ViiV Healthcare, a joint venture between GlaxoSmithKline, Pfizer and Shionogi, will be thrilled with news that US regulators have issued a green light for its new once-daily HIV pill Tivicay.

The US Food and Drug Administration has approved its use, in combination with other antiretrovirals, for the treatment of HIV-1 in a broad patient population of both treatment-naive and treatment-experienced adults and children aged 12 years and older weighing at least 40kg. 

Tivicay (dolutegravir) is an integrase inhibitor that blocks HIV replication by preventing the viral DNA from integrating into the genetic material of human immune cells (T-cells), an essential step in the HIV replication cycle.

Earlier this year, the drug's application was granted a priority review on the back of four pivotal Phase III clinical trials that treated 2,553 patients with HIV/AIDS across the treatment spectrum showing that it might offer a significant improvement over existing therapies.

In the SINGLE trial, 88% of study participants on the Tivicay regimen were virologically suppressed versus 81% taking Atripla (efavirenz/emtricitabine/tenofovir) after 48 weeks' treatment. Though ViiV and Shionogi did note that differences in efficacy were partially down to a higher rate of discontinuation due to adverse events on the Atripla arm.

Tivicay is expected to pull in sales around $900 million by 2017, according to an average forecast by six analysts polled by Thomson Reuters.

Global access?

Given its advantages over drugs in the same class and those widely used today, Tivicay will likely become part of first-line therapy in wealthy countries. However, it is still unclear whether people across the developing world will have access to the drug, as initial indications from ViiV to enable affordable access "have not been encouraging," according to medical humanitarian organisation Médecins Sans Frontières. 

“Based on studies to date, dolutegravir holds important advantages for use in developing countries, but as treatment providers, our biggest concern is what the price will be,” said Manica Balasegaram, Executive Director of MSF’s Access Campaign. “A promising new drug will only translate into more lives saved if it is affordable, so that people who need it have access.”

The group claims that Viiv has indicated it will 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".

But a spokesperson for ViiV stressed to PharmaTimes that the company is "committed to helping patients receive access to effective HIV treatment in the US and across the globe".

In July 2010, the firm announced it would make its portfolio and pipeline available to generic manufacturers in all least developed, low income and sub-Saharan African countries, through voluntary licences.

"As a result, Tivicay qualifies for our global access policy—in fact, we are concluding negotiations with a generic company to sign a voluntary license agreement to manufacture Tivicay for these countries," the spokesperson said.