In 2017, the drug naloxone is almost a household name. It’s a frontline therapy for reviving individuals that have overdosed on opioids such as heroin, oxycontin, and fentanyl — an increasingly common occurrence in U.S. towns ravaged by an epidemic of opioid abuse.
Opiant Pharmaceuticals has been part of that crusade with the FDA approval and widespread use of its proprietary nasal naloxone spray. Now, the Santa Monica, California company is turning its attention to other addictive disorders — including bulimia nervosa.
On Monday, the publicly-traded company announced the initiation of an up to 80-patient Phase 2 trial of an opioid antagonist (receptor blocking) nasal spray in the widespread and potentially life-threatening disorder.
According to the National Eating Disorders Association (NEDA) bulimia is characterized by “a cycle of bingeing and compensatory behaviors such as self-induced vomiting designed to undo or compensate for the effects of binge eating.” Patients typically have low self-esteem and feel out of control when around food.
Many neural pathways, including dopamine, acetylcholine, and serotonin, have been implicated in the disorder. The latter served as the basis for the approval of Prozac, a selective serotonin reuptake inhibitor (SSRI), as a treatment for bulimia. Studies suggest such antidepressants “may be modestly effective in BN over the long term.”
A significant unmet need remains, which is why Opiant is targeting the addictive properties of dopamine.
A 2012 review of the brain pathways involved in the disorder points to a dysregulation of the dopamine and opioid systems. The authors note a number of studies that have shown opioid blockers such as naloxone and naltrexone can help limit excessive eating in animal models of the disease.
In an email forwarded by a company representative, CEO Roger Crystal explained the addictive cycle.
“The reward from binging on foods arises from the ingestion of food high in sugar, fat or salt, that activates the opioid system in the brain through the release of the body’s own endorphins when these foods are eaten,” Crystal said. “The activation of the opioid system in the brain is thought to cause the release of dopamine, that causes the reward sensation.”
With its fast-acting mechanism, Opiant’s nasal spray could be used when the individual feels susceptible to a binging episode. By blocking opioid receptors in the brain, the reward pathway could be shut down, suppressing the urge to overeat and thus, the self-perceived need for subsequent purging.
Crystal noted that the company has early Phase 2 data from binge eating disorder, which also involves extreme overeating. That’s important because translating the physiology into humans presents a challenge. Animal models can’t capture the complex underlying emotions that fuel the disorder.
It would seem many societal pressures are at play, with far more women than men affected. An estimated 1.5 percent of American women will develop the condition at some point in their lives.
Opiant expects to report topline data from this study in the first half of 2018, gauging safety and tolerability, as well as its impact on clinical outcomes, including changes in eating behavior.
Photo: Des Green, Getty Images