US biopharmaceutical companies are currently developing 44 new medicines and vaccines for HIV/AIDS treatment and prevention, according to new industry figures.

Products in the pipeline include 25 antivirals, 16 vaccines and three cell/gene therapies, all of which are either in clinical trials or awaiting review by the Food and Drug Administration (FDA), reports the Pharmaceutical Research and Manufacturers of America (PhRMA). They include:

- a first-in-class medicine (attachment inhibitor) intended to prevent HIV from breaking through the cell membrane;

- a cell therapy that modifies a patient’s own cells with the aim of making them resistant to HIV; and

- a therapeutic vaccine designed to induce responses from T cells that play a role in immune protection against viral infections.

There are currently 94 active clinical trials for HIV medicines and vaccines in the US. Of these 43 have either not yet started recruiting patients or have recently begun seeking participants, while the remaining 51 are ongoing but not recruiting new patients., adds PhRMA. 

The therapies being investigated include:

- attachment inhibitor: a new class of medicines, one of which now in development attaches to gp120, a part of the virus, and inhibits entry of the virus into cells by blocking the interaction between gp120 and the cell receptors; 

- gene modification: one cell therapy in development is designed to modify the DNA sequence of CCR5 – a co-receptor on the surface of cells that allows HIV to enter and infect T cells – with the aim of making the patient’s own cells resistant to infection by HIV. The patient’s cells are extracted, modified and then reinserted into the patient, to provide a population of cells that can fight HIV and opportunistic infections; and

- inducing T cell responses: deficits of CD4+ T cells, which play a key role in immune protection against viral infections, are associated with virus reactivation, vulnerability to opportunistic infections and poor vaccine efficacy. 

Since AIDS was first reported in 1981, nearly 40 medicines have been approved to treat HIV infection in the US, says PhRMA. They have made HIV infection a manageable chronic disease, but opportunities for greater progress remain, and the current research projects are focused on improved treatment regimens, more effective therapies and preventative vaccines.

Globally, approximately 35 million people are infected with HIV, but new infections have dropped by 38% since 2001, according to UNAIDS, the Joint United Nations Programme on HIV/AIDS