Haemophylia A is 6 times more frequent than haemophilia B. However, no one expected that the gene therapy for haemophyllia A would prove effective so quickly, because the size of the viral capside (the protein coating in which the DNA is found) did not match those of the factor VIII gene, which has 7 kilobases, being larger than the DNA sequence corresponding to factor IX.
A study conducted by BioMarin and also published in the New England Journal of Medicine assessed gene therapy in haemophilia A.
For inclusion in the study, 9 adults with severe haemophilia A with no history of inhibitor development were selected. 8 participants were on prophylactic treatment, and one used the factor, when needed.
Patients were divided into 3 groups, based on vector concentration – low, intermediate and high dose groups. All patients who had previously received prophylactic therapy were removed from prophylaxis, but were allowed factor self-administration in case of hemorrhagic events after the gene therapy.
The main objective of the study was the safety profile. For the assessment of therapy efficiency an VIII factor activity of at least 5 IU/DL was pursued in week 16 after the genetic transfer.
The results show that:
• In the group that received high doses, the activity of factor VIII was greater than 5 IU/DL between weeks 2 and 9 after the genetic transfer for all the patients included
• For 6 out of 7 patients in that group the level has increased to normal values ( > 50 IU/DL) and was maintained for up to one year
• In the group that received high doses, the average annual blood rate decreased from 16 hemorrhagic events prior to the study to only one event after the gene therapy
• After 52 weeks, the average level was 77 IU/DL
• The main adverse reaction was an increase in ALT values 1.5 times higher than normal
• No anti-factor VIII antibodies were detected
How long does the effect of this therapy last? Is it cost-effective?
The follow-up period is short, just one year, it is too early to evaluate the long-term efficacy, but Dr. Lindsey George, from Children’s Hospital of Philadelphia, investigator in the study on haemophilia B, believes that this therapy can be administered once in the patient’s life. Other studies have shown that the effect lasts up to 8 years in human subjects and 12 years in animal models.
The costs per year for a patient who administers his coagulation factor amount to 200,000 dollars, and for those with inhibitions are much higher.
If approved as a reference therapy for haemophilia, gene therapy could reach $ 1 million per dose.However, Mark Skinner, the former president of the World Federation of Hemophilia, explains that the costs per year for a patient with severe haemophilia can reach up to $ 750,000, and gene therapy is administered only once.
If gene therapy leads to the long-awaited revolution, patients with inhibitors will not be eligible from the beginning. The reason is the possibility of developing antibodies to viral material introduced into the body, although this has not happened so far.
Glenn Pierce, a researcher at BioMarin, believes that since the current treatment for those with inhibitors is the administration of a higher amount of factor, the same can be done with gene therapy:
“Let’s build a small bioreactor in the body that makes constant amounts of factor VIII”
Notwithstanding, no company is willing to invest in this regard until a product is first validated for patients with haemophilia without inhibitors. Biomarin plans to carry out two more studies, one at the end of this year and one at the beginning of next year, using different doses for haemophilia A.
Condemmed to a nightmare life, because after they turn 18 they no longer have access to treatment until they reach to specialized doctors with serious health problems. In civilized countries, considerable amounts are allocated to patients suffering from haemophilia. Their lives do not differ much from ours, the healthy ones.If in Romania they have no chance to live a decent life, in the neighboring country, that is in Hungary, this category of people even play football.
Also called the “Kings’ Disease”, haemophilia has been detected since antiquity. It became known as members of several royal houses in Europe were found to be suffering from this disease. For this reason it was named in this way. Heirs to the royal families in Russia, Great Britain, Spain or the Netherlands have suffered from haemophilia. In the monarchies of the past centuries, marriages between blood relatives were frequently encountered, so that the inheritance was not wasted. Because of this, the chances of transmitting haemophilia were increased.
Legally, in Romania, marriages between relatives are prohibited. But it is only by trust. No one can check whether some families still maintain the tradition of the past, namely that their wealth is not shared, but increased, through such marriages.
“The world is God-fearing. Primary or second-degree cousins do not marry each other. But, what is true, there are other such cohabitation relationships. Some of them let themselves be driven by feelings. But if they give birth to a child, he may be born with such conditions,” says the mayor of a locality in Romania.
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