SAN FRANCISCO, Sept. 28 /PRNewswire/ -- The HIV medication TRIZIVIR(R) (abacavir sulfate, lamivudine, and zidovudine) administered twice daily provides comparable efficacy to a regimen containing COMBIVIR(R) (3TC/ZDV) administered twice daily plus atazanavir administered once-daily, in patients who have never taken antiretroviral therapy.
The ACTION study -- short for Atazanavir, Combivir, Trizivir in Only Naive Patients -- followed treatment-naive patients with low viral load for 48 weeks. The study, sponsored by GlaxoSmithKline, defined low viral load as HIV-1 RNA of less than 200,000 copies/mL. The data were presented at the 46th Interscience Conference on Antimicrobial Agents and Chemotherapy.
In the study, approximately 60% of patients taking either a TRIZIVIR or COMBIVIR/atazanavir regimen achieved a viral load of less than 50 copies/mL without virologic failure.
TRIZIVIR and COMBIVIR are two of GlaxoSmithKline’s fixed-dose combination antiretrovirals used in the treatment of HIV. TRIZIVIR was the first medication to provide a complete regimen in a single pill.
This randomized, open-label, multicenter non-inferiority study included 279 HIV-positive patients who had not yet started a treatment regimen. Patients were randomized 1:1 to receive either TRIZIVIR twice daily or COMBIVIR twice daily plus 400 mg of atazanavir once daily for 48 weeks. Sixty-two percent (85/138) of the patients in the TRIZIVIR arm and 59 percent (83/140) of the patients in the COMBIVIR + atazanavir arm achieved HIV-1 RNA <50 copies/mL. Patients taking TRIZIVIR alone with baseline viral loads between 100,000 and 200,000 copies/mL were less likely to achieve HIV-1 RNA <50 copies/mL compared to those taking TRIZIVIR alone with baseline viral loads <100,000 copies/mL. The median increase in CD4+ cell count at week 48 was 147 cells/mm3 in both the TRIZIVIR and the COMBIVIR + atazanavir arms.
In this study, the most common (>/=5%) grade 2-4 adverse events in the COMBIVIR + atazanavir arm were hyperbilirubinemia and neutropenia. In the TRIZIVIR alone arm they were nausea, neutropenia, and fatigue. The overall rate of suspected abacavir hypersensitivity was 5%.
Important Safety Information about TRIZIVIR and COMBIVIR
HIV medicines do not cure HIV infection/AIDS or prevent passing HIV to others.
TRIZIVIR was the first and remains the only FDA-approved HIV drug therapy that combines three nucleoside reverse transcriptase inhibitors (NRTIs) into one tablet. TRIZIVIR is indicated in combination with other antiretroviral agents or alone for the treatment of HIV-1 infection. TRIZIVIR is one of multiple products containing abacavir sulfate, also known as ZIAGEN. Before starting a patient on TRIZIVIR, physicians should review medical history for prior exposure to any abacavir-containing product in order to avoid reintroduction in a patient with a history of hypersensitivity to abacavir.
Limited data exist on the use of TRIZIVIR alone in patients with higher baseline viral load levels (>100,000 copies/mL). The daily dosing recommendation for TRIZIVIR is one tablet taken twice daily, with or without food or water.
Hypersensitivity reaction, which can be life threatening and has been fatal in some cases, is the most serious adverse event associated with ZIAGEN and products containing abacavir. Before starting a regimen including an abacavir-containing product, patients’ medical histories should be reviewed for prior exposure to avoid reintroduction in a patient with a history of hypersensitivity to the drug.
Abacavir has been associated with serious and sometimes fatal hypersensitivity reactions. Hypersensitivity to abacavir is a multi-organ clinical syndrome usually characterized by a sign or symptom in two or more of the following groups: 1) fever, 2) rash, 3) gastrointestinal symptoms, including nausea, vomiting, diarrhea or abdominal pain, 4) constitutional symptoms, including generalized malaise, fatigue or achiness and/or 5) respiratory symptoms such as dyspnea, cough or pharyngitis. Symptoms of this reaction usually occur within the first six weeks of treatment although these reactions can occur at any time during therapy. To avoid a delay in diagnosis and minimize the risk of a life-threatening hypersensitivity reaction, discontinue abacavir-containing product as soon as a hypersensitivity reaction is suspected. Discontinue abacavir-containing product if hypersensitivity cannot be ruled out, even when other diagnoses are possible (e.g., acute onset respiratory disease, gastroenteritis or reactions to other medication). Following a hypersensitivity reaction to abacavir, never restart any abacavir-containing product because more severe symptoms can occur within hours and may include life-threatening hypotension and death. Reintroduction of any abacavir-containing product, even in patients who have no identified history or unrecognized symptoms of hypersensitivity to abacavir therapy, can result in serious or fatal hypersensitivity reactions. Such reactions can occur within hours. A Medication Guide and Warning Card for abacavir-containing products must be provided by the pharmacists to the patient with each new and refill prescription in order to provide further information to the patient on this drug.
COMBIVIR is a combination tablet containing lamivudine and zidovudine. COMBIVIR in combination with other antiretroviral agents is indicated for the treatment of HIV infection.
Zidovudine has been associated with hematologic toxicity including neutropenia and severe anemia particularly in patients with advanced HIV disease. Prolonged use of zidovudine has been associated with symptomatic myopathy.
Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues alone or in combination, including abacavir, zidovudine, lamivudine and other antiretrovirals.
TRIZIVIR Tablets are contraindicated in patients with hepatic impairment.
Severe acute exacerbations of hepatitis B have been reported in patients who are coinfected with hepatitis B virus (HBV) and HIV and have discontinued lamivudine, which is one component in COMBIVIR and TRIZIVIR. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue COMBIVIR or TRIZIVIR and are coinfected with HIV and HBV. If appropriate, initiation of anti-hepatitis B therapy may be warranted.
Hepatic decompensation (some fatal) has occurred in HIV/HCV co-infected patients receiving combination antiretroviral therapy for HIV/HCV co-infected patients receiving combination antiretroviral therapy for HIV and interferon with or without ribavirin. Patients receiving interferon with or without ribavirin and TRIZIVIR or COMBIVIR should be closely monitored for treatment associated toxicities, especially hepatic decompensation, neutropenia, and anemia. Discontinuation of TRIZIVIR or COMBIVIR should be considered as medically appropriate.
Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy, including TRIZIVIR or COMBIVIR. During the initial phase of combination antiretroviral treatment, patients whose immune system responds may develop an inflammatory response to indolent or residual opportunistic infections (such as Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia [PCP], or tuberculosis), which may necessitate further evaluation and treatment.
Redistribution/accumulation of body fat has been observed in patients receiving antiretroviral therapy. The causal relationship, mechanism and long-term consequences of these events are currently unknown.
The most common adverse events (>/=5%) of at least moderate intensity associated with the use of TRIZIVIR include nausea, headache, malaise and fatigue, nausea and vomiting, hypersensitivity reaction, diarrhea, fever and/or chills, depressive disorders, musculoskeletal pain, skin rashes, ear/nose/throat infections, viral respiratory infections and anxiety.
The most common side effects with COMBIVIR are headache (35 percent), nausea (33 percent), tiredness (27 percent) and nasal signs and symptoms (20 percent).
GlaxoSmithKline is one of the world’s leading research-based pharmaceutical and healthcare companies and an industry leader in HIV research and therapies. GSK is a leader in the development of fixed-dose combination products. The company is engaged in basic research programs designed to investigate new targets to treat HIV. For full prescribing information please go to http://www.treathiv.com.
Media contact: Marc Meachem
GlaxoSmithKline 919/483-2839
