AbbVie has filed its next generation hepatitis C combo with US regulators, putting it in good stead to take second place out of three top contenders racing to get new, more convenient and more effective therapies on the market.

The drugmaker has submitted a New Drug Application to the US Food and Drug Administration seeking to market its regimen for the treatment of adults with chronic genotype 1 (GT1) hepatitis C virus (HCV) infection, including data from six Phase III studies involving more than 2,300 patients.

Combining three difference antivirals - ABT-450/ritonavir (150/100mg) co-formulated with ombitasvir, (ABT-267) 25mg, dosed once daily, and dasabuvir (ABT-333) 250mg, dosed twice daily - AbbVie's treatment offers three different mechanisms of action interrupting the HCV replication process.

Clinical data certainly seems pretty impressive for the drug, showing cure rates of 97% within just 12 weeks of therapy, and like its rivals, AbbVie's therapy offers crucial advantages over traditional treatments in that it is oral as opposed to injected and does not involve interferon which has nasty side effects.

On the downside, it comes with a high pill burden, with patients having to take six pills a day in some cases, although some experts believe this is negated by short treatment duration.

Gilead likely first to market

AbbVie's submission comes hot on the heels of Gilead's US filing of a combination of its antiviral Sovaldi (sofosbuvir) and the NS5A inhibitor ledipasvir in February, which is likely to become the first oral treatment regimen for patients with genotype 1 HCV infection.

Merck & Co also recently posted strong mid-stage data on its own offering (MK-5172 and MK-8742), which showed 98% cure rates in patients with hepatitis C (HCV) genotype 1.

The efficacy of future HCV treatments is certainly exciting, but there are serious concerns over patient access, given their potentially incredibly high cost - treatment with Sovaldi alone costs an eye-watering $84,000 per 12-week course.

The HCV market is worth billions, and Express Scripts forecasts that the US will spend 1,800% more on treatments in 2016 than it did last year, noting that "no major therapy class has experienced this high of a spending increase" in the 21 years it has measured such data.

It is estimated that 3.2 million people are living with HCV in the US alone.