Cytokinetics and Astellas Pharma have expanded a year-and-a-half-old collaboration focused on research, development and commercialization of skeletal muscle activators. The companies said today they will advance development of CK-2127107, a fast skeletal troponin activator, into Phase II for Spinal Muscular Atrophy (SMA) and potentially other neuromuscular indications.

Cytokinetics will conduct a Phase II clinical trial of CK-2127107 in patients with SMA, set to begin in 2015. Cytokinetics and Astellas also said they will jointly develop and may jointly commercialize CK-2127107 and other fast skeletal troponin activators in neuromuscular indications. The companies have extended their joint research program focused on the discovery of additional skeletal sarcomere activators through 2016.

The collaboration extension is expected to generate more than $600 million for Cytokinetics in pre-commercialization and commercialization milestone payments—on top of up to $75 million in short-term cash from Astellas.

Of the short-term cash, Cytokinetics will receive $30 million as an upfront license fee, plus $10 million for Astellas’ purchase of Cytokinetics’ common stock, and a $15 million milestone payment tied to Astellas advancing CK-2127107 into Phase II clinical development. Cytoklinetics said it expects potentially more than an additional $20 million from Astellas toward planned research and development expenses over the next two years.

Cytokinetics retains its option to co-fund development of CK-2127107 in SMA and other neuromuscular indications in exchange for increased milestone payments and royalties. The agreed terms also provide for escalating royalties to Cytokinetics with increased sales.

Should Cytokinetics exercise a co-promotion option, Astellas will reimburse Cytokinetics for certain expenses associated with its promotion activities.

The companies launched an up-to-$490 million collaboration in 2013, when Cytokinetics exclusively licensed to Astellas rights to co-develop and commercialize CK-2127107 for potential application in non-neuromuscular indications. Cytokinetics has since completed Phase I clinical development activities and other Phase II readiness activities.

The Phase I trial, a first-time-in-humans study, met its primary objective of demonstrating safety and tolerability of single doses of CK-2127107 administered orally to healthy male volunteers. Planned single doses of CK-2127107 up to 4000 mg, the highest dose administered, were well-tolerated without an emerging pattern of adverse events; a maximum tolerated dose could not be defined, according to Cytokinetics.

“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,” Yoshihiko Hatanaka, Astellas’ President and CEO, said in a statement. “The expansion of our alliance is a testament to our productive collaboration together and illustrates the broad potential that we envision for this program.”

Outside the collaboration, Cytokinetics said it may continue to independently develop tirasemtiv, a fast skeletal troponin activator, in amyotrophic lateral sclerosis (ALS) and other neuromuscular indications subject to agreed limitations. Tirasemtiv recently completed a Phase II clinical trials program in ALS.

As with tirasemtiv, CK-2127107 is designed to work by slowing the rate of calcium release from the regulatory troponin complex of fast skeletal muscle fibers, which sensitizes the sarcomere to calcium.

Previous articleSelecta Receives $3.2M from Skolkovo Foundation for Immuno-oncology Program
Next articleProMetic, Generium Partner to Manufacture Plasma-Derived Biopharmaceuticals