Gene Therapy

The differences between gene therapies for hemophilia A and hemophilia B

admin November 27, 2023

This is a paid public announcement from CSL Behring and does not constitute an endorsement of products or services. When you click on the links in this blog entry, you will be directed to the CSL Behring website. LA Kelley Communications always advises you to be a savvy consumer when contacting any company; do not reveal identifying information against your will.

Hemophilia is a genetic condition
Both hemophilia A and B are caused by mutations in the gene for blood clotting factor. Hemophilia A is caused by a mutation in the gene that creates factor VIII (FVIII) and hemophilia B is caused by a mutation in the gene that creates factor IX (FIX). Both the F8 and F9 genes are located on the X chromosome at different points.

Low factor levels lead to the inability of blood to clot, resulting in numerous physical and lifestyle burdens, including unexpected breakthrough bleeds and other chronic health problems. Over half the people with hemophilia A or B have factor levels less than 1% of normal.

Gene therapies for hemophilia A and B target different genes
Gene therapy is a long-term treatment option for people with hemophilia that offers extended bleed protection, which could eliminate the need for prophylaxis. Gene therapy uses an innovative approach that redefines treatment by either introducing a functioning gene into the body, or turning off or changing the gene that is causing the condition. Current gene therapies approved for hemophilia introduce a new, fully functioning gene into the body. The mutations causing hemophilia A and B have been characterized in thousands of people, and it is clear from the large number of mutations that the molecular basis of the condition is extremely diverse.

There are differences between gene therapies for hemophilia A and B
All gene therapy for hemophilia targets the liver. However, since there are differences in how the body produces FVIII and FIX, there are also fundamental differences in how gene therapy works in the liver.

For people with hemophilia B, gene therapy targets liver cells, known as hepatocytes, where factor IX proteins are naturally made. By delivering a functional F9 gene straight to the liver, it enables a person to start creating their own factor IX proteins that are missing or not working and causing the disorder.

In hemophilia A, a functional F8 gene is delivered to the liver, allowing it to start creating the missing or nonworking factor VIII proteins that cause the disorder. However, the way gene therapy for hemophilia A works is slightly different, since FVIII is produced by different liver cells and tissues than those that produce FIX. The F8 gene is larger and structurally complex, which creates additional challenges.

How gene therapy works
Working genes are usually delivered into the cells of the body by inserting them into an inactive viral shell, known as the vector.

Vectors being used in research are commonly made from adeno-associated viruses (AAVs). The AAV, naturally existing in the world at large, is deactivated, eliminating its ability to cause any illness while it performs its new task to deliver a therapy. In AAV-based gene therapy or gene transfer, a working gene is inserted into an AAV vector. An AAV vector protects and delivers the new gene to its destination through a one-time infusion. Current gene therapies for hemophilia A and B use different AAV vectors to deliver that new gene.

The size and simplicity of the F9 gene made it a promising target for gene therapy
Hemophilia B has long been a promising target for gene therapy because it is caused by a single gene mutation, which is both small in size and structurally simpler in comparison to hemophilia A.

In 2022, HEMGENIX®, etranacogene dezaparvovec-drlb, was approved by the FDA as the first and only gene therapy for hemophilia B. A one-time dose of HEMGENIX has been shown to offer elevated factor IX levels for years, with 37% average factor IX activity sustained at 2 years. HEMGENIX also offers greater bleed protection than prophylaxis. In a clinical trial, annualized bleed rate (ABR) for all bleeds decreased by 54% from an average of 4.1 for patients on prophylaxis during the lead-in period to 1.9 in months 7–18 after treatment. And 94% of, or 51 out of 54, people remained entirely free of continuous routine factor IX prophylaxis.

Hemophilia A has been a more challenging target for gene therapy

Due to constraints with AAV vectors, hemophilia A proved to be a challenging target for gene therapy. However, that changed recently, when the first gene therapy for hemophilia A was approved by the FDA. Administered as a single dose, gene therapy for hemophilia A has been shown to increase blood levels of factor VIII and reduce the risk of uncontrolled bleeding vs prophylaxis.

With gene therapies being approved for both hemophilia A and B, the future treatment landscape has irrevocably changed for anyone managing the condition.

IMPORTANT SAFETY INFORMATION

What is HEMGENIX?

HEMGENIX®, etranacogene dezaparvovec-drlb, is a one-time gene therapy for the treatment of adults with hemophilia B who:

  • Currently use Factor IX prophylaxis therapy, or
  • Have current or historical life-threatening bleeding, or
  • Have repeated, serious spontaneous bleeding episodes.

HEMGENIX is administered as a single intravenous infusion and can be administered only once.

What medical testing can I expect to be given before and after administration of HEMGENIX?

To determine your eligibility to receive HEMGENIX, you will be tested for Factor IX inhibitors. If this test result is positive, a retest will be performed 2 weeks later. If both tests are positive for Factor IX inhibitors, your doctor will not administer HEMGENIX to you. If, after administration of HEMGENIX, increased Factor IX activity is not achieved, or bleeding is not controlled, a post-dose test for Factor IX inhibitors will be performed.

HEMGENIX may lead to elevations of liver enzymes in the blood; therefore, ultrasound and other testing will be performed to check on liver health before HEMGENIX can be administered. Following administration of HEMGENIX, your doctor will monitor your liver enzyme levels weekly for at least 3 months. If you have preexisting risk factors for liver cancer, regular liver health testing will continue for 5 years post-administration. Treatment for elevated liver enzymes could include corticosteroids.

What were the most common side effects of HEMGENIX in clinical trials?

In clinical trials for HEMGENIX, the most common side effects reported in more than 5% of patients were liver enzyme elevations, headache, elevated levels of a certain blood enzyme, flu-like symptoms, infusion-related reactions, fatigue, nausea, and feeling unwell. These are not the only side effects possible. Tell your healthcare provider about any side effect you may experience.

What should I watch for during infusion with HEMGENIX?

Your doctor will monitor you for infusion-related reactions during administration of HEMGENIX, as well as for at least 3 hours after the infusion is complete. Symptoms may include chest tightness, headaches, abdominal pain, lightheadedness, flu-like symptoms, shivering, flushing, rash, and elevated blood pressure. If an infusion-related reaction occurs, the doctor may slow or stop the HEMGENIX infusion, resuming at a lower infusion rate once symptoms resolve.

What should I avoid after receiving HEMGENIX?

Small amounts of HEMGENIX may be present in your blood, semen, and other excreted/secreted materials, and it is not known how long this continues. You should not donate blood, organs, tissues, or cells for transplantation after receiving HEMGENIX.

Please see full prescribing information for HEMGENIX.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch , or call 1-800-FDA-1088.

You can also report side effects to CSL Behring’s Pharmacovigilance Department at 1-866-915-6958.

HEMGENIX is manufactured by uniQure Inc. and distributed by CSL Behring LLC.

HEMGENIX® is a registered trademark of CSL Behring LLC.

©2023 CSL Behring LLC 1020 First Avenue, PO Box 61501, King of Prussia, PA 19406-0901 USA

www.CSLBehring.com   USA-HGX-0466-NOV23

Gene therapy for hemophilia B offers long-term bleed protection with a one-time infusion

admin September 24, 2023

This is a paid public announcement from CSL Behring and does not constitute an endorsement of products or services. When you click on the links in this blog entry, you will be directed to the CSL Behring website. LA Kelley Communications always advises you to be a savvy consumer when contacting any company; do not reveal identifying information against your will.

The current standard of care for moderate to severe hemophilia B, factor IX prophylactic therapy, does offer bleed protection. However, it requires lifelong, routine infusions to maintain protective factor levels, and those who regularly infuse factor IX replacement products can still experience breakthrough bleeds, leading to joint damage, pain, and reduced quality of life. There is a need for a treatment option that offers consistent bleed protection with a one-time infusion that lasts years instead of weeks.

After years of scientific research and clinical studies, that option is here—HEMGENIX® (etranacogene dezaparvovec-drlb), the first and only gene therapy for hemophilia B.*

Hemophilia B is an appropriate target for treatment with gene therapy

Hemophilia B is caused by a mutation of a single gene—the F9 gene. Approaches using gene therapy to treat inherited conditions stemming from a single genetic mutation, including hemophilia B, have predominantly focused on the delivery of a working, or functional, gene using a viral vector.

Hemophilia B is an appropriate target for treatment with gene therapy because it is caused by a mutation of a single gene, the F9 gene, which is small enough that it can be packaged into an adeno-associated viral (AAV) vector.

How HEMGENIX gene therapy for hemophilia B works

HEMGENIX uses a gene therapy approach called gene transfer. Gene transfer therapy for hemophilia B starts by developing a package of genetic instructions—the functional, or working, gene. Then AAV vectors are created, which will eventually enter targeted liver cells. The package of genetic instructions is loaded into an AAV vector shell, acting as a delivery truck. Through a single IV infusion, the delivery truck heads toward the liver with its package.

Once delivered into the liver cells, the package of instructions is unloaded, enabling the liver to start generating factor IX, with the goal of allowing a person to produce their own elevated and protective levels of factor IX. After delivering its package, the AAV vector shell is broken down and eliminated. However, the genetic instructions remain to continue producing factor IX.

Built on science you can trust

Gene therapy is built on decades of clinical research. The first patients received gene therapy in 1970, and there are more than 250 AAV-based clinical trials currently underway across a variety of conditions. So not only is gene therapy with HEMGENIX EMHa great fit for hemophilia B, it’s based on years of scientific research.

Interested in learning more about the science behind HEMGENIX, a one-time infusion that offers years of consistent bleed protection? Explore all that gene therapy might offer for people with hemophilia B today!

*HEMGENIX was studied in a clinical trial of 54 male adults with moderately severe or severe hemophilia B. All people in the trial were taking factor IX prophy to treat their hemophilia B and were observed for at least 6 months on prophy before receiving HEMGENIX.

†AAV5, adeno-associated viral vector serotype 5.

IMPORTANT SAFETY INFORMATION

What is HEMGENIX?

HEMGENIX®, etranacogene dezaparvovec-drlb, is a one-time gene therapy for the treatment of adults with hemophilia B who:

  • Currently use Factor IX prophylaxis therapy, or
  • Have current or historical life-threatening bleeding, or
  • Have repeated, serious spontaneous bleeding episodes.

HEMGENIX is administered as a single intravenous infusion and can be administered only once.

What medical testing can I expect to be given before and after administration of HEMGENIX?

To determine your eligibility to receive HEMGENIX, you will be tested for Factor IX inhibitors. If this test result is positive, a retest will be performed 2 weeks later. If both tests are positive for Factor IX inhibitors, your doctor will not administer HEMGENIX to you. If, after administration of HEMGENIX, increased Factor IX activity is not achieved, or bleeding is not controlled, a post-dose test for Factor IX inhibitors will be performed.

HEMGENIX may lead to elevations of liver enzymes in the blood; therefore, ultrasound and other testing will be performed to check on liver health before HEMGENIX can be administered. Following administration of HEMGENIX, your doctor will monitor your liver enzyme levels weekly for at least 3 months. If you have preexisting risk factors for liver cancer, regular liver health testing will continue for 5 years post-administration. Treatment for elevated liver enzymes could include corticosteroids.

What were the most common side effects of HEMGENIX in clinical trials?

In clinical trials for HEMGENIX, the most common side effects reported in more than 5% of patients were liver enzyme elevations, headache, elevated levels of a certain blood enzyme, flu-like symptoms, infusion-related reactions, fatigue, nausea, and feeling unwell. These are not the only side effects possible. Tell your healthcare provider about any side effect you may experience.

What should I watch for during infusion with HEMGENIX?

Your doctor will monitor you for infusion-related reactions during administration of HEMGENIX, as well as for at least 3 hours after the infusion is complete. Symptoms may include chest tightness, headaches, abdominal pain, lightheadedness, flu-like symptoms, shivering, flushing, rash, and elevated blood pressure. If an infusion-related reaction occurs, the doctor may slow or stop the HEMGENIX infusion, resuming at a lower infusion rate once symptoms resolve.

What should I avoid after receiving HEMGENIX?

Small amounts of HEMGENIX may be present in your blood, semen, and other excreted/secreted materials, and it is not known how long this continues. You should not donate blood, organs, tissues, or cells for transplantation after receiving HEMGENIX.

Please see full prescribing information [LINK TO: https://labeling.cslbehring.com/PI/US/Hemgenix/EN/Hemgenix-Prescribing-Information.pdf] for HEMGENIX.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch [LINK TO: www.fda.gov/medwatch], or call 1-800-FDA-1088.

You can also report side effects to CSL Behring’s Pharmacovigilance Department at 1-866-915-6958.

HEMGENIX is manufactured by uniQure Inc. and distributed by CSL Behring LLC. HEMGENIX® is a registered trademark of CSL Behring LLC.

©2023 CSL Behring LLC 1020 First Avenue, PO Box 61501, King of Prussia, PA 19406-0901 USA

www.CSLBehring.com USA-HGX-0464-MAY23

Gene therapy for hemophilia B offers long-term bleed protection with a one-time infusion

admin June 18, 2023

This is a paid public announcement from CSL Behring and does not constitute an endorsement of products or services. When you click on the links in this blog entry, you will be directed to the CSL Behring website. LA Kelley Communications always advises you to be a savvy consumer when contacting any company; do not reveal identifying information against your will.

The current standard of care for moderate to severe hemophilia B, factor IX prophylactic therapy, does offer bleed protection. However, it requires lifelong, routine infusions to maintain protective factor levels, and those who regularly infuse factor IX replacement products can still experience breakthrough bleeds, leading to joint damage, pain, and reduced quality of life. There is a need for a treatment option that offers consistent bleed protection with a one-time infusion that lasts years instead of weeks.

After years of scientific research and clinical studies, that option is here—HEMGENIX® (etranacogene dezaparvovec-drlb), the first and only gene therapy for hemophilia B.*

Hemophilia B is an appropriate target for treatment with gene therapy

Hemophilia B is caused by a mutation of a single gene—the F9 gene. Approaches using gene therapy to treat inherited conditions stemming from a single genetic mutation, including hemophilia B, have predominantly focused on the delivery of a working, or functional, gene using a viral vector.

Hemophilia B is an appropriate target for treatment with gene therapy because it is caused by a mutation of a single gene, the F9 gene, which is small enough that it can be packaged into an adeno-associated viral (AAV) vector.

How HEMGENIX gene therapy for hemophilia B works

HEMGENIX uses a gene therapy approach called gene transfer. Gene transfer therapy for hemophilia B starts by developing a package of genetic instructions—the functional, or working, gene. Then AAV vectors are created, which will eventually enter targeted liver cells. The package of genetic instructions is loaded into an AAV vector shell, acting as a delivery truck. Through a single IV infusion, the delivery truck heads toward the liver with its package.

Once delivered into the liver cells, the package of instructions is unloaded, enabling the liver to start generating factor IX, with the goal of allowing a person to produce their own elevated and protective levels of factor IX. After delivering its package, the AAV vector shell is broken down and eliminated. However, the genetic instructions remain to continue producing factor IX.

Built on science you can trust

Gene therapy is built on decades of clinical research. The first patients received gene therapy in 1970, and there are more than 250 AAV-based clinical trials currently underway across a variety of conditions. So not only is gene therapy with HEMGENIX EMHa great fit for hemophilia B, it’s based on years of scientific research.

Interested in learning more about the science behind HEMGENIX, a one-time infusion that offers years of consistent bleed protection? Explore all that gene therapy might offer for people with hemophilia B today!

*HEMGENIX was studied in a clinical trial of 54 male adults with moderately severe or severe hemophilia B. All people in the trial were taking factor IX prophy to treat their hemophilia B and were observed for at least 6 months on prophy before receiving HEMGENIX.

†AAV5, adeno-associated viral vector serotype 5.

IMPORTANT SAFETY INFORMATION

What is HEMGENIX?

HEMGENIX®, etranacogene dezaparvovec-drlb, is a one-time gene therapy for the treatment of adults with hemophilia B who:

  • Currently use Factor IX prophylaxis therapy, or
  • Have current or historical life-threatening bleeding, or
  • Have repeated, serious spontaneous bleeding episodes.

HEMGENIX is administered as a single intravenous infusion and can be administered only once.

What medical testing can I expect to be given before and after administration of HEMGENIX?

To determine your eligibility to receive HEMGENIX, you will be tested for Factor IX inhibitors. If this test result is positive, a retest will be performed 2 weeks later. If both tests are positive for Factor IX inhibitors, your doctor will not administer HEMGENIX to you. If, after administration of HEMGENIX, increased Factor IX activity is not achieved, or bleeding is not controlled, a post-dose test for Factor IX inhibitors will be performed.

HEMGENIX may lead to elevations of liver enzymes in the blood; therefore, ultrasound and other testing will be performed to check on liver health before HEMGENIX can be administered. Following administration of HEMGENIX, your doctor will monitor your liver enzyme levels weekly for at least 3 months. If you have preexisting risk factors for liver cancer, regular liver health testing will continue for 5 years post-administration. Treatment for elevated liver enzymes could include corticosteroids.

What were the most common side effects of HEMGENIX in clinical trials?

In clinical trials for HEMGENIX, the most common side effects reported in more than 5% of patients were liver enzyme elevations, headache, elevated levels of a certain blood enzyme, flu-like symptoms, infusion-related reactions, fatigue, nausea, and feeling unwell. These are not the only side effects possible. Tell your healthcare provider about any side effect you may experience.

What should I watch for during infusion with HEMGENIX?

Your doctor will monitor you for infusion-related reactions during administration of HEMGENIX, as well as for at least 3 hours after the infusion is complete. Symptoms may include chest tightness, headaches, abdominal pain, lightheadedness, flu-like symptoms, shivering, flushing, rash, and elevated blood pressure. If an infusion-related reaction occurs, the doctor may slow or stop the HEMGENIX infusion, resuming at a lower infusion rate once symptoms resolve.

What should I avoid after receiving HEMGENIX?

Small amounts of HEMGENIX may be present in your blood, semen, and other excreted/secreted materials, and it is not known how long this continues. You should not donate blood, organs, tissues, or cells for transplantation after receiving HEMGENIX.

Please see full prescribing information [LINK TO: https://labeling.cslbehring.com/PI/US/Hemgenix/EN/Hemgenix-Prescribing-Information.pdf] for HEMGENIX.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch [LINK TO: www.fda.gov/medwatch], or call 1-800-FDA-1088.

You can also report side effects to CSL Behring’s Pharmacovigilance Department at 1-866-915-6958.

HEMGENIX is manufactured by uniQure Inc. and distributed by CSL Behring LLC. HEMGENIX® is a registered trademark of CSL Behring LLC.

©2023 CSL Behring LLC 1020 First Avenue, PO Box 61501, King of Prussia, PA 19406-0901 USA

www.CSLBehring.com USA-HGX-0464-MAY23

The Age of Gene Therapy: Why Plasma?

Laurie Kelley December 4, 2022

It’s happened: gene therapy is available, at least for hemophilia B patients in the US. The idea that hemophilia can be treated as a “cure,” or at least using one shot to cover your bleeding episodes for at least a few years, is tantalizing. And if not that, we still have recombinant products that have never touched human blood.

We just updated our factor chart here, which compares all the products available on the market for hemophilia A and B. You have lots of treatments to consider! But why are we still making plasma-derived products?

A few reasons. But first, understand where plasma-derived products come from.

Plasma-derived products come from human blood plasma. Plasma donors undergo strict screening for disease risk factors, and their plasma is tested for several viral diseases. Recombinant products are not derived from blood; they originate from genetically engineered mammalian cells containing the human gene for factor. Recombinants are produced in large bioreactors, with human and animal proteins used in the culture medium in first- and second-generation recombinant factor. Third-generation products contain no human or animal proteins in the culture medium or the final product. Fourth-generation products are made from human cell lines.

Although plasma-derived products potentially risk transmitting blood-borne viruses, all US factor products, whether plasma derived or recombinant, are considered safe by the FDA.

Why would anyone intentionally choose a plasma-derived product instead of recombinant? After all, recombinant factor is the product recommended by NHF’s MASAC. And now we have gene therapy for hemophilia B. Why inject anything other than the missing factor into your child?

For some people, it’s all about cost. Plasma-derived factor is less expensive than recombinant factor. And gene therapy is expected to cost about $3.5 million per shot. People who have high out-of-pocket expenses need safe products, but may choose less expensive ones. Sometimes, the decision depends on the type of bleeding disorder being treated. For example, intermediate purity factor VIII products contain factor VIII combined with VWF (the way it’s naturally found in the blood) and are useful in treating von Willebrand disease.

When choosing your factor therapy, always discuss options with your HTC! Use our factor product guide here, which now includes bispecific antibody products and gene therapy, and bring it with you, and ask what’s best for your loved one or you.

Stunning Breakthrough: Hemgenix

Laurie Kelley November 27, 2022

Last week we shared an essay by Paul Clement about the approval for gene therapy for hemophilia A, approved only in Europe, and asked, when for the US?

While that question is still valid for hemophilia A, the stunning news this week was that gene therapy–at long last—is approved, for hemophilia B!

The news straight from CSL Behring: “This historic approval provides a new treatment option that reduces the rate of annual bleeds, reduces or eliminates the need for prophylactic therapy and generates elevated and sustained factor IX levels for years after a one-time infusion.”

The news was so startling, it made front page on CNN.com. But I suspect not for the scientific reason but for the economic reason: it comes with a $3.5 million price tag, making it the most expensive drug on earth currently.

Hemophilia Economics 101

While high prices are nothing new in hemophilia—factor therapy has always been among the world’s most expensive drugs—the sticker price was shocking to many. So many people have asked me through the years when is the price of factor going to come down, as if it were a high-tech consumer item like camcorders, Walkmans or DVD players. Remember those? They get mass produced, offshored, and millions upon millions of consumers buy them, which eventually drives the price down. And don’t forget competition. Basic supply and demand.

Hemophilia drugs are nothing like that. There are many factors that determine price but here are three: the research and development (R&D) that was spent to create the drug; the finite marketplace; and whether insurance will cover the cost.

R&D for drugs such as Roctavian, the brand name of BioMarin Pharmaceutical’s gene therapy product approved in Europe for hemophilia A, and Hemgenix, the brand name of CSL Behring’s gene therapy product approved by the U.S. FDA for hemophilia B, can surge to the hundreds of millions, if not billions, of dollars. The money needs to be recouped, and reinvested in the company, and to investors.  

The smaller the target audience, the higher the price. How can you recoup the R&D with such a small consumer audience as hemophilia B? In the U.S., there are approximately 20,000 with hemophilia, of which about 15% have hemophilia B. Not everyone of these patients will want gene therapy; not everyone can afford it.

By afford it, I mean have insurance cover it, which is the final piece of the pricing puzzle. Who will pay the $3.5 million per patient? State Medicaid plans? Commercial insurance? What if a patient on Blue Cross Blue Shield is approved, gets the gene therapy, has it reimbursed, but the following year switches plans? How does this benefit the bottom line at BCBS? Will insurance companies say no to gene therapy based on these concerns?

Advocacy is Key

This is where our decades of strong advocacy in the hemophilia community will make a difference. In a way, we’ve been preparing for this moment our whole lives. While the new drugs are not being touted as a cure, those of us old enough remember the slogan “A Cure by 2000!” We have fought for compensation for those infected by HIV and hepatitis from unsafe blood products. We fought for the new recombinant drugs, when insurance denied us. We fought for longer half-life drugs, for prophy, for bi-specific antibody products. All of these came with higher price tags, and eventually we prevailed.

And now?

We will all need to be educated about this new gene therapy, and how to approach our insurance companies, if we want it. As we have been preaching since 2005, when everything changed in insurance for hemophilia, you need to learn to speak the insurance company’s language; debate with them in a way they are used to; work with your healthcare team; stand with your state hemophilia group.

There are so many excellent products available to treat hemophilia, will insurance companies use this to deny gene therapy? At this point, no one knows, but we do know we need to get prepared. Why?

BioMarin is actively working on getting Rotavian approved for hemophilia A in the US. And that will impact thousands more in our community. How the insurance reimbursement of Hemgenix plays out could be a harbinger of things to come.

Read CSL Behring’s press release here.

HemaBlog Archives
Categories