Prescription medicine
Brincidofovir Brand names: Tembexa
Brincidofovir (Tembexa) is a prescription medicine with an FDA approval on record since 2021. No generic is listed in FDA's NDC Directory.
- No generic listed
- Boxed warning
Check it at the source: the brincidofovir FDA label on DailyMed (effective July 1, 2025, Emergent BioDefense Operations Lansing LLC); the NDA 214461 record on Drugs@FDA; every brincidofovir label on DailyMed.
Highlights of the record
FDA label of July 1, 2025; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026
INCREASED RISK FOR MORTALITY WHEN USED FOR LONGER DURATION.
An increased incidence of mortality was seen in TEMBEXA-treated subjects compared to placebo-treated subjects in a 24-week clinical trial when TEMBEXA was evaluated in another disease [see Warnings and Precautions ( 5.1 )]. WARNING: INCREASED RISK FOR MORTALITY WHEN USED FOR LONGER DURATION See full prescribing information for complete boxed warning. An increased incidence of mortality was seen in TEMBEXA- treated subjects compared to placebo-treated subjects in a 24-week clinical trial when TEMBEXA was evaluated in another disease [see Warnings and Precautions ( 5.1 )].
Used for
From the label: indications and usageTEMBEXA is an orthopoxvirus nucleotide analog DNA polymerase inhibitor and is indicated for the treatment of human smallpox disease in adult and pediatric patients, including neonates.
Forms and strengths
- 100 mg
- 10 mg/ml
Film-coated tablet; suspension.
On the market
- Earliest approval on file
- June 4, 2021 Tembexa, Emergent Biodefense; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- No generic approved
- Labelers listed (NDC)
- 1 of which 0 under generic applications, 1 under brand applications, repackagers included
- Last listed patent
- July 30, 2034 Tembexa oral suspension; not a generic launch date
Supply and safety
- Pharmacy cost (NADAC)
- Not in the survey
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- No recall recorded
- FAERS reports
- 137 through July 30, 2026
What is brincidofovir used for?
From the label: indications and usageTEMBEXA is an orthopoxvirus nucleotide analog DNA polymerase inhibitor and is indicated for the treatment of human smallpox disease in adult and pediatric patients, including neonates. ( 1.1 ) Limitations of Use:
TEMBEXA is not indicated for the treatment of diseases other than human smallpox disease. ( 1.2 )
The effectiveness of TEMBEXA for treatment of smallpox disease has not been determined in humans because adequate and well-controlled field trials have not been feasible, and inducing smallpox disease in humans to study the drug’s efficacy is not ethical. ( 1.2 )
TEMBEXA efficacy may be reduced in immunocompromised patients based on studies in immune deficient animals. […]
Source: FDA drug label (Tembexa), Emergent BioDefense Operations Lansing LLC, effective July 1, 2025 (SPL set 209aa94b-c613-4880-ad89-41be83d12c0a), via openFDA; the full label on DailyMed
Is there a generic for brincidofovir (Tembexa)?
No generic brincidofovir is approved (Drugs@FDA, October 8, 2026).
The Orange Book lists 1 patent for Tembexa oral suspension: the compound patent runs to July 30, 2034; a patent listed only for Tembexa tablets runs to October 10, 2034. A patent or exclusivity date is not the date a generic goes on sale: court cases and settlements move it either way.
- 2021 earliest approval on file
- 2034 last listed patent
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What does the brincidofovir label say about other medicines?
The brincidofovir label names 6 other medicines in its interaction, contraindication or warning sections. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Cidofovir | warnings and precautions | Coadministration with Related Products: TEMBEXA should not be coadministered with intravenous cidofovir. |
| Clarithromycin | drug interactions | Drugs on TEMBEXA Inhibitors for Organic Anion Transporting Polypeptide (OATP) 1B1 and 1B3 Concomitant use of TEMBEXA with OATP1B1 and 1B3 inhibitors (clarithromycin, cyclosporine, erythromycin, gemfibrozil, human immunodeficiency virus [HIV] and hepatitis C virus [HCV] protease inhibitors, rifampin [single dose]) … |
| Cyclosporine | drug interactions | Drugs on TEMBEXA Inhibitors for Organic Anion Transporting Polypeptide (OATP) 1B1 and 1B3 Concomitant use of TEMBEXA with OATP1B1 and 1B3 inhibitors (clarithromycin, cyclosporine, erythromycin, gemfibrozil, human immunodeficiency virus [HIV] and hepatitis C virus [HCV] protease inhibitors, rifampin [single dose]) … |
| Erythromycin | drug interactions | Drugs on TEMBEXA Inhibitors for Organic Anion Transporting Polypeptide (OATP) 1B1 and 1B3 Concomitant use of TEMBEXA with OATP1B1 and 1B3 inhibitors (clarithromycin, cyclosporine, erythromycin, gemfibrozil, human immunodeficiency virus [HIV] and hepatitis C virus [HCV] protease inhibitors, rifampin [single dose]) … |
| Gemfibrozil | drug interactions | Drugs on TEMBEXA Inhibitors for Organic Anion Transporting Polypeptide (OATP) 1B1 and 1B3 Concomitant use of TEMBEXA with OATP1B1 and 1B3 inhibitors (clarithromycin, cyclosporine, erythromycin, gemfibrozil, human immunodeficiency virus [HIV] and hepatitis C virus [HCV] protease inhibitors, rifampin [single dose]) … |
| Rifampin | drug interactions | … erythromycin, gemfibrozil, human immunodeficiency virus [HIV] and hepatitis C virus [HCV] protease inhibitors, rifampin [single dose]) increase brincidofovir AUC and C max which may increase TEMBEXA-associated adverse reactions [see Clinical Pharmacology ( 12.3 )]. |
Source: FDA drug label (Tembexa), Emergent BioDefense Operations Lansing LLC, effective July 1, 2025 (SPL set 209aa94b-c613-4880-ad89-41be83d12c0a), via openFDA; the full label on DailyMed
What do FAERS reports show for brincidofovir?
The FDA Adverse Event Reporting System holds 137 reports that list brincidofovir among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 57 are coded as a death and 41 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What next?
- Brincidofovir side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other