Gilead Sciences, Inc. (Nasdaq: GILD) has announced that the European Commission has granted marketing authorisation for Stribild® (elvitegravir 150mg/cobicistat 150mg/emtricitabine 200mg/tenofovir disoproxil (as fumarate) 245mg), a single tablet regimen for the treatment of HIV-1 infection in adults who are antiretroviral treatment-naïve or are infected with HIV-1 without known mutations associated with resistance to any of the three antiretroviral agents in Stribild.
This approval allows for the marketing of Stribild in all 27 countries of the European Union.
“Single tablet regimens make it easier for HIV patients to take their treatment consistently every day, which may improve their health outcomes,” said Jürgen Rockstroh, MD, Professor of Medicine, University of Bonn, Germany and a lead investigator for one of the Stribild pivotal studies. “Stribild is a highly effective and well tolerated HIV treatment regimen, and is an important addition to the growing arsenal of simplified therapies in Europe.”
This approval is supported by 48-week data from two pivotal Phase 3 studies in which Stribild met its primary objective of non-inferiority compared to Atripla® (efavirenz 600 mg/emtricitabine 200 mg/tenofovir disoproxil (as fumarate) 245 mg) (Study 102) and to a regimen containing ritonavir-boosted atazanavir plus Truvada® (emtricitabine/tenofovir disoproxil (as fumarate)) (Study 103).
“We look forward to making Stribild available to HIV-treating physicians and their patients throughout the European Union as quickly as possible,” said John C. Martin, PhD, Chairman and Chief Executive Officer, Gilead Sciences.
Stribild is also approved in the United States, Canada, Australia, South Korea, Japan and Turkey.
Stribild is the third single tablet HIV regimen developed by Gilead to become available in Europe. The first, Atripla, was approved in the European Union in 2007 and is marketed by Gilead in partnership with Bristol-Myers Squibb and Merck & Co. The second, Eviplera®▼ (emtricitabine/rilpivirine/tenofovir disoproxil (as fumarate) 245mg)), is marketed by Gilead and Janssen R&D Ireland and received European marketing authorisation in November 2011.
Stribild contains four Gilead compounds in a complete once-daily, single tablet regimen: elvitegravir 150mg; cobicistat 150mg; emtricitabine 200mg; and tenofovir disoproxil (as fumarate) 245mg.
Elvitegravir is a member of the integrase inhibitor class of antiretroviral compounds. Integrase inhibitors interfere with HIV replication by blocking the ability of the virus to integrate into the genetic material of human cells. Elvitegravir was licensed by Gilead from Japan Tobacco Inc. (JT) in March 2005. Under the terms of Gilead’s agreement with JT, Gilead has exclusive rights to develop and commercialise elvitegravir in all countries of the world, excluding Japan, where JT retains rights.
Cobicistat is Gilead’s proprietary potent mechanism-based inhibitor of cytochrome P450 3A (CYP3A), an enzyme that metabolises drugs in the body.
Marketing applications for elvitegravir and cobicistat as standalone agents are currently under review in the European Union. In the United States, on April 29, 2013, Gilead announced it had received Complete Response Letters from the US Food and Drug Administration (FDA) on its New Drug Applications for elvitegravir and cobicistat as standalone agents. The company is working to address the questions raised in FDA’s letters as quickly as possible.
Elvitegravir and cobicistat as standalone agents are investigational products and their safety and efficacy have not yet been established.
EU Important Product Information About Stribild
Lactic acidosis, usually associated with hepatic steatosis, has been reported with the use of nucleoside analogues. Lactic acidosis has a high mortality and patients at increased risk should be followed closely.
Stribild should not be taken with any of the following due to the potential for serious and/or life‑threatening events or loss of virologic response and possible resistance to Stribild:
- alpha 1‑adrenoreceptor antagonists: alfuzosin
- antiarrhythmics: amiodarone, quinidine
- anticonvulsants: carbamazepine, phenobarbital, phenytoin
- antimycobacterials: rifampicin
- ergot derivatives: dihydroergotamine, ergometrine, ergotamine
- gastrointestinal motility agents: cisapride
- herbal products: St. John’s wort (Hypericum perforatum)
- HMG Co‑A reductase inhibitors: lovastatin, simvastatin
- neuroleptics: pimozide
- PDE‑5 inhibitors: sildenafil for treatment of pulmonary arterial hypertension
- sedatives/hypnotics: orally administered midazolam, triazolam
As a fixed combination, Stribild should not be administered concomitantly with other medicinal products containing tenofovir disoproxil (as fumarate), lamivudine or adefovir dipivoxil used for the treatment of hepatitis B virus infection.
Emtricitabine and tenofovir are primarily excreted by the kidneys by a combination of glomerular filtration and active tubular secretion. Renal failure, renal impairment, elevated creatinine, hypophosphataemia and proximal tubulopathy (including Fanconi syndrome) have been reported with the use of tenofovir disoproxil (as fumarate).
Patients who have previously discontinued treatment with tenofovir disoproxil (as fumarate) due to renal toxicity should not be treated with Stribild.
Patients should have creatinine clearance calculated and urine glucose and urine protein determined prior to initiating Stribild therapy.
Stribild should not be initiated in patients with creatinine clearance below 70 mL/min. It is recommended that Stribild is not initiated in patients with creatinine clearance < 90 mL/min unless, after review of the available treatment options, it is considered that Stribild is the preferred treatment for the individual patient.
Creatinine clearance, serum phosphate, urine glucose and urine protein should be monitored every four weeks during the first year and then every three months. More frequent monitoring of renal function should be considered in patients at risk for renal impairment.
Cobicistat inhibits the tubular secretion of creatinine and may cause modest increases in serum creatinine and modest declines in creatinine clearance. Patients who experience a confirmed increase in serum creatinine of greater than 26.5 μmol/L (0.3 mg/dL) from baseline should be closely monitored for renal safety.
Renal function should be re-evaluated within 1 week if serum phosphate is < 0.48 mmol/L (1.5 mg/dL) or creatinine clearance decreases to < 70 mL/min during Stribild therapy.
If creatinine clearance is confirmed as < 50 mL/min or serum phosphate decreases to < 0.32 mmol/L (1.0 mg/dL) then Stribild should be discontinued.
There are currently inadequate data to determine whether co-administration of tenofovir disoproxil fumarate and cobicistat is associated with a greater risk of renal adverse reactions compared with regimens that include tenofovir disoproxil fumarate without cobicistat.
Stribild should be avoided with concurrent or recent use of a nephrotoxic medicinal product due to the increased risk of renal adverse reactions (with the TDF component of Stribild).
Bone abnormalities (infrequently leading to fractures) may be associated with proximal renal tubulopathy and appropriate consultation should be obtained if suspected.
Stribild has not been studied in patients with severe hepatic impairment (CPT Score C).
Discontinuation of Stribild therapy in patients co-infected with HIV and hepatitis B virus (HBV) may be associated with severe acute exacerbations of hepatitis. Patients co-infected with HIV and HBV who discontinue Stribild should be closely monitored with both clinical and laboratory follow-up for at least several months after stopping treatment.
If appropriate, initiation of hepatitis B therapy may be warranted. In patients with advanced liver disease or cirrhosis, treatment discontinuation is not recommended since post treatment exacerbation of hepatitis may lead to hepatic decompensation.
Immune Reactivation Syndrome has been reported in patients treated with combination therapy, including the components of Stribild.
Combination therapy has been associated with the redistribution of body fat (lipodystrophy) in HIV patients. The long-term consequences of these events are currently unknown.