Hemgenix's $3.5 Million Gene Therapy Drug Is Approved By The FDA
HEMGENIX is the first and only once-and-done gene therapy for adults with a severe form of Hemophilia B. In clinical studies, HEMGENIX decreased the number of yearly bleeds by 94% and allowed 94% of patients to stop using factor IX prophylaxis. The U.S. Food and Drug Administration (FDA) has approved.
The United States Federal Drug Administration (FDA) has just approved a new treatment for a rare blood clotting disease, one with a hefty price tag. It will cost $3.5 million for a single dosage, making it the most expensive pharmaceutical product available anywhere in the world.
At first look, the price seems outrageous;, but a recent analysis on the cost-effectiveness of the drug suggests that's a relatively 'fair' price for what the treatment achieves – at least in the U.S..
The drug, which is named Hemgenix, is a gene therapy treatment for hemophilia B. Hemophilia B is an extremely uncommon hereditary illness that results in the blood, not clotting as well as it normally would. Some of the most concerning signs include uncontrollable bleeding that occurs spontaneously and often and is difficult to stop.
Hemophilia B is a rare bleeding condition that lasts a person's whole life and is caused by a mutation in a single gene. This mistake leads to the inadequate synthesis of factor IX, a protein that is largely generated by the liver and assists in the formation of blood clots. Prophylactic infusions of factor IX replacement therapy are used to temporarily replace or supplement low levels of a blood-clotting factor in patients with moderate to severe hemophilia B. Although these therapies are effective, patients with hemophilia B must adhere to strict, lifelong infusion schedules. They may still endure spontaneous bleeding episodes, restricted mobility, joint damage, or extreme pain as a consequence of the illness. Additionally, they may still be at risk for developing the condition. HEMGENIX makes it possible for persons living with hemophilia B who are acceptable candidates to create their own factor IX, which may reduce the likelihood of bleeding complications.
Before Hemgenix, repeated treatments of Hemophilia B required intravenous infusions. Hemgenix was evaluated by 57 male subjects ranging in age from 18 to 75 years old. The subjects had "severe or moderately severe hemophilia B," the FDA report said.
CSL Behring is a company that creates novel medications.
"As part of our promise to patients, CSL is committed to delivering innovative and groundbreaking solutions to address unmet medical needs, and we are proud to introduce the next wave of breakthrough medicines for people living with hemophilia B," said Paul Perreault, CSL CEO, and Managing Director.
Hemgenix reportedly reduced the number of yearly bleeds by 94%, as stated in a news release issued by CSL Behring.
Existing gene therapies have a track record of being especially expensive. The cost of Zynteglo, a treatment that assists in the production of a component of hemoglobin, is approximately $2.8 million. Zolgensma, which treats spinal muscle atrophy, was introduced with a price point of about $2.1 million.
Hemophilia B tends to be more common in men than women, and while an exact number is hard to come by, estimates suggest nearly 8,000 men in the U.S. currently suffer from the lifelong disease.
The main medication currently used to treat hemophilia B in the U.S. bestows patients with a much-needed clotting factor, but its lifetime treatment costs are steep. In those with severe symptoms, a routine and expensive treatment regime is required, one that can begin to wane in effectiveness over time.
Today, researchers estimate the adult lifetime cost for every patient with moderate to severe hemophilia B is around US$21 to $23 million. Treatment costs in the UK are cheaper than in the U.S. or elsewhere in Europe but still add up to tens of millions of dollars per patient over their lifetime.
Hemgenix, on the other hand, is a one-time intravenous product given in a single dose at a fraction of the price. The product is carried into the body via a viral-based vector, which is engineered to deliver DNA to target cells in the liver. This genetic information is then replicated by cells, spreading the instructions for a clotting protein known as Factor IX.
Two studies have so far tested the efficacy and safety of Hemgenix. In one study among 54 participants with severe or moderately severe hemophilia B, researchers found increased Factor IX activity levels, reducing the need for routine replacement therapies currently available to patients.
After receiving the gene therapy, the rate at which patients developed uncontrolled bleeds fell by over 50 percent compared to their baseline rate.
Side effects include headaches, flu-like symptoms, and enzyme elevations in the liver, all of which should be monitored carefully by physicians going forward. "
Gene therapy for hemophilia has been on the horizon for more than two decades. Despite advancements in the treatment of hemophilia, the prevention and treatment of bleeding episodes can adversely impact individuals' quality of life," says Peter Marks, the director of the FDA's Center for Biologics Evaluation and Research.
The clearance from the FDA was based on the findings of the HOPE-B experiment, which is now underway and is the biggest gene therapy trial in hemophilia B to date. The trial findings indicated that individuals who took HEMGENIX could generate a mean factor IX activity of 39 percent at six months and 36.7 percent at 24 months after receiving the medication. Seven to eighteen months after the factor IX preventive replacement treatment infusion, the mean adjusted annualized bleeding rate (ABR) for all bleeds decreased by 54 percent compared to the six-month lead-in phase (4.1 to 1.9). In addition, after being treated with HEMGENIX, 94% (51 out of 54) of patients stopped using prophylaxis and stayed free of any prior ongoing regular prophylactic medication. The adverse responses that occurred most often (frequency of more than or equal to 5%) were liver enzyme elevations, headaches, high levels of a particular blood enzyme, symptoms similar to the flu, infusion-related reactions, exhaustion, nausea, and a general sense of not being well.
"Today's approval provides a new treatment option for patients with hemophilia B and represents important progress in the development of innovative therapies for those experiencing a high burden of disease associated with this form of hemophilia."
It's not yet clear whether this gene therapy treatment is a cure for hemophilia B, but the initial results are promising.
The FDA has a special designation for serious yet rare disorders like hemophilia B to incentivize medical research. Hemgenix, for instance, is classified as an 'orphan drug' because it will only treat a small number of patients.
The multi-year clinical research effort for HEMGENIX was led by uniQure (Nasdaq: QURE), and sponsorship of the clinical trials was shifted to CSL after the firm gained international commercialization rights. As part of this designation, the Hemgenix manufacturer, CSL Behring, has exclusive rights to the U.S. marketplace for the next seven years.
The incentives employed by the U.S. government to spur scientific research is a useful way to boost innovation into rare diseases that would otherwise fall by the wayside, but this policy presents a double-edged sword.
It also means that the U.S. market shoulders the cost of propping up drug monopolies while other nations that restrict drug prices reap the benefits of international research.
Today, U.S. citizens pay between two and six times more for prescription drugs than in other countries worldwide.
The previous record holder for the most expensive drug was another 'one shot' form of gene therapy for treating spinal muscular atrophy. An estimated US$2 million per course also generated heated debate over how drug companies fund their businesses.
While many drug manufacturers have taken advantage of the orphan drug status over the past few decades to create medicine monopolies, this latest product could be one case where the policy might work for at least some people.
The upfront costs are certainly immense, but for those who might be fortunate enough to have a supportive insurance company, Hemgenix could save millions in medical expenses, improving lives in immeasurable ways.
The European Medicines Agency and its drug regulator counterparts in the United Kingdom and Australia are reviewing the gene therapy treatment for use.
It will be interesting to see how much drug manufacturers can charge for Hemgenix in other parts of the world.