FAQs
Q. What are second-line antiretrovirals? How are they different from first-line ARVs and why do they cost more?
A. Over time, a patient’s initial regimen of ARV medications (“first-line” therapy) may start failing to
control the level of the HIV virus in the body as the virus develops resistance to the first-line drugs.
The likelihood of developing resistance varies greatly between patients. When this occurs, there is a
need to switch the patient to a new combination of ARV medications that together comprise
“second-line” therapy. One of the drugs typically in “second-line” regimens is a protease inhibitor, a
class of ARVs that is not generally included in first-line therapy in developing countries and that is
primarily responsible for the efficacy of second-line treatment.
Drugs included in second-line regimens, and particularly protease inhibitors, are typically bigger and
more complex than first-line drugs at a molecular level. A number of second-line drugs are also
dosed at higher levels, requiring more active ingredient per day of treatment. These features help to
explain the greater cost of second-line medicines. Low production volumes also play an important
role. There has been little demand for second-line medications in most of the developing world as
treatment programs are relatively young and most patients have not begun to encounter treatment
failure. The limited demand has prevented manufacturers from achieving volume-based efficiencies
and cost savings. Increasing volumes over the coming years will enable further price reductions.
