Tivicay: GSK, Pfizer JV's HIV drug bound for blockbuster status

Tivicay
Project name: dolutegravir
Disease: HIV
Peak sales estimate: $5 billion
Approved: Aug. 12
Companies: GlaxoSmithKline and Pfizer (ViiV Healthcare)

The Scoop:
Back in 2009, when GlaxoSmithKline ($GSK) and Pfizer ($PFE) entered into the joint venture ViiV Healthcare, analysts wondered whether it was just a roundabout way for the companies to eventually move out of the controversial HIV market area. But leadership asserted that ViiV, majority-owned by Glaxo, would help develop a more productive HIV pipeline capable of competing with market powerhouse Gilead ($GILD).

Fast-forward to the fall of 2012, when Japan's Shionogi joined ViiV, grabbing 10% of the venture and bringing with it its late-stage integrase inhibitor dolutegravir, which had been shown in earlier studies to prevent HIV from penetrating cells. With the deal, Viiv was already shaping up to be a power player in the arena. Then, in late summer of 2013, after a priority review, the FDA approved dolutegravir, to be sold as Tivicay, providing what analysts expected to be a sure blockbuster against Gilead's rival treatments and the joint venture's first new product.

Tivicay is the third integrase inhibitor on the market after Merck's ($MRK) Isentress, approved in 2007, and Gilead's fixed-dose combination Stribild.

Majority owner Glaxo had the numbers to back it up. Compared with Gilead's Atripla, Tivicay demonstrated in a head-to-head study a year prior to its approval to have blocked all signs of HIV in 88% of patients after 48 weeks of treatment--Atripla blocked 81%. Riding these results, analysts were all but sure of the drug's regulatory success and potential sales of almost $5 billion a year.

But, as usual, the price tag came under scrutiny right away. Tivicay, to be used along with the two standard generically available HIV drugs Ziagen and Zeffix, would cost $14,105 per year, a ViiV spokesman told FiercePharma at the time, comparable to other drugs in the arena. Medecins Sans Frontieres (MSF/Doctors Without Borders) criticized the cost immediately following the approval, noting its potential inaccessibility in the developing world. But this critique was double-sided for Glaxo: It was also a testament to the drug's promising future.

Drug data researchers saw another blip on Tivicay's horizon pointing to the beginning of the end of branded HIV drugs. According to EvaluatePharma shortly after the approval, the market would continue to grow to about $20.6 billion in 2016 but then would taper off as soon as 2018 as patents for some successful blockbusters such as Johnson & Johnson's ($JNJ) Prestiza and Bristol-Myers Squibb's ($BMY) Reyataz fall by the wayside in the next few years.

Tivicay raked in one more win in November as the Committee for Medicinal Products for Human Use (CHMP) recommended the drug for approval. Time will tell whether the drug lives up to its high potential, but one thing is sure: ViiV has a blockbuster on its hands. -- Michael Gibney (email | Twitter)

For more:
GlaxoSmithKline JV wins FDA OK on HIV blockbuster dolutegravir
FDA promises swift review of GSK's blockbuster HIV hopeful
GSK antes up Viiv stake, grabs control of potential HIV blockbuster
Glaxo/Pfizer venture touts blockbuster potential of HIV drug

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Tivicay: GSK, Pfizer JV's HIV drug bound for blockbuster status