Gilead’s IP fight for the experimental hepatitis C treatment sofosbuvir continues. Bloomberg reports the company is suing Merck for a court decision that will indicate the predicted blockbuster drug does not infringe on Merck’s intellectual property. Merck previously asked Gilead to pay a 10% royalty on the pipeline drug, saying it owns a share of the rights. FierceBiotech notes that Roche has also asked for a cut of the drug’s sales, if and when it makes it to market. In Roche’s case, the chain of ownership includes now-Gilead subsidiary Pharmasset, which Gilead bought to gain control of sofosbuvir. According to Fierce, Roche believes its deal with Pharmasset gives it the sofosbuvir license, which means it is entitled to a piece of sales. Expectations for the drug are high: not only does it circumvent the need to use interferon, but the National Institutes of Health released a study last week that showed pairing sofosbuvir and ribavirin effectively cleared the virus in two hard-to-treat types of patients: those with severe liver damage and African-Americans. FactSet forecast the drug could have sales of $6.4 billion by 2017.

Researchers found that breathlessness is coming between patients and their Brilinta prescriptions, reported Reuters. Results of the small 367-patient study were presented at the European Society of Cardiology and showed 14% of patients stopped taking the blood thinner, usually do to feeling short of breath. The discontinuation rate is higher than in clinical trials. Drug maker AstraZeneca told Reuters that although the number of real-world dropouts was higher than those in the clinical study, the difference is no big deal, and pointed to a similar situation Sanofi experienced with its anti-platelet drug Plavix.

Data from one of two Phase II trials for the Amgen/Cytokinetics drug omecamtiv mecarbil are in, and results shows the drug missed its target for reducing breathlessness in acute heart failure patients. The study examined three doses among 613 patients. The highest-dose patients showed some improvement, but the overall impact among the three levels was that it still missed its mark. Amgen said in a statement Tuesday that results from the second Phase II study, combined with these results, will determine if the drug moves into Phase III trials.

The FDA handed Otsuka a Complete Response Letter asking for more information about its drug tolvaptan, reports BioCentury. The drug is already approved for hypervolemic and euvolemic hyponatremia in the US under the name Samsca, and Otsuka is looking to expand the indication to include slowing kidney disease for patients with atutosoma dominant polycystic kidney disease. An FDA advisory panel voted against this added indication in August.