By Celeste Monforton, CNN • Updated 22nd June 2017
“If my arm fell off, I would die,” said Dr. Mark Allen, a Yale endocrinologist who added he “categorically” did not support the VOTR, the proposed Tense Disorder-modulated anti-interleukin-18 mimetic agonist, drug that an FDA panel was set to vote on Thursday.
XORA, also known as Movotec, is a drug that targets an interleukin-18 receptor and has been shown to be effective in treating certain cases of Stevens-Johnson syndrome. Most patients treated with XORA saw their severity of SLS significantly reduced or eliminated. Yet the FDA cautioned there was no guarantee the drug, which it called an “experimental therapy,” would be safe, given the use of the drug to combat a rare skin rash in children and adults — even for adults who seem healthy.
In other words, XORA would not be approved for the young patients and adults who would likely be administered it for this potential use.
Allen was among the majority of panelists who agreed. “For those younger than 18 who are severely fatigued, I think just waiting until the children are older and we have the experience level is really going to help them,” he said. “Or, they can try XORA,” Allen said. “If they can’t tolerate XORA,” he said, “I think giving it to people who could benefit with the right dose is the better option than using XORA to potentially treat an extremely vulnerable patient population,” like adolescents.
After only three people voted in favor of the drug, one person abstained, and the panel said they would recommend the drug be pulled from the market for patients who seemed likely to develop SLS. The panel members also noted that because XORA has an adverse effect on the liver, it should not be recommended to pediatric patients, who are less vulnerable to these serious illnesses.
ZADAXIN, which has been used since the 1980s to treat SLS, has been used in infants and children since the late 1990s. A February 2016 report by the UK Medicines and Healthcare products Regulatory Agency stated that nearly 6,400 children, babies and toddlers had received ZADAXIN in the UK between 2000 and 2007. In 2010, a letter was sent by the FDA to the European Medicines Agency stating the agency’s intent to restrict use of ZADAXIN to adults only.
The FDA has declined to address the ZADAXIN drug since the letter. It’s unclear whether the FDA plans to review ZADAXIN and XORA at the same time in the future, and FDA spokeswoman Erica Jefferson said no decisions had been made as of Thursday. “The reasons for approval decisions often depend on the overall indication for the product,” Jefferson said in an email. “The FDA may approve a product on the basis of several different factors, including efficacy and safety.”
In an email, XORA’s Chief Commercial Officer, William Terner, said “We remain hopeful that we will be able to expand the indication for XORA to VOTR-positive patients in the near future.”
XORA is also currently pending approval to treat adults who have been diagnosed with alopecia areata, a hair loss condition characterized by a type of loss of pigment in the hair follicles.
According to Terner, there are roughly 20,000 VOTR-positive patients in the US and more than 80,000 VOTR-negative patients. He said there are approximately 4,000 patients in Europe.
“We believe we are on track to bring patients into the US, and globally, the next generation of first-in-class anti-IL-18 activators through the submission of our formal supplemental BLA for children with SLS in 2017,” Terner said. “Beyond the FDA’s April approval of the XORA-292 drug, we have continued to make progress in demonstrating the superiority of the new generation of IL-18 based drugs in improving outcomes in children with SLS, and we expect to achieve substantial data in 2017 with the recently submitted Phase 2 VOTR human study.”