Final analysis from the Phase IIIb STASEY study, including data from 193 people with hemophilia A, further support the benefit/risk profile of Hemlibra, with no new safety signals identified. STASEY is one of the largest open-label studies primarily assessing safety and tolerability of a medicine for people with hemophilia A with factor VIII inhibitors. Hemlibra also continued to demonstrate effective bleed control with a high proportion of participants (82.6%) achieving zero treated bleeds.
Genentech, a member of the Roche Group (SIX: RO, ROG; OTCQX: RHHBY), today announced results from the final analysis of the Phase IIIb STASEY study, which confirm the favorable safety profile of Hemlibra® (emicizumab-kxwh), consistent with the Phase III HAVEN clinical program. In the analysis, no new safety signals were identified with longer-term Hemlibra treatment in adults and adolescents with hemophilia A with inhibitors to factor VIII, the clotting protein that is missing or defective in people with hemophilia A. The data were presented at the virtual International Society on Thrombosis and Haemostasis (ISTH) 2021 Congress, July 17-21.
“As the treatment landscape evolves, determining the long-term benefit/risk profile of medicines for people living with hemophilia A remains a top priority for the community,” said Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development. “These results provide further confidence in Hemlibra’s favorable safety profile in people with hemophilia A with factor VIII inhibitors, who have historically faced significant treatment challenges.”
Nearly one in three people with severe hemophilia A develop factor VIII inhibitors, antibodies that bind to and block the efficacy of replacement factor VIII. People with hemophilia A with factor VIII inhibitors are at greater risk of more frequent bleeding, including life-threatening bleeds, and may face greater challenges in their day-to-day lives than people with hemophilia who do not have factor VIII inhibitors. Hemlibra has been approved in more than 100 countries worldwide for the treatment of people with hemophilia A with factor VIII inhibitors.
The final analysis of the STASEY study included data from 193 people with hemophilia A with factor VIII inhibitors who received Hemlibra prophylaxis once-weekly for up to two years (median treatment duration of 103.1 weeks). The analysis did not show any new cases of thrombotic microangiopathy or serious thrombotic events (adverse events [AEs] that have been observed in people with bleeding disorders) related to Hemlibra. The most common AEs occurring in 10% or more of people in the STASEY study were joint pain (arthralgia; 17.1%), common cold symptoms (nasopharyngitis; 15.5%), headache (15.0%), injection site reaction (ISR) (11.4%) and fever (pyrexia; 10.9%). Thirty-five (18.1%) people reported a Hemlibra-related AE, with ISRs being the most common (9.8%).
In addition, the STASEY study reinforced that Hemlibra is associated with a low incidence of anti-drug antibody (ADA) development. Ten (5.2%) participants tested positive for ADAs, five (2.6%) of whom were classified as having ADAs that were neutralizing in vitro. In all 10 participants, ADA development did not affect the efficacy or safety of Hemlibra; none of the participants had ADAs that resulted in a decrease in Hemlibra plasma concentration, and none of the ADA-positive participants experienced a treated bleed. In addition, the ADAs disappeared over time, as all study participants tested negative for ADAs at their last visit.
Hemlibra also continued to demonstrate effective bleed control in the STASEY study, with 82.6% of participants experiencing no bleeding episodes that required treatment. Annualized bleeding rates were consistent with previously reported observations from the pivotal HAVEN studies.
Hemlibra is approved to treat people with hemophilia A with factor VIII inhibitors in more than 100 countries worldwide and people with hemophilia A without factor VIII inhibitors in more than 80 countries worldwide, including the U.S., EU and Japan. Hemlibra has been studied in one of the largest clinical trial programs in hemophilia A with and without factor VIII inhibitors, including eight Phase III studies.
Hemlibra is a bispecific factor IXa- and factor X-directed antibody. It is designed to bring together factor IXa and factor X, proteins required to activate the natural coagulation cascade and restore the blood clotting process for hemophilia A patients. Hemlibra is a prophylactic (preventative) treatment that can be administered by an injection of a ready-to-use solution under the skin (subcutaneously) once weekly, every two weeks or every four weeks. Hemlibra was created by Chugai Pharmaceutical Co., Ltd. and is being co-developed globally by Chugai, Roche and Genentech.
Hemlibra U.S. Indication
Hemlibra is a prescription medicine used for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and children, ages newborn and older, with hemophilia A with or without factor VIII inhibitors.
Important Safety Information
What is the most important information to know about Hemlibra?
Hemlibra increases the potential for blood to clot. Patients should carefully follow their healthcare provider’s instructions regarding when to use an on-demand bypassing agent or factor VIII, and the dose and schedule to use for breakthrough bleed treatment. Hemlibra may cause the following serious side effects when used with activated prothrombin complex concentrate (aPCC; FEIBA®), including:
- Thrombotic microangiopathy (TMA). This is a condition involving blood clots and injury to small blood vessels that may cause harm to one’s kidneys, brain, and other organs. Patients should get medical help right away if they have any of the following signs or symptoms during or after treatment with Hemlibra:
- swelling of arms and legs
- yellowing of skin and eyes
- stomach (abdomen) or back pain
- nausea or vomiting
- feeling sick
- decreased urination
- Blood clots (thrombotic events). Blood clots may form in blood vessels in the arm, leg, lung, or head. Patients should get medical help right away if they have any of these signs or symptoms of blood clots during or after treatment with Hemlibra:
- swelling in arms or legs
- pain or redness in the arms or legs
- shortness of breath
- chest pain or tightness
- fast heart rate
- cough up blood
- feel faint
- numbness in the face
- eye pain or swelling
- trouble seeing
If aPCC (FEIBA®) is needed, patients should talk to their healthcare provider in case they feel they need more than 100 U/kg of aPCC (FEIBA®) total.
Before using Hemlibra, patients should tell their healthcare provider about all of their medical conditions, including if they:
- are pregnant or plan to become pregnant. It is not known if Hemlibra may harm an unborn baby. Females who are able to become pregnant should use birth control (contraception) during treatment with Hemlibra.
- are breastfeeding or plan to breastfeed. It is not known if Hemlibra passes into breast milk.
Patients should tell their healthcare provider about all the medicines they take, including prescription medicines, over-the-counter medicines, vitamins, or herbal supplements. Patients should keep a list of them to show their healthcare provider and pharmacist when they get a new medicine.
How should patients use Hemlibra?
Patients should see the detailed “Instructions for Use” that comes with Hemlibra for information on how to prepare and inject a dose of Hemlibra, and how to properly throw away (dispose of) used needles and syringes.
- Stop (discontinue) prophylactic use of bypassing agents the day before starting Hemlibra prophylaxis.
- Patients may continue prophylactic use of factor VIII for the first week of Hemlibra prophylaxis.
What should patients know about lab monitoring?
Hemlibra may interfere with laboratory tests that measure how well blood is clotting and may cause a false reading. Patients should talk to their healthcare provider about how this may affect their care.
The most common side effects of Hemlibra include: redness, tenderness, warmth, or itching at the site of injection; headache; and joint pain.
These are not all of the possible side effects of Hemlibra. Patients should speak to their healthcare provider for medical advice about side effects.
Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Patients should not use Hemlibra for a condition for which it was not prescribed. Patients should not give Hemlibra to other people, even if they have the same symptoms that they have. It may harm them. Patients can ask their pharmacist or healthcare provider for information about Hemlibra that is written for health professionals.
Side effects may be reported to the FDA at (800) FDA-1088 or http://www.fda.gov/medwatch. Side effects may also be reported to Genentech at (888) 835-2555.
About hemophilia A
Hemophilia A is an inherited, serious disorder in which a person’s blood does not clot properly, leading to uncontrolled and often spontaneous bleeding. Hemophilia affects around 20,000 people in the United States, with hemophilia A being the most common form and approximately 50-60 percent of people living with a severe form of the disorder.
People with hemophilia A either lack or do not have enough of a clotting protein called factor VIII. In a healthy person, when a bleed occurs, factor VIII brings together the clotting factors IXa and X, which is a critical step in the formation of a blood clot to help stop bleeding. Depending on the severity of their disorder, people with hemophilia A can bleed frequently, especially into their joints or muscles. These bleeds can present a significant health concern as they often cause pain and can lead to chronic swelling, deformity, reduced mobility and long-term joint damage.
A serious complication of treatment is the development of inhibitors to factor VIII replacement therapies. Inhibitors are antibodies developed by the body’s immune system that bind to and block the efficacy of replacement factor VIII, making it difficult, if not impossible, to obtain a level of factor VIII sufficient to control bleeding.
About Genentech in hemophilia
In 1984, Genentech scientists were the first to clone recombinant factor VIII in response to the contaminated hemophilia blood supply crisis of the early 1980s. For more than 20 years, Genentech has been developing medicines to bring innovative treatment options to people with diseases of the blood within oncology, and in hemophilia A. Genentech is committed to improving treatment and care in the hemophilia community by delivering meaningful science and clinical expertise. For more information visit http://www.gene.com/hemophilia.
Founded more than 40 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious and life-threatening medical conditions. The company, a member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit http://www.gene.com.
Source: Genentech, July 18, 2021