Virus to the Rescue

Posted on the 09 January 2012 by Billcookonline @billcookonline

Today’s post is a guest blog from Stephen Vogt, PharmD, President and CEO of BioPlus Specialty Pharmacy. He shares fantastic hope for those affilicted with hemophilia:

For the first time ever, gene therapy successfully treated hemophilia B and even allowed some patients to give up their regular injections of clotting factor altogether. This landmark study spearheaded by researchers from the University College London and the St. Jude Children’s Research Hospital in Memphis injected six hemophilia B patients with a virus that expressed the blood clotting factor missing in hemophilia B.

Why does this study have so many doctors and their hemophilia patients excited? Because it’s the first to show (in actual people, not just lab animals) that gene therapy can bring about long-term expression of a blood protein in a large enough amount that treatment is no longer needed. Gene therapy uses a virus to replace a person’s defective copies of genes with an intact version. If additional research confirms the safety and efficacy of this gene therapy for hemophilia B, then prophylactic injections of clotting factor – which are incredibly expensive and burdensome to the patient – could be a thing of the past.

Hemophilia B, which is also known as Christmas disease, is the second most common type of hemophilia. In hemophilia B, there is a deficiency in clotting factor IX, which results in longer bleeding time, spontaneous bleeding, and joint damage from internal bleeding. One in 20,000 to 34,500 males worldwide have hemophilia B.

In this current study, just one injection of an adenovirus-associated virus vector that expresses clotting factor IX was able to treat patients for more than a year. Each of the patients in this study expressed clotting factor for more than six months and every patient’s prophylactic need for clotting factor was totally eliminated or at least reduced.

Imagine: our patients at BioPlus Specialty Pharmacy with severe hemophilia B may get three injections a week (that’s 156 needle sticks per year!) of clotting factor and if this gene therapy gets FDA approval, those patients could get the same level of treatment from a single injection each year. Who wouldn’t want to trade in 156 jabs for just one shot?

Patient quality of life could certainly improve, but how about we sweeten the pot with some cost savings to the health care system?

In the U.S., just one hemophilia B patient can incur a lifetime treatment cost of more than $20 million, since each year of on-demand therapy with clotting factor injection rings in at about $150,000 and it’s twice that per year for people who require regular prophylactic injections. Meanwhile, this gene therapy injection runs just $30,000 per patient, which obviously represents significant cost savings for payers and patients alike.

It can’t all be good news, though, can it? Unfortunately, the hazards of this gene therapy are not completely clear. One patient in this trial experienced rising liver enzyme levels (about five times the upper limit of normal) two months after getting the gene therapy. Prednisolone therapy normalized this person’s liver enzymes.

Certainly we need more studies about gene therapy and hemophilia under our belt, especially studies showing long-term outcome results. With this necessary scientific process, it will be years before hemophilia B patients can remove infusion from their to-do list.

In the meantime, there are many questions that remain unanswered in regards to gene therapy and hemophilia, including whether it can work with other types of hemophilia which have different sized clotting proteins (gene therapy may not be feasible with larger molecules). Nonetheless, this current study – which was published last month, in December – certainly brought the hope of Christmas to thousands of hemophilia patients.

Stephen C Vogt, PharmD
President and CEO
BioPlus SP

www.bioplusrx.com