USE OF CANNABIDIOL IN THE TREATMENT OF SEIZURES ASSOCIATED WITH RARE EPILEPSY SYNDROMES RELATED TO GENETIC ABNORMALITIES

Abstract

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 inpatients with mutation in the potassium channel (KCN) gene. In a further embodiment the types of seizures include tonic, tonic-clonic, absence and focal seizures with impairment. Preferably the dose of CBD is between 5 mg/kg/day to 50 mg/kg/day.

Claims

1. A cannabidiol (CBD) preparation for use in the treatment of seizures associated with potassium channel (KCN) gene mutation, wherein the KCN gene mutation is in one of KCNA1 and/or KCNQ2.

2. A CBD preparation for use according to any of the preceding claims, wherein the seizures associated with KCN gene mutation are tonic, tonic-clonic, absence and focal seizures with impairment.

3. A CBD preparation for use according to any of the preceding claims, wherein the CBD preparation comprises greater than 95% (w/w) CBD and not more than 0.15% (w/w) tetrahydrocannabinol (THC).

4. A CBD preparation for use according to any of the preceding claims, wherein 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.

5. A CBD preparation to any of the preceding claims, wherein the CBD preparation is used in combination with one or more concomitant anti-epileptic drugs (AED).

6. A CBD preparation for use according to claim 5, wherein the one or more AED is selected from the group consisting of: clobazam, vigabatrin, phenobarbital, diazepam and zonisamide.

7. A CBD preparation for use according to any of the preceding claims, wherein the CBD is present is isolated from cannabis plant material.

8. A CBD preparation for use according to any of the preceding claims, wherein at least a portion of at least one of the cannabinoids present in the CBD preparation is isolated from cannabis plant material.

9. A CBD preparation for use according to claims 1 to 6, wherein the CBD is present as a synthetic preparation.

10. A CBD preparation for use according to claim 9, wherein at least a portion of at least one of the cannabinoids present in the CBD preparation is prepared synthetically.

11. A CBD preparation for use according to any of the preceding claims, wherein the dose of CBD is greater than 5 mg/kg/day.

12. A CBD preparation for use according to any of the preceding claims, wherein the dose of CBD is 20 mg/kg/day.

13. A CBD preparation for use according to any of the preceding claims, wherein the dose of CBD is 25 mg/kg/day.

14. A CBD preparation for use according to any of the preceding claims, wherein the dose of CBD is 50 mg/kg/day.

15. A method of treating seizures associated with potassium channel (KCN) gene mutation comprising administering a cannabidiol (CBD) preparation to the subject in need thereof, wherein the KCN gene mutation is in one of KCNA1 and/or KCNQ2.

Description

DETAILED DESCRIPTION

Preparation of Highly Purified CBD Extract

[0050] The following describes the production of the highly-purified (>95% w/w) cannabidiol extract which has a known and constant composition.

[0051] 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.

TABLE-US-00001 TABLE A Composition of highly purified CBD extract Cannabinoid Concentration CBD >95% w/w CBDA NMT 0.15% w/w CBDV NMT 1.0% w/w Δ.sup.9 THC NMT 0.15% w/w CBD-C4 NMT 0.5% w/w >greater than NMT-not more than

Preparation of Botanically Derived Purified CBD

[0052] 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.

[0053] 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.

[0054] 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).

[0055] 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.

[0056] 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.

TABLE-US-00002 TABLE B CBD botanical raw material specification Test Method Specification Identification: Visual Complies A TLC Corresponds to standard (for CBD & CBDA) B HPLC/UV Positive for CBDA C Assay: In-house NLT 90% of assayed CBDA + CBD (HPLC/UV) cannabinoids by peak area Loss on Drying Ph.Eur. NMT 15% Aflatoxin UKAS method NMT 4 ppb Microbial: Ph.Eur. NMT10.sup.7 cfu/g TVC NMT10.sup.5 cfu/g Fungi NMT10.sup.2 cfu/g E. coli Foreign Matter: Ph.Eur. NMT 2% Residual Herbicides and Ph.Eur. Complies Pesticides

TABLE-US-00003 TABLE C Specification of an exemplary botanically derived purified CBD preparation Test Test Method Limits Appearance Visual Off-white/pale yellow crystals Identification A HPLC-UV Retention time of major peak corresponds to certified CBD Reference Standard Identification B GC-FID/MS Retention time and mass spectrum of major peak corresponds to certified CBD Reference Standard Identification C FT-IR Conforms to reference spectrum for certified CBD Reference Standard Identification D Melting Point 65-67° C. Identification E Specific Optical Conforms with certified CBD Reference Rotation Standard; −110° to −140° (in 95% ethanol) Total Purity Calculation ≥98.0% Chromatographic Purity 1 HPLC-UV ≥98.0% Chromatographic Purity 2 GC-FID/MS ≥98.0% CBDA HPLC-UV NMT 0.15% w/w CBDV 0.2-1.0% w/w THC 0.01-0.1% w/w CBD-C4 0.3-0.5% w/w Residual Solvents: GC NMT 0.5% w/w Alkane NMT 0.5% w/w Ethanol Residual Water Karl Fischer NMT 1.0% w/w

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] Production of CBD Botanical Drug Substance

[0064] An overview of the steps to produce a botanical extract, the intermediate, are as follows: [0065] a) Growing [0066] b) Direct drying [0067] c) Decarboxylation [0068] d) Extraction—using liquid CO.sub.2 [0069] e) Winterization using ethanol [0070] f) Filtration [0071] g) Evaporation

[0072] 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.

[0073] Decarboxylation of CBDA to CBD was carried out using heat. BRM was decarboxylated at 115° C. for 60 minutes.

[0074] Extraction was performed using liquid CO.sub.2 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.

[0075] Production of Botanically Derived Purified CBD Preparation

[0076] The manufacturing steps to produce the botanically derived purified CBD preparation from BDS were as follows: [0077] a) Crystallization using C.sub.5-C.sub.12 straight chain or branched alkane [0078] b) Filtration [0079] c) Vacuum drying

[0080] The BDS produced using the methodology above was dispersed in C.sub.5-C.sub.12 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 C.sub.5-C.sub.12 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.

[0081] Physicochemical Properties of the Botanically Derived Purified CBD

[0082] 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).

[0083] 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.

[0084] 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.

[0085] Clearly a CBD preparation could be produced synthetically by producing a composition with duplicate components.

[0086] 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 KCN gene mutation.

Example 1: Clinical Efficacy and Safety of Purified Pharmaceutical Cannabidiol (CBD) in the Treatment of Patients with Potassium Channel Gene Mutation

[0087] Study Design

[0088] Subjects were 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.

[0089] Patients were administered botanically derived purified CBD in a 100 mg/mL sesame oil-based solution.

[0090] A maximum dose of 50 mg/kg/day could be utilised for patients who were tolerating the medication but had not achieved seizure control; these patients had further weekly titration by 5 mg/kg/day.

[0091] There were three patients in this study, and each received CBD for various durations of time. Modifications were made to concomitant AEDs as per clinical indication.

[0092] 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.

[0093] Statistical Methods:

[0094] 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:

[00001]$\%\mathrm{change}\mathrm{seizure}\mathrm{frequency}=\frac{\begin{array}{c}(\left(\mathrm{weekly}\mathrm{seizure}\mathrm{frequency}\mathrm{time}\mathrm{interval}\right)-\\ \left(\mathrm{weekly}\mathrm{seizure}\mathrm{frequency}\mathrm{Baseline}\right))\end{array}}{\left(\mathrm{weekly}\mathrm{seizure}\mathrm{frequency}\mathrm{Baseline}\right)}\times 100$

[0095] 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:

[00002]$\%\mathrm{reduction}\mathrm{seizure}\mathrm{frequency}=\frac{\begin{array}{c}(\left(\mathrm{weekly}\mathrm{seizure}\mathrm{frequency}\mathrm{Baseline}\right)-\\ \left(\mathrm{weekly}\mathrm{seizure}\mathrm{frequency}\mathrm{End}\right))\end{array}}{\left(\mathrm{weekly}\mathrm{seizure}\mathrm{frequency}\mathrm{Baseline}\right)}\times 100$

Results

[0096] Patient Description

[0097] The three patients enrolled in the open label, expanded-access program had mutations in the KCN gene. These patients experienced several different seizure types including tonic, tonic-clonic, absence and focal seizures with impairment and were taking several concomitant AEDs.

[0098] The age of patients ranged from 1-10 years, two were male and one was female as detailed in Table 1 below.

TABLE-US-00004 TABLE 1 Patient demographics, seizure type and concomitant medication Patient Age Concomitant Number (years) Sex Seizure types AEDS Etiology 1 6.67 M Tonic-clonic, ZNS, PHB KCNA1 focal with gene impairment mutation 2 1.89 M Tonic CLB, VGB KCNQ2 gene mutation 3 10.02 F Tonic-clonic, DZP KCNQ2 absence gene mutation CLB = clobazam, VGB = vigabatrin, ZNS = zonisamide, PHB = phenobarbital, DZP = diazepam

[0099] Study Medication and Concomitant Medications

[0100] All three patients were titrated up to at least 25 mg/kg/day of CBD. The average number of concomitant AEDs at the time of starting CBD was two per patient (range: 1-2).

[0101] Clinical Changes

[0102] Tables 2A-C illustrate the seizure frequency for each patient as well as the dose of CBD given.

TABLE-US-00005 TABLE 2A Seizure frequency data for Patient 1 Patient 1 Seizure Type Dose CBD Tonic- Focal with (mg/kg/ Time clonic impairment day) Baseline 1.0 10.0 —  2 weeks 0.0 16.0 10.0  4 weeks 0.0 0.0 20.0  8 weeks 1.0 1.0 25.0 12 weeks 0.0 0.0 25.0 16 weeks 0.0 0.0 25.0 24 weeks 0.0 5.3 25.0 36 weeks 2.0 10.0 25.0 48 weeks 0.7 8.3 25.0 60 weeks 0.0 0.8 25.0 84 weeks 0.0 0.0 25.0

[0103] Patient 1 was treated for 84 weeks and experienced a 100% reduction in tonic-clonic seizures and a 100% reduction in focal seizures with impairment over the treatment period.

TABLE-US-00006 TABLE 2B Seizure frequency data for Patient 2 Patient 2 Seizure Type Dose CBD Time Tonic (mg/kg/day) Baseline 42.8 —  2 weeks 9.6 3.4  4 weeks 32.8 10.6  8 weeks 0.0 26.0 12 weeks 14.8 26.1 16 weeks 6.0 26.9 24 weeks 31.0 27.7

[0104] Patient 2 was treated for 24 weeks and experienced a 27.6% reduction in tonic seizures over the treatment period.

TABLE-US-00007 TABLE 2C Seizure frequency data for Patient 3 Patient 3 Seizure Type Dose CBD Time Tonic-clonic Absence (mg/kg/day) Baseline 10.0 624.0 —  8 weeks 1.0 48.0 25.0 16 weeks 1.0 200.0 25.0

[0105] Patient 3 was treated for 16 weeks and experienced a 90% reduction in tonic-clonic seizures and a 67.9% reduction in absence seizures over the treatment period.

[0106] Overall, patients reported reductions of 27.6-100% in seizures over period of treatment with CBD.

[0107] Significantly, one patient (#1) became completely seizure free after 84 weeks of treatment with CBD.

[0108] CBD was effective in reducing the frequency of the following seizure types: tonic, tonic-clonic, absence and focal seizures with impairment.

Conclusions

[0109] These data indicate that CBD was able to significantly reduce the number of seizures associated with KCN gene mutation. Clearly the treatment is of significant benefit in this difficult to treat epilepsy syndrome given the high response rate experienced in all patients.

[0110] Of interest is that patients with tonic-clonic seizures (patients 1 and 3) obtained significant benefit.

[0111] In conclusion, this study signifies the use of CBD for treatment of seizures associated with KCN gene mutation. Seizure types include tonic, tonic-clonic, absence and focal seizures with impairment for which seizure frequency rates decreased by significant rates, by between 28-100%.

REFERENCES

[0112] 1. Borlot et al. (2020) “KCNTI-related epilepsy: An international multicenter cohort of 27 paediatric cases.” Epilepsia, 2020 [0113] 2. Poisson et al. (2020) “Response to cannabidiol in epilepsy of infancy with migrating focal seizures associated with KCNTI mutations: An open-label, prospective, interventional study”, European Journal of Paediatric Neurology, Vol 25; pp 77-81