Merck calls off $100M Ranbaxy deal; Pharmasset touts hep C data; Ligand inks China drug development pact;

@FierceBiotech:  Zafgen drug registers rapid weight loss in early-stage study. Report | Follow @FierceBiotech

@JohnCFierce: Alfred Mann doubles down on MannKind stock--as others short it. CFO says he has close to a billion invested now. Report | Follow @JohnCFierce

> Merck is calling off its five-year, $100 million deal to develop anti-infectives with India's Ranbaxy. The companies confirmed the story, first reported by the Economic Times, but declined comment. Story

> Pharmasset says that a pair of new hepatitis C therapies demonstrated significant promise in new studies. Report

> China's Chiva Biotech has struck a deal to develop multiple Ligand assets and technology. Ligand has the potential to earn over $100 million in milestones and royalties on potential sales along with a 10 percent equity position in Chiva. Ligand release

> France's Immutep is granting GSK exclusive worldwide rights to ImmuTune IMP731 and any other antibodies that deplete LAG-3 positive cells. GSK will assume all development responsibility and associated costs for IMP731 while Immutep will receive an upfront payment and milestones of up to $100 million. Immutep release

> San Diego-based Receptos has forged a collaboration with Eli Lilly to research and develop small molecule modulators of an undisclosed GPCR target. Receptos release

> Lexington, MA-based Antigenics is changing its name to Agenus. Antigenics release

> Plexxikon has struck a deal with Genentech to co-promote PLX4032 (RG7204) in the United States. Plexxikon release

> Isis Pharmaceuticals has added a new cancer drug and obesity treatment to its pipeline. Report

And Finally... In an essay, David Nichols, the Robert C. and Charlotte P. Anderson Distinguished Chair of Pharmocology at Purdue University, anguishes over some of the dangerous products his drug research work has helped spawn. Story