In a Dovato vs. Biktarvy Comparison, Dovato Is Better on Weight Gain

Weight gain is a serious side effect of HIV treatment, so results of trial showing that people treated with Dovato (dolutegravir/lamivudine) gained less weight than those treated with Biktarvy (bictegravir/emtricitabine]/tenofovir alafenamide fumarate) could affect prescribing patterns.

The results of the phase 4 study, which were presented in July at the International AIDS Society’s 25th International AIDS Conference in Munich, Germany, showed that those who switched to Biktarvy gained almost twice as much weight, on average, than those who switched to Dovato (1.81 kilograms [kg], or almost 4 pounds vs. 0.89 kg, or just under 2 pounds) at week 48. Other weight-gain data from trial showed that the proportion of study participants with weight gain greater than 5% at week 48 was higher among those in the Biktarvy group than among those randomly assigned to Dovato (29.9% vs. 20.0%).

Weight gain was, though, a secondary outcome of the trial. The primary outcome of the trial was maintaining viral suppression, and the results showed that Dovato was noninferior to Biktarvy in that regard.

ViiV Healthcare manufactures and markets Dovato, which was first approved by the FDA in 2019. ViiV, a company that specializes in HIV treatment, that is majority owned by GSK, a British pharmaceutical company. ViiV highlighted the weight gain results in a new release about the trial results issued before the International AIDS Conference.

“The HIV treatment regimens that are commonly prescribed today are all highly effective, which makes it critical that we study the impact of these therapies beyond just viral suppression,” Esteban Martínez, M.D., Ph.D., an infectious disease expert at the Hospital Clinic of Barcelona in Spain, and chief executive investigator of the trial, was quoted as saying in the news release.

In the same news release, Harmony P. Garges, M.D., M.P.H., ViiV’s chief medical officer, was quoted as saying that weight gain difference between Dovato and Biktarvy was “a meaningful outcome, as treatment-related weight gain is an important topic for many people living with HIV.”

The Paso Doble trial was an open-label, multicenter study conducted at 30 sites in Spain. The 553 study participants were people living with HIV who were virologically suppressed but being treated in way that was less than optimal: they were taking multiple pills or on regimens containing pharmacokinetic boosting agents or drugs with cumulative toxicity, such as efavirenz or tenofovir disoproxil fumarate. Martinez and his colleagues randomly assigned them to switch to Dovato (277 study participants) or Biktarvy (276 study participants).

The efficacy endpoint was the proportion of participants with viral RNA copies of HIV of 50 per milliliter or more at 48 weeks with a 4% noninferiority margin in the exposed intention-to-treat population. At 48 weeks, risk difference between Dovato (2.2%) and Biktarvy (0.7%) was 1.4%, according to the ViiV news release. One participant in the Biktarvy group and none in Dovato arm had protocol-defined confirmed virological failure.

The weight gain differences were affected by the drugs that the study participant had been taking previously, according to the study results as described in the news release. The proportion of trial participants experiencing greater than 5% weight gain with Biktarvy was approximately 45% higher than those taking Dovato when switching from a regimen with abacavir and about twofold higher when switching from a regimen with tenofovir disoproxil fumarate.