You may have heard of Sovaldi, the infamous hepatitis C drug that costs $1,000 per pill, or $84,000 for a 12-week course of treatment. Despite its price tag, Solvadi has been a runaway hit. But now there's a new hepatitis C drug that's even more expensive than Sovaldi, and becoming even more popular.

Meet Harvoni, which launched in October and costs $1,125 per pill, or $94,500 for a 12-week course of treatment. The drug comes from Gilead Sciences, which earlier this year broke records with $2.3 billion in first quarter sales of Sovaldi.

Just eight weeks into Harvoni's launch, CVS Health reports that the new drug is being prescribed at rates 2.5 times higher than Sovaldi was at the same point into that drug's launch. Within six weeks, prescription rates for Harvoni had surpassed those of Sovaldi within CVS's pharmacy benefits management business,which has 65 million members.

Why are people willing to pay more for Harvoni? Some patients will be able to complete Harvoni's treatment course in just eight weeks, at a cost of $63,000. It's also the first hepatitis C treatment most patients cantake without also having to take injections of interferon, which can come with nasty side effects.

Both Harvoni and Sovaldi are big improvements upon previous treatments, and there are hopes in the patient community that these and other new drugs can lead to eradication of hepatitis C. But there's plenty of angst about how to pay for these drugs and who should reap the benefits of keeping these patients healthy. Just last week, Gilead saw its first lawsuit challenging Sovaldi's price.

When Sovaldi was launched last December, its price tag caught health insurers and states off guard. Both have set up different barriers over the past year limiting who has access to these high-price hepatitis C cures, which are far more effective than previous treatments for the liver-damaging virus that more than 3 million Americans are infected with.

Many of those infected with hepatitis C can live years without symptoms or even knowing they have the virus, so some health-care payers are trying to limit access to the sickest patients as they try to negotiate better deals or hope new treatments will mean more competitive pricing.

Gilead won't announce Harvoni's first full quarter of sales until mid-January. But the new CVS data show it could be on pace for another sales record and further fuel the growing debate over drug prices.

