Spotlight on access issues
Affordability remains an issue with abacavir (ABC), despite the 94% decrease in price of the generic version since 2001. The current lowest generic price per patient per year for abacavir 300mg tablet is still more than double the lowest generic ppy of tenofovir (TDF) 300mg and zidovudine (AZT) 300mg.
GSK could not apply for the basic patents on ABC in countries which did not grant patents on pharmaceuticals before the full implementation of the TRIPS agreement. The basic patents on ABC have now expired in China.43
In addition, GSK applied for patents on the hemisulfate salt of ABC in India but withdrew this application in October 2007 after it was opposed by civil society groups in a pre-grant opposition procedure.44 However the same application on the hemisulfate salt of ABC was also filed by GSK in China in May 1998. It was granted in 2008 and will effectively block generic versions until 2018.
GSK also applied for a patent on the oral solution of ABC particularly relevant for paediatric use, which was granted in December 2007.46 This patent raised concerns over the continued generic availability of the ABC paediatric formulation. However, the paediatric composition patent has not been used by GSK to block the development of the ABC/3TC FDC for children.
Two patents of ABC on the composition for paediatric use and the hemisulfate salt were granted in ARIPO countries, while a patent on the hemisulfate salt was granted in OAPI countries.47
ABC is approved for use in children. In its 2010 guidelines for antiretroviral therapy for HIV in infants and children, WHO recommends ABC as one of the possible NRTIs to be given with lamivudine (3TC) and either an NNRTI or a PI in the first line. WHO guidelines recommend a preferential order of NRTIs to be used in first-line regimens, with AZT preferred over ABC and ABC preferred over stavudine (d4T).29
ABC can also be part of a second-line regimen, depending on what has been used as first line.
There are currently three prequalified generic sources of the ABC 60mg tablet. However, the price of this formulation is still high despite the fact that the lowest generic price has decreased from US$134 ppy in 2011 to $122 ppy in 2012. ABC 60mg is also combined in a paediatric FDC with 3TC 30mg tablet, the 2012 reported price for which is $140 ppy. Please refer to the ABC/3TC drug profile.
Despite there being three qualified generic sources of the ABC 20mg/ml solution, price is still an issue. Currently, the lowest generic ppy for the abacavir solution is about double the lowest prequalified generic price ppy of the AZT 10mg/ml solution.