Viread

tenofovir disoproxil fumarate

This is a summary of the European public assessment report (EPAR) for Viread. It explains how the Committee for Medicinal Products for Human Use (CHMP) assessed the medicine to reach its opinion in favour of granting a marketing authorisation and its recommendations on the conditions of use for Viread.

What is Viread?

Viread is a medicine containing the active substance tenofovir disoproxil. It is available as tablets (245 mg).

What is Viread used for?

Viread is used to treat adults who are infected with the following viruses:

• human immunodeficiency virus type 1 (HIV 1), a virus that causes acquired immune deficiency syndrome (AIDS). Viread is taken in combination with other antiviral medicines. For patients who have taken medicines to treat HIV infection before, doctors should only prescribe Viread once they have looked at the antiviral medicines the patient has taken before or the likelihood of the virus’s response to antiviral medicines.
• hepatitis B virus, a virus that can cause hepatitis B (a disease of the liver). Viread is used in patients with chronic (long-term) infection whose liver is damaged. This includes patients whose liver has stopped working properly and those whose liver may still be working properly but show signs of liver damage in the blood and in liver tissue samples.

The medicine can only be obtained with a prescription.

How is Viread used?

Treatment with Viread should be started by a doctor who has experience in the treatment of HIV infection or chronic hepatitis B. The recommended dose of Viread is one tablet taken once a day with food. In exceptional cases, patients who have particular difficulty swallowing can crush the tablet in at least 100 ml of water, orange juice or grape juice, and drink the resulting suspension. In patients with kidney problems, Viread should only be used if the expected benefits of the medicine outweigh its risks. The frequency of dosing may need to be reduced in patients who have moderate or severe problems with their kidneys.

Patients who are infected with the hepatitis B virus, with or without HIV, should be monitored closely for flare-ups of hepatitis (liver inflammation) if they stop taking Viread.

How does Viread work?

The active substance in Viread, tenofovir disoproxil, is a ‘prodrug’ that is converted into tenofovir in the body.

Tenofovir is a nucleotide reverse transcriptase inhibitor (NRTI). In HIV infection, it blocks the activity of reverse transcriptase, an enzyme produced by HIV that allows it to infect cells and make more viruses. Viread, taken in combination with other antiviral medicines, reduces the amount of HIV in the blood and keeps it at a low level. Viread does not cure HIV infection or AIDS, but it may delay the damage to the immune system and the development of infections and diseases associated with AIDS.

Tenofovir also interferes with the action of an enzyme produced by the hepatitis B virus called ‘DNA polymerase’, which is involved in the formation of viral DNA. Viread stops the virus making DNA and prevents it from multiplying and spreading.

How has Viread been studied?

For the treatment of HIV, Viread has been studied in three main studies involving 1,343 HIV-infected adults. The first two studies compared the effects of adding Viread with those of adding placebo (a dummy treatment) to existing treatment in 741 patients who had been taking HIV treatments for at least four years, but were not responding to them. Viread was also assessed in a study of 602 treatment-naïve patients (who had not taken HIV treatment before), comparing Viread with stavudine (another antiviral medicine), taken in combination with lamivudine and efavirenz (other antiviral medicines). A fourth study in 90 adolescents (12 to 18 years of age) compared the effects of adding Viread with those of adding placebo to existing treatment. All studies looked at the levels of HIV in the blood as the main measure of effectiveness.

For the treatment of hepatitis B, the effectiveness of Viread was compared with that of adefovir dipivoxil (another antiviral medicine) in two studies. The first study involved 382 ‘HBeAg-negative’ patients (infected with a virus that has mutated [changed], leading to a form of hepatitis B that is more difficult to treat), and the second involved 272 ‘HBeAg-positive’ patients (infected with the common type of the hepatitis B virus). Both studies looked at the number of patients who had responded completely to treatment after 48 weeks, as determined by level of virus in the blood being below 400 copies/ml and a reduction in liver damage as seen using a biopsy (when a sample of liver tissue is taken and viewed under the microscope). A third study involved 112 hepatitis B patients whose liver had stopped working properly. The patients were given Viread alone, entecavir (another hepatitis medicine) or Viread with emtricitabine (another antiviral medicine). Although this study looked mainly at the safety of the medicine, it also looked at measures of effectiveness such as the number of patients with a blood virus level below 400 copies/ml after 48 weeks.

What benefit has Viread shown during the studies?

In HIV-infected adults, Viread, taken in combination with other antiviral medicines, caused a reduction in viral load (the amount of virus found in the blood). In the two studies of treatment-experienced patients, adding Viread resulted in a fall in viral load of around 75% after four and after 24 weeks, compared with a small rise or fall in viral load of around 5% in the patients taking placebo. In treatment-naïve patients, Viread was as effective as stavudine, with similar numbers of patients in the Viread and stavudine groups having viral loads below 400 copies/ml after 48 weeks. In the study in adolescents, after 48 weeks, there was no benefit of adding Viread to existing treatment compared with adding placebo.

In patients with hepatitis B, Viread was more effective than adefovir dipivoxil. After 48 weeks, 71% of the HBeAg-negative and 67% of the HBeAg-positive patients taking Viread had a complete response, compared with 49% and 12%, respectively, of the patients taking adefovir dipivoxil. In the third study, around 70% of patients taking Viread or entecavir had a viral level below 400 copies/ml. The figure for the combination treatment with Viread with emtricitabine was 88%.

What is the risk associated with Viread?

The most common side effects with Viread (seen in more than 1 patient in 10) are nausea (feeling sick), vomiting, diarrhoea, dizziness, hypophosphataemia (low levels of phosphate in the blood), rash and asthenia (weakness). For the full list of side effects reported with Viread, see the package leaflet.

Viread must not be used in people who are hypersensitive (allergic) to tenofovir, to tenofovir disoproxil fumarate, or to any of the other ingredients.

Why has Viread been approved?

The CHMP decided that Viread’s benefits are greater than its risks and recommended that it be given marketing authorisation.

Other information about Viread

The European Commission granted a marketing authorisation valid throughout the European Union for Viread on 5 February 2002.

For more information about treatment with Viread, read the package leaflet (also part of the EPAR) or contact your doctor or pharmacist.

This EPAR was last updated on 06/02/2012 .

More detail is available in the summary of product characteristics

Product details

Publication details

Product information

31/01/2012  Viread -EMEA/H/C/000419 -II/0104

Contents

• Annex I - Summary of product characteristics
• Annex IIA - Manufacturing-authorisation holder responsible for batch release
• Annex IIB - Conditions of the marketing authorisation
• Annex IIIA - Labelling
• Annex IIIB - Package leaflet

Please note that the size of the above document can exceed 50 pages.

You are therefore advised to be selective about which sections or pages you wish to print.

Pharmacotherapeutic group

Antivirals for systemic use

Therapeutic indication

HIV-1 infection: Viread is indicated in combination with other antiretroviral medicinal products for the treatment of HIV-1 infected adults over 18 years of age.

The demonstration of benefit of Viread in HIV-1 infection is based on results of one study in treatment-naïve patients, including patients with a high viral load (> 100,000 copies/ml) and studies in which Viread was added to stable background therapy (mainly tritherapy) in antiretroviral pre-treated patients experiencing early virological failure (< 10,000 copies/ml, with the majority of patients having < 5,000 copies/ml).

The choice of Viread to treat antiretroviral experienced patients with HIV-1 infection should be based on individual viral resistance testing and/or treatment history of patients.

Hepatitis B infection
Viread is indicated for the treatment of chronic hepatitis B in adults with:

• compensated liver disease, with evidence of active viral replication, persistently elevated serum alanine aminotransferase (ALT) levels and histological evidence of active inflammation and/or fibrosis.
• Decompensated liver disease.

Changes since initial authorisation of medicine

Initial marketing-authorisation documents