Newly Approved HIV Medications

Ian Villaluz, PharmD Candidate 2021; Glenn R. Grantner, PharmD, BCPS

Disclosures

US Pharmacist. 2020;45(10):17-25. 

In This Article

Fostemsavir (Rukobia)

Fostemsavir is a novel ARV indicated for combination therapy in HTE adults with known MDR HIV-1, specifically for patients who are failing current ART due to potential resistance, intolerance, or safety considerations.[4] It is the first FDA-approved attachment inhibitor. After enzymatic activation to the active molecule temsavir, it binds to gp120, a viral envelope glycoprotein necessary for viral attachment to CD4 cells. This prevents viral entry into CD4 cells, effectively stopping viral replication. Because of this novel mechanism, fostemsavir is unlikely to induce resistance to itself through the selective pressure associated with most other ARVs.[6,17]

Fostemsavir was evaluated for both safety and efficacy in a randomized, double-blinded, placebo-controlled clinical trial (BRIGHTE) including 371 HTE HIV-1 patients.[16,17] Patients in the main cohort were treated with both their baseline ART regimen together with either fostemsavir 600 mg twice daily or placebo for a total of 8 days. Upon assessment on day 8, fostemsavir patients demonstrated significantly lower serum levels of viral HIV-RNA. After this initial treatment period, all patients were transitioned to fostemsavir 600 mg twice daily. At the 24-week mark, 53% of study participants achieved effective undetectable levels of viral suppression, with suppression improving to 60% at week 96.[17,18]

The most commonly reported adverse effect from fostemsavir was nausea. More severe reactions including elevations in liver enzymes were reported in patients with hepatitis B or C coinfection.[17,18] Other studies reported minor incidence of headache, rash, and diarrhea. The active metabolite temsavir is metabolized by CYP3A4, so strong inducers such as carbamazepine, rifampin, and St. John's wort should be avoided to prevent decreased serum temsavir concentration.[17–19]

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