Sanofi palms off MyoKardia heart disease pact

Sanofi has walked away from a four-year-old alliance with US biotech MyoKardia, handing back rights to three drugs for heart disease.

The decision comes ahead of data readouts for two of the clinical candidates – mavacamten and MYK-491 – within the next 12 to 24 months, and comes as Sanofi is in the midst of a radical restructuring of its business and refocusing of its research priorities into areas such as cancer.

The Californian biotech put a positive spin on the development of course, and its chief executive Tassos Gianakakos said regaining rights to the programmes “enables us to capture the full value of the data being generated” for mavacamten and MYK-491, and stressed that there were no efficacy or safety problems behind Sanofi’s decision.

He also suggested that Sanofi had in fact been interested in extending the agreement to include US commercial rights to mavacamten, as well as additional rights in heart failure, and decided to exit the deal after MyoKardia said that wouldn’t be an option.

The company is determined to take the programmes forward on its own for the time being, and says that with around $412 million in cash it has the funds needed to operate to the end of 2020.

That should be enough to usher its lead programme to the registration stage. Data from the phase II MAVERICK trial of mavacamten in non-obstructive hypertrophic cardiomyopathy (HCM) is due in the second half of this year, and if positive could set up the drug to become the first treatment for the condition, which is characterised by an overexertion of the heart muscles that causes them to thicken and impede the organ’s normal function.

Also coming down the pipeline is data from an open-label study in obstructive HCM, plus a phase III readout from the EXPLORER-HCM trial in that indication due in the second half of 2020.

There will also be phase 2a proof-of-concept data for MYK-491 in dilated cardiomyopathy (DCM), a life-threatening disease that often needs to be treated with a battery of drugs. Meanwhile, a third candidate – HCM-2 – is still in preclinical development for hypertrophic cardiomyopathy. Cardiomyopathies are a leading cause of heart failure.

Cardiovascular diseases haven’t seen the dramatic strides forward in drug therapy that have transformed other illnesses like cancer in recent years, so MyoKardia’s programmes – which are both based on novel mechanisms of action – have been keenly anticipated by physicians and patients alike.

Mavacamten is a small-molecule myosin inhibitor and is thought to work by inhibiting the binding of myosin to actin in muscle contraction, while MYK-491 works differently, enabling more myosin to engage actin and thereby increasing contractility.

Sanofi has already paid out around $230 million since the two companies started working together in 2014, and has built an approximately 11% equity stake in the US biotech. Gianakakos told investors that the drugmaker will likely sell off its position in future.