The most expensive drug in the world has a $3.5 million price tag. 2 potential patients share their hopes and fears for the one-time treatment.

• The FDA has approved a new gene therapy to treat hemophilia B, a genetic bleeding disorder.
• The drugmaker CSL Behring set a $3.5 million price for the one-time treatment.

Bryen Lackey enjoyed bowling, until his blood disorder got in the way.

Lackey is learning to live with a severe case of hemophilia B, a rare genetic condition that keeps blood from clotting properly. That disease required him to have surgery on his right elbow, one of his problematic joints, which has kept the 18-year-old out of his bowling league.

As Lackey prepares to start college next spring, he said he's excited about the potential of a newly approved treatment that could make his life less centered on hemophilia. On November 22, the Food and Drug Administration approved Hemgenix, the first gene therapy to treat hemophilia B. Hematologists hope the one-time treatment could end the weekly infusions that patients like Lackey receive to prevent bleeds.

While the treatment breaks ground as the first approved gene therapy for hemophilia, its price is also unprecedented. The drug's seller, the Australian pharma company CSL Behring, set a list price of $3.5 million for a single treatment, making it the world's most expensive drug — and it remains unclear whether insurance companies will pay for it.

In interviews with Insider, patients shared mixed reactions to that price. Lackey, for instance, estimates his insurance spends $900,000 to $1 million a year on his treatments. That means the gene therapy's price may not be obscene in the long run if its effects last years.

"It seems a little steep," Lackey told Insider, "but compared to what we pay, it doesn't seem too terrible."

A 'good bet' or unfair? Patients and experts are split on $3.5 million price

CSL's new drug is the latest in a series of new gene therapies, which are medicines that modify a patient's DNA to fix the genetic mutation that causes their disease. These treatments can be dramatically effective, with a single infusion leading to transformative benefits.

But a critical unknown in judging CSL's $3.5 million price is the durability of the treatment. It's unclear how long the treatment will last, as the effects of other gene therapies wane over time. A clinical study of 54 hemophilia B patients showed the one-time treatment reduced bleeds by 64% through 18 months, and 98% of treated patients stopped needing regular preventive infusions.

Leonard Valentino, the CEO of the nonprofit National Hemophilia Foundation, called the price a "good bet," as he expects the therapy to last six to 10 years or even longer, based on clinical data in humans and dogs. The typical cost of regular preventive treatments is $300,000 to $600,000 a year for a patient with severe hemophilia B, he said, which means the gene therapy would be cost effective if it kept patients off of those treatments for many years.

Additionally, the number of patients who are eligible for Hemgenix will be small, meaning the drug's impact on US healthcare costs will be limited. Valentino estimated that 700 to 1,000 adults with hemophilia B in the US might be interested and eligible to receive this gene therapy.

But not all patients think the $3.5 million price is justified. Jerry McMillan Jr., a 47-year-old who has severe hemophilia B, told Insider he believed it's "not a fair price at all" and worried that some insurers might not cover the treatment. He's interested in receiving the gene therapy but said he's worried his Medicare insurance might not cover the cost for him or others. The federal agency hasn't announced yet whether it will cover the cost.

Hemophilia has loomed large through McMillan's life. As a child he went to the emergency room 20 to 24 times a month, and he recently had surgery to replace his left ankle. He's preparing for knee-replacement surgery in January — both operations stemming from the cumulative damage of bleeds throughout his life, he said. He hopes gene therapy could prevent future damage — if he can access and afford it.

"There's going to be a lot of poor people who can't afford this," McMillan said.

Robert Lojewski, a senior vice president and general manager at CSL, told Insider the company would offer co-pay support for people with commercial insurance if insurance companies didn't cover the whole cost of treatment.

Hemgenix is the latest in a string of multimillion-dollar gene-therapy drugs

The Swiss pharma giant Novartis came out with what was then the world's most expensive drug in 2019, when it priced a gene therapy for spinal muscular atrophy at $2.1 million. That record has been passed three times in just the past few months, with Bluebird Bio respectively pricing two gene therapies at $2.8 million and $3 million, before CSL's $3.5 million price.

Lojewski said the $3.5 million price wasn't guided by other gene-therapy prices. Instead, he said that the drug's price came from its value to patients and society and that it could save money for the American healthcare system compared with the lifetime cost of today's hemophilia treatments. The company also plans to offer commercial health insurers a refund on an undisclosed percentage of the cost if the treatment's effect isn't durable, he added.

"From a payer's perspective, whether it's commercial or government, there's savings realized, and the savings are meaningful," Lojewski said.

Benjamin Rome, a health-policy researcher at Brigham and Women's Hospital and Harvard Medical School, told Insider the US healthcare system needed sweeping reform to pay for these one-time treatments. The current system is designed around daily pills taken for chronic conditions, not complex one-time treatments that could be curative, he added.

"A one-time fee is not the best solution," Rome said, "but we don't have a healthcare system that can think about any other ways to do this."