Patent Application
20230285419
The present invention relates to the use of cannabidiol (CBD) for the treatment of seizures associated with rare epilepsy syndromes. In particular the seizures associated with rare epilepsy syndromes that are treated are those which are experienced in patients with BRAF mutation. In a further embodiment the types of seizures include tonic-clonic seizures. Preferably the dose of CBD is between 5 mg/kg/day to 50 mg/kg/day.
In a further embodiment the CBD used is in the form of a highly purified extract of cannabis such that the CBD is present at greater than 95% of the total extract (w/w) and the cannabinoid tetrahydrocannabinol (THC) has been substantially removed, to a level of not more than 0.15% (w/w).
Preferably the CBD used is in the form of a botanically derived purified CBD which comprises greater than or equal to 98% (w/w) CBD and less than or equal to 2% (w/w) of other cannabinoids. More preferably the other cannabinoids present are THC at a concentration of less than or equal to 0.1% (w/w); CBD-C1 at a concentration of less than or equal to 0.15% (w/w); CBDV at a concentration of less than or equal to 0.8% (w/w); and CBD-C4 at a concentration of less than or equal to 0.4% (w/w). The botanically derived purified CBD preferably also comprises a mixture of both trans-THC and cis-THC. Alternatively, a synthetically produced CBD is used.
Most preferably the other cannabinoids present are THC at a concentration of about 0.01% to about 0.1% (w/w); CBD-C1 at a concentration of about 0.1% to about 0.15% (w/w); CBDV at a concentration of about 0.2% to about 0.8% (w/w); and CBD-C4 at a concentration of about 0.3% to about 0.4% (w/w). Most preferably still the THC is present at a concentration of about 0.02% to about 0.05% (w/w).
Where the CBD is given concomitantly with one or more other anti-epileptic drugs (AED), the CBD may be formulated for administration separately, sequentially or simultaneously with one or more AED or the combination may be provided in a single dosage form.
Epilepsy occurs in approximately 1% of the population worldwide, (Thurman et al., 2011) of which 70% are able to adequately control their symptoms with the available existing anti-epileptic drugs (AED). However, 30% of this patient group, (Eadie et al., 2012), are unable to obtain seizure freedom from the AED that are available and as such are termed as suffering from intractable or “treatment-resistant epilepsy” (TRE).
Intractable or treatment-resistant epilepsy was defined in 2009 by the International League Against Epilepsy (ILAE) as “failure of adequate trials of two tolerated and appropriately chosen and used AED schedules (whether as monotherapies or in combination) to achieve sustained seizure freedom” (Kwan et al., 2009).
Individuals who develop epilepsy during the first few years of life are often difficult to treat and as such are often termed treatment resistant. Children who undergo frequent seizures in childhood are often left with neurological damage which can cause cognitive, behavioral and motor delays.
Childhood epilepsy is a relatively common neurological disorder in children and young adults with a prevalence of approximately 700 per 100,000. This is twice the number of epileptic adults per population.
When a child or young adult presents with a seizure, investigations are normally undertaken in order to investigate the cause. Childhood epilepsy can be caused by many different syndromes and genetic mutations and as such diagnosis for these children may take some time.
The main symptom of epilepsy is repeated seizures. In order to determine the type of epilepsy or the epileptic syndrome that a patient is suffering from an investigation into the type of seizures that the patient is experiencing is undertaken. Clinical observations and electroencephalography (EEG) tests are conducted and the type(s) of seizures are classified according to the ILEA classification.
Generalized seizures, where the seizure arises within and rapidly engages bilaterally distributed networks, can be split into six subtypes: tonic-clonic (grand mal) seizures; absence (petit mal) seizures; clonic seizures; tonic seizures; atonic seizures and myoclonic seizures.
Focal (partial) seizures where the seizure originates within networks limited to only one hemisphere, are also split into sub-categories. Here the seizure is characterized according to one or more features of the seizure, including aura, motor, autonomic and awareness/responsiveness. Where a seizure begins as a localized seizure and rapidly evolves to be distributed within bilateral networks this seizure is known as a bilateral convulsive seizure, which is the proposed terminology to replace secondary generalized seizures (generalized seizures that have evolved from focal seizures and are no longer remain localized).
Focal seizures where the subject's awareness/responsiveness is altered are referred to as focal seizures with impairment and focal seizures where the awareness or responsiveness of the subject is not impaired are referred to as focal seizures without impairment.
The BRAF gene codes for a protein that is part of a signaling pathway called the RAS/MAPK pathway, which plays a role in the multiple cell functions including proliferation, differentiation, cell migration, and apoptosis. Chemical signaling through this pathway is essential for normal development before birth.
The BRAF gene is an oncogene and so when mutated, it has the potential to turn normal cells into cancerous cells. Somatic mutations in the BRAF gene are common in several types of cancer. Normally, the BRAF protein is switched on and off in response to signals that control cell growth and development. However, mutations can cause the BRAF protein to be continuously active and to transmit messages to the nucleus even in the absence of signals. Consequently, the overactive protein contributes to the growth of cancers by allowing abnormal cells to grow and divide without external signals.
The V600E mutation is the most common BRAF gene mutation found in human cancers. This mutation has frequently been found in cancers of the colon and rectum, ovary, and thyroid gland. Several other somatic mutations in the BRAF gene have also been associated with cancer.
The BRAF-V600E mutation has been found in about half of epilepsy-associated paediatric brain tumours. Such paediatric brain tumours often cause epileptic seizures that are resistant to therapies. Treatment for such conditions is difficult because the tumors do not respond to existing antiepileptic drugs and debilitate children's development.
Cannabidiol (CBD), a non-psychoactive derivative from the cannabis plant, has demonstrated anti-convulsant properties in several anecdotal reports, pre-clinical and clinical studies both in animal models and humans. Three randomized control trials showed efficacy of the purified pharmaceutical formulation of CBD in patients with Dravet and Lennox-Gastaut syndrome.
Based on these three trials, a botanically derived purified CBD preparation was approved by FDA in June 2018 for the treatment of seizures associated with Dravet and Lennox-Gastaut syndromes.
An article by Hsu et al.1 discloses a single case study whereby a patient with glioma-related epilepsy attempted CBD for their seizures. The patient's glioma was caused by IDH1 mutation. There is no disclosure nor any suggestion as to the type of CBD treatment used.
EP3646868 relates to a use for diagnosis and treatment of ganglioglioma using a biomarker of ganglioglioma. It discloses that the BRAF-V600E mutation amongst others has been found in glioma-related epilepsy. The treatment claimed is the use of a BRAF-V600E protein activity inhibitor, such as Vemurafenib or Dabrafenib. There is no mention of the use of cannabinoids.
Koh et al.2 investigated epileptogenic mechanisms underlying brain tumours by studying mouse models harbouring the BRAF-V600E mutation. They suggest that the proteins BRAF and REST could be treatment targets for intractable epilepsy and point to FDA-approved BRAF-V600E inhibitor, vemurafenib, amongst others for the treatment of brain tumour-related epilepsy. There is no reference of the use of cannabinoids.
Kakkar et al.3 and Martinoni et al.4 are further documents that found the BRAF-V600E mutation as being frequent in gliomas, the former recommending this as a target for personalised therapy. Again, there is no hint of the use of cannabinoids in either of the two documents.
More generally, several publications mention the use of CBD in the treatment of seizures associated with rare and refractory epilepsies. However, none of these disclosures contain any data of patients with BRAF mutation being successfully treated with highly purified CBD.
Hausman-Kedem et al.5 discloses an uncontrolled open-label trial that investigated the use of CBD in the treatment of seizures. The trial involved one patient with brain tumour-related seizures, but the underlying cause is not disclosed. The CBD treatment used had a ratio of 20:1 CBD:THC.
Szaflarski et al.6 describe results from an Expanded Access Program whereby children with severe treatment-resistant epilepsies, Lennox-Gastaut syndrome or Dravet syndrome, received CBD treatment. Amongst the diagnoses, there is no mention of brain tumours let alone specific causes such as BRAF mutations being any of the conditions treated.
Porter & Jacobson7 report on a parent survey conducted via a Facebook group which explored the use of cannabis in children with epilepsy, the majority diagnosed with Dravet Syndrome. The children surveyed for this paper were taking cannabis that was purported to contain CBD in a high concentration although the amount of CBD present and the other constituents including THC were not known. Indeed, whilst CBD levels ranged from 0.5 to 28.6 mg/kg/day (in those extracts tested), THC levels as high as 0.8 mg/kg/day were reported.
Rosenberg et al.8 disclose a study that looked at Quality of Life markers in patients with epilepsy enrolled in a prospective, open-label clinical study of CBD. Such markers included fatigue, memory, control, and other cognitive functions, distinct from any seizure-reducing effects. Etiology of patients did not include BRAF mutation.
The applicant has found by way of an open label, expanded-access program that treatment with CBD resulted in a significant reduction in tonic-clonic seizures in patients with BRAF mutation.
In accordance with a first aspect of the present invention there is provided a cannabidiol (CBD) preparation for use in the treatment of seizures associated with BRAF mutation.
In a further embodiment, the seizures associated with BRAF mutation are tonic-clonic seizures.
In a further embodiment, the CBD preparation comprises greater than 95% (w/w) CBD and not more than 0.15% (w/w) tetrahydrocannabinol (THC).
Preferably the CBD preparation comprises greater than or equal to 98% (w/w) CBD and less than or equal to 2% (w/w) other cannabinoids, wherein the less than or equal to 2% (w/w) other cannabinoids comprise the cannabinoids tetrahydrocannabinol (THC); cannabidiol-C1 (CBD-C1); cannabidivarin (CBDV); and cannabidiol-C4 (CBD-C4), and wherein the THC is present as a mixture of trans-THC and cis-THC.
Preferably the CBD preparation is used in combination with one or more concomitant anti-epileptic drugs (AED).
Preferably the one or more AED is selected from the group consisting of: valproic acid, levetiracetam, clobazam, lacosamide, N-desmethylclobazam and clorazepate.
In one embodiment the CBD is present is isolated from cannabis plant material. Preferably at least a portion of at least one of the cannabinoids present in the CBD preparation is isolated from cannabis plant material.
In a further embodiment the CBD is present as a synthetic preparation. Preferably at least a portion of at least one of the cannabinoids present in the CBD preparation is prepared synthetically.
Preferably the dose of CBD is greater than 5 mg/kg/day. More preferably the dose of CBD is 20 mg/kg/day. More preferably the dose of CBD is 25 mg/kg/day. More preferably the dose of CBD is 50 mg/kg/day.
In accordance with a second aspect of the present invention there is provided a method of treating seizures associated with BRAF mutation comprising administering a cannabidiol (CBD) preparation to the subject in need thereof.
Definitions of some of the terms used to describe the invention are detailed below:
Over 100 different cannabinoids have been identified, see for example, Handbook of Cannabis, Roger Pertwee, Chapter 1, pages 3 to 15. These cannabinoids can be split into different groups as follows: Phytocannabinoids; Endocannabinoids and Synthetic cannabinoids (which may be novel cannabinoids or synthetically produced phytocannabinoids or endocannabinoids).
“Phytocannabinoids” are cannabinoids that originate from nature and can be found in the cannabis plant. The phytocannabinoids can be isolated from plants to produce a highly purified extract or can be reproduced synthetically.
“Highly purified cannabinoids” are defined as cannabinoids that have been extracted from the cannabis plant and purified to the extent that other cannabinoids and non-cannabinoid components that are co-extracted with the cannabinoids have been removed, such that the highly purified cannabinoid is greater than or equal to 95% (w/w) pure.
“Synthetic cannabinoids” are compounds that have a cannabinoid or cannabinoid-like structure and are manufactured using chemical means rather than by the plant.
Phytocannabinoids can be obtained as either the neutral (decarboxylated form) or the carboxylic acid form depending on the method used to extract the cannabinoids. For example, it is known that heating the carboxylic acid form will cause most of the carboxylic acid form to decarboxylate into the neutral form.
“Treatment-resistant epilepsy” (TRE) or “intractable epilepsy” is defined as per the ILAE guidance of 2009 as epilepsy that is not adequately controlled by trials of one or more AED.
“Tonic-clonic seizures” consist of two phases: the tonic phase and the clonic phase. In the tonic phase the body becomes entire rigid, and in the clonic phase there is uncontrolled jerking. Tonic-clonic seizures may or may not be preceded by an aura, and are often followed by headache, confusion, and sleep. They may last mere seconds or continue for several minutes. These seizures are also known as a grand mal seizure.
The following describes the production of the highly-purified (>95% w/w) cannabidiol extract which has a known and constant composition.
In summary the drug substance used is a liquid carbon dioxide extract of high-CBD containing chemotypes of Cannabis sativa L. which had been further purified by a solvent crystallization method to yield CBD. The crystallisation process specifically removes other cannabinoids and plant components to yield greater than 95% CBD. Although the CBD is highly purified because it is produced from a cannabis plant rather than synthetically there is a small number of other cannabinoids which are co-produced and co-extracted with the CBD. Details of these cannabinoids and the quantities in which they are present in the medication are as described in Table A below.
The following describes the production of the botanically derived purified CBD which comprises greater than or equal to 98% w/w CBD and less than or equal to other cannabinoids was used in the open label, expanded-access program described in Example 1 below.
In summary the drug substance used in the trials is a liquid carbon dioxide extract of high-CBD containing chemotypes of Cannabis sativa L. which had been further purified by a solvent crystallization method to yield CBD. The crystallisation process specifically removes other cannabinoids and plant components to yield greater than 95% CBD w/w, typically greater than 98% w/w.
The Cannabis sativa L. plants are grown, harvested, and processed to produce a botanical extract (intermediate) and then purified by crystallization to yield the CBD (botanically derived purified CBD).
The plant starting material is referred to as Botanical Raw Material (BRM); the botanical extract is the intermediate; and the active pharmaceutical ingredient (API) is CBD, the drug substance.
All parts of the process are controlled by specifications. The botanical raw material specification is described in Table B and the CBD API is described in Table C.
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The purity of the botanically derived purified CBD preparation was greater than or equal to 98%. The botanically derived purified CBD includes THC and other cannabinoids, e.g., CBDA, CBDV, CBD-C1, and CBD-C4.
In some embodiments, the CBD preparation comprises not more than 0.15% THC based on total amount of cannabinoid in the preparation. In some embodiments, the CBD preparation comprises about 0.01% to about 0.1% THC based on total amount of cannabinoid in the preparation. In some embodiments, the CBD preparation comprises about 0.02% to about 0.05% THC based on total amount of cannabinoid in the preparation.
In some embodiments, the CBD preparation comprises about 0.2% to about 1.0% CBDV based on total amount of cannabinoid in the preparation. In some embodiments, the CBD preparation comprises about 0.2% to about 0.8% CBDV based on total amount of cannabinoid in the preparation.
In some embodiments, the CBD preparation comprises about 0.3% to about 0.5% CBD-C4 based on total amount of cannabinoid in the preparation. In some embodiments, the CBD preparation comprises about 0.3% to about 0.4% CBD-C4 based on total amount of cannabinoid in the preparation.
In some embodiments, the CBD preparation comprises about 0.1% to about 0.15% CBD-C1 based on total amount of cannabinoid in the preparation.
Distinct chemotypes of the Cannabis sativa L. plant have been produced to maximize the output of the specific chemical constituents, the cannabinoids. Certain chemovars produce predominantly CBD. Only the (−)-trans isomer of CBD is believed to occur naturally. During purification, the stereochemistry of CBD is not affected.
An overview of the steps to produce a botanical extract, the intermediate, are as follows:
High CBD chemovars were grown, harvested, dried, baled and stored in a dry room until required. The botanical raw material (BRM) was finely chopped using an Apex mill fitted with a 1 mm screen. The milled BRM was stored in a freezer prior to extraction.
Decarboxylation of CBDA to CBD was carried out using heat. BRM was decarboxylated at 115° C. for 60 minutes.
Extraction was performed using liquid CO2 to produce botanical drug substance (BDS), which was then crystalized to produce the test material. The crude CBD BDS was winterized to refine the extract under standard conditions (2 volumes of ethanol at −20° C. for approximately 50 hours). The precipitated waxes were removed by filtration and the solvent was removed to yield the BDS.
The manufacturing steps to produce the botanically derived purified CBD preparation from BDS were as follows:
The BDS produced using the methodology above was dispersed in C5-C12 straight chain or branched alkane. The mixture was manually agitated to break up any lumps and the sealed container then placed in a freezer for approximately 48 hours. The crystals were isolated via vacuum filtration, washed with aliquots of cold C5-C12 straight chain or branched alkane, and dried under a vacuum of <10 mb at a temperature of 60° C. until dry. The botanically derived purified CBD preparation was stored in a freezer at −20° C. in a pharmaceutical grade stainless steel container, with FDA food grade approved silicone seal and clamps.
The botanically derived purified CBD used in the clinical trial described in the invention comprises greater than or equal to 98% (w/w) CBD and less than or equal to 2% (w/w) of other cannabinoids. The other cannabinoids present are THC at a concentration of less than or equal to 0.1% (w/w); CBD-C1 at a concentration of less than or equal to 0.15% (w/w); CBDV at a concentration of less than or equal to 0.8% (w/w); and CBD-C4 at a concentration of less than or equal to 0.4% (w/w).
The botanically derived purified CBD used additionally comprises a mixture of both trans-THC and cis-THC. It was found that the ratio of the trans-THC to cis-THC is altered and can be controlled by the processing and purification process, ranging from 3.3:1 (trans-THC:cis-THC) in its unrefined decarboxylated state to 0.8:1 (trans-THC:cis-THC) when highly purified.
Furthermore, the cis-THC found in botanically derived purified CBD is present as a mixture of both the (+)-cis-THC and the (−)-cis-THC isoforms.
Clearly a CBD preparation could be produced synthetically by producing a composition with duplicate components.
Example 1 below describes the use of a botanically derived purified CBD in an open label, expanded-access program to investigate the clinical efficacy and safety of purified pharmaceutical cannabidiol formulation (CBD) in the treatment of seizures associated with BRAF mutation.
The subject was required to be on one or more AEDs at stable doses for a minimum of two weeks prior to baseline and to have stable vagus nerve stimulation (VNS) settings and ketogenic diet ratios for a minimum of four weeks prior to baseline.
The patient was administered botanically derived purified CBD in a 100 mg/mL sesame oil-based solution at an initial dose of 10 milligrams per kilogram per day (mg/kg/day) in two divided doses.
A maximum dose of 50 mg/kg/day could be utilised if the patient was tolerating the medication but had not achieved seizure control; the patient had further weekly titration by 5 mg/kg/day.
There one patient in this study, and they received CBD for 132 weeks. Modifications were made to concomitant AEDs as per clinical indication.
Seizure frequency, intensity, and duration were recorded by caregivers in a diary during a baseline period of at least 28 days. Changes in seizure frequency relative to baseline were calculated after at least 2 weeks and at defined timepoints of treatment.
Patients may be defined as responders if they had more than 50% reduction in seizure frequency compared to baseline. The percent change in seizure frequency was calculated as follows:
The percent change of seizure frequency may be calculated for any time interval where seizure number has been recorded. For the purpose of this example the percent change of seizure frequency for the end of the treatment period was calculated as follows:
One patient enrolled in the open label, expanded-access program had BRAF mutation. These patients experienced several different seizure types including tonic-clonic seizures and was taking several concomitant AEDs.
The patient was 18 years old and he was male as detailed in Table 1 below.
The patient on the study was titrated up to 30 mg/kg/day of CBD. The patient was on six concomitant AEDs at the time of starting CBD.
Table 2 illustrates the seizure frequency for the patient as well as the dose of CBD given.
Patient 1 was treated for 132 weeks and experienced a 20% reduction in tonic-clonic seizures over the treatment period.
Overall, the patient reported a reduction of 20% in tonic-clonic seizures over period of treatment with CBD. CBD was effective in reducing the frequency of tonic-clonic seizures.
These data indicate that CBD was able to significantly reduce the number of seizures associated with BRAF mutation. Clearly the treatment is of significant benefit in this difficult to treat epilepsy syndrome given the high response rate experienced in the patient.
In conclusion, this study signifies the use of CBD for treatment of seizures associated with BRAF mutation. Seizure types include tonic-clonic seizures for which seizure frequency rates decreased by 20%.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011153.0 | Jul 2020 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/069906 | 7/15/2021 | WO |
