Researchers conducting the first human trial on a lab-manufactured antibody resulted in “significantly” lowered levels of HIV blood with no side effects. Despite the short-term success, the antibody’s effect didn’t last and some people in the study seemed even to develop a resistance to the drug.

The study suggests that the designer molecule, called 3BNC117, could be most beneficially used in conjunction with other drugs. The team also highlighted the promise of a new approach to fighting HIV which includes immunotherapy-based measures and practices.

“This represents potentially a new class of drugs with activity against HIV,” said study co-author Marina Caskey of New York’s Rockefeller University. “It is possible that 3BNC117 and antibodies like it will boost the patient’s own immune responses, leading to better control of their infection.”

The current treatment of HIV includes a cocktail of drugs meant to simply suppress the replication of the virus, for which no true cure exists. Cloned from a single parent immune call, monoclonal antibodies like 3BNC117 boast our best chance of truly eradicating the HIV virus in a patient.

The naturally produced antibodies within all of us behave by latching on to foreign bodies and flagging them for attack by our immune systems. The problem with the AIDS virus is that it constantly mutates to avoid antibodies. By cloning bNAb antibodies (known for their “broadly-neutralizing” quality), scientists hope to treat HIV infections before the virus mutates.

Resistance to the antibody is an issue, and Caskey says, “One antibody alone, like one drug alone, will not be sufficient to suppress viral load for a long time because resistance will arise.” She also says that the next step is to test whether 3BNC117 can maintain undetectable blood levels of HIV in patients during a pause in antiretroviral therapy, as well as tests of its function in combination with antiretrovirals. Besides the possibility of HIV treatment, the study also raises prospects for a vaccine.