Europe, USA. The EMEA, US FDA and Swissmedic are informing physicians of reports of a high rate of early virologic non-response observed in a GlaxoSmithKline (GSK)-sponsored clinical study of therapy naïve adults receiving once daily three drug combination therapy with tenofovir (Viread), lamivudine (Epivir) and abacavir (Ziagen). The precise nature of any interaction leading to non-response is currently unknown. The Marketing Authorization Holders have been requested to further explore the nature of these interactions through in vivo/in vitro studies. In the meanwhile physicians are advised that,

• abacavir and lamivudine, in combination with tenofovir should not be used as a triple antiretroviral therapy when considering a new treatment regimen for naïve or pretreated patients, particularly as a once-daily regimen

• patients currently controlled with this combination should be frequently monitored with a sensitive viral load test and considered for modification of therapy at the first sign of viral load increase.

GlaxoSmithKline has issued a ‘Dear Healthcare Provider’ letter for the above information. Patients about to receive or, currently on this combination therapy are advised to inform their physician immediately.

Reference:

1. EMEA Public Statement, EMEA/20194-03, 30 Jul 2003. Available from URL: http://www.emea.eu.int

2. ‘Dear Healthcare Provider’ letter from GlaxoSmithKline, 31 Jul 2003. Available from URL: http://www.fda.gov

3. Important Information on Human Medicines: Swissmedic, 6 Aug 2003. Available from URL: http://www.swissmedic.ch