4 ML pemivibart 125 MG/ML Injection [Pemgarda]

EMERGENCY USE AUTHORIZATION FOR PEMGARDA The U.S. Food and Drug Administration (FDA) has issued an Emergency Use Authorization (EUA) for the emergency use of the unapproved product PEMGARDA (pemivibart) for the pre-exposure prophylaxis of coronavirus disease 2019 (COVID-19) in adults and adolescents (12 years of age and older weighing at least 40 kg): Who are not currently infected with SARS-CoV-2 and who have not had a known recent exposure to an individual infected with SARS-CoV-2 and Who have moderate-to-severe immune compromise due to a medical condition or receipt of immunosuppressive medications or treatments and are unlikely to mount an adequate response to COVID-19 vaccination. Medical conditions or treatments that may result in moderate to severe immune compromise and an inadequate immune response to COVID-19 vaccination include: Active treatment for solid tumor and hematologic malignancies Hematologic malignancies associated with poor responses to COVID-19 vaccines regardless of current treatment status (e.g., chronic lymphocytic leukemia, non-Hodgkin lymphoma, multiple myeloma, acute leukemia) Receipt of solid-organ transplant or an islet transplant and taking immunosuppressive therapy Receipt of chimeric antigen receptor (CAR)-T-cell or hematopoietic stem cell transplant (within 2 years of transplantation or taking immunosuppressive therapy) Moderate or severe primary immunodeficiency (e.g., common variable immunodeficiency disease, severe combined immunodeficiency, DiGeorge syndrome, Wiskott-Aldrich syndrome) Advanced or untreated HIV infection (people with HIV and CD4 cell counts <200/mm 3 , history of an AIDS-defining illness without immune reconstitution, or clinical manifestations of symptomatic HIV) Active treatment with high-dose corticosteroids (i.e., ≥20 mg prednisone or equivalent per day when administered for ≥2 weeks), alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapeutic agents classified as severely immunosuppressive, and biologic agents that are immunosuppressive or immunomodulatory (e.g., B-cell depleting agents) Limitations of Authorized Use PEMGARDA is not authorized for use: -For treatment of COVID-19, or -For post-exposure prophylaxis of COVID-19 in individuals who have been exposed to someone infected with SARS-CoV-2. PEMGARDA is authorized for use only when the combined national frequency of variants with substantially reduced susceptibility to PEMGARDA is less than or equal to 90%, based on available information including variant susceptibility to PEMGARDA and national variant frequencies FDA will monitor conditions to determine whether use is consistent with the scope of authorization, referring to available information, including information on variant susceptibility (e.g., Section 12.4 of the authorized Fact Sheet for Healthcare Providers) and CDC variant frequency data available at: https://covid.cdc.gov/covid-data-tracker/#variant-proportions. . Pre-exposure prophylaxis with PEMGARDA is not a substitute for vaccination in individuals for whom COVID-19 vaccination is recommended. Individuals for whom COVID-19 vaccination is recommended, including individuals with moderate-to-severe immune compromise who may derive benefit from COVID-19 vaccination, should receive COVID‑19 vaccination. In individuals who have recently received a COVID-19 vaccine, PEMGARDA should be administered at least 2 weeks after vaccination. PEMGARDA may only be prescribed for an individual patient by physicians, advanced practice registered nurses, and physician assistants that are licensed or authorized under State law to prescribe drugs. PEMGARDA has been authorized by FDA for the emergency use described above. PEMGARDA is not FDA-approved for any use, including use for pre-exposure prophylaxis of COVID-19. PEMGARDA is authorized only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of PEMGARDA under section 564(b)(1) of the FD&C Act, 21 U.S.C. § 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner. Justification for Emergency Use of Drugs During the COVID‑19 Pandemic: There is currently an outbreak of coronavirus disease 2019 (COVID‑19) caused by SARS‑CoV‑2, a novel coronavirus. The Secretary of the U.S. Department of Health and Human Services (HHS) has: Determined that there is a public health emergency, or significant potential for a public health emergency See U.S. Department of Health and Human Services, Determination of a Public Health Emergency and Declaration that Circumstances Exist Justifying Authorizations Pursuant to Section 564(b) of the Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 360bbb-3. February 4, 2020; https://www.federalregister.gov/documents/2020/02/07/2020-02496/determination-of-public-health-emergency. See also U.S. Department of Health and Human Services, Amended Determination of a Public Health Emergency or Significant Potential for a Public Health Emergency Pursuant to Section 564(b) of the Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 360bbb-3(b). March 15, 2023 (“Amended Determination”); https://www.federalregister.gov/documents/2023/03/20/2023-05609/covid-19-emergency-use-authorization-declaration. . Declared that circumstances exist justifying the authorization of emergency use of drugs and biological products for the prevention or treatment of COVID-19 See U.S. Department of Health and Human Services, Declaration that Circumstances Exist Justifying Authorizations Pursuant to Section 564(b) of the Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 360bbb-3, 85 FR 18250 (April 1, 2020); https://www.federalregister.gov/documents/2020/04/01/2020-06905/emergency-use-authorization-declaration. See also Amended Determination (“The declarations issued pursuant to section 564(b)(1) of the FD&C Act that circumstances exist justifying the authorization of emergency use of certain in vitro diagnostics, personal respiratory protective devices, other medical devices and drugs and biological products, as set forth in those declarations, and that are based on the February 4, 2020 determination, remain in effect until those declarations are terminated in accordance with section 564 of the FD&C Act.”). . An EUA is an FDA authorization for the emergency use of an unapproved product or unapproved use of an approved product (i.e., drug, biological product, or device) in the United States under certain circumstances including, but not limited to, when the Secretary of HHS declares that there is a public health emergency that affects the national security or the health and security of United States citizens living abroad, and that involves biological agent(s) or a disease or condition that may be attributable to such agent(s). Criteria for issuing an EUA include: The biological agent(s) can cause a serious or life-threatening disease or condition. Based on the totality of the available scientific evidence (including data from adequate and well controlled clinical trials, if available), it is reasonable to believe that: the product may be effective in diagnosing, treating, or preventing the serious or life-threatening disease or condition; and the known and potential benefits of the product - when used to diagnose, prevent, or treat such disease or condition - outweigh the known and potential risks of the product, taking into consideration the material threat posed by the biological agent(s). There is no adequate, approved, and available alternative to the product for diagnosing, preventing, or treating the serious or life-threatening disease or condition. Information Regarding Available Alternatives for the EUA Authorized Use There are no adequate, approved, and available alternatives to PEMGARDA for the pre-exposure prophylaxis of COVID-19 in individuals who are unlikely to mount an adequate immune response to COVID-19 vaccination. For information on clinical studies of PEMGARDA and other

DOSAGE AND ADMINISTRATION 2.1 Dosage for Emergency Use of PEMGARDA Initial Dosing : The initial dosage of PEMGARDA in adults and adolescents (12 years of age and older weighing at least 40 kg) is 4500 mg administered as a single intravenous (IV) infusion [see Clinical Pharmacology (1 2.3 ) ]. Repeat Dose : The repeat dosage is 4500 mg of PEMGARDA administered as a single IV infusion every 3 months. Repeat dosing should be timed from the date of the most recent PEMGARDA dose. The recommendations for dosing are based on the totality of the scientific evidence including clinical pharmacology data, antiviral activity data, and clinical study data [see Clinical Pharmacology (12.3 ) , Microbiology ( 12.4 ), and Clinical Studies ( 14 ) ] . 2.2 Dosage Adjustment in Specific Populations No dosage adjustment is recommended in pregnant or lactating individuals, in geriatrics, or in individuals with renal or hepatic impairment [see Use in Specific Populations ( 8 ) ] . 2.3Dose Preparation and Administration General Information : PEMGARDA should be prepared and administered by a qualified healthcare provider using aseptic technique . Vials of PEMGARDA are for one-time use only. Visually inspect the vials for particulate matter and discoloration. PEMGARDA is a clear to slightly opalescent, colorless to yellow solution. Discard the vial if the solution is cloudy, discolored, or if visible particles are observed. PEMGARDA should be administered as an IV infusion diluted with 0.9% sodium chloride. Materials Needed: 9 single-dose vials of PEMGARDA (125 mg/mL) 50 mL prefilled bag of 0.9% sodium chloride (normal saline) for IV injection IV extension set with inline 0.2-micron filter Infusion pump or gravity infusion set 0.9% sodium chloride injection for flushing Preparation : Remove PEMGARDA vials from refrigerated storage and allow to equilibrate to room temperature (18℃ to 26℃ [64℉ to 79℉]) for 10 minutes before preparation. Do not expose to direct heat. Do not shake vials. Inspect the vials. Prepare IV bag by removing and discarding 36 mL from a 50 mL prefilled bag of 0.9% sodium chloride for IV injection. Withdraw 36 mL of PEMGARDA from nine (9) vials into appropriately sized polypropylene syringe(s) (e.g., one 40 mL syringe or two 20 mL syringes) and inject into prepared 0.9% sodium chloride IV bag. The final product for administration will contain 50 mL: 36 mL of PEMGARDA and 14 mL of 0.9% sodium chloride. This product is preservative-free and therefore should be administered immediately. If immediate administration is not possible, the diluted solution may be stored at room temperature under ambient light for up to 4 hours. Do not shake the diluted solution. Administration: PEMGARDA should only be administered in settings in which healthcare providers have immediate access to medications to treat a severe hypersensitivity reaction, such as anaphylaxis, and the ability to activate the emergency medical system (EMS), as necessary [see Warnings and Precautions ( 5.1 ) ] . Attach infusion set including inline 0.2-micron filter to prepared IV bag, then prime the infusion set. Administer the entire 50 mL infusion using infusion pump or gravity infusion set over a minimum of 60 minutes. Due to potential overfill, the entire contents of prepared IV bag should be administered to avoid underdosing. Once infusion is complete, flush line with 0.9% sodium chloride. Clinically monitor patients during infusion and observe patients for at least 2 hours after infusion is complete [see Warnings and Precautions (5.1 ) ] . 2.1 Dosage for Emergency Use of PEMGARDA Initial Dosing : The initial dosage of PEMGARDA in adults and adolescents (12 years of age and older weighing at least 40 kg) is 4500 mg administered as a single intravenous (IV) infusion [see Clinical Pharmacology (1 2.3 ) ]. Repeat Dose : The repeat dosage is 4500 mg of PEMGARDA administered as a single IV infusion every 3 months. Repeat dosing should be timed from the date of the most recent PEMGARDA dose. The recommendations for dosing are based on the totality of the scientific evidence including clinical pharmacology data, antiviral activity data, and clinical study data [see Clinical Pharmacology (12.3 ) , Microbiology ( 12.4 ), and Clinical Studies ( 14 ) ] . 2.2 Dosage Adjustment in Specific Populations No dosage adjustment is recommended in pregnant or lactating individuals, in geriatrics, or in individuals with renal or hepatic impairment [see Use in Specific Populations ( 8 ) ] . 2.3Dose Preparation and Administration General Information : PEMGARDA should be prepared and administered by a qualified healthcare provider using aseptic technique . Vials of PEMGARDA are for one-time use only. Visually inspect the vials for particulate matter and discoloration. PEMGARDA is a clear to slightly opalescent, colorless to yellow solution. Discard the vial if the solution is cloudy, discolored, or if visible particles are observed. PEMGARDA should be administered as an IV infusion diluted with 0.9% sodium chloride. Materials Needed: 9 single-dose vials of PEMGARDA (125 mg/mL) 50 mL prefilled bag of 0.9% sodium chloride (normal saline) for IV injection IV extension set with inline 0.2-micron filter Infusion pump or gravity infusion set 0.9% sodium chloride injection for flushing Preparation : Remove PEMGARDA vials from refrigerated storage and allow to equilibrate to room temperature (18℃ to 26℃ [64℉ to 79℉]) for 10 minutes before preparation. Do not expose to direct heat. Do not shake vials. Inspect the vials. Prepare IV bag by removing and discarding 36 mL from a 50 mL prefilled bag of 0.9% sodium chloride for IV injection. Withdraw 36 mL of PEMGARDA from nine (9) vials into appropriately sized polypropylene syringe(s) (e.g., one 40 mL syringe or two 20 mL syringes) and inject into prepared 0.9% sodium chloride IV bag. The final product for administration will contain 50 mL: 36 mL of PEMGARDA and 14 mL of 0.9% sodium chloride. This product is preservative-free and therefore should be administered immediately. If immediate administration is not possible, the diluted solution may be stored at room temperature under ambient light for up to 4 hours. Do not shake the diluted solution. Administration: PEMGARDA should only be administered in settings in which healthcare providers have immediate access to medications to treat a severe hypersensitivity reaction, such as anaphylaxis, and the ability to activate the emergency medical system (EMS), as necessary [see Warnings and Precautions ( 5.1 ) ] . Attach infusion set including inline 0.2-micron filter to prepared IV bag, then prime the infusion set. Administer the entire 50 mL infusion using infusion pump or gravity infusion set over a minimum of 60 minutes. Due to potential overfill, the entire contents of prepared IV bag should be administered to avoid underdosing. Once infusion is complete, flush line with 0.9% sodium chloride. Clinically monitor patients during infusion and observe patients for at least 2 hours after infusion is complete [see Warnings and Precautions (5.1 ) ] .

WARNINGS AND PRECAUTIONS 5.1 Anaphylaxis Anaphylaxis has been observed with PEMGARDA in 4 of 623 (0.6%) participants in a clinical trial [see Adverse Reactions (6.1 )] . Two participants had anaphylaxis during the first infusion, and two participants had anaphylaxis during the second infusion. Anaphylaxis can be life-threatening, and two of the anaphylactic reactions in the clinical trial were reported as life-threatening. Manifestations included pruritus, flushing, urticaria, erythema, angioedema, diaphoresis, dizziness, tinnitus, wheezing, dyspnea, chest discomfort, and tachycardia. In all 4 cases, PEMGARDA was permanently discontinued. Prior to administering PEMGARDA, consider the potential benefit of COVID-19 prevention along with the risk of anaphylaxis [see Adverse Reactions (6.1 ), and Clinical Studies (14 )] . Administer PEMGARDA only in settings in which healthcare providers have immediate access to medications to treat anaphylaxis and the ability to activate the emergency medical system (EMS), as necessary. Clinically monitor individuals during the 60-minute infusion and for at least two hours after completion of the infusion. If signs or symptoms of an anaphylactic reaction occur, immediately discontinue administration, and initiate appropriate medications and/or supportive therapy. Discontinue PEMGARDA use permanently in individuals who experience signs or symptoms of anaphylaxis [see Contraindications (4 )] . 5.2 Hypersensitivity and Infusion-Related Reactions Hypersensitivity and infusion-related reactions occurring during the infusion and up to 24 hours after the infusion have been observed with administration of PEMGARDA. Hypersensitivity or infusion-related reactions may be severe or life threatening. If signs or symptoms of a clinically significant hypersensitivity or infusion-related reaction occur, immediately discontinue administration, and initiate appropriate medications and/or supportive therapy. Signs and symptoms of hypersensitivity or infusion-related reactions may include: Fever, difficulty breathing, reduced oxygen saturation, chills, fatigue, arrhythmia (e.g., atrial fibrillation, sinus tachycardia, bradycardia), chest pain or discomfort, weakness, altered mental status, nausea, headache, bronchospasm, hypotension, hypertension, angioedema, throat irritation, rash including urticaria, pruritus, myalgia, vasovagal reactions (e.g., pre-syncope, syncope), dizziness, and diaphoresis. If a mild infusion-related reaction occurs, consider slowing or stopping the infusion and administer appropriate medications and/or supportive care. Clinically monitor individuals during infusion and for at least two hours after completion of the infusion for signs and symptoms of hypersensitivity. Hypersensitivity reactions occurring more than 24 hours after the infusion have also been reported with the use of SARS-CoV-2 monoclonal antibodies under Emergency Use Authorization. 5.3 Risk of Cross-Hypersensitivity With COVID-19 Vaccines PEMGARDA contains polysorbate 80, which is in some COVID-19 vaccines and is structurally similar to polyethylene glycol (PEG), an ingredient in other COVID-19 vaccines [see Description (11 ) ] . For individuals with a history of a severe hypersensitivity reaction to a COVID-19 vaccine, consider consultation with an allergist-immunologist prior to PEMGARDA administration. Administration of PEMGARDA should be done under the supervision of a healthcare provider with appropriate medical support to manage severe hypersensitivity reactions. If signs and symptoms of a clinically significant hypersensitivity reaction or anaphylaxis occur during administration of PEMGARDA, immediately discontinue administration and initiate appropriate medications and/or supportive care. Clinically monitor individuals after infusion and observe for at least two hours. 5.4 Risk for COVID-19 Due to SARS-CoV-2 Viral Variants with Substantially Reduced Susceptibility to PEMGARDA Certain SARS-CoV-2 viral variants may emerge that have substantially reduced susceptibility to PEMGARDA. PEMGARDA may not be effective at preventing COVID-19 caused by these SARS‑CoV-2 viral variants. The cell culture neutralization activity of PEMGARDA against SARS-CoV-2 viral variants is described in Microbiology ( 12.4 ). Inform individuals of the increased risk, compared to other variants, for COVID-19 due to emergent SARS-CoV-2 viral variants that exhibit substantially reduced susceptibility to PEMGARDA. If signs or symptoms of COVID-19 occur, advise individuals to test for COVID-19 and seek medical attention, including starting treatment for COVID-19 as appropriate. Symptoms of COVID-19 may include fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, or diarrhea. For additional information on the symptoms of COVID-19, please see https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html. 5.1 Anaphylaxis Anaphylaxis has been observed with PEMGARDA in 4 of 623 (0.6%) participants in a clinical trial [see Adverse Reactions (6.1 )] . Two participants had anaphylaxis during the first infusion, and two participants had anaphylaxis during the second infusion. Anaphylaxis can be life-threatening, and two of the anaphylactic reactions in the clinical trial were reported as life-threatening. Manifestations included pruritus, flushing, urticaria, erythema, angioedema, diaphoresis, dizziness, tinnitus, wheezing, dyspnea, chest discomfort, and tachycardia. In all 4 cases, PEMGARDA was permanently discontinued. Prior to administering PEMGARDA, consider the potential benefit of COVID-19 prevention along with the risk of anaphylaxis [see Adverse Reactions (6.1 ), and Clinical Studies (14 )] . Administer PEMGARDA only in settings in which healthcare providers have immediate access to medications to treat anaphylaxis and the ability to activate the emergency medical system (EMS), as necessary. Clinically monitor individuals during the 60-minute infusion and for at least two hours after completion of the infusion. If signs or symptoms of an anaphylactic reaction occur, immediately discontinue administration, and initiate appropriate medications and/or supportive therapy. Discontinue PEMGARDA use permanently in individuals who experience signs or symptoms of anaphylaxis [see Contraindications (4 )] . 5.2 Hypersensitivity and Infusion-Related Reactions Hypersensitivity and infusion-related reactions occurring during the infusion and up to 24 hours after the infusion have been observed with administration of PEMGARDA. Hypersensitivity or infusion-related reactions may be severe or life threatening. If signs or symptoms of a clinically significant hypersensitivity or infusion-related reaction occur, immediately discontinue administration, and initiate appropriate medications and/or supportive therapy. Signs and symptoms of hypersensitivity or infusion-related reactions may include: Fever, difficulty breathing, reduced oxygen saturation, chills, fatigue, arrhythmia (e.g., atrial fibrillation, sinus tachycardia, bradycardia), chest pain or discomfort, weakness, altered mental status, nausea, headache, bronchospasm, hypotension, hypertension, angioedema, throat irritation, rash including urticaria, pruritus, myalgia, vasovagal reactions (e.g., pre-syncope, syncope), dizziness, and diaphoresis. If a mild infusion-related reaction occurs, consider slowing or stopping the infusion and administer appropriate medications and/or supportive care. Clinically monitor individuals during infusion and for at least two hours after completion of the infusion for signs and symptoms of hypersensitivity. Hypersensitivity reactions occurring more than 24 hours after the infusion have also been reported with the use of SARS-CoV-2 monoclonal antibodies under Emergency Use Authorization. 5.3 Risk of Cross-Hypersensitivity With COVID-19 Vaccines PEMGARDA

CONTRAINDICATIONS PEMGARDA is contraindicated in individuals with previous severe hypersensitivity reactions, including anaphylaxis, to any component of PEMGARDA.

CLINICAL PHARMACOLOGY 12.1Mechanism of Action Pemivibart is a SARS-CoV-2 antiviral drug [see Microbiology ( 12.4 )]. 12.2 Pharmacodynamics Available data suggest a positive relationship between serum neutralizing antibody titers and COVID-19 pre-exposure-prophylactic efficacy using clinical data (completed prior to the emergence of Omicron and Omicron lineage VOCs) and drug concentration data of neutralizing human monoclonal antibodies against SARS-CoV-2. Following single-dose administration of pemivibart 4500 mg IV, calculated geometric mean titer values (pemivibart concentration divided by the pseudotyped virus-like particle neutralization assay EC50 value against JN.1) [ see Microbiology ( 12.4 ) ] range from 2839 (on Day 90) to 20246 (end of infusion on Day 1). After the repeat dose of pemivibart 4500 mg IV every 3 months, it is anticipated that the range of titers at steady-state will be approximately 33% higher than those observed following the first dose administration. 12.3 Pharmacokinetics A summary of PK parameters of pemivibart following administration of a single 4500 IV dose of pemivibart to adults based on population PK modeling is provided in Table 1. Table 1. Summary Statistics of Population PK Parameters of Pemivibart Following a Single 4500 mg Intravenous Dose in Adults Parameter Pemivibart C max (μg/mL) 1820 (18.4) C Day 28 (μg/mL) 468 (23.9) C Day 90 (μg/mL) 188 (40.4) AUC 0-3 months (days × μg/mL) 40500 (22.5) T 1/2 (days) 49.0 (18.4-190) Accumulation ratio 1.33 CL (L/d) 0.0862 (31.1) V ss (L) 5.62 (17.3) Metabolism Catabolic pathways; same manner as endogenous IgG Excretion Not likely to undergo renal excretion AUC 0-3 months= area under the serum concentration-time curve from Day 0 to Month 3; CL=renal clearance; C max =maximum concentration; PK=pharmacokinetic; T 1/2 =half-life; V ss =steady state volume of distribution. Note: All values presented as geometric mean (% coefficient of variation), except for T 1/2 , which is presented as median (min, max), and for accumulation ratio, which is represented as median. Numerical values are post-hoc PK parameter estimates for participants enrolled in Phase 3 CANOPY. Specific Populations : The PK of pemivibart was not substantially affected by age, sex, or race based on a population PK analysis to the pooled data from VYD222-1-001 and Phase 3 CANOPY. Body weight is not expected to have a clinically relevant effect on the PK of pemivibart in individuals with body weights ranging from 43 to 190 kg through 3 months postdose. Patients with Immune Compromise Population PK analysis showed immune compromise status had no clinically relevant effect on the PK of pemivibart. Pediatric Patients The PK of pemivibart in pediatric individuals has not been evaluated. The dosing regimen is expected to result in comparable plasma exposures of pemivibart in pediatric individuals 12 years of age or older who weigh at least 40 kg as observed in adult individuals [see Use in Specific Populations ( 8.4 )] . Patients with Renal Impairment Renal impairment is not expected to impact the PK of pemivibart since mAbs with molecular weight >69 kDa are known not to undergo renal elimination. Similarly, dialysis is not expected to impact the PK of pemivibart. Patients with Hepatic Impairment Pemivibart is not anticipated to be impacted by hepatic impairment. Pemivibart is expected to be degraded into small peptides and amino acids via catabolic pathways in the same manner as other IgG mAbs and human endogenous IgG antibodies. 12.4 Microbiology Mechanism of Action: Pemivibart is a recombinant human monoclonal IgG1λ antibody that targets the SARS-CoV-2 spike protein receptor binding domain (RBD), thereby inhibiting virus attachment to the human angiotensin-converting enzyme 2 (ACE2) receptor on host cells. Amino acid substitutions in the Fc region (M435L/N441A) of pemivibart extend serum half-life. Pemivibart binds the spike RBD proteins of ancestral SARS‑CoV-2 B.1 (D614G) and Omicron variants BA.1, BA.2, and BA.4/5 with equilibrium dissociation constants (KD) of 2.1 nM, 18 nM, 13.5 nM, and 15.9 nM, respectively, and blocks attachment of ancestral SARS-CoV-2 and BA.2.86 variant RBD proteins to the human ACE2 receptor with IC 50 values of 0.068 nM (10 ng/mL) and 23 nM (3,370 ng/mL), respectively. Antiviral Activity: Pemivibart neutralized authentic SARS-CoV-2 isolates in Vero E6 or Vero E6-TMPRSS2 cells with EC 50 values of 0.165-0.230 nM (24.3-34 ng/mL) against B.1, and 0.075 nM (11 ng/mL) against B.1.617.2 (Delta). For Omicron variants, EC 50 values were 0.096 nM (14.2 ng/mL) against BA.1, 0.039 nM (5.8 ng/mL) against BA.2, 0.175 nM (25.8 ng/mL) against BA.4.1, 0.80-4.48 nM (118-661.2 ng/mL) against XBB.1.16, 1.97-3.25 nM (290-479.9 ng/mL) against XBB.1.5, 9.8 nM (1,445 ng/mL) against EG.5.1, and 3.59 nM (529.4 ng/mL) against HV.1 (last authentic virus variant tested). The antiviral activity of pemivibart against historical and contemporary SARS-CoV-2 variants was evaluated using the Monogram Biosciences PhenoSense ® Anti-SARS-CoV-2 Neutralizing Antibody Assay (Monogram Biosciences/LabCorp), a pseudotyped virus-like particle (VLP) assay 1 . Pemivibart neutralized SARS-CoV-2 spike protein-pseudotyped VLPs representing 9 pre-Omicron variants, including B.1 and Delta (B.1.617.2), with EC 50 values ranging from 0.022 to 0.083 nM (3.2 to 12.2 ng/mL). Pemivibart neutralized pseudotyped VLPs representing 48 Omicron-lineage variants, including major variants BA.1, BA.2, BA.5, BQ.1.1, XBB.1.5, and JN.1, with EC 50 values ranging from 0.198 to 14.3 nM (29.2 to 2,112 ng/mL). Pseudotyped VLPs representing 25 variants of the currently dominant JN.1 lineage, including JN.1, JN.1.11.1, KP.3, KP.3.1.1, XEC, LP.8.1, and XFG, had EC 50 values ranging from 0.41 to 4.7 nM (60.3 to 687.3 ng/mL) Table 2. Table 2: Pemivibart Pseudotyped Virus-Like Particle Neutralization Data for Contemporary SARS‑CoV-2 Variants Pango lineage SARS-CoV-2 spike substitutions, insertions, and deletions relative to Wuhan-Hu-1 present in pseudotyped VLPs a Pemivibart Mean EC 50 values ng/mL (SD) b, c Fold-change from JN.1 Dominant Variant Circulating at Time of Emergency Use Authorization JN.1 Ins16MPLF, T19I, R21T, L24del, P25del, P26del, A27S, S50L, H69del, V70del, V127F, G142D, Y144del, F157S, R158G, N211del, L212I, V213G, L216F, H245N, A264D, I332V, G339H, K356T, S371F, S373P, S375F, T376A, R403K, D405N, R408S, K417N, N440K, V445H, G446S, N450D, L452W, L455S, N460K, S477N, T478K, N481K, V483del, E484K, F486P, Q498R, N501Y, Y505H, E554K, A570V, D614G, P621S, H655Y, I670V, N679K, P681R, N764K, D796Y, S939F, Q954H, N969K, P1143L 74.6 (5.8) 1.0 d Other Tested JN.1-lineage Spike Variants JN.1.11.1 Ins16MPLF, T19I, R21T, L24del, P25del, P26del, A27S, S50L, H69del, V70del, V127F, G142D, Y144del, F157S, R158G, N211del, L212I, V213G, L216F, H245N, A264D, I332V, G339H, K356T, S371F, S373P, S375F, T376A, R403K, D405N, R408S, K417N, N440K, V445H, G446S, N450D, L452W, L455S, F456L, N460K, S477N, T478K, N481K, V483del, E484K, F486P, Q498R, N501Y, Y505H, E554K, A570V, D614G, P621S, H655Y, N679K, P681R, N764K, D796Y, S939F, Q954H, N969K, V1104L, P1143L 288.0 (64.9) 3.9 d JN.1.13.1 Ins16MPLF, T19I, R21T, L24del, P25del, P26del, A27S, S50L, F59S, H69del, V70del, V127F, G142D, Y144del, F157S, R158G, N211del, L212I, V213G, L216F, H245N, A264D, I332V, G339H, R346T, K356T, S371F, S373P, S375F, T376A, R403K, D405N, R408S, K417N, N440K, V445H, G446S, N450D, L452W, L455S, N460K, S477N, T478K, N481K, V483del, E484K, F486P, Q498R, N501Y, Y505H, E554K, A570V, D614G, P621S, H655Y, N679K, P681R, N764K, D796Y, S939F, Q954H, N969K, A1087S, P1143L 220.3 (32.5) 3.0 d JN.1.50 Ins16MPLF, T19I, R21T, L24del, P25del, P26del, A27S, S50L, A67V, H69del, V70del, V127F, G142D, Y144del, F157S, R158G, N211del, L212I, V213G, L216F, H245N, L249F, A264D, I332V, G339H, R346T, K356T, S371F, S373P, S375F, T376A, R403K, D405N, R408S, K417N, N440K, V445P, G446S, N450D, L452W, L455S, F456L, N460K, S477N, T47