SAN DIEGO — A .
The solution, also known as 10XB101, “has been demonstrated to cause adipolysis,” Kavita Darji, MD, an American Society for Dermatologic Surgery (ASDS) cosmetic and dermatologic laser surgery fellow at a practice in San Diego, said during a late-breaking session at the annual meeting of the American Academy of Dermatology. “It shows less inflammation and release of cytokines TNF-alpha and MCP-1 by macrophages than deoxycholic acid, which is currently used for submental fat reduction.”
Dr. Darji
Dr. Kavita Darji
In a phase 2b clinical trial conducted at four sites, investigators enrolled 51 patients and assigned them to one of four dose cohorts: 2%, 3%, or 4.5% 10XB101, or vehicle. Each treatment consisted of up to 50 injections at 0.2 mL per injection, and they were administered up to six times 4 weeks apart. Study endpoints included a composite of the Clinician Submental Fat Score (CSFS) and Patient Submental Fat Score (PSFS) on a 0-4–point scale. The researchers graded local skin reactions such as erythema, edema, tenderness on palpation, bruising, pain, and burning/stinging as 0 (none), 1 (mild), 2 (moderate), or 3 (severe). They also obtained lab tests and performed electrocardiograms.
Dr. Darji and colleagues analyzed two populations: the intent to treat (ITT) population, which included all 51 enrolled subjects who received any injection of the test agent, and a completer population of 40 subjects. “These patients had at least four treatments or completed the treatments per protocol, completed the 4 weeks after final treatment assessments, or did not have any significant protocol deviations that would impact the evaluation of efficacy,” she explained.
To compare how 10XB101 performed compared with deoxycholic acid (Kybella), which is approved by the FDA to improve the appearance of moderate to severe submental fat, the researchers drew from pooled findings of Refine 1 and 2, in which adults received up to six treatment sessions with deoxycholic acid or placebo.
The ITT analysis of the 3% and 4.5% 10XB101 dose groups showed about a fourfold increase in a 2-grade or better improvement in the composite endpoint relative to the pooled findings of deoxycholic acid (62% vs. 16%, respectively). In addition, 80% of the completer population achieved a 2-grade improvement in the composite endpoint. “Importantly, 10% to 33% also received a 3-grade improvement, depending on the dose they were assigned to,” Dr. Darji said.
On average, patients in both cohorts achieved a 1-grade improvement after two treatments, and about 50% achieved a 2-grade improvement after four treatments — which is consistent with a more rapid onset when compared with deoxycholic acid, she said.
Both study endpoints were achieved by 31% of patients in the ITT group vs. 33% of completers, respectively, with the 2% dose; 62% vs. 80% with the 3% dose; and 54% vs. 79% for the 4.5% dose. “This is a 2- to 5-times increase in success” when compared with the results of deoxycholic acid in the published pooled analysis, Dr. Darji said. The researchers measured adverse events by spontaneous and elicited reports and by assessments of recorded local skin reactions. They found that 80% of all measured local skin reactions rated as 0 while 98% of all measured local skin reactions rated as a 0 or 1. One myocardial infarction occurred, which was mild and resolved. This case was not related to the study drug, Dr. Darji said in an interview after the meeting. Otherwise, no safety laboratory or ECG signals were noted.
In findings limited to the 3% dose of 10XB101, mild bruising occurred in 8% of patients at postinjection visit 2, 18% of those at postinjection visit 3, 20% of those at postinjection visit 4, and in 20% of those at postinjection visit 5. Reports of mild pain/burning/stinging occurred in 8% of patients at postinjection visit 2 but at no other subsequent visits. Meanwhile, edema occurred in 42% of patients at postinjection visit 2, 45% of those at postinjection visit 3, 50% of those at postinjection visits 4 and 5, and 38% of those at postinjection visit 6.
“Patients resumed normal activity within 1-3 days and had fewer side effects that lasted longer than 30 days,” Dr. Darji concluded, adding that the results “imply a potential opportunity to expand the treatment to other anatomic areas, which is a future direction.”
One of the session moderators, Andrew Blauvelt, MD, MBA, of Oregon Medical Research Center, Portland, noted that the study was not a head-to-head trial of polidocanol vs. deoxycholic acid, so he cautioned against drawing strong conclusions about the comparative data presented.
Asked to comment on the results Lawrence J. Green, MD, of the department of dermatology at George Washington University, Washington, said that 10XB101 “showed excellent efficacy with much fewer adverse events when compared to what we found in studies with Kybella, the only currently FDA-approved injection for submental fat reduction.”
Dr. Green
Dr. Lawrence J. Green
In addition, “much less pain after injection was to me the most obvious differentiator between this and Kybella studies. I look forward to seeing if larger studies confirm the efficacy and safety from this phase 2 study, as 10XB101 has potential to be a more effective, and safer option to reduce submental fat,” he added. He was not involved with the study.
Dr. Darji reported having no disclosures. Mitchel P. Goldman, MD, the study’s lead investigator, is a minority investor in 10XBio, which is developing 10XB101. Dr. Blauvelt and Dr. Green disclosed conflicts of interest from many pharmaceutical companies.