-- Pfizer Inc. (NYSE: PFE) today shared top-line results from the Phase 2/3 EPIC-PEP (Evaluation of Protease Inhibition for COVID-19 in Post-Exposure Prophylaxis) study evaluating PAXLOVID™ (nirmatrelvir [PF-07321332] tablets and ritonavir tablets) for post-exposure prophylactic use. In this trial, compared to placebo, Pfizer observed risk reductions of 32% and 37% in adults who received PAXLOVID for five and ten days, respectively, to prevent infection. These results, however, were not statistically significant and, as such, the primary endpoint of reducing the risk of confirmed and symptomatic COVID-19 infection in adults who had been exposed to the virus through a household contact was not met.
Available safety data for PAXLOVID has been generally consistent in more than 3,500 PAXLOVID-treated participants across the EPIC-HR, EPIC-SR and EPIC-PEP studies, as well as in reported post-market safety experience. In EPIC-PEP, this safety profile remained generally consistent when PAXLOVID was used for either five or ten days. Analyses of all secondary endpoints and sub-groups are ongoing, and results will be included in the publication or presentation of the final study results.
"We designed the clinical development program for PAXLOVID to be comprehensive and ambitious with the aim of being able to help combat COVID-19 in a very broad population of patients," said Albert Bourla, Chairman and Chief Executive Officer, Pfizer. "While we are disappointed in the outcome of this particular study, these results do not impact the strong efficacy and safety data we've observed in our earlier trial for the treatment of COVID-19 patients at high risk of developing severe illness, and we are pleased to see the growing global use of PAXLOVID in that population."
PAXLOVID is currently approved or authorized for conditional or emergency use in more than 60 countries across the globe to treat high-risk COVID-19 patients.
Please see Full Emergency Use Authorization (EUA) Prescribing Information available at www.fda.gov and www.COVID19oralRx.com.
About the Phase 2/3 EPIC-PEP Study
The top-line analysis evaluated data from 2,957 adults. Enrolled adults had a negative SARS-CoV-2 rapid antigen test result and were asymptomatic household contacts with exposure within 96 hours to an individual who was symptomatic and recently tested positive for SARS-CoV-2. Each patient was randomized (1:1:1) to receive orally twice daily one of the following: (i) PAXLOVID for five days followed by placebo for 5 days, (ii) PAXLOVID for ten days or (iii) placebo for ten days.
Recruitment began in September 2021 and was completed during the peak of the COVID-19 Omicron wave.
Additional details on the study are available on clinicaltrials.gov (NCT05047601). Full study data are expected to be released in the coming months and submitted to a peer-reviewed publication.
U.S. FDA Emergency Use Authorization Statement
PAXLOVID has not been approved, but has been authorized for emergency use by FDA under an EUA, for the treatment of mild-to-moderate COVID-19 in adults and pediatric patients (12 years of age and older weighing at least 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.
The emergency use of PAXLOVID 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 Act, 21 U.S.C. § 360bbb-3(b)(1), unless the declaration is terminated or authorization revoked sooner.
AUTHORIZED USE
The U.S. Food and Drug Administration (FDA) has issued an Emergency Use Authorization (EUA) for the emergency use of the unapproved product PAXLOVID for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in adults and pediatric patients (12 years of age and older weighing at least 40 kg) with positive results of direct severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral testing, and who are at high risk for progression to severe COVID-19, including hospitalization or death.
LIMITATIONS OF AUTHORIZED USE
• PAXLOVID is not authorized for initiation of treatment in patients requiring hospitalization due to severe or critical COVID-19
• PAXLOVID is not authorized for use as pre-exposure or post-exposure prophylaxis for prevention of COVID-19
• PAXLOVID is not authorized for use for longer than 5 consecutive days
PAXLOVID 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 PAXLOVID belongs (i.e., anti-infectives).
PAXLOVID is not approved for any use, including for use for the treatment of COVID-19.
PAXLOVID is authorized only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use of PAXLOVID under 564(b)(1) of the Food Drug and Cosmetic Act unless the authorization is terminated or revoked sooner.
IMPORTANT SAFETY INFORMATION
PAXLOVID is contraindicated in patients with a history of clinically significant hypersensitivity reactions (eg, toxic epidermal necrolysis [TEN] or Stevens-Johnson syndrome) to its active ingredients (nirmatrelvir or ritonavir) or any other components of the product.
PAXLOVID is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated concentrations are associated with serious and/or life-threatening reactions:
• Alpha1-adrenoreceptor antagonist: alfuzosin
• Analgesics: pethidine, propoxyphene
• Antianginal: ranolazine
• Antiarrhythmic: amiodarone, dronedarone, flecainide, propafenone, quinidine
• Anti-gout: colchicine
• Antipsychotics: lurasidone, pimozide, clozapine
• Ergot derivatives: dihydroergotamine, ergotamine, methylergonovine
• HMG-CoA reductase inhibitors: lovastatin, simvastatin
• PDE5 inhibitor: sildenafil (Revatio®) when used for pulmonary arterial hypertension
• Sedative/hypnotics: triazolam, oral midazolam
PAXLOVID is contraindicated with drugs that are potent CYP3A inducers where significantly reduced nirmatrelvir or ritonavir plasma concentrations may be associated with the potential for loss of virologic response and possible resistance. PAXLOVID cannot be started immediately after discontinuation of any of the following medications due to the delayed offset of the recently discontinued CYP3A inducer:
• Anticancer drugs: apalutamide
• Anticonvulsant: carbamazepine, phenobarbital, phenytoin
• Antimycobacterials: rifampin
• Herbal Products: St. John's Wort (hypericum perforatum)
There are limited clinical data available for PAXLOVID. Serious and unexpected adverse events may occur that have not been previously reported with PAXLOVID use.
Risk of Serious Adverse Reactions Due to Drug Interactions: Initiation of PAXLOVID, a CYP3A inhibitor, in patients receiving medications metabolized by CYP3A or initiation of medications metabolized by CYP3A in patients already receiving PAXLOVID, may increase plasma concentrations of medications metabolized by CYP3A. Initiation of medications that inhibit or induce CYP3A may increase or decrease concentrations of PAXLOVID, respectively. These interactions may lead to:
• Clinically significant adverse reactions, potentially leading to severe, life-threatening, or fatal events from greater exposures of concomitant medications
• Clinically significant adverse reactions from greater exposures of PAXLOVID
• Loss of therapeutic effect of PAXLOVID and possible development of viral resistance
Consult Table 1 of the Fact Sheet for Healthcare Providers for clinically significant drug interactions, including contraindicated drugs. Consider the potential for drug interactions prior to and during PAXLOVID therapy; review concomitant medications during PAXLOVID therapy and monitor for the adverse reactions associated with the concomitant medications.
Hypersensitivity reactions have been reported with PAXLOVID including urticaria, angioedema, dyspnea, mild skin eruptions, and pruritus. Cases of anaphylaxis, TEN, and Stevens-Johnson syndrome have also been reported with components of PAXLOVID (refer to NORVIR labeling). If signs and symptoms of a clinically significant hypersensitivity reaction or anaphylaxis occur, immediately discontinue PAXLOVID and initiate appropriate medications and/or supportive care.
Hepatotoxicity: Hepatic transaminase elevations, clinical hepatitis, and jaundice have occurred in patients receiving ritonavir. Therefore, caution should be exercised when administering PAXLOVID to patients with pre-existing liver diseases, liver enzyme abnormalities, or hepatitis.
Because nirmatrelvir is co-administered with ritonavir, there may be a risk of HIV-1 developing resistance to HIV protease inhibitors in individuals with uncontrolled or undiagnosed HIV-1 infection.
Adverse events in the PAXLOVID group (≥1%) that occurred at a greater frequency (≥5 subject difference) than in the placebo group were dysgeusia (6% and
The following adverse reactions have been identified during post-authorization use of PAXLOVID. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Immune System Disorders: Hypersensitivity reactions
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 PAXLOVID within 7 calendar days from the healthcare provider's awareness of the event.
Submit adverse event and medication error reports to FDA MedWatch using one of the following methods:
• Online: https://www.fda.gov/medwatch/report.htm
• Complete and submit a postage-paidFDA Form 3500and returning by mail/fax
• Call
