Dec 18 (Reuters) - Gilead Sciences Inc, based on favorable new clinical trial data, said it will seek U.S. approval in the first quarter of 2014 for a once-daily tablet containing two new treatments for hepatitis C.
The company previously said it would seek marketing approval in the first half of next year for the combination tablet, which would pair Gilead's recently approved Sovaldi (sofosbuvir) and its experimental drug ledipasvir.
Gilead on Wednesday said the drug combination, in three late-stage clinical trials, produced high cure rates in as little as eight weeks in patients with the most common, but hardest to treat, genotype 1 strain of the liver virus. And it did so without patients having to take the standard injectable treatment interferon, which causes flu-like symptoms and must be used for up to a year.
Gilead shares rose 2.2 percent on the favorable new data and the likelihood of a speedier approval from the U.S. Food and Drug Administration for the drug, which some analysts expect to generate annual sales of $3 billion or more.
"We see (trial) results and a more-convenient regimen bolstering Gilead's market prospects over rivals, and expect FDA approval for this regimen before the end of 2014," S&P Capital IQ said in a research report.
Sovaldi, approved earlier this month by U.S. regulators, belongs to a new class of drugs known as nucleotide analog polymerase inhibitors, or "nukes," designed to block an enzyme the hepatitis C virus needs to copy itself.
For patients with genotype 1, which accounts for about 70 percent of U.S. infections, Sovaldi currently must be used with both interferon and a standard antiviral pill called ribavirin, which can have its own harsh side effects, such as anemia. But Sovaldi can be considered for use in patients with genotype 1 infections who cannot tolerate or use interferon.
Sovaldi can be used in combination with ribavirin for patients with genotypes 2 and 3 infections, which account for about 28 percent of U.S. patients infected with the virus.
Ledipasvir belongs to a different, promising new class of drugs that work by blocking the NS5A protein, which the virus also needs to replicate itself.
Gilead is ahead of the pack, as drugmakers vie to develop all-oral hepatitis C drugs that have far milder side effects than standard treatments, and knock down the virus far more quickly. Current standard regimens include both interferon and ribavirin and are taken for 24 to 48 weeks, and typically cure about 75 percent of treated patients.
In a mid-stage clinical trial called 'Lonestar,' Sovaldi and ledipasvir in a fixed-dose tablet, taken with or without ribavirin, eliminated the liver virus in almost all patients after either eight weeks or 12 weeks of treatment.
Gilead on Wednesday reported similarly high cure rates for both previously treated and untreated patients- ranging from 93.1 percent to 99.1 percent, in three far larger, late-stage trials, called ION-1, ION-2 and ION-3. The results were seen in patients treated with or without ribavirin for 8, 12 or 24-week weeks.
Hepatitis C affects an estimated 170 million people worldwide, and if left untreated can lead to cirrhosis, liver cancer, or the need for a new liver. The virus can be spread by shared needles, especially among drug users. In earlier decades, before improved blood screening, it was largely spread through tainted blood tranfusions.