Data from experiments in healthy volunteers showed that Resunab prevented the infiltration of immune cells, called neutrophils, and changed blood flow in a manner that had both anti-inflammatory effects and promoted the resolution of inflammation.
Resunab is a synthetic compound mimicking the actions of a type of molecule, called endocannabinoids, naturally existing in the body. The drug binds to a receptor called CB2, which exists on activated immune cells and on a type of connective tissue cell called fibroblast.
In animal studies, experiments have shown that the drug lowered TGF-beta and collagen levels, known to be higher in patients with scleroderma.
The study was performed in 15 volunteers, who had experimental inflammation triggered in their arm by the injection of dead bacteria under the skin. Participants was divided into three groups: five individuals received a placebo, five received 5 mg Resunab twice a day, and five were given 20 mg of Resunab twice a day. The higher dose is the same used in ongoing clinical trials of the drug, including one in scleroderma patients.
Analyses showed that Resunab-treated individuals had about 70 percent fewer neutrophils at the site of inflammation. Four hours after injection of the bacteria, those receiving active treatment had a lower blood flow in microscopic blood vessels in the inflamed area.
Another check, between 10 and 24 hours later, found blood flow in the Resunab-treated individuals progressively improving, an effect that researchers believe contributes to an efficient inflammatory response and, more importantly, its resolution.
“These are very exciting data. While conventional immune modulatory agents dampened the signs and symptoms of inflammation, none are curative while most have undesirable side effects; the latter may arise from interfering with the body’s own healing process of resolution,” Gilroy said in a news release.
The results are similar to what researchers previously observed in animal models of inflammation, and support the notion that Resunab may be the first drug able to resolve inflammation.
““With Resunab, we have a drug which is both anti-inflammatory and pro-resolution. We are particularly excited by these findings and to understand the internal signaling systems used by Resunab that exhibits such a favorable result in humans,” added Gilroy.
“The results from this study support the intended pharmacological activity of Resunab, which is resolution of chronically activated innate immune responses, including tissue inflammation and fibrosis. We look forward to continued collaborations with Dr. Gilroy and his colleagues, to further define the impact of Resunab on inflammatory responses — especially resolution — in humans,” said Barbara White, MD, the company’s chief medical officer.
Resunab is being explored for safety, tolerability, pharmacokinetics, and efficacy, against placebo, in a Phase 2 clinical trial (NCT02465437) in 36 patients with diffuse cutaneous scleroderma. The patients are being treated for 84 days, and then will be followed for another 28 days. Top-line data is expected to be reported later this year.
In addition, clinical trials to assess Resunab’s safety and efficacy in patients with cystic fibrosis (NCT02465450) and dermatomyositis (NCT02466243) are ongoing. These two studies are currently recruiting participants; information is available by clicking on each trial’s identification number.