Gilead Sciences says it is close to completing its $11 billion acquisition of hepatitis C specialist Pharmasset.

The company has completed its offer and over 72 million shares have been tendered. This represents about 95% of the outstanding shares in Pharmasset and Gilead is paying $137 per share in cash.

The acquisition, sees Gilead get access to Pharmasset's three candidates for HCV, headed by PSI-7977, a uracil nucleotide analogue which has recently been advanced into two Phase III studies in genotype 2 and 3 patients and is being studied in combination with ribavirin. PSI-938, a guanosine nucleotide analogue, is being tested in a Phase IIb trial as monotherapy and in combination with PSI-7977, while mericitabine, a cytidine nucleoside analogue, is partnered with Roche and is being evaluated in three Phase IIb trials.

When the deal was announced in November, analysts were stunned at the price tag. Speaking earlier this week at the JP Morgan Global Healthcare Conference in San Francisco, Gilead chief executive John Martin said he has  indeed had to defend the Pharmasset purchase but assured investors the company has a "strategic rationale" for the Pharmasset acquisition.

He added that the deal will give his firm the most advanced HCV nucleotide analogue in development, noting "we have a lot of ways to combine our products into once-daily regimens" for the treatment of the disease.