The world’s first gene therapy for Hemophilia has not been released into the market, according to a  press release from Biomarin Pharmaceutical (BioMarine). The new drug could be the most expensive in the world, its cost was estimated at $ 3 million. However, the US regulator ordered the company to wait until the end of 2021 – thus it will have to confirm that the therapy is effective in the long term.

For a long time, hereditary diseases differed from all others because they were incurable in principle. The mutations that every cell of the body carries within it, until recently, it was impossible to fix. There remained only substitution or maintenance therapy, to which the patient was attached for life. For example, in the case of Hemophilia, human cells do not produce enough factor VIII, one of the blood coagulation proteins. In order not to suffer from bleeding, the patient needs constant injections of the missing protein, which entails costs of several hundred thousand dollars a year.

Recently, there has been a way to solve these problems once and for all – with the help of gene therapy. A neutralized virus is injected into the patient’s blood, which “infects” the cells of the body and injects them with a missing copy of a healthy gene. Gene therapy is already approved for several diseases – for example, some types of blindness.

However, this method of treatment is often not only effective but also expensive. In short, the fact is that manufacturers can afford to charge a high price for a single injection precisely because it avoids annual costs of hundreds of thousands of dollars and pays for itself in just a few years. That is why the most expensive drug in the world today is a gene therapy drug. This is Zolgensma, a single injection designed to relieve patients of spinal muscular atrophy. Its cost is $ 2.125 million in the United States.

The development of Biomarin Pharmaceutical was supposed to become even more expensive. According to preliminary estimates, the company was going to ask for about three million dollars for getting rid of Hemophilia A. Biomarin Pharmaceutical has already had successful clinical trials on its account and according to the results of phase 1-2, the amount of factor VIII in the blood of patients has steadily increased, and the number of injections required has decreased from an average of 136 to 5 annually.

Nevertheless, according to the observations of doctors, the concentration of protein in the blood gradually decreased. And while it was still within the normal range for nearly all patients at the end of the trial (some doctors described the condition as “mild Hemophilia”), it raised concerns about the long-term consequences.

The company applied for registration of its drug based on the results of Phase 1-2 trials, considering them quite successful. The third phase is now ongoing, patients have already received therapy, and the final results are expected in November 2021. However, the US Food and Drug Administration (FDA) denied registration, citing differences in the design of phases 1-2 and 3 of the trials. The FDA suggested that the company wait until the end of Phase 3 and then provide full data on the sustainability of the treatment effect. Thus, the possible registration of the world’s first gene therapy drug for Hemophilia has been postponed for at least a year or more.