clinical trials on cannabinoids and other compounds interacting with the endocannabinoid system, regardless of the investigated medical condition, assessed health outcomes, or choice of comparator, were included, provided they had a therapeutic or drug development purpose. Data on the primary sponsor, type of sponsor, date of registration, recruitment status, number of participants, study design, the phase of the study, country, medical conditions, investigated cannabinoids, and the route of administration were extracted. The therapeutic area and class of cannabinoids were identified based on the details of each trial.

Results: We included 834 out of 2966 reviewed clinical trials. The number of registered clinical trials has constantly increased from 30 in 2013 to 103 in 2021. More than 40% of registered clinical trials in 2021 were phase II and phase III clinical trials. The mean number of trial enrollments for completed, ongoing, and terminated studies were 128, 156, and 542, respectively. Clinical research on Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and the oral routes of administration dominate the field. Approximately two-thirds of clinical trials were conducted in five therapeutic areas (i.e., ‘Chronic pain,’ ‘Mental, behavioral or neurodevelopmental disorders,’ ‘Nervous system diseases,’ ‘Endocrine, nutritional or metabolic diseases,’ and ‘Neoplasms’). Pharmaceutical companies sponsored 39% of all clinical trials. However, trial sponsorships vary noticeably in different jurisdictions, likely due to, in part, different regulatory frameworks.

Conclusion: Our review highlights the diversification of clinical trials on cannabinoid-based medications in the past 21 years. This review underlines the increased interest in conducting clinical studies on new cannabinoid administration methods such as topical applications and on the investigation of emerging phyto- and synthetic cannabinoids. Moreover, more clinical trials have been designed to explore the potential therapeutic benefits of cannabinoids in areas such as mental, behavioral, or neurodevelopmental disorders and skin diseases. There is a need for granular analyses of clinical trials on more commonly studied therapeutic areas such as chronic pain, nervous system diseases, and mental and behavioral disorders to generate more actionable information and insight for all stakeholders.”

https://pubmed.ncbi.nlm.nih.gov/36357543/

https://link.springer.com/article/10.1007/s40290-022-00447-7

Ghana’s preparedness to exploit the medicinal value of industrial hemp

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“Background: Interest in industrial hemp is increasing steadily, as can be seen by the growing number of countries that have either decriminalized industrial hemp or are contemplating its decriminalization. In line with this trend, Ghana recently decriminalized the cultivation of industrial hemp (the cannabis variety with low Δ9-tetrahydrocannabinol (THC) and high cannabidiol (CBD) content), resulting in the need for research into its benefits to Ghanaians. This article examines cannabis (including industrial hemp) production, facilities for industrial hemp exploitation, and the potential benefits of industrial hemp in Ghana.

Main body: Indigenous cannabis strains in Ghana have high THC to CBD ratios suggesting the need for the government to purchase foreign hemp seeds, considering that the alternative will require significant research into decreasing the THC to CBD ratio of indigenous cannabis strains. Furthermore, there are several facilities within the country that could be leveraged for the production of medicinal hemp-based drugs, as well as the existence of a number of possible regulatory bodies in the country, suggesting the need for less capital. Research has also shown the potential for treatment of some medical conditions prevalent among Ghanaians using medicinal hemp-based products. These reasons suggest that the most feasible option may be for the government to invest in medicinal hemp.

Conclusion: Considering the challenges associated with the development of other hemp-based products, the availability of resources in the country for exploitation of medicinal hemp, and the potential benefits of hemp-based drugs to Ghanaians, investing in medicinal hemp may be the best option for the government of Ghana.”

https://pubmed.ncbi.nlm.nih.gov/36329502/

“Considering the challenges associated with the development of other hemp-based products, the availability of resources in the country for exploitation of medicinal hemp, and the potential benefits of hemp-based drugs to Ghanaians, investing in medicinal hemp may be the best option for the government of Ghana.”

https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-022-00167-4

Chitosan-based films with cannabis oil as a base material for wound dressing application

Scientific Reports

“This study focuses on obtaining and characterizing novel chitosan-based biomaterials containing cannabis oil to potentially promote wound healing. The primary active substance in cannabis oil is the non-psychoactive cannabidiol, which has many beneficial properties. In this study, three chitosan-based films containing different concentrations of cannabis oil were prepared. As the amount of oil increased, the obtained biomaterials became rougher as tested by atomic force microscopy. Such rough surfaces promote protein adsorption, confirmed by experiments assessing the interaction between human albumin with the obtained materials. Increased oil concentration also improved the films’ mechanical parameters, swelling capacity, and hydrophilic properties, which were checked by the wetting angle measurement. On the other hand, higher oil content resulted in decreased water vapour permeability, which is essential in wound dressing. Furthermore, the prepared films were subjected to an acute toxicity test using a Microtox. Significantly, the film’s increased cannabis oil content enhanced the antimicrobial effect against A. fischeri for films in direct contact with bacteria. More importantly, cell culture studies revealed that the obtained materials are biocompatible and, therefore, they might be potential candidates for application in wound dressing materials.”

https://pubmed.ncbi.nlm.nih.gov/36333591/

https://www.nature.com/articles/s41598-022-23506-0

Herbal Cannabis Use Is Not Associated with Changes in Levels of Endocannabinoids and Metabolic Profile Alterations among Older Adults

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“Activation of the endocannabinoid system has various cardiovascular and metabolic expressions, including increased lipogenesis, decreased blood pressure, increased heart rate, and changes in cholesterol levels. There is a scarcity of data on the metabolic effects of exogenous cannabis in older adults; therefore, we aimed to assess the effect of exogenous cannabis on endocannabinoid levels and the association with changes in 24 h ambulatory blood pressure and lipid levels. We conducted a prospective study of patients aged 60 years or more with hypertension treated with a new prescription of herbal cannabis. We assessed changes in endocannabinoids, blood pressure, and metabolic parameters prior to and following three months of cannabis use. Fifteen patients with a mean age of 69.47 ± 5.83 years (53.3% male) underwent complete evaluations. Changes in 2-arachidonoylglycerol, an endocannabinoid, were significantly positively correlated with changes in triglycerides. Changes in arachidonic acid levels were significantly positively correlated with changes in C-reactive protein and with changes in mean diastolic blood pressure. Exogenous consumption of cannabidiol was negatively correlated with endogenous levels of palmitoylethanolamide and oleoylethanolamide. On average, cannabis treatment for 3 months does not result in a significant change in the levels of endogenous cannabinoids and thus has a safe metabolic risk profile.”

https://pubmed.ncbi.nlm.nih.gov/36294974/

“The endocannabinoid system is a complex cell-signaling system that has numerous effects on the human body, including on the heart, blood vessels, and metabolism. In this study, we aimed to assess the effects of exogenous herbal medical cannabis use on the components of the endocannabinoid system among older adults with a diagnosis of hypertension. Medical cannabis is a product containing cannabinoids used for medical purposes. Herbal cannabis contains many types of cannabinoids, the most well-known of which are Δ9-tetrahydrocannabinol and cannabidiol. We followed people aged 60 years and older and conducted a number of tests, including endocannabinoids levels, before they started using cannabis and following three months of daily cannabis treatment. Fifteen patients (53.3% male; mean age, 69.5 years) underwent complete evaluations. We found positive correlations between the components of the endocannabinoid system and blood lipids, markers of inflammation, and blood pressure. On average, cannabis treatment for 3 months does not result in a significant change in the levels of endogenous cannabinoids and thus has a safe metabolic risk profile. This study provides additional evidence for the safety of medical cannabis use among older adults.”

https://www.mdpi.com/2075-1729/12/10/1539/htm

Antimicrobial and Cytotoxic Effects of Cannabinoids: An Updated Review with Future Perspectives and Current Challenges

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“The development of new antibiotics is urgently needed to combat the threat of bacterial resistance. New classes of compounds that have novel properties are urgently needed for the development of effective antimicrobial agents.

The extract of Cannabis sativa L. has been used to treat multiple ailments since ancient times. Its bioactivity is largely attributed to the cannabinoids found in its plant. Researchers are currently searching for new anti-infective agents that can treat various infections. Although its phytocannabinoid ingredients have a wide range of medical benefits beyond the treatment of infections, they are primarily associated to psychotropic effects.

Different cannabinoids have been demonstrated to be helpful against harmful bacteria, including Gram-positive bacteria. Moreover, combination therapy involving the use of different antibiotics has shown synergism and broad-spectrum activity. The purpose of this review is to gather current data on the actions of Cannabis sativa (C. sativa) extracts and its primary constituents such as terpenes and cannabinoids towards pathogens in order to determine their antimicrobial properties and cytotoxic effects together with current challenges and future perspectives in biomedical application.”

https://pubmed.ncbi.nlm.nih.gov/36297340/

“C. sativa is a plant with an untapped potential. This versatile plant can be used for various purposes. Given its complex metabolic profile and excessive use as a recreational substance, its therapeutic benefits should not be ignored or overshadowed. Due to the limited effectiveness of antibiotics against MDR bacteria, the use of these drugs can be limited. This is why the discovery of an antimicrobial agent that can be used by plants has been regarded as a great step in the development of anti-infectives [8]. Multiple cannabinoids have been shown to have potent antimicrobial properties against Gram-positive pathogens, such as MRSA. In vitro studies have shown that cannabinoids can be useful in the removal of harmful microbes from the environment. Combination therapy with antibiotics that have different modes of action has shown broad-spectrum activities and synergism. There is also evidence that compounds found in C. sativa can have antimicrobial properties. This suggests that further investigations are needed to understand their potential. As the development of antibiotic resistance continues, cannabinoids have the potential to become a new source of treatment for bacterial infections.”

https://www.mdpi.com/1424-8247/15/10/1228/htm

Effect of Cannabidiolic Acid, N- Trans-Caffeoyltyramine and Cannabisin B from Hemp Seeds on microRNA Expression in Human Neural Cells

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“Given the increasing interest in bioactive dietary components that can modulate gene expression enhancing human health, three metabolites isolated from hemp seeds-cannabidiolic acid, Ntrans-caffeoyltyramine, and cannabisin B-were examined for their ability to change the expression levels of microRNAs in human neural cells. To this end, cultured SH-SY5Y cells were treated with the three compounds and their microRNA content was characterized by next-generation small RNA sequencing. As a result, 31 microRNAs underwent major expression changes, being at least doubled or halved by the treatments. A computational analysis of the biological pathways affected by these microRNAs then showed that some are implicated in neural functions, such as axon guidance, hippocampal signaling, and neurotrophin signaling. Of these, miR-708-5p, miR-181a-5p, miR-190a-5p, miR-199a-5p, and miR-143-3p are known to be involved in Alzheimer’s disease and their expression changes are expected to ameliorate neural function. Overall, these results provide new insights into the mechanism of action of hemp seed metabolites and encourage further studies to gain a better understanding of their biological effects on the central nervous system.”

https://pubmed.ncbi.nlm.nih.gov/36286061/

https://www.mdpi.com/1467-3045/44/10/347/htm

Cannabis sativa in Phytotherapy : Reappraisal of therapeutic potential and regulatory aspects

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“Cannabis sativa is widely used as a folk medicine in many parts of the globe and has been reported to be a treasure trove of phytoconstituents, including cannabinoids, terpenoids, and flavonoids.

Accumulating evidence from various pre-clinical and clinical studies revealed the therapeutic potential of these constituents in various pathological conditions, including chronic pain, inflammation, neurological disorders, and cancer.

However, the psychoactive effect and addiction potential associated with cannabis use limited its clinical application. In the past two decades, extensive research on cannabis has led to the resurgence of interest in the clinical application of its constituents, particularly cannabinoids.

This review summarizes the therapeutic effect and molecular mechanism of various phytoconstituents of cannabis. Furthermore, recently developed nanoformulations of cannabis constituents have also been reviewed. Since cannabis is often associated with illicit use, regulatory aspects are of vital importance and this review therefore also documented the regulatory aspects of cannabis use along with clinical data and commercial products of cannabis.”

https://pubmed.ncbi.nlm.nih.gov/36281862/

https://www.eurekaselect.com/article/127142

Cannabidiol as a modulator of α7 nicotinic receptors

SpringerLink

“Cannabidiol (CBD), an important terpenoid compound from marijuana with no psychoactive effects, has become of great pharmaceutical interest for several health conditions. As CBD is a multitarget drug, there is a need to establish the molecular mechanisms by which CBD may exert therapeutic as well as adverse effects. The α7 nicotinic acetylcholine receptor (α7 nAChR) is a cation-permeable ACh-gated channel present in the nervous system and in non-neuronal cells. It is involved in different pathological conditions, including neurological and neurodegenerative disorders, inflammation, and cancer. By high-resolution single-channel recordings and confocal microscopy, we here reveal how CBD modulates α7 nAChR ionotropic and metabotropic functions. CBD leads to a profound concentration-dependent decrease of α7 nAChR single-channel activity with an IC50 in the sub-micromolar range. The inhibition of α7 nAChR activity, which takes place through a membrane pathway, is neither mediated by receptor phosphorylation nor overcome by positive allosteric modulators and is compatible with CBD stabilization of resting or desensitized α7 nAChR conformational states. CBD modulation is complex as it also leads to the later appearance of atypical, low-frequency α7 nAChR channel openings. At the cellular level, CBD inhibits the increase in intracellular calcium triggered by α7 nAChR activation, thus decreasing cell calcium responses. The modulation of α7 nAChR is of pharmacological relevance and should be considered in the evaluation of CBD potential therapeutic uses. Thus, our study provides novel molecular information of CBD multiple actions and targets, which is required to set the basis for prospective applications in human health.”

https://pubmed.ncbi.nlm.nih.gov/36282426/

https://link.springer.com/article/10.1007/s00018-022-04600-y

“Targeting α7 nicotinic acetylcholine receptors for chronic pain”

https://pubmed.ncbi.nlm.nih.gov/36245927/

The safety and efficacy of low oral doses of cannabidiol: An evaluation of the evidence

“Global interest in the non-intoxicating cannabis constituent, cannabidiol (CBD), is increasing with claims of therapeutic effects across a diversity of health conditions. At present, there is sufficient clinical trial evidence to support the use of high oral doses of CBD (e.g., 10-50 mg/kg) in treating intractable childhood epilepsies. However, a question remains as to whether “low-dose” CBD products confer any therapeutic benefits. This is an important question to answer, as low-dose CBD products are widely available in many countries, often as nutraceutical formulations. The present review therefore evaluated the efficacy and safety of low oral doses of CBD. The review includes interventional studies that measured the clinical efficacy in any health condition and/or safety and tolerability of oral CBD dosed at less than or equal to 400 mg per day in adult populations (i.e., ≥18 years of age). Studies were excluded if the product administered had a Δ9 -tetrahydrocannabinol content greater than 2.0%.

Therapeutic benefits of CBD became more clearly evident at doses greater than or equal to 300 mg. Increased dosing from 60 to 400 mg/day did not appear to be associated with an increased frequency of adverse effects. At doses of 300-400 mg, there is evidence of efficacy with respect to reduced anxiety, as well as anti-addiction effects in drug-dependent individuals. More marginal and less consistent therapeutic effects on insomnia, neurological disorders, and chronic pain were also apparent. Larger more robust clinical trials are needed to confirm the therapeutic potential of lower (i.e., <300 mg/day) oral doses of CBD.”

https://pubmed.ncbi.nlm.nih.gov/36259271/

https://ascpt.onlinelibrary.wiley.com/doi/10.1111/cts.13425

The inverse association of state cannabis vaping prevalence with the e-cigarette or vaping product-use associated lung injury

Lopiccolo & Chang in PLoS ONE – BU Linguistics

“The e-cigarette or vaping product-use-associated lung injury (EVALI) epidemic was primarily associated with the use of e-cigarettes containing tetrahydrocannabinol (THC)- the principal psychoactive substance in cannabis, and vitamin-E-acetate- an additive sometimes used in informally sourced THC-containing e-liquids. EVALI case burden varied across states, but it is unclear whether this was associated with state-level cannabis vaping prevalence. We, therefore, used linear regression models to assess the cross-sectional association between state-level cannabis vaping prevalence (obtained from the 2019 behavioral Risk Factor Surveillance System) and EVALI case burden (obtained from the Centers for Disease Control and Prevention) adjusted for state cannabis policies. Cannabis vaping prevalence ranged from 1.14%(95%CI, 0.61%-2.12%) in Wyoming to 3.11%(95%CI, 2.16%-4.44%) in New Hampshire. EVALI cases per million population ranged from 1.90(0.38-3.42) in Oklahoma to 59.10(19.70-96.53) in North Dakota.

There was no significant positive association but an inverse association between state cannabis vaping prevalence and EVALI case burden (Coefficient, -18.6; 95%CI, -37.5-0.4; p-value, 0.05).

Thus, state-level cannabis vaping prevalence was not positively associated with EVALI prevalence, suggesting that there may not be a simple direct link between state cannabis vaping prevalence and EVALI cases, but rather the relationship is likely more nuanced and possibly reflective of access to informal sources of THC-containing e-cigarettes.”

https://pubmed.ncbi.nlm.nih.gov/36251673/

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0276187