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Japan Becomes 1st Country to Approve Regeneron Antibody Cocktail

For the Treatment of Mild to Moderate COVID-19

Regeneron Pharmaceuticals, Inc.today announced that Japan's Ministry of Health, Labour and Welfare (MHLW) has approved Regeneron's casirivimab and imdevimab antibody cocktail to treat patients with mild to moderate COVID-19. This marks the first time the antibody cocktail, known as REGEN-COVTM in the U.S. and Ronapreve in other countries, has received a full approval to treat COVID-19. Emergency or temporary pandemic use authorizations are currently in place in more than 20 countries, including in the U.S., European Union, India, Switzerland and Canada.

"After a record-speed discovery and development program, we are pleased that our COVID-19 antibody cocktail continues to reach even more people around the globe," said George D. Yancopoulos, M.D., Ph.D., President and Chief Scientific Officer of Regeneron. "Unfortunately, this virus continues to spread despite increasing rates of vaccination, and there will be an important continued need for treatments that remain active against the variants of concern." 

In Japan, the antibody cocktail was granted a Special Approval Pathway under article 14-3 of the Pharmaceuticals and Medical Devices Act. The approval was based on results from a Phase 3 trial in high-risk non-hospitalized patients, which showed the antibody cocktail reduced the risk of hospitalization or death by 70%, as well as results from a Phase 1 trial that examined the safety, tolerability and pharmacokinetics in Japanese people.

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Regeneron invented REGEN-COV and is collaborating with Roche to increase global supply of the antibody cocktail, with Roche primarily responsible for development and distribution outside the U.S. In December 2020, Chugai obtained development and exclusive commercialization rights in Japan from Roche, and is working with the Japanese government to ensure an appropriate and timely supply of the antibody cocktail.

The development and manufacturing of REGEN-COV have been funded in part with federal funds from the Biomedical Advanced Research and Development Authority (BARDA), part of the U.S. Department of Health and Human Services' Office of the Assistant Secretary for Preparedness and Response, under OT number: HHSO100201700020C.

About the REGEN-COV Antibody Cocktail
REGEN-COV (casirivimab and imdevimab) is a cocktail of two monoclonal antibodies that was designed specifically to block infectivity of SARS-CoV-2, the virus that causes COVID-19, using Regeneron's proprietary VelocImmune and VelociSuite technologies. The two potent, virus-neutralizing antibodies that form the cocktail bind non-competitively to the critical receptor binding domain of the virus's spike protein, which diminishes the ability of mutant viruses to escape treatment and protects against spike variants that have arisen in the human population, as detailed in Science.

Over the past few months Regeneron has announced results from multiple Phase 3 trials demonstrating the ability of REGEN-COV to reduce the burden of COVID-19, from prevention through to hospitalization. This includes trials assessing the ability of REGEN-COV to treat outpatients already infected with SARS-COV-2 (including symptomatic outpatients and recently infected asymptomatic patients) and in certain hospitalized patients, including the RECOVERY trial.

Multiple analyses, including a recent publication in Cell, have shown that REGEN-COV retains potency against the main variants of concern circulating within the U.S.; consequently, REGEN-COV remains available for use in all 50 states. REGEN-COV retains potency against variants including Delta (B.1.162.2; first identified in India), Gamma (P.1; first identified in Brazil), Beta (B.1.351; first identified in South Africa).

REGEN-COV is available throughout the U.S. – information on availability in your area is available from the Department of Health and Human Services and the National Infusion Center Association. REGEN-COV has not been approved by the U.S. Food and Drug Administration (FDA), but is currently authorized in the U.S. under an Emergency Use Authorization (EUA) to treat mild-to-moderate COVID-19 in adults and pediatric patients (12 years of age and older weighing ≥40 kg) with positive results of direct SARS-CoV-2 viral testing, and who are at high risk for progression to severe COVID-19, including hospitalization or death. This use is authorized only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use under section 564(b)(1) of the Act, 21 U.S.C. § 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner. REGEN-COV is not authorized for use in patients who are hospitalized due to COVID-19 or require oxygen therapy, or for people currently using chronic oxygen therapy because of an underlying comorbidity who require an increase in baseline oxygen flow rate due to COVID-19.

In the U.S., REGEN-COV can be administered by intravenous infusion (as short as 20 minutes) or by subcutaneous injection (4 injections), which is an alternative when intravenous infusion is not feasible and would lead to a delay in treatment. It is now authorized as a co-formulated single vial, or in individual vials to be administered together.

Regeneron and Roche share a commitment to making the antibody cocktail available to COVID-19 patients around the globe and will support access in low- and lower-middle-income countries through drug donations to be made in partnership with public health organizations.

About Regeneron's VelocImmune Technology
Regeneron's VelocImmune technology utilizes a proprietary genetically engineered mouse platform endowed with a genetically humanized immune system to produce optimized fully human antibodies. When Regeneron's President and Chief Scientific Officer George D. Yancopoulos was a graduate student with his mentor Frederick W. Alt in 1985, they were the first to envision making such a genetically humanized mouse, and Regeneron has spent decades inventing and developing VelocImmune and related VelociSuite technologies. Dr. Yancopoulos and his team have used VelocImmune technology to create approximately a quarter of all original, FDA-approved fully human monoclonal antibodies currently available. This includes REGEN-COV (casirivimab and imdevimab), Dupixent (dupilumab), Libtayo (cemiplimab-rwlc), Praluent (alirocumab), Kevzara (sarilumab), Evkeeza

  • REGEN-COV has not been approved, but has been authorized for emergency use by FDA
  • This use is authorized only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use under section 564(b)(1) of the Act, 21 U.S.C. § 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner
  • Healthcare providers should review the Fact Sheet for Healthcare Providers for information on the authorized use of REGEN-COV and mandatory requirements of the EUA and must comply with the requirements of the EUA. The FDA Letter of Authorization is available for reference, as well as the Dear Healthcare Provider Letter and Patient Fact Sheet

Limitations of Authorized Use

  • REGEN-COV (casirivimab and imdevimab) is not authorized for use in patients:
  • who are hospitalized due to COVID-19, OR
  • who require oxygen therapy due to COVID-19, OR
  • who require an increase in baseline oxygen flow rate due to COVID-19 in those on chronic oxygen therapy due to underlying non-COVID-19 related comorbidity
  • Benefit of treatment with REGEN-COV has not been observed in patients hospitalized due to COVID-19. Monoclonal antibodies, such as REGEN-COV, may be associated with worse clinical outcomes when administered to hospitalized patients with COVID-19 requiring high-flow oxygen or mechanical ventilation

Definition of High Risk Patients
The following medical conditions or other factors may place adults and pediatric patients (age 12-17 years and weighing at least 40 kg) at higher risk for progression to severe COVID-19:

  • Older age (for example, age ≥65 years of age)
  • Obesity or being overweight (for example, BMI >25 kg/m2, or if age 12-17, have BMI ≥85th percentile for their age and gender based on CDC growth charts,
  • Pregnancy
  • Chronic kidney disease
  • Diabetes
  • Immunosuppressive disease or immunosuppressive treatment
  • Cardiovascular disease (including congenital heart disease) or hypertension
  • Chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma [moderate-to-severe], interstitial lung disease, cystic fibrosis and pulmonary hypertension)
  • Sickle cell disease
  • Neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies)
  • Having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation (not related to COVID 19))

Other medical conditions or factors (for example, race or ethnicity) may also place individual patients at high risk for progression to severe COVID-19 and authorization of REGEN-COV under the EUA is not limited to the medical conditions or factors listed above. 

Important Safety Information
REGEN-COV (casirivimab and imdevimab) is an unapproved investigational therapy, and there are limited clinical data available. Serious and unexpected adverse events may occur that have not been previously reported with REGEN-COV use

Warnings and Precautions: 

  • Hypersensitivity Including Anaphylaxis and Infusion-Related Reactions: Serious hypersensitivity reactions, including anaphylaxis, have been observed with administration of REGEN-COV. If signs or symptoms of a clinically significant hypersensitivity reaction or anaphylaxis occur, immediately discontinue administration and initiate appropriate medications and/or supportive therapy. Hypersensitivity reactions occurring more than 24 hours after the infusion have also been reported with the use of REGEN-COV under EUA. Infusion-related reactions, occurring during the infusion and up to 24 hours after the infusion, have been observed with administration of REGEN-COV. These reactions may be severe or life threatening
  • Signs and symptoms of infusion-related reactions may include: fever, difficulty breathing, reduced oxygen saturation, chills, nausea, arrythmia (e.g., atrial fibrillation, tachycardia, bradycardia), chest pain or discomfort, weakness, altered mental status, headache, bronchospasm, hypotension, hypertension, angioedema, throat irritation, rash including urticaria, pruritus, myalgia, vasovagal reactions (e.g., pre-syncope, syncope), dizziness, fatigue and diaphoresis. Consider slowing or stopping the infusion and administer appropriate medications and/or supportive care if an infusion-related reaction occurs
  • Clinical Worsening After REGEN-COV Administration: Clinical worsening of COVID-19 after administration of REGEN-COV has been reported and may include signs or symptoms of fever, hypoxia or increased respiratory difficulty, arrythmia (e.g., atrial fibrillation, tachycardia, bradycardia), fatigue, and altered mental status. Some of these events required hospitalization. It is not known if these events were related to REGEN-COV use or were due to progression of COVID-19
  • Limitations of Benefit and Potential for Risk in Patients with Severe COVID-19: Benefit of treatment with REGEN-COV has not been observed in patients hospitalized due to COVID-19. Monoclonal antibodies, such as REGEN-COV, may be associated with worse clinical outcomes when administered to hospitalized patients with COVID-19 requiring high-flow oxygen or mechanical ventilation. Therefore, REGEN-COV is not authorized for use in patients who are hospitalized due to COVID-19, OR who require oxygen therapy due to COVID-19, OR who require an increase in baseline oxygen flow rate due to COVID-19 in those on chronic oxygen therapy due to underlying non-COVID-19–related comorbidity.

Adverse Reactions:

  • In a pooled phase 1/2/3 analysis of COV-2067, infusion-related reactions (adverse event assessed as causally related by the investigator) of grade 2 or higher severity have been observed in 10/4,206 (0.2%) of those who received REGEN-COV at the authorized dose or a higher dose
  • Overall, in Phase 1/2/3, three subjects receiving the 8,000 mg dose of REGEN-COV, and one subject receiving the 1,200 mg casirivimab and 1,200 mg imdevimab, had infusion-related reactions (urticaria, pruritus, flushing, pyrexia, shortness of breath, chest tightness, nausea, vomiting, rash) which resulted in permanent discontinuation of the infusion. All events resolved
  • Anaphylactic reactions have been reported in the clinical program in subjects receiving REGEN-COV. The events began within 1 hour of completion of the infusion, and in at least one case required treatment including epinephrine. The events resolved
  • The safety with subcutaneous administration is based on analysis from HV-2093, a randomized double-blind, placebo-controlled trial evaluating the safety and pharmacokinetic profile in healthy volunteer adult subjects. Subjects were randomized 3:1 to REGEN-COV (n=729) or placebo (n=240). Injection site reactions were observed in 12% and 4% of subjects following single dose administration in the casirivimab and imdevimab, and placebo arms respectively; the remaining safety findings with subcutaneous administration in the casirivimab and imdevimab arm were similar to the safety findings observed with intravenous administration in COV-2067
  • Patient Monitoring Recommendations: Clinically monitor patients during infusion and observe patients for at least 1 hour after intravenous infusion or subcutaneous dosing is complete

Use in Specific Populations:

  • Pregnancy: There are insufficient data to evaluate a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. REGEN-COV should only be used during pregnancy if the potential benefit    outweighs the potential risk for the mother and the fetus
  • Lactation: There are no available data on the presence of casirivimab and/or imdevimab in human milk or animal milk, the effects on the breastfed infant, or the effects of the drug on milk production. The development and  health benefits of breastfeeding should be considered along with the mother's clinical need for REGEN-COV and any potential adverse effects on the breastfed child from REGEN-COV or from the underlying maternal condition.

Source: Regeneron
Date: Jul 20, 2021


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