The FDA has cleared Palo Alto, Calif.-based Eiger Biopharmaceuticals Inc.’s Zokinvy (lonafarnib) as the first and only therapy for Hutchinson-Gilford progeria syndrome, also known as progeria, and processing-deficient progeroid laminopathies (PL).
Progeria and PL are ultra-rare, genetic, premature aging diseases that accelerate mortality in young patients, who develop symptoms that include growth failure, loss of body fat and hair, aged-looking skin, stiffness of joints, hip dislocation, generalized atherosclerosis, cardiovascular disease and stroke. Untreated children with progeria die of heart disease at an average age of 14.5 years. In the U.S., 20 children and young adults with progeria and PL have been identified and followed.
Zokinvy, which blocks the farnesylation of progerin, was tested in children and young adults with progeria and was shown to reduce the incidence of mortality by 60% (p=0.0064), while increasing the average survival time by two and a half years. The most commonly reported adverse reactions were gastrointestinal (vomiting, diarrhea, nausea), mostly mild or moderate (grade 1 or 2). Many progeria patients already have received continuous Zokinvy therapy for more than 10 years, Eiger noted.
Survival benefit turned up in two open-label clinical trials involving a total of 62 patients, conducted at Boston Children's Hospital. The analysis compared Zokinvy-treated with Zokinvy-naïve subjects with progeria born during or after 1991 by age, gender and geographic location. Zokinvy-naïve patients originated from a separate natural history study with 81 subjects, conducted by the Progeria Research Foundation (PRF).
Zokinvy was granted priority review and breakthrough status. With the approval, the FDA issued a rare pediatric disease priority review voucher to Eiger, which the company sold for $95 million, splitting the proceeds under the terms of the collaboration and supply agreement with the PRF. According SEC paperwork, the buyer was Abbvie Inc., of New York.
Zokinvy is undergoing a phase III study, called D-Livr, in hepatitis D. Although it’s the same active drug as for progeria, Eiger plans to use different dosing, packaging and a separate commercial strategy to maintain higher pricing in progeria and PL. “We estimate a launch price of $750,00 per year,” Jefferies analyst Maury Raycroft wrote in a report, though the company “could reasonably price as high as $1.5 million to $2 million.” Shares of Eiger (NASDAQ:EIGR) were trading at $9.40, down 63 cents.