Switching from a toxicity-causing antiretroviral to enfuvirtide in patients with HIV: the SWITCH TOX study.
OBJECTIVE
Treatment-related toxicities frequently limit antiretroviral therapy for patients with HIV-1 infection. This study evaluated the changes in treatment-limiting toxicities when the primary toxicity-causing agent was replaced with enfuvirtide.


METHODS
Adult patients with HIV-1 infection (N = 91) with antiretroviral treatment-limiting toxicities were enrolled in this multicenter, open-label, single-arm, 24-week study. Enfuvirtide 90 mg bid was administered instead of a single toxicity-causing component of the previous antiretroviral regimen. Changes in severity of antiretroviral toxicity, safety, tolerability, and maintenance of efficacy of the enfuvirtide regimen were evaluated at baseline and at 4, 8, 12, and 24 weeks.


RESULTS
Eighty-four percent of participants completed the study. Injection site reactions with enfuvirtide caused premature withdrawal in 5 participants (5%); a further 10 participants (11%) also withdrew early. Overall antiretroviral-related, treatment-limiting toxicities improved or resolved in 53% of participants switching to enfuvirtide, remained unchanged in 43%, and worsened in 3%. At Week 24, 66% of participants (60/91; intent-to-treat population) maintained or improved their viral load category and 73% of participants (66/91) maintained or improved their CD4 cell counts.


CONCLUSIONS
Replacing a toxicity-causing antiretroviral with enfuvirtide may reduce toxicity without compromising the efficacy of different antiretroviral regimens.
Streinu-Cercel
Adrian
A
Matei Bals Infectious Disease Institute, Bucharest, Romania.
de Gorgolas
Miguel
M
Müller
Markus
M
Portilla
Joaquin
J
Rugina
Sorin
S
Böcher
Wulf
W
Staszewski
Schlomo
S
Pulik
Piotr
P
Rowell
Lucy
L
Salgo
Miklos
M
Stoll
Matthias
M
D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000009:adverse effects* / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D000077560:Enfuvirtide; D005260:Female; D015700:HIV Envelope Protein gp41 / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D023581:HIV Fusion Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D017320:HIV Protease Inhibitors / Q000009:adverse effects*; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D010446:Peptide Fragments / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D011788:Quality of Life; D012367:RNA, Viral / Q000097:blood; D018894:Reverse Transcriptase Inhibitors / Q000009:adverse effects*; D016896:Treatment Outcome; D019562:Viral Load; D055815:Young Adult
D019380:Anti-HIV Agents; D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D017320:HIV Protease Inhibitors; D010446:Peptide Fragments; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D000077560:Enfuvirtide