The US Food and Drug Administration’s approval of Tivicay (dolutegravir), a new drug to treat HIV-1 infection last week is significant because it has also been approved for children ages 12 years and older weighing at least 40 kilograms (kg) who are treatment-naïve or treatment-experienced but have not previously taken other integrase strand transfer inhibitors.
However, international medical humanitarian organisation Médecins Sans Frontières/ Doctors Without Borders (MSF) questioned when people in developing countries would be able to access this promising new drug as initial indications from the drug’s producer ViiV (Pfizer + GlaxoSmithKline + Shionogi) to enable affordable access have not been encouraging.
Tivicay is an integrase strand transfer inhibitor that interferes with one of the enzymes necessary for HIV to multiply. It is a pill taken daily in combination with other antiretroviral drugs.
Tivicay is approved for use in a broad population of HIV-infected patients. It can be used to treat HIV-infected adults who have never taken HIV therapy (treatment-naïve) and HIV-infected adults who have previously taken HIV therapy (treatment-experienced), including those who have been treated with other integrase strand transfer inhibitors.
The MSF release analyses that studies have shown dolutegravir to be well-tolerated and extremely effective in stopping replication of the HIV virus, with a high barrier to HIV resistance. Thus given its advantages over drugs in the same class and those widely used today, dolutegravir will likely become part of first-line therapy in wealthy countries. About 50,000 Americans become infected with HIV each year and about 15,500 died from the disease in 2010, according to the Centers for Disease Control and Prevention.
“HIV-infected individuals require treatment regimens personalized to fit their condition and their needs,” said Edward Cox, Director of the Office of Antimicrobial Products, FDA’s Center for Drug Evaluation and Research. “The approval of new drugs like Tivicay that add to the existing options remains a priority for the FDA.”
Tivicay’s safety and efficacy in adults was evaluated in 2,539 participants enrolled in four clinical trials. Depending on the trial, participants were randomly assigned to receive Tivicay or Isentress (raltegravir), each in combination with other antiretroviral drugs, or Atripla, a fixed-dose combination of efavirenz, emtricitabine and tenofovir. Results showed Tivicay-containing regimens were effective in reducing viral loads.
A fifth trial established the pharmacokinetics, safety and activity of Tivicay as part of treatment regimens for HIV-infected children ages 12 years and older weighing at least 40 kg who have not previously taken integrase strand transfer inhibitors.
Common side effects observed during clinical studies include difficulty sleeping (insomnia) and headache. Serious side effects include hypersensitivity reactions and abnormal liver function in participants co-infected with hepatitis B and/ or C. The Tivicay label gives advice on how to monitor patients for the serious side effects.
Tivicay is marketed by ViiV Healthcare and manufactured by GlaxoSmithKline, both based in Research Triangle Park, NC Isentress is marketed by Whitehouse Station, NJ-based Merck, and Atripla is marketed by San Francisco, Calif-based Gilead.
MSF points out that ViiV’s position on access to dolutegravir in developing countries is concerning, with the company indicating it would pursue a ‘tiered-pricing’ strategy that will keep the drug out of reach for people who need it, limiting the use and sale of generic versions to only 67 countries, excluding many low- and middle-income countries where millions of people with HIV live.
“We are deeply concerned that ViiV’s business strategy will result in dolutegravir being priced out of reach in countries excluded from ViiV’s licensing deals”, said Rohit Malpani, Director of Policy and Analysis, MSF’s Access Campaign. “We have seen in the past that excluded countries are left paying exorbitant prices.”
An MSF release goes on to advocate that ViiV should take proactive steps to make sure dolutegravir will be available and affordable for people in need, especially through registration of the product and by allowing the availability of generic versions in low- and middle-income countries. One way to improve access to more affordable dolutegravir could be through a licence agreement with the Medicines Patent Pool, which would need to include all low- and middle-income countries and have no restrictions on where the drug can be manufactured or active pharmaceutical ingredients can be sourced.
“Where dolutegravir is priced out of reach, the onus will be on countries to overcome patent barriers by making full use of public health safeguards and flexibilities in international trade rules, which allow for more affordable versions to be produced or imported,” said Malpani.
The release goes on to state that competition among generic producers of HIV medicines, primarily in India, is what caused the price of treatment to drop by a dramatic 99 per cent over the last decade, from more than $10,000 per person per year to roughly $120 today. However, patents blocking generic production have resulted in newer drugs remaining priced out of reach, with a possible salvage regimen today costing, at best, more than $2,000 per person, even in the poorest countries, nearly 15 times the price of today’s first-line therapy. Middle-income countries face prices that are far higher.
EP News Bureau – Mumbai
- Advertisement -
