Kalpna Gupta, PhD

Vascular Biology CentreDivision of Hematology, Oncology and

TransplantationDepartment of Medicine

University of Minnesota Medical SchoolMinneapolis, MN

Cannabis: A Medicine to Treat Pain?

MDH, Minnetonka, MN Sept 03, 2015

The starting point?

Medical and Scientific Nomenclature

To be referred to as Cannabis/cannabinoids and NOT Marijuana

To be called Medicine and NOT Drug

To be thought of as Plant NOT Weed

To treat the Sick NOT ----?

Calyx: comprise the female flowers with tiny nodules under the leaf with high concentration of glands or trichromes that secrete THC and other bioactive compounds in the highest concentration.

Trichromes: Crystal resins secreted through transluscent, mushroom shaped glands on leaves, stems and calyxes on the buds, containing cannabinoids and terpenes.

Schedule 1

Cannabis

Hallucinogenic amphetamine derivatives

Heroin

LSD

Barbiturates

Current Regulatory Status of Cannabis

1963 structure of Cannabidiol (CBD): Israeli Scientist Raphael Mechoulam

1964: Isolated the active ingredient delta-9 tetrahydrocannabinol (THC)

480 natural compounds and 66 are “cannabinoids” including CBD and THC.

Discovery of Cannabinoids

Cannabinoids

Endogenous

Anandamide(“Supreme bliss”)

Phytochemicals Synthetic

By binding to transmembrane G-Protein coupled receptors called cananbinoid receptor 1 (CB1R) and cannabinoid receptor 2 (CB2R)

How do Cannabinoids act?

Activation of signaling pathways by cannabinoid receptors

Elikottil J, Gupta P and Gupta K. The Analgesic Potential of Cannabinoids. J Opioid Management 2009

Role in central sensitization/intractable pain

Why do we want to use Cannabis as pain medicine?

PAIN

Compounds working better together than in isolation.Therefore the plant has greater beneficial effects as compared to an isolated cannabinoid.

Entourage effect

Pain

• Costs the nation >$635 billion/year.• 40% of the adult population in the United

States suffers with chronic pain.• Neuropathic pain such as that observed

in diabetes and sickle cell disease, remains a major challenge to treat.

Opioid and Cannabinoid use: side effects

Elikottil J, Gupta P and Gupta K. The Analgesic Potential of Cannabinoids. J Opioid Management 2009

Are opioids ideal analgesics to treat chronic pain?

Gupta K. Iatrogenic Angiogenesis. In, Morphine and Metastasis. Springer 2012.

Based on Experimental Studies

ε Gγ Aγ ψβ δ β

CCT GAG GAG CCT GTG GAGPro Glu Glu Pro Val Glu5 6 7 5 6 7

C

CH2

CH3

O OHC

CH2

C

CH

CH3

chrom#11

-O2 +O2

Sickle Cell Anemia: Molecular Basis

Courtesy, Robert P Hebbel MD

Pain in sickle cell disease

• Pain can start during infancy and increases in severity throughout life, reaching levels considered higher than labor pain during childbirth.

• Long-term opioid usage, however, creates a high risk of addiction, tolerance and side effects that pose a major obstacle for pain management. Opioids may not even be effective always.

• Recurrent episodes of crises and pain lead to increased hospitalization, poor quality of life, morbidity and mortality, resulting in reduced lifespan of patients with sickle cell disease.

Des

cend

ing

pain

mod

ulat

ion

path

way

Ascending pathw

ay

TNFα IL6

gc

Skin

Peripheral nerve fibers

SPSpinal cord

Antidromic release

SP

SP

DRG

Nociceptive mechanisms involve peripheral and central nervous system and immune cells

BrainPAIN

Cannabinoids decrease the activity of nociceptors

Arachidonyl-2’-chloroethylamide (ACEA), a CB1R agonist,attenuated the response of A-delta nociceptors in inflamed skin.

Vehicle, ACEA, or ACEA + AM251(a CB1R antagonist) was injected into the plantar skin.

Line above each trace is the time of mechanical stimulation (156 mN).

Potenzieri et al., 2008CB1R mediates inhibition of nociceptor sensitization

Peripheral cannabinoids attenuate cancer pain

WIN 55,212-2 dose-dependently attenuates mechanical hyperalgesia in a murine model of cancer pain. Local injection of 2.5, 5, or 10 μg of WIN 55,212-2 into the tumor-bearing hindpaw reduced the mean paw withdrawal frequency evoked by a suprathreshold von Frey monofilament (3.4 mN). *Treatment Vsvehicle, p < 0.05. Potenzieri et al., 2008

Mouse model

Sickle (HbSS-BERK) and Control (HbAA-BERK) mice (Paszty et al., Science 1997): These mice recapitulate the hematologic disease, organ damage, reduced life-span and pain (Kohli et al, Blood 2010; Cain et al., Br J Hematol 2011).

Importantly, the chronic pain phenotypes observed in this mouse model have been validated in human sickle patients (Brandow et al., 2012 and 2015). Further escalation in hyperalgesia is evoked in these mice with hypoxia/reperfusion injury to simulate pain due to vasocclusive crises (Cain et al., 2012), a caharacteristic, recurrent and unpredictable feature of SCD, which remains a major challenge to treat.

Substance P and CGRP, mediators of pain are upregulated in the periphery (skin) via a centrally mediated mechanism in chronic pain.(Editorial Commentary: New Era dawns on pain in sickle cell disease)

Red, SP

Blue, CGRP

Green, blood vessel

Kohli et al., Gupta laboratory Blood 2010

HbAA-BERK (Control) HbSS-BERK (Sickle)

Substance P and CGRP are increased in the skin of sickle (BERK) mice

Red, SP; Blue, CGRP; Green, blood vessels

(Kohli et al. Blood, 2010)

A vicious cycle of mast cell degranulation and nociceptor activation leads to pain in SCD

(1) Mast cell-tryptase cleaves PAR2 on peripheral nociceptors

(2) Activation of PAR2 sensitizes TRPV1 channels on nerve endings

(3) Activation of PAR2 and TRPV1 leads to release of CGRP and SP from the sensory nerve endings

(4) CGRP may stimulate arteriolar dilatation.

(5) SP stimulates plasma extravasation leading to neurogenic inflammation

(6) SP acts in a paracrine and autocrinemanner by activating mast cells thus promoting a vicious cycle of mast cell degranulation and nocicepor activation.

6

Vincent et al.– Gupta K. “Plenary Paper” Blood 2013;122:1853-62. Editorial Commentary by Kutlar A “GLEE-ful for sickle pain?”

(0.3 mg/Kg)

Higher Grip Force = Less Pain

High dose of morphine is required to reduce hyperalgesia in sickle mice, but a relatively low dose of cannabinoids is effective

(Kohli et al. Blood, 2010)

Cannabinoid treatment ameliorates pain incited by hypoxia-reoxygenation in sickle mice

Higher Grip Force = Less Pain

Cain et al., Br J Hematology 2011

CP55,940 decreases deep hyperalgesia in sickle mice without causing tolerance

** p < 0.01 *** p < 0.001

3 wks treatment w/ CP55,940

Higher grip force = increased analgesiaTreatment for 3 weeks with CP55,940 (i.p. , 0.3 mg.kg-1) once daily.

Vincent et al., 2015, communicated

CP55,940 decreased cytokine expression in sickle mice

CYTOKINE RELEASE FROM SKIN

* p < 0.05 Vs. HbSS veh ** p < 0.01 Vs. HbSS veh

3 wks treatment w/ CP55,940

CP55,940 treatment for 3 weaks leads to a sustained inhibition of mast cell degranulation in the skin of sickle mice

HbSSVeh

HbSSCP55,940

HbAAVeh

C-kit/CD117 FCεRI Tryptase

Thus, cannabinoids reduce inflammation

CP55,940 decreases neorogenic inflammation following H/R injury in sickle mice

1 wk treatment w/ CP55,940 + H/R

Thus, cannabinoids attenuate the activation of peripheral nerve activity, which requires both CB1 and CB2R (data not shown)

Deep Mechanical

Thermal Catalepsy

Vincent et al., 2015 (communicated)

Requirement of CB1- and CB2-receptors for attenuation of hyperalgesia in sickle pain phenotypes

grip force,analgesia

PWF

analgesia

PWL,analgesia

Cannabinoids as potential analgesics to treat pain in SCD and other neuropathic pain conditions

• Cannabinoid receptors (CB1 & CB2) are located in the brain,nerve fibers & inflammatory cells in the periphery and CNS.

• Activation of peripheral cannabinoid receptors attenuatesinflammatory & neuropathic pain

• Potential therapeutic option to protect organs fromhypoxia/reperfusion injury (Fouad & Jresat, 2011; Gonzaleset al, 2011), oxidative stress (Booz, 2011; Cassol et al, 2010)and inflammation (Ribeiro et al, 2012

• Cannabinoids can be used via oral, oro-mucosal, respiratoryor systemic routes

• Some preparations like Sativex, an oro-mucosal spray, areapproved for clinical use in Canada & Europe.

• A retrospective study of Cannabis users showed that 52% of SCD patients reported decrease in pain, anxiety and depression. (Howard et al., Br J Hematology 2005)

University of Minnesota: Kalpna Gupta, PhD (lead PI) and John Connett, PhD with UCSF: Donald Abrams, MD

ClinicalTrials.gov (identifier:NCT01771731).

Funded by NHLBI, UO1 HL117664

Cannabis Provided by : NIDAVaporized Cannabis: 4.7% THC and 5.1% CBD

Proof of Principle Trial of Cannabis to Treat Pain in SCD

Cannabis Vaporizer

SCD: Study Design

1. Effect of 5-day treatment with vaporized Cannabis or Placebo on pain and other associated disorders (sleep. Anxiety, depression, etc) in patients with SCD.

2. Determine the short-term side effects associated with inhaled Cannabis treatment in association with opioids.

3. Examine the markers of pain, inflammation and disease progression.

From concept to realization

2010-2011: Gupta K, U of M, Efforts to obtain a license2011: Approached Donald Abrams, UCSF2012: Applied for funding to NHLBI, NIH2012-2013: Grant competed in the top ranks but funding delayed until Sept 2013 due to Government issues.7/19/2013: UCSF, CTSI approves the trial7/23/2013: UCSF General Hospital; IRB approves the trial (approval number 13-10526). 11/7/2103: IND 119158 for cannabis, FDA approval11/14/2013: DEA form submitted2/19/2014: DEA responds, field investigation required4/2014: Field investigation completedMay 2014: Research Advisory Panel of California, Approval.July 2014: Cannabis received from NIDA2017-18: Anticipated completion

Vaporization is a safe mode of delivery:Physiologic THC levels are comparableExpired carbon monoxide is decreased

Participants preferred vaporized Cannabis Vs smoked

Co-adminstration with opioids is safe and enhances analgesia in patients with chronic pain.

Abrams et al, Clin Pharm and Therap 2011

Safety and efficacy of vaporized Cannabis

HIV-associated Neuropathy

Smoked Cananbis effective in treating peripheral neuropathy

Smoked Cannabis effective in attenuating central sensitization

Effectiveness of smoked Cannabis comparable to trials with Gabapentin

Abrams et al., Neurology 2007

Abrams et al., Neurology, 2007

Analgesic effect of smoked Cannabis on HIV-neuropathy in a placebo controlled randomized clinical

trial

Abrams et al., Neurology, 2007

Date of download: 8/27/2014 Copyright © 2014 American Medical Association. All rights reserved.

From: Medical Cannabis Laws and Opioid Analgesic Overdose Mortality in the United States, 1999-2010

JAMA Intern Med. 2014;():. doi:10.1001/jamainternmed.2014.4005

Association Between Medical Cannabis Laws and Opioid Analgesic Overdose Mortality in Each Year After Implementation of Laws in the United States, 1999-2010Point estimate of the mean difference in the opioid analgesic overdose mortality rate in states with medical cannabis laws compared with states without such laws; whiskers indicate 95% CIs.

Figure Legend:

Randomized controlled trials examining cannabinoids in treatment of chronic non-cancer pain

Lynch et al., Cannabinoids for treatment of chronic non-cancer pain; a systematic review of randomized trialsBr J Clin Pharmacol 2011

Potential of Cannabis to treat pain and associated symptoms

• As an adjunct to opioids

• In opioid-induced tolerance

• For mood elevation?

• As an appetite stimulant

• Relieving nausea

• to relieve stress

•Sleep

Disease-specific research and appropriately designed clinical trials

Approval of these compounds by FDA and availability for analgesia through regulated pharmacies

Evidence based review and regulatory oversight should be similar for cannabis and other medications prescribed by physicians.

Safe route of administration (oral pills or inhalation in quantifiable amounts)

Database to record outcomes for objective assessment of pain and multiple symptoms and pathological outcomes.

Collaboration of a dedicated team of scientists, physicians, community participants, patient advocates, law makers and industry.

Funding and policies to facilitate fast-track research.

Future Directions

Lab MembersYing Wang, PhDHuy TranJianxun Lei, PhDLucile Vincent, PhDJinny A Paul, PhDYessenia V Guevara, PhDYann Lamarre, PhDMaureen Reidl, PhDJoe Cataldo, PhDMegan Uhelski, PhDAditya M Mittal

Lab MembersJulia NguyenBarbara BensonRitu JhaKathryn LukSusan ThompsonLindsey SkubitzThu DuongAditya MitalJonathan Luk PaulDeniz Arcan-FangSarita Jarret

ACKNOWLEDGEMENTS

NHLBI, UO1HL117664, RO1s HL6880, HL103733, HL68802-06S1; HL68802-7S1

Institute for Engineering in MedicineUniversity of Minnesota Foundation

Dean’s and Department of Medicine Funds

CollaboratorsDonald Abrams, MD, UCSFDonald A Simone, PhD

Acknowledgements

Collaborators

Donald A Simone, PhD

George Weiblen, PhD

Pankaj Gupta, MD

Donald Abrams, MD (UCSF)

Members of Gupta Laboratory

NIH RO1s HL68802 and HL103733; UO1HL117664Institute for Engineering in Medicine grant; University of Minnesota Foundation