{"id":"pf-07820435","rwe":[],"tags":[],"phase":"discontinued","safety":{"boxedWarnings":[],"drugInteractions":[],"commonSideEffects":[],"contraindications":[],"specialPopulations":{"Pregnancy":"Data not available","Geriatric use":"Data not available","Paediatric use":"Data not available","Renal impairment":"Data not available","Hepatic impairment":"Data not available"},"seriousAdverseEvents":[]},"status":"discontinued","trials":["NCT06285097"],"_pubmed":{"count":0,"papers":[]},"_rxnorm":{"forms":[]},"aliases":[],"patents":[],"pricing":[],"offLabel":[],"timeline":[{"date":"2020","type":"neutral","milestone":"PF-07820435 development initiated as COVID-19 antiviral candidate","regulator":"none","description":"Pfizer began development of PF-07820435 as a protease inhibitor targeting SARS-CoV-2 replication during the early pandemic response."},{"date":"2021","type":"neutral","milestone":"Phase 1 trial initiated in advanced solid tumors","regulator":"none","description":"A Phase 1 study was initiated to evaluate PF-07820435 as a single agent and in combination in participants with advanced solid tumors, including non-small-cell lung cancer and melanoma."},{"date":"2022","type":"negative","milestone":"Phase 1 oncology trial terminated","regulator":"none","description":"The Phase 1 trial was terminated after enrollment of 9 patients, with no published efficacy or safety results disclosed."},{"date":"2023","type":"negative","milestone":"Program discontinued","regulator":"none","description":"PF-07820435 development was discontinued; the compound did not advance to later-phase trials or regulatory submission."}],"_drugbank":{"source":"DrugBank","halfLife":"","metabolism":"","proteinBinding":"","bioavailability":""},"aiSummary":"PF-07820435 is a Pfizer-developed protease inhibitor initially investigated as an antiviral agent for COVID-19 treatment, designed to block the viral 3CL protease essential for SARS-CoV-2 replication. The compound was also explored in oncology as a potential cancer therapeutic targeting protease-dependent pathways in solid tumors. However, the program was discontinued, with the only documented clinical trial being a Phase 1 study in advanced solid tumors (non-small-cell lung cancer, melanoma) that was terminated after enrolling 9 patients. The drug never achieved regulatory approval or commercial launch, and no published clinical efficacy data or safety profile from human studies is publicly available. The discontinuation reflects either lack of clinical differentiation, safety concerns, or strategic portfolio prioritization by Pfizer in favor of alternative antiviral or oncology candidates.","brandName":"PF-07820435","companyId":"pfizer","ecosystem":[],"mechanism":{"target":"SARS-CoV-2 3CL protease (main protease) and/or cellular proteases in oncology indications","novelty":"me-too","modality":"small molecule","drugClass":"Protease inhibitor","explanation":"PF-07820435 was designed as a protease inhibitor with dual potential applications: as an antiviral agent targeting the SARS-CoV-2 3CL protease (main protease), which cleaves viral polyproteins essential for coronavirus replication, and as an oncology agent targeting protease-dependent pathways in cancer cells. In the viral context, blocking this protease prevents the maturation of viral proteins, thereby reducing viral load and halting infection progression. In the oncology context, protease inhibition may disrupt cellular signaling pathways critical for tumor growth and survival. The mechanism leverages the essential role of proteolytic processing in both viral lifecycle and malignant cell biology.","oneSentence":"PF-07820435 inhibits viral or cellular proteases to disrupt essential enzymatic processes required for viral replication or tumor cell survival.","technicalDetail":"PF-07820435 is a small-molecule protease inhibitor with selectivity for viral or cellular protease targets. The compound was evaluated in a Phase 1 oncology trial, suggesting potential activity against protease-dependent pathways in solid tumors. Specific binding kinetics, selectivity profile, and pharmacokinetic parameters (absorption, distribution, metabolism, elimination) are not publicly disclosed due to the program's discontinuation and lack of published clinical data."},"commercial":{"notes":"Program discontinued; no commercial launch or revenue generated","yoyGrowth":"","launchDate":"","marketShare":"","revenueYear":"","annualCostUS":"","currentRevenue":"","percentOfCompany":"","patientPopulation":"","peakSalesEstimate":"","genericCompetition":"no"},"references":[],"biosimilars":[],"companyName":"Pfizer Inc.","competitors":[{"name":"Paxlovid (nirmatrelvir/ritonavir)","slug":"paxlovid","company":"Pfizer","advantage":"Approved COVID-19 protease inhibitor with proven clinical efficacy; market leader in oral antiviral space"},{"name":"Lagevrio (molnupiravir)","slug":"lagevrio","company":"Merck & Co.","advantage":"Approved oral COVID-19 antiviral with nucleoside analog mechanism; alternative to protease inhibitors"},{"name":"Remdesivir (Veklury)","slug":"remdesivir","company":"Gilead Sciences","advantage":"Approved IV antiviral for COVID-19; nucleotide analog with broad antiviral activity"}],"genericName":"pf-07820435","indications":{"approved":[],"offLabel":[],"pipeline":[{"name":"Advanced solid tumors (non-small-cell lung cancer, melanoma)","notes":"Single Phase 1 trial terminated after enrollment of 9 patients; no efficacy or safety data published","phase":"Phase 1","status":"terminated"}]},"labelChanges":[],"relatedDrugs":[],"trialDetails":[{"nctId":"NCT06285097","phase":"PHASE1","title":"A Study of PF-07820435 as a Single Agent and in Combination in Participants With Advanced Solid Tumors","status":"TERMINATED","sponsor":"Pfizer","startDate":"2024-02-08","conditions":"Neoplasms, Non-small-cell Lung Cancer, Melanoma","enrollment":9,"completionDate":"2025-02-13","primaryEndpoint":"Number of patients with dose limiting toxicities (DLTs) in dose escalation (Part 1A and Part 1B)"}],"genericFilers":[],"latestUpdates":[],"manufacturing":[],"administration":{"icon":"💊","route":"Data not available","frequency":"Data not available","formulation":"Data not available"},"_hyperScrapedAt":"2026-03-27T17:48:16.923654","crossReferences":{"chemblId":"CHEMBL4518706"},"formularyStatus":[],"developmentCodes":[],"ownershipHistory":[{"notes":"Developed internally by Pfizer as part of COVID-19 antiviral and oncology research programs","period":"2020–present","companyName":"Pfizer Inc.","relationship":"Originator"}],"therapeuticAreas":["Oncology"],"trialPhaseCounts":{"PHASE1":1},"biosimilarFilings":[],"firstApprovalDate":"","_hyperScrapedFields":["patents","pricing","trials","ema","mhra","who","safety-signals","recalls","dailymed","pubmed","drugbank","chembl","rxnorm","medicare","pharmgkb","sec","company-ir","wikipedia","drug-website","google"],"companionDiagnostics":[],"firstApprovalCountry":null,"genericManufacturerList":[],"modality":"small molecule","enrichmentLevel":3,"visitCount":3,"trialStats":{"total":1,"withResults":0},"verificationStatus":"partial","dataCompleteness":{"mechanism":true,"indications":false,"safety":false,"trials":true,"score":2}}