Eiger BioPharmaceuticals announced the U.S. Food and Drug Administration (FDA) has approved ZokinvyTM (lonafarnib) for the treatment of Hutchinson-Gilford Progeria Syndrome (HGPS or Progeria) and processing-deficient Progeroid Laminopathies (PL).

Progeria and Progeroid Laminopathies are separate and distinct ultra-rare, genetic, premature aging diseases that accelerate mortality in young patients. Disease manifestations 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. There are 20 children and young adults with Progeria and PL identified and followed in the U.S.

Zokinvy is a disease-modifying agent that has demonstrated a statistically significant survival benefit in children and young adults with Progeria. In patients with Progeria, Zokinvy reduced the incidence of mortality by 60% (p=0.0064) and increased average survival time by 2.5 years. The most commonly reported adverse reactions were gastrointestinal (vomiting, diarrhea, nausea), and most were mild or moderate (Grade 1 or 2) in severity. Many Progeria patients have received continuous Zokinvy therapy for more than 10 years.

The increase in survival observed with Zokinvy was derived from two open-label clinical trials (N=62) conducted at Boston Children's Hospital. The survival analysis compared Zokinvy-treated versus Zokinvy-na?ve subjects with Progeria born in or after 1991, by age, gender, and geographic location. Zokinvy-na?ve patients originated from a separate natural history study (n=81) conducted by The Progeria Research Foundation.

With this approval, the FDA issued a Rare Pediatric Disease Priority Review Voucher (PRV) to Eiger. The Rare Pediatric Disease Priority Review Voucher program is designed to encourage development of new drugs and biologics for the prevention or treatment of rare pediatric diseases. Eiger plans to sell the PRV and under the terms of the Collaboration and Supply Agreement with the Progeria Research Foundation (PRF) will share the proceeds equally with PRF.

"The FDA approval of Zokinvy is the result of a pioneering partnership between Eiger BioPharmaceuticals and PRF to bring the first approved therapy to children, young adults and families living with this devastating disease," said David Cory, President and CEO of Eiger. "We are very proud that the first drug approval at Eiger confers a survival benefit to patients with one of the most ultra-rare, and ultimately fatal, pediatric diseases. We are extremely grateful to all the children, young adults and their families who have made this possible through participation in the Zokinvy clinical trials."

"The approval of this breakthrough therapy is a critical milestone for the Progeria community and also for Eiger," said Thomas Dietz, PhD, Chairman of the Board at Eiger. "The Eiger Board congratulates and commends the management team for their incredible dedication leading the company through its first NDA filing and approval, a major accomplishment for Eiger."

Zokinvy blocks the accumulation of defective, farnesylated proteins which form tight associations with the nuclear envelope, leading to cellular instability and the process of premature aging in children and young adults with Progeria and processing-deficient Progeroid Laminopathies.

Eiger licensed exclusive worldwide rights to lonafarnib from Merck, known as MSD outside of the United States and Canada. Merck will not receive any milestone payments for the development of lonafarnib for the treatment of Progeria, and has waived royalty obligations from Eiger for a specified quantity of lonafarnib.

Progeria, also known as Hutchinson–Gilford Progeria Syndrome (HGPS), and Progeroid Laminopathies are separate and distinct ultra-rare, fatal, genetic premature aging diseases that accelerate mortality in young patients.

Progeria is caused by a point mutation in the LMNA gene, yielding the farnesylated aberrant protein, progerin. Progeroid Laminopathies are genetic conditions of accelerated aging caused by a constellation of mutations in the LMNA and/or Zmpste24 genes yielding farnesylated proteins that are distinct from progerin. While non–progerin producing, these genetic mutations result in disease manifestations with phenotypes that have overlap with, but are distinct from, Progeria.

Without Zokinvy therapy, children with Progeria die of the same heart disease that affects millions of normally aging adults (arteriosclerosis), but at an average age of 14.5 years. Disease manifestations include severe failure to thrive, scleroderma–like skin, global lipodystrophy, alopecia, joint contractures, skeletal dysplasia, global accelerated atherosclerosis with cardiovascular decline, and debilitating strokes. It is estimated that there are 400 children worldwide with Progeria and 200 children with Progeroid Laminopathies. Of these patients, approximately 180 children and young adults have been identified, including 20 in the U.S. and 23 in Europe.