Dexanabinol

The Opportunity

Dexanabinol is the leading compound in Pharmos’ CNS program. Dexanabinol is a novel synthetic compound with neuroprotective activity that has potent anti-inflammatory and anti-oxidant properties. Dexanabinol was designed to provide neuroprotection against damage associated with ischemic brain conditions such as Traumatic Brain Injury (TBI) and stroke, and is currently in clinical trials for those indications.

Tagged as a “silent epidemic” nearly a decade ago, Traumatic Brain Injury (TBI) is a leading cause of death and disability among a predominately young male population. Estimates run as high as 10 million cases of TBI per year worldwide. Annually, within the U.S., there are about 2 million emergency room visits for head injury, roughly 475,000 admissions for head trauma, nearly 52,000 deaths and approximately 80,000 cases of severe long-term disability.

In the U.S. alone, there are more than 5.3 million people living with TBI-related disabilities. The incidence of TBI far exceeds the annual incidence rates of Multiple Sclerosis, Parkinson’s Disease and Alzheimer’s Disease.

According to the National Institutes of Health, the economic consequences of TBI are enormous. The annual cost of acute care and rehabilitation in the U.S. for new cases is estimated to be as high as $10 billion. A study by the National Foundation for the Brain estimated the annual cost in the U.S. for TBI at $48.3 billion.

The annual market potential for treating TBI in the U.S. is estimated to be over $500 million. The worldwide estimate for the treatment of TBI is estimated at $1 billion. Currently there is no FDA approved product for the treatment of severe head injury.

The Technology

Dexanabinol is an optic isomer, arranged in the mirror image, of THC, the active molecule of the cannabis (marijuana) plant. This design prevents dexanabinol from binding with the cannabinoid receptors in the brain thereby allowing the compound to be used therapeutically without psychotropic side effects. Dexanabinol was invented by Professor Raphael Mechoulam of The Hebrew University in Jerusalem, the world leader in cannaboid chemistry.

Injury to the brain, by motor vehicle accident, stroke, or other insult, results in the development of a cascade of biological events that can dangerously inflame or kill brain cells. Within minutes of the insult, toxic chemicals and excitatory amino acids are released in the brain. Within hours of the injury, calcium ions enter the cell and trigger intracellular toxic biochemical events that result in cell death. Inflammatory cytokines are also sythesized and are massively released causing the breakdown of the vascular blood brain barrier and cell death (apoptosis). Within hours, the intracranial pressure (ICP) is elevated. This elevation causes further ischemia and the brain suffers a secondary neurological injury that may increase the probability of a bad clinical outcome for the patient.

Dexanabinol, administered within hours after the initial insult, may inhibit the synthesis, release and activity of the neuro-toxic chemicals, thereby, rescuing the brain cells and shielding the brain from an increase in ICP. This could ultimately result in an improved neurological outcome for the patient.

Pharmos has selected TBI as the first treatment indication in clinical trials and has completed Phase II trials. The second indication for clinical investigation is stroke and one Phase I clinical trial has been completed. Dexanabinol is also seen as a potential treatment for seizures, multiple sclerosis, inhalation of nerve gas and other neurological conditions associated with inflammatory processes.