A multicenter study published in Lancet compares a new drug against the AIDS virus (HIV-1), called dolutegravir, with raltegravir, another antiviral of the same family marketed since 2007. The study concludes that both drugs have the same efficacy and safety. In other studies, dolutegravir has proved superior to the reference treatment, more resistant against HIV-1 mutations. The new antiviral does not need to be promoted with other drugs and can be administered in a single daily dose. This fact makes dolutegravir an effective option for treating HIV-1 infection. Researchers at the Bellvitge Biomedical Research Institute (IDIBELL) in the Bellvitge University Hospital have participated in the study.

Both raltegravir and dolutegravir are part of the family of integrase inhibitors, a group of drugs that block an enzyme involved in the virus replication process. This group of antiretrovirals inhibits the virus more quickly, are well tolerated and have few interactions with other medicines. Raltegravir was the first drug of this family to be approved in 2007. The summer of 2012 the FDA, in the United States, approved the second one, elvitegravir, which is pending approval in Europe. It is expected that dolutegravir will be marketed in the USA during 2013.

The study involved more than 800 people who were recently infected with HIV-1. Patients who participated in the clinical trial are in hospitals around the world as part of the study SPRING-2. Bellvitge University Hospital contributed seventeen patients. Half of the participants were treated with raltegravir and half with dolutegravir. In both cases, the treatment was supplemented, as it is indicated, with two antiretroviral belonging to the inhibitors of reverse transcriptase family.

Treatment response was similar in both cases, both in terms of efficacy and side effects. The Director of the HIV/AIDS Program at the Infectious Diseases Service of the Bellvitge University Hospital and IDIBELL researcher, Daniel Podzamczer, stresses that dolutegravir can be administered in a single daily pill, while the daily dose of raltegravir has to be divided in two tablets. Podzamczer stresses that, unlike elvitegravir, “dolutegravir does not need to be boosted with ritonavir [antiretroviral used in low doses to boost the effects of other HIV drugs] nor cobicistat and seems to have a higher genetic barrier than the other two drugs family, which means that it would take more mutations in the virus to become resistant.”

Dolutegravir is administered with other antiretroviral agents, and it is expected to be sold in a single tablet. However, the editorial accompanying the article speculates that dolutegravir could become effective without combining it with other antiretrovirals, so it could become the first integrase inhibitor administered as monotherapy, which could significantly reduce side effects and cost. Still, however, there is insufficient evidence to suggest this possibility.

Reference
Raffi F, Rachlis A, Stellbrink HJ, Hardy WD, Torti C, Orkin C, Bloch M, Podzamczer D*, Pokrovsky V, Pulido F, Almond S, Margolis D, Brennan C, Min S; on behalf of the SPRING-2 study group. Once-daily dolutegravir versus raltegravir in antiretroviral-naive adults with HIV-1 infection: 48 week results from the randomised, double-blind, non-inferiority SPRING-2 study. Lancet. 2013 Jan 7. pii: S0140-6736(12)61853-4. doi: 10.1016/S0140-6736(12)61853-4. [Epub ahead of print]

*Investigador de l’IDIBELL a l’Hospital Universitari de Bellvitge.