ViiV Healthcare has reported positive results for its phase 3 BRIGHTE study of investigational fostemsavir at 48 weeks in heavily treatment-experienced (HTE) patients with HIV-1 infection.
Fostemsavir, in combination with optimised background treatment (OBT), maintained virologic suppression from Week 24 to Week 48 in this difficult-to-treat population. Results show 54% of patients in the randomised cohort (n = 146/272) achieved virologic suppression (<40 copies/mL) at 48 weeks of treatment with fostemsavir plus optimised background therapy.
Additionally, patients in the randomised cohort showed immunologic improvement through week 48 as demonstrated by an increase in CD4+ T-cell counts (mean change from baseline of +139 cells/µL). These data at 48 weeks build on the primary endpoint data (day 8) announced last year.
Most patients who received fostemsavir experienced at least one adverse event (AE) by week 48. The most commonly reported drug-related AEs were diarrhoea, nausea and headache.
Thirty-five percent of participants had one or more serious adverse events (SAE), most commonly related to infections, and these occurred in the most immunocompromised patients. Three percent (3%) of SAEs related to the study medication, and seven percent (7%) of participants discontinued due to an AE.
ViiV Healthcare chief scientific and medical officer John Pottage, Jr said: “We are excited by the results of the BRIGHTE study which evaluated fostemsavir, a first-in-class attachment inhibitor, specifically developed for heavily treatment-experienced patients.
“People living with HIV who participated in this study were failing on their current antiretroviral regimens and had few treatment options left available to them; we were encouraged to see that treatment with fostemsavir resulted in both meaningful reductions in viral load and improvements in the health of their immune systems.
“At ViiV Healthcare we remain dedicated to developing innovative medicines for all people living with HIV and expect to seek regulatory approval for fostemsavir in 2019.”
Searching for new ways to prevent the HIV virus from replicating is important, especially for those who develop resistance to their treatment regimens.
Fostemsavir is a prodrug that is metabolised to the active compound, temsavir, a first-in-class attachment inhibitor that binds to glycoprotein 120 (gp120) on the envelope of the HIV, locking gp120 in a conformational state that inhibits initial interaction between the virus and host immune cells, preventing viral attachment and entry into the host CD4+ T-cell.
Because of its mechanism of action there is no in-vitro cross-resistance to other classes of ARVs, which may help patients who have become resistant to most other medicines.
In addition to the primary efficacy results, a pre-specified subgroup analysis was also conducted and showed numerically higher rates of virologic response in patients >50 years, females, or in patients who self-reported their race as “black” or “African-American” compared to their respective counterparts through Week 48.
Not unique to the BRIGHTE study was the fact that subgroups with high baseline HIV-1 RNA (>=100,000 c/mL) and low baseline CD4+ cell counts (<20 cells/mm3) had lower rates of virologic response through Week 48.
There were comparable increases in CD4+ T-cell counts across subgroups of: age, gender, race, and geographic region.
Notably, subjects with the lowest baseline CD4 counts (<20 cells/μL), had comparable improvement in mean change in baseline CD4 count to those with the highest baseline CD4 values (>200 cells/μL); +145 and +150 cells/μL, respectively.
Source: Company Press Release