After decades of research, a gene therapy to correct a specific genetic mutation is on the brink of being approved by the FDA. 
 
 Spark Therapeutics’ Luxturna for an inherited form of blindness was unanimously backed by an advisory committee yesterday, despite questions from agency reviewers about the clinical endpoints used in the biotech’s pivotal trial and safety, and the FDA will now decide whether to greenlight it by Jan. 12. 
 
 The 16 members of the panel were all persuaded by the data for Luxturna (voretigene neparvovec), a one-shot treatment for a currently untreatable condition called biallelic RPE65-mediated inherited retinal dystrophy (IRD) that affects around 3,500 individuals in the U.S. and Europe. Impassioned testimony from people treated with the therapy also played its part. 
 
 In the primary phase 3 trial used to back the application for Luxturna, 93% of the participants showed some improvement in their functional vision as measured by their ability to navigate obstacles in low light—a measured known as the bilateral multiluminance mobility test (MLMT). 
 
 People with biallelic RPE65-mediated IRD are born with poor vision and typically go on to lose their sight completely. Those treated in Spark’s study showed functional improvements at 30 days—the therapy can’t restore normal sight—and that was maintained out to one year and in one case out to four years after dosing. 
 
 Patients described what that level of improvement meant to their daily lives, for example allowing them to read facial expressions, recognize colors and go out at night. 
 
 Albert Maguire, M.D., of the Scheie Eye Institute, who led the trial, said: “As a practicing physician who often speaks with patients and families living with IRDs, these conversations have been, up to now, frustrating in that there has been nothing to offer. 
 
 “Today’s advisory committee vote is an important step closer to the day that discussion can include potentially treating the blindness caused by their IRD.” 
 
 Philadelphia-based Spark said the positive vote “moves us closer to bringing this investigational adeno-associated viral (AAV) vector gene therapy to patients,” while analysts at Jefferies said approval by the FDA would be a “watershed moment” for the entire gene therapy field. 
 
 With approval looking likely, the conversation has swiftly switched to pricing, but the biotech isn’t revealing its plans on that just yet, saying it will do so once FDA has delivered its verdict. Some analysts have suggested, however, that a price tag of $1 million could be on the cards, following in the footsteps of uniQure and its Glybera for lipoprotein lipase deficiency (LPLD), which was the first gene therapy to be approved in Europe. 
 
 uniQure’s therapy was a commercial disaster, however, and was withdrawn from the market earlier this year due to lack of demand. GlaxoSmithKline was the second company to get the OK for a gene therapy in Europe and priced its product—Strimvelis for severe combined immunodeficiency (SCID) due to adenosine deaminase deficiency—at a more modest $650,000 a year, but hasn’t said much about takeup. 
 
 The closest comparator for Luxturna to date is Novartis’ CAR-T therapy Kymriah (tisagenlecleucel), which has a one-off treatment price of $475,000 but addresses a larger patient population, and most observers seem to expect Luxturna to come in a little higher than that. 
 
 The panel vote is just one of a number of positive developments for Spark of late, coming after encouraging data for its hemophilia A and Pfizer-partnered hemophilia B programs and the filing of Luxturna in Europe. 
 
 Shares in the company were up nearly 8% in after-hours trading and have been rising steadily over the last six months on expectations that Luxturna was heading for approval. ||||| A drug whose inventors claim it can cure a rare form of blindness is to be one of the most expensive medicines ever sold at $850,000 (£630,000). 
 
 Luxturna is injected directly into the eye to address the root cause of visual impairment by replacing a defective gene in the retina. It is the first gene therapy to be approved for use in the US, and was given the go-ahead by the Federal Drug Administration last month. However, the price of the treatment has only just been revealed. 
 
 Spark Therapeutics, the company behind the treatment, had previously claimed the treatment was worth $1m, citing the cost of a lifetime of blindness in lost earnings and wages for caregivers. But the firm said it had settled for the lower price of $850,000, or $425,000 per eye. It will also offer ways to spread the cost to health insurers, which have expressed concern about their ability to cover the expense. 
 
 “We wanted to balance the value and the affordability concerns with a responsible price that would ensure access to patients,” said Spark Therapeutics’ chief executive, Jeff Marrazzo. 
 
 Luxturna is one of an emerging breed of gene therapies that differ from more established medicines administered over a period of time. Such treatments involve a one-off procedure to alter defective DNA, allowing the body to repair the problem itself. 
 
 They include a treatment for haemophilia and another for so-called “bubble baby” syndrome, where sufferers have to live in a sterile environment, which is to be offered on the NHS despite a £500,000 price tag. 
 
 The sky-high price of some drugs – and so-called price-gouging by drug firms – became an issue in the US presidential election after Martin Shkreli, a US hedge fund entrepreneur, bought the drug Daraprim, used in the treatment of Aids and cancer, and hiked its price from $13.50 to $750. 
 
 But the starting price of some new drugs has soared. Glybera, a gene therapy for a rare protein disorder, was launched in 2012 with a price tag of $1.2m. However, it was never approved in the US and was discontinued by manufacturers uniQure because of a lack of demand. 
 
 Facebook Twitter Pinterest A vial of Spark Therapeutics’ Luxturna (voretigene neparvovec-rzyl), which was approved for use by the FDA on Tuesday. Photograph: AP 
 
 Gene therapy is not alone in commanding staggering sums, particularly when it comes to treatments for rare diseases. Soliris, a drug that treats a condition called paroxysmal nocturnal hemoglobinuria that attacks red blood cells, can cost up to $700,000 a year, while Elaprase, used in the treatment of Hunter syndrome, costs $500,000 a year. 
 
 Luxturna could potentially become available free on the NHS in the UK after being submitted for approval by the European Medicines Agency (EMA). A green light from the EMA is a prerequisite for approval by the National Institute for Health and Care Excellence, the UK’s healthcare costs watchdog. 
 
 In clinical trials, injections of Luxturna restored eyesight to people with severe visual impairment due to retinal dystrophy. Spark estimates that up to 2,000 people in the US suffer from the condition, with the number of sufferers rising to 6,000 when Europe and other markets where it could sell the treatment are included. 
 
 The company said it had agreed bespoke deals with US insurers, which cover the cost of most US prescriptions, and they will get a refund if the drug doesn’t work as expected. 
 
 Spark is also discussing a proposalfor insurers to pay for the drug in instalments over several years. The Philadelphia-based company said it would also pay transport costs not covered by insurance to help patients get access to treatment centres. ||||| Surprisingly, a single treatment helped most of the 21 volunteers who got it, reversing vision loss almost immediately. 
 
 Drug companies usually make money by selling drugs over and over again to the same patients and to new patients. For instance, cholesterol-lowering drugs must be taken daily for life and they are taken by millions of people. 
 
 Related: New group takes on higher drug prices 
 
 But how does a company make money on a one-time drug that costs so much to prepare? 
 
 Spark Therapeutics, which makes Luxturna, says it has a plan. 
 
 “We have been working with stakeholders across the health care sector to help ensure that appropriate patients have access to a product that challenges all of the current conventions of how patients are treated, how products are delivered and how payments are handled,” said Jeffrey Marrazzo, chief executive officer of Spark Therapeutics. 
 
 Related: Could your health insurance company be costing you money? 
 
 “Over these past few months, we have been working with health insurers to create innovative pathways for access to Luxturna that may serve as models for other one-time administered gene therapies in the future,” Marrazzo said in a statement. 
 
 “Our work is not done, but we believe that the offerings we are announcing today will help ensure that eligible U.S. patients have the coverage and financial support they need to gain access to both Luxturna and the specialized medical care required to deliver the product at treatment centers.” 
 
 "It's wildly expensive but, to be very frank, I think they've priced it what I'll call responsibly." "It's wildly expensive but, to be very frank, I think they've priced it what I'll call responsibly." 
 
 For instance, it’s negotiated an agreement to refund money to Harvard Pilgrim, a not-for-profit health services company, if patients don’t get better vision long-term. 
 
 And it’s in negotiations with the Centers for Medicare and Medicaid Services, the federal government health insurance agency, to come up with ways to let insurers pay by installments. 
 
 “We are also eager to work with CMS to enable more meaningful rebates as part of the pay-for-performance model,” Marrazzo said. 
 
 Related: Congress may be to blame for higher drug prices 
 
 "It's wildly expensive but, to be very frank, I think they've priced it what I'll call responsibly," Dr. Steve Miller, chief medical officer of pharmacy benefits manager Express Scripts, told CNBC. 
 
 "The product is just phenomenally innovative, and we've been talking about gene therapy for over 20 years; we're now at the threshold of having gene therapy reaching patients." 
 
 Express Scripts has a deal with Spark to distribute Luxturna. 
 
 “We've got to figure this out, because — let's be frank — there are going to be more of these drugs coming to the marketplace for even bigger populations,” Miller said. 
 
 Another company making pricey treatments has a plan to offer rebates if patients don’t get better. Novartis announced in August that it had made a deal with CMS, that it would not charge for patients who did not respond within the first month to its cancer therapy Kymriah, which costs $475,000 per treatment. 
 
 But patient advocate groups aren't buying it. 
 
 “Spark Therapeutics is charging as much for Luxturna as they think they can get away with," said David Mitchell, a patient with incurable blood cancer and the president of Patients For Affordable Drugs. 
 
 “Luxturna offers hope to hundreds of patients. But the question that must be asked is this: what is a fair price that will maximize affordability and accessibility and provide a reasonable return for the drug? The answer to that is certainly not the $850,000 price tag announced today.” 
 
 If insurance companies pay for patients to be treated, they'll pass along the costs to other patients in the form of higher premiums, Public Citizen's Peter Maybarduk said. 
 
 "Spark CEO Jeffrey Marrazzo’s comments, implying that $850,000 represents something other than greed, are absurd and obscene," Maybarduk said. 
 
 "Our health care system is cracking under the strain. Congress and the Trump administration must establish basic disciplines for medicine affordability," he added. 
 
 Gene therapy can be especially risky and expensive to develop, but the company got tax breaks, Public Citizen noted. 
 
 "Spark must disclose its research and development costs for Luxturna so that analysts, payers and the public have a basis to assess Spark’s decision. The public deserves to know what return we can expect on our taxpayer support for Luxturna," Maybarduk said.
– It's a gradual and cruel fate: an inherited form of vision loss that typically ends in blindness and has had no cure. But for those with mutations in a gene known as RPE65 comes a balm. The FDA in December approved Luxturna, a new gene therapy that can treat the progressive blindness, and on Wednesday, its maker revealed the staggering cost: $425,000 per eye. Pricing it was entering a bit of a brave new world: NBC News reports Luxturna is the first "true gene therapy" that's gotten the green light here for an inherited disease, and unlike other pharmaceutical companies' workhorses—drugs that patients take for weeks, months, or even a lifetime—Luxturna is expensive to create and delivered just once. And as the Washington Post explains, Luxturna isn't necessarily a cure for the up to 2,000 Americans who suffer from the disease. In trials, it has "worked" for patients for as long as four years (FierceBiotech explains patients are born with poor vision, and their vision doesn't become "normal" with Luxturna but does functionally improve), though there are indications its effects could extend beyond that mark. The Guardian reports that maker Spark Therapeutics had previously tossed out the figure $1 million when discussing the total treatment cost, saying that was a fair amount when you consider the cost of blindness. The Post says it went with the lower figure in part because insurers indicated $500,000 per eye would shrink the pool of those who qualified, and the company is discussing rebate and payment plan options. But one critic tells NBC he wants Spark to release its R&D costs so "analysts, payers, and the public have a basis to assess Spark's decision."