Astellas has signed a major expansion of its collaboration with US biotech Cytokinetics to include neuromuscular diseases.
The two companies have been working together since 2013 on a $490m project focusing on compounds that activate the skeletal sarcomere – the basic unit of muscle contraction – in non-neuromuscular applications, but have widened the scope of the alliance to include diseases such as spinal muscular atrophy.
Astellas is paying $55m upfront to license rights to CK-2127107 – a small-molecule fast skeletal troponin activator with potential in SMA – with another $20m going to fund Cytokinetics’ development of the drug over the next two years including a phase II trial.
Added to that tally is another $600m in milestone payments if the compound meets regulatory and commercial targets, along with royalties on any future sales.
CK-2127107 slows the rate of calcium release from the regulatory troponin complex of fast skeletal muscle fibres, which sensitises the sarcomere to calcium and increases muscle force whilst reducing fatigue.
In a phase I trial reported at the end of last year, CK-2127107 (also known as CY 5011) was found to be well-tolerated at all three doses tested with pharmacokinetics supporting once- or twice-daily oral dosing.
It works in a similar way to Cytokinetics’ tirasemtiv which is already in phase II trials for amyotrophic lateral sclerosis (ALS), myasthenia gravis and peripheral artery disease. The latter drug will continue to be developed by the US firm “subject to certain agreed limitations”.
San Francisco-based Cytokinetics has retained an option to co-fund the development of CK-2127107 in SMA and other neuromuscular indications in exchange for increased milestone payments and royalties.
Yoshihiko Hatanaka, Astellas’ chief executive, said: “We are encouraged by the result of the completed phase I studies for CK-2127107 and are hopeful for the future of this new frontier of muscle biology.
“The expansion of our alliance is a testament to our productive collaboration together and illustrates the broad potential that we envision for this programme.”