Gene therapy for rare retinal disorder to cost $425,000 per eye

Spark Therapeutics Inc., the Philadelphia-based maker of voretigene neparvovec, announced Wednesday in a statement that it reached an agreement in principle with Harvard Pilgrim and affiliates of Express Scripts to make the one-time treatment available to patients with a rare genetic defect that often leads to blindness.

The mutation affects both eyes, usually at the same pace, so most patients would need treatment for both eyes, a Spark Therapeutics spokeswoman said.

In some cases, the gene therapy will be available under an "outcomes-based rebate arrangement." The company also stated that its proposal to the Centers for Medicare and Medicaid Services, the government program that covers about 100 million Americans, would allow installment payments for the drug.

"For a one-time therapy, like Luxturna, a non-traditional payment and distribution model is necessary to ensure needs of all parties -- patients, payers and providers -- are addressed," said Jennifer Luddy, a spokeswoman for Express Scripts.

At least one patient advocate disagrees.

"The new payment models announced today are merely a way to disguise a price that is simply too high," David Mitchell, president and founder of Patients For Affordable Drugs, said in a statement. "Spark Therapeutics is charging as much for Luxturna as they think they can get away with."

Spark Therapeutics CEO Jeff Marrazzo co-authored a recent blog post in the journal Health Affairs that said "the current payment system -- accustomed to ongoing treatment of chronic diseases -- creates significant challenges" for gene therapies and other treatments.

One-time-only treatments for rare genetic disorders are still unique, he noted.

The drug is intended for patients with retinal dystrophy due to a mutation of the RPE65 gene. This rare genetic defect causes severe visual impairment beginning in infancy and can eventually lead to blindness. The company believes the total "population in the US, Europe and select additional markets in the Americas and Asia/Pacific is up to approximately 6,000 individuals" who have the mutation targeted by Luxturna, explained Monique da Silva, a spokeswoman for Spark Therapeutics.

The drug will be available in the United States in early spring, with an estimated 1,000 to 2,000 people in the US standing to benefit from this treatment, according to Spark.

Luxturna is only the third gene therapy approved for use in the United States; two others were also approved in 2017. This is the first to correct an inherited genetic mutation.

Luxturna is a liquid that is injected directly into the eye with a microscopic needle during a surgical procedure. The drug supplies a third gene -- a normal RPE65 gene -- to cells in the retina, a layer of tissue lining the back of the eye. This third version of the gene does not remove or replace the two mutated genes causing the disease, which remain inside the cells. However, the normal gene delivered by the treatment is able to function within the retinal cells and correct vision problems.

In the phase 3 clinical trial, 27 out of 29 participants -- 93% -- who received the gene therapy demonstrated a gain in functional vision as assessed by a mobility test performed in a maze, according to the company. Risks of the treatment include cataracts, elevated eye pressure, retinal tears and holes and inflammation.

The company's offer of unusual payer models, including rebates and installment payments, will "help ensure patients' individual financial situation does not hinder access to treatment," da Silva said.

"New technologies such as gene and cell therapies hold out the potential to transform medicine," FDA Commissioner Dr. Scott Gottlieb said in a statement announcing the August approval of Kymriah, considered to be the first gene therapy to be approved for the US market.

Kymriah is a leukemia treatment made by pharmaceutical giant Novartis. Similar to Luxturna, Kymriah is a one-time treatment, and its price tag is $475,000. However, Novartis said this price will not be charged to patients who do not respond within a month of treatment.