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Recommendations for Use of Antiretroviral Drugs in Pregnant HIV-1-Infected Women for Maternal Health and Interventions to Reduce Perinatal HIV Transmission in the United States

Entry Inhibitors

Enfuvirtide (Fuzeon, T-20)

(Last updated: March 28, 2014; last reviewed: March 28, 2014)

Enfuvirtide is classified as Food and Drug Administration (FDA) Pregnancy Category B. 

Animal Carcinogenicity Studies

Enfuvirtide was neither mutagenic nor clastogenic in a series of in vitro and animal in vivo screening tests. Long-term animal carcinogenicity studies of enfuvirtide have not been conducted.

Reproduction/Fertility Animal Studies

Reproductive toxicity has been evaluated in rats and rabbits. Enfuvirtide produced no adverse effects on fertility of male or female rats at doses up to 30 mg/kg/day administered SQ (1.6 times the maximum recommended adult human daily dose on an m2 body surface area basis).

Teratogenicity/Developmental Toxicity Animal Studies

Studies in rats and rabbits revealed no evidence of harm to the fetus from enfuvirtide administered in doses up to 27 times and 3.2 times, respectively, the adult human daily dose on an m2 basis.

Placental and Breast Milk Passage

In vitro and in vivo studies suggest that enfuvirtide does not readily cross the human placenta. Published reports of a total of 8 peripartum patients and their neonates and data from an ex vivo human placental cotyledon perfusion model demonstrated minimal placental passage of enfuvirtide.1-5 Studies of radiolabeled enfuvirtide administered to lactating rats indicated radioactivity in the milk; however, it is not known if this reflected radiolabeled enfuvirtide or metabolites (e.g., amino acid and peptide fragments) of enfuvirtide. 

Human Studies in Pregnancy

Data on the use of enfuvirtide in human pregnancy are limited to case reports of a small number of women treated with the drug.1,5-10 


  1. Brennan-Benson P, Pakianathan M, Rice P, et al. Enfurvitide prevents vertical transmission of multidrug-resistant HIV-1 in pregnancy but does not cross the placenta. AIDS. 2006;20(2):297-299. Available at
  2. Ceccaldi PF, Ferreira C, Gavard L, Gil S, Peytavin G, Mandelbrot L. Placental transfer of enfuvirtide in the ex vivo human placenta perfusion model. Am J Obstet Gynecol. 2008;198(4):433 e431-432. Available at
  3. Peters PJ, Polle N, Zeh C, et al. Nevirapine-associated hepatotoxicity and rash among HIV-infected pregnant women in Kenya. J Int Assoc Physicians AIDS Care (Chic). 2012;11(2):142-149. Available at
  4. Moisan A, Desmoyer A, Bourgeois-Moine A, et al. Placental transfer of antiretroviral drugs in HIV-infected women: a retrospective study from 2002 to 2009. Abstract 1. Paper presented at: 11th International Workshop on Clinical Pharmacology of HIV Therapy; 2010; Sorrento, Italy.
  5. Weizsaecker K, Kurowski M, Hoffmeister B, Schurmann D, Feiterna-Sperling C. Pharmacokinetic profile in late pregnancy and cord blood concentration of tipranavir and enfuvirtide. Int J STD AIDS. 2011;22(5):294-295. Available at
  6. Cohan D, Feakins C, Wara D, et al. Perinatal transmission of multidrug-resistant HIV-1 despite viral suppression on an enfuvirtide-based treatment regimen. AIDS. 2005;19(9):989-990. Available at
  7. Meyohas MC, Lacombe K, Carbonne B, Morand-Joubert L, Girard PM. Enfuvirtide prescription at the end of pregnancy to a multi-treated HIV-infected woman with virological breakthrough. AIDS. 2004;18(14):1966-1968. Available at
  8. Furco A, Gosrani B, Nicholas S, et al. Successful use of darunavir, etravirine, enfuvirtide and tenofovir/emtricitabine in pregnant woman with multiclass HIV resistance. AIDS. 2009;23(3):434-435. Available at
  9. Sued O, Lattner J, Gun A, et al. Use of darunavir and enfuvirtide in a pregnant woman. Int J STD AIDS. 2008;19(12):866-867. Available at
  10. Madeddu G, Calia GM, Campus ML, et al. Successful prevention of multidrug resistant HIV mother-to-child transmission with enfuvirtide use in late pregnancy. Int J STD AIDS. 2008;19(9):644-645. Available at

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