Today, the Food and Drug Administration (FDA) announced that it has approved a new drug to treat a form of Gaucher disease, an enzyme deficiency condition which prevents the breakdown of certain fats in the body. This drug, from Protalix Biotherapeutics Inc and Pfizer Inc, is going to be marketed under the brand name, Elelyso (generic name: (taliglucerase alfa).
And what are the side effects of this new drug, if any? Well, according to the FDA, the most common side effects of the drug are infusion reactions and allergic reactions. The agency went on to state that the symptoms of infusion reactions include “headache, chest pain or discomfort, weakness, fatigue, hives, skin redness, increased blood pressure, back pain, joint pain, and flushing. As with other intravenous protein products, anaphylaxis has been observed in some patients during Elelyso infusion.”
What is anaphylaxis, you ask? It may sound like the name of a harmless insect but anaphylaxis is anything but harmless.
According to the U.S. National Library of Medicine (aka The World’s Largest Medical Library), anaphylaxis is a “life-threatening type of allergic reaction”.
So there, it ain’t a harmless insect but a deadly allergy. Here’s more from the NLM:
Anaphylaxis is a severe, whole-body allergic reaction to a chemical that has become an allergen. After being exposed to a substance such as bee sting venom, the person’s immune system becomes sensitized to it. On a later exposure to that allergen, an allergic reaction may occur. This reaction happens quickly after the exposure, is severe, and involves the whole body.
If you are lucky and are not allergic to Elelyso, you should still watch out for the other common side effects such as “upper respiratory tract infection, common cold-like symptoms (nasopharyngitis), joint pain (arthralgia), influenza, headache, extremity pain, back pain, and urinary tract infections”. According to the FDA, more than one in ten of the patients treated with the drug have exhibited these side effects.
Is Elelyso effective? Before approving the drug, the FDA looked at two clinical trials which involved a total of 56 patients. The first trial involved 31 patients “who had not previously received enzyme replacement therapy” and who were selected at random to receive either a dose of 30 units per kilogram or a higher dosage of 60 units per kilo.
After a period of nine months, the group who got a dose of 30 units per kilogram were found to have reduced their spleen volume by an average of 29 percent. Meanwhile, the reduction for those who received a dose of 60 units per kilogram is even higher at 40 percent average.
Liver volume, blood platelet counts, and red blood cell (hemoglobin) levels also improved according to the FDA.
The second clinical trial involved a group of 25 patients who were already using another enzyme replacement therapy medication, imiglucerase, for at least two years. In this experiment, the patients “were switched to Elelyso infusions every other week at the same dose of imiglucerase.”
The result? The FDA media release states that the “sesults showed Elelyso was effective in maintaining spleen and liver volumes, blood platelet counts, and hemoglobin levels over a nine month evaluation period”.
We were hoping the agency would state whether Elelyso is more effective than the prior medication taken by the patients but maybe they can’t tell the difference given the design of the trial. Oh well, maybe another trial will come up with the data in the future.