The clinical trials of two combined drugs from Johnson & Johnson and ViiV Healthcare showed promising results in containing HIV with monthly or bimonthly injections. The two companies have set up a 96-week clinical trial among 309 patients for combination drugs and the results of the first 32 weeks look encouraging.

Initial results showed that the combined drug treatment, when taken every four or eight weeks, lowered the amount of virus in study patients just as much as the traditional pill treatment taken three times a day. While additional tests are needed, the approval of a combination drug would be a pioneer in HIV treatment.

One of the drugs in the combined study is called rilpivirine, which is sold in the market as Edurant by Johnson & Johnson's Janssen unit. Rilpivirine has been approved for HIV patients who have not taken other HIV drugs prior and whose HIV level in the blood is not high.

The second drug is an experimental one called cabotegravir by ViiV Healthcare. Cabotegravir is similar to the approved HIV drug dolutegravir sold under the brand name Tivicay by GlaxoSmithKline.

The study participants first received three pills until the virus in their blood were rendered untraceable. The three pills included cabotegravir and two nucleoside reverse transcriptase inhibitors (NRTI) drugs. The participants were divided into three groups, with one group receiving the rilpivirine-cabotegravir injection every four weeks. The second group received the combination drug every eight weeks, while the third group continued the three-pills-a-day maintenance treatment.

After 32 weeks, patients who got the monthly injections had a 94 percent viral suppression rate, while those who received bimonthly injections had a 95 percent viral suppression. Lastly, those who stayed on the maintenance treatment had a 91 percent viral suppression rate.

The existing drug therapy for HIV patients involves taking three pills every day. The drugs are often combination pills that keep patients fairly strong for several years. This current HIV therapy needs to be followed religiously; otherwise, it could lead to the revival of the virus which can grow resilient to the current treatment.

AIDS expert Dr. Daniel Kuritzkes expressed that the initial reports "provide an extremely important proof of concept that this approach is feasible." However, the injectable therapy needs more and longer clinical trials that involves more patients. The late-stage study of the combination drug is already underway. Kuritzkes, a professor of medicine at Harvard Medical School, is also a consultant to ViiV but he was not involved in the study.

Created in November 2009, ViiV Healthcare is a pharmaceutical company that specializes in developing HIV therapies as a joint venture by GlaxoSmithKline, Pfizer and Shionogi Ltd.

Photo: National Institute of Allergy and Infectious Diseases (NIAID) | Flickr