Merck Underscores Continued Commitment to Fighting Infectious Diseases with More than 40 Data Presentations Across Vaccines, Antibacterials and Antivirals, Including Respiratory Syncytial Virus, Pneumococcal Disease and HIV

For the First Time, Full Results will be Highlighted from the Phase 2b/3 Trial of Clesrovimab (MK-1654), an Investigational Respiratory Syncytial Virus Preventative Monoclonal Antibody for Infants

RAHWAY, N.J.--(BUSINESS WIRE)--$MRK #MRK--Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced its plans to present new research findings demonstrating the continued impact of its increasingly broad and diverse vaccines and infectious disease portfolio and the potential of its innovative pipeline at IDWeek 2024 in Los Angeles, CA, from October 16-19.

Data to be presented include a late-breaker oral presentation of positive detailed results from the Phase 2b/3 trial evaluating clesrovimab (MK-1654), an investigational prophylactic monoclonal antibody designed to protect infants from respiratory syncytial virus (RSV) disease; data from the Phase 3 STRIDE-8 trial evaluating CAPVAXIVE (Pneumococcal 21-valent Conjugate Vaccine) in adults 18-64 years of age at increased risk of pneumococcal disease; as well as a late-breaker oral presentation of Week 48 data from the Phase 2 study evaluating an investigational once-weekly oral combination regimen of islatravir, the company's nucleoside reverse transcriptase translocation inhibitor (NRTTI), and Gilead's lenacapavir, a first-in-class capsid inhibitor, for treatment of people with HIV-1 infection.

"The breadth of innovative research we will showcase during IDWeek 2024 is a testament to our ongoing commitment to advancing science with the pursuit of addressing persisting global health needs, such as RSV," said Dr. Paula Annunziato, senior vice president, infectious diseases and vaccines, Global Clinical Development, Merck Research Laboratories. "We are proud of our company's longstanding legacy and continued momentum in helping to treat and prevent a variety of potentially serious infectious diseases for individuals around the world and across all stages of life – from birth through older adulthood – and we look forward to sharing these data."

Key data from Merck's portfolio and pipeline to be presented during IDWeek 2024:

• First time data from the Phase 2b/3 study evaluating a single dose of clesrovimab (MK-1654) administered to pre-term and full-term infants (Abstract #166, Late Breaker Oral Abstract Session: Respiratory Viruses Across All Ages);
• First presentation of results from the interim analysis of the Phase 3 trial evaluating the safety and efficacy of clesrovimab versus palivizumab in infants and children at increased risk for severe RSV disease (Abstract #167, Late Breaker Oral Abstract Session: Respiratory Viruses Across All Ages);
• First presentation of data from the Phase 3 STRIDE-8 trial evaluating CAPVAXIVE in vaccine-naïve adults 18-64 years of age at increased risk of pneumococcal disease (Abstract #45, Poster Session: Adult Vaccines);
• Week 48 data from the Phase 2 study evaluating once-weekly oral islatravir plus lenacapavir (Abstract #577, Late Breaker Oral Abstract Session: What's Going Viral);
• Data from the SPECTRA (Study of Prescribing patterns and Effectiveness of Ceftolozane/Tazobactam [C/T] Real-world Analysis) study (multiple abstracts) and updates from the SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance program (multiple abstracts).

Details on abstracts listed above and additional key abstracts for Merck:

About Clesrovimab (MK-1654)

Clesrovimab (MK-1654) is an investigational, extended half-life monoclonal antibody (mAb) developed as a passive immunization for the prevention of RSV. Clesrovimab is designed to be administered as the same single dose, regardless of birth weight, and is being studied in healthy pre-term, full-term and at-risk infants to provide direct, rapid and durable protection through their first RSV season against mild, moderate and severe RSV.

About CAPVAXIVE

CAPVAXIVE is Merck's approved 21-valent pneumococcal conjugate vaccine indicated for active immunization for the prevention of invasive disease and pneumonia in adults 18 years of age and older. CAPVAXIVE is specifically designed to help address Streptococcus pneumoniae serotypes predominantly responsible for adult invasive pneumococcal disease (IPD), including eight unique serotypes, 15A, 15C, 16F, 23A, 23B, 24F, 31, and 35B compared to other pneumococcal vaccines. CAPVAXIVE is administered as a single dose.

Select Safety Information for CAPVAXIVE

Do not administer CAPVAXIVE to individuals with a history of a severe allergic reaction (eg, anaphylaxis) to any component of CAPVAXIVE or to diphtheria toxoid.

Individuals with altered immunocompetence, including those receiving immunosuppressive therapy, may have a reduced immune response to CAPVAXIVE.

The most commonly reported (>10%) solicited adverse reactions in individuals 18 through 49 years of age who received CAPVAXIVE were: injection-site pain (73.1%), fatigue (36.0%), headache (27.5%), myalgia (16.4%), injection-site erythema (13.8%), and injection-site swelling (13.3%).

The most commonly reported (>10%) solicited adverse reactions in individuals 50 years of age and older who received CAPVAXIVE were: injection-site pain (41.2%), fatigue (19.7%), and headache (11.0%).

Vaccination with CAPVAXIVE may not protect all vaccine recipients.

Authorized Use of LAGEVRIO (molnupiravir) in the U.S.

LAGEVRIO (molnupiravir) is authorized for use under an Emergency Use Authorization (EUA) for the treatment of adults with mild-to-moderate coronavirus disease 2019 (COVID-19):

• who are at high risk for progression to severe COVID-19, including hospitalization or death, and
• for whom alternative COVID-19 treatment options approved or authorized by FDA are not accessible or clinically appropriate.

LAGEVRIO is not approved for any use, including the treatment of COVID-19, but is authorized for emergency use by the FDA under an Emergency Use Authorization (EUA).

The emergency use of LAGEVRIO is only authorized for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of drugs and biological products during the COVID-19 pandemic under Section 564(b)(1) of the Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 360bbb-3(b)(1) unless the declaration is terminated or authorization revoked sooner.

Limitations of Authorized Use

LAGEVRIO is not authorized:

• for use in patients who are less than 18 years of age
• for initiation of treatment in patients hospitalized due to COVID-19. Benefit of treatment with LAGEVRIO has not been observed in subjects when treatment was initiated after hospitalization due to COVID-19
• for use for longer than 5 consecutive days
• for pre-exposure or post-exposure prophylaxis for prevention of COVID-19

LAGEVRIO 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 in the therapeutic class to which LAGEVRIO belongs (ie, anti-infectives).

Selected Safety Information for LAGEVRIO

Contraindications

No contraindications have been identified based on the limited available data on the emergency use of LAGEVRIO authorized under this EUA.

Warnings and Precautions

There are limited clinical data available for LAGEVRIO. Serious and unexpected adverse events may occur that have not been previously reported with LAGEVRIO use.

LAGEVRIO is not recommended for use during pregnancy. Based on findings from animal reproduction studies, LAGEVRIO may cause fetal harm when administered to pregnant individuals. There are no available human data on the use of LAGEVRIO in pregnant individuals to evaluate the risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes.

LAGEVRIO is authorized to be prescribed to a pregnant individual only after the healthcare provider has determined that the benefits would outweigh the risks for that individual patient. If the decision is made to use LAGEVRIO during pregnancy, the prescribing healthcare provider must document that the known and potential benefits and the potential risks of using LAGEVRIO during pregnancy were communicated to the pregnant individual.

There is a pregnancy registry that monitors pregnancy outcomes in individuals exposed to LAGEVRIO during pregnancy. The prescribing healthcare provider must document that a pregnant individual was made aware of the pregnancy registry at or 1-800-616-3791. Pregnant individuals exposed to LAGEVRIO or their healthcare providers can also report the exposure by contacting Merck Sharp & Dohme LLC, Rahway, NJ, USA at 1-877-888-4231.

Advise individuals of childbearing potential of the potential risk to a fetus and to use an effective method of contraception correctly and consistently during treatment with LAGEVRIO and for 4 days after the final dose.

Prior to initiating treatment with LAGEVRIO, assess whether an individual of childbearing potential is pregnant or not, if clinically indicated.

Hypersensitivity reactions, including anaphylaxis, have been reported with LAGEVRIO. If signs and symptoms of a clinically significant hypersensitivity reaction or anaphylaxis occur, immediately discontinue LAGEVRIO and initiate appropriate medications and/or supportive care.

LAGEVRIO is not authorized for use in patients less than 18 years of age because it may affect bone and cartilage growth. The safety and efficacy of LAGEVRIO have not been established in pediatric patients.

Adverse Reactions

The most common adverse reactions occurring in ≥1% of subjects in the LAGEVRIO treatment group in the Phase 3 double-blind MOVe-OUT study were diarrhea (2% versus placebo at 2%), nausea (1% versus placebo at 1%), and dizziness (1% versus placebo at 1%) all of which were Grade 1 (mild) or Grade 2 (moderate).

Serious adverse events occurred in 7% of subjects receiving LAGEVRIO and 10% receiving placebo; most serious adverse events were COVID-19 related. Adverse events leading to death occurred in 2 (<1%) of the subjects receiving LAGEVRIO and 12 (2%) of subjects receiving placebo.

Drug Interactions

No drug interactions have been identified based on the limited available data on the emergency use of LAGEVRIO. No clinical drug-drug interaction trials of LAGEVRIO with concomitant medications, including other treatments for mild-to-moderate COVID-19, have been conducted.

Pregnancy/Breastfeeding

There are no data on the presence of molnupiravir or its metabolites in human milk. It is unknown whether molnupiravir has an effect on the breastfed infant or effects on milk production. Based on the potential for adverse reactions in the infant from LAGEVRIO, breastfeeding is not recommended during treatment with LAGEVRIO and for 4 days after the final dose. A lactating individual may consider interrupting breastfeeding and may consider pumping and discarding breast milk during treatment and for 4 days after the last dose of LAGEVRIO.

Males of Reproductive Potential

While the risk is regarded as low, there is a theoretical risk for LAGEVRIO to affect offspring of treated males based on its mechanism of action. Advise sexually active individuals with partners of childbearing potential to use a reliable method of contraception correctly and consistently during treatment and for at least 3 months after the last dose of LAGEVRIO. The risk beyond three months after the last dose of LAGEVRIO is unknown.

Required Reporting for Serious Adverse Events and Medication Errors

The prescribing healthcare provider and/or the provider's designee is/are responsible for mandatory reporting of all serious adverse events and medication errors potentially related to LAGEVRIO within 7 calendar days from the healthcare provider's awareness of the event.

Submit adverse event and medication error reports, using FDA Form 3500, to FDA MedWatch using one of the following methods:

Complete and submit the report online:

• Complete and submit a postage-paid FDA Form 3500 () and return by:
  • Mail to MedWatch, 5600 Fishers Lane, Rockville, MD 20852-9787, or
  • Fax to 1-800-FDA-0178, or
• Call 1-800-FDA-1088 to request a reporting form

In addition, please provide a copy of all FDA MedWatch forms to:

Merck Sharp & Dohme LLC, Rahway, NJ, USA by:

• Fax: 215-616-5677
• Email: dpoc.usa@merck.com

Indications for PREVYMIS (letermovir)

PREVYMIS is indicated for prophylaxis of cytomegalovirus (CMV) infection and disease in adult and pediatric patients 6 months of age and older and weighing at least 6 kg who are CMV-seropositive recipients [R+] of an allogeneic hematopoietic stem cell transplant (HSCT).

PREVYMIS is indicated for prophylaxis of CMV disease in adult and pediatric patients 12 years of age and older and weighing at least 40 kg who are kidney transplant recipients at high risk (Donor CMV seropositive/Recipient CMV seronegative [D+/R-]).

Selected Safety Information for PREVYMIS

Contraindications

PREVYMIS is contraindicated in patients receiving pimozide or ergot alkaloids.

• Increased pimozide concentrations may lead to QT prolongation and torsades de pointes.
• Increased ergot alkaloids concentrations may lead to ergotism.

PREVYMIS is contraindicated with pitavastatin and simvastatin when co-administered with cyclosporine. Significantly increased pitavastatin or simvastatin concentrations may lead to myopathy or rhabdomyolysis.

Warnings and Precautions

The concomitant use of PREVYMIS and certain drugs may result in potentially significant drug interactions, some of which may lead to adverse reactions (PREVYMIS or concomitant drugs) or reduced therapeutic effect of PREVYMIS or the concomitant drug.

Intravenous formulation of PREVYMIS contains the excipient hydroxypropyl betadex. PREVYMIS injection should be used only in patients unable to take oral therapy and patients should be switched to oral PREVYMIS as soon as they are able to take oral medications. If possible, intravenous administration should not exceed 4 weeks.

In patients with renal impairment, accumulation of hydroxypropyl betadex may occur. In adult patients with CLcr less than 50 mL/min and in pediatric patients with a similar degree of renal impairment (based on age-appropriate assessment of renal function) receiving PREVYMIS injection, closely monitor serum creatinine levels.

Animal studies have shown the potential for hydroxypropyl betadex to cause ototoxicity. The active ingredient, letermovir, is not known to be associated with ototoxicity.

Adverse Reactions

The rate of adverse events occurring in at least 10% of adult HSCT recipients treated with PREVYMIS and at a frequency at least 2% greater than placebo were nausea (27% vs 23%), diarrhea (26% vs 24%), vomiting (19% vs 14%), peripheral edema (14% vs 9%), cough (14% vs 10%), headache (14% vs 9%), fatigue (13% vs 11%), and abdominal pain (12% vs 9%).

Hypersensitivity reaction, with associated moderate dyspnea, occurred in one adult HSCT recipient following the first infusion of IV PREVYMIS after switching from oral PREVYMIS, leading to treatment discontinuation.

The most common adverse event occurring in at least 10% of adult kidney transplant recipients treated with PREVYMIS and at a frequency greater than valganciclovir was diarrhea (32% vs 29%).

The safety profile of PREVYMIS in pediatric subjects was consistent with the safety profile observed in clinical trials of PREVYMIS in adults.

Drug Interactions

If PREVYMIS is co-administered with cyclosporine, the dosage of PREVYMIS should be decreased to 240 mg once daily in adult and pediatric patients 12 years of age and older. If PREVYMIS is co-administered with cyclosporine in pediatric patients less than 12 years of age, dose adjustment may be required.

Co-administration of PREVYMIS may alter the plasma concentrations of other drugs and other drugs may alter the plasma concentrations of PREVYMIS. Consult the full Prescribing Information prior to and during treatment for potential drug interactions.

Closely monitor serum creatinine levels in patients with CLcr less than 50 mL/min using PREVYMIS injection.

PREVYMIS is not recommended for patients with severe (Child-Pugh Class C) hepatic impairment.

Use in Specific Populations

The safety and effectiveness of PREVYMIS have not been established for:

• HSCT recipients less than 6 months of age or weighing less than 6 kg, or
• Kidney transplant recipients less than 12 years of age or weighing less than 40 kg.

For patients with creatinine clearance (CLcr) greater than 10 mL/min (by Cockcroft-Gault equation), no dosage adjustment of PREVYMIS is required based on renal impairment. The safety of PREVYMIS in patients with end-stage renal disease (CLcr less than 10 mL/min), including patients on dialysis, is unknown.

Following the completion of PREVYMIS prophylaxis, monitoring for CMV reactivation in HSCT recipients is recommended.

Indications and usage for RECARBRIO (imipenem, cilastatin, and relebactam)

RECARBRIO is indicated for the treatment of patients 18 years of age and older with hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP), caused by the following susceptible gram-negative microorganisms: Acinetobacter calcoaceticus-baumannii complex, Enterobacter cloacae, Escherichia coli, Haemophilus influenzae, Klebsiella aerogenes, Klebsiella oxytoca, Klebsiella pneumoniae, Pseudomonas aeruginosa and Serratia marcescens.

RECARBRIO is indicated in patients 18 years of age and older who have limited or no alternative treatment options, for the treatment of complicated urinary tract infections (cUTI), including pyelonephritis, caused by the following susceptible gram-negative microorganisms: Enterobacter cloacae, Escherichia coli, Klebsiella aerogenes, Klebsiella pneumoniae, and Pseudomonas aeruginosa.

RECARBRIO is indicated in patients 18 years of age and older who have limited or no alternative treatment options for

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