Ono takes a long look at Seikagaku arthritis candidate

Japanese drugmaker Seikagaku has taken a step towards lining up a big pharma partner for its phase 3 osteoarthritis drug SI-613, with Ono taking an option on the drug.

SI-613 draws on Seikagaku's long-standing experience with hyaluronic acid, which is widely used in preparations used to treat osteoarthritis and is thought to improve the functioning of joints.  The company's scientists have bound hyaluronic acid to a nonsteroidal anti-inflammatory drug (NSAID) using a proprietary linker technology to add long-lasting pain relief and anti-inflammatory properties to the molecule.

Importantly, the drug keeps the NSAID localized within the joint, with little escaping into the circulation to cause systemic side effects such as gastric irritation, according to its developer.

Seikagaku has already completed phase 2 trials of the drug in patients with osteoarthritis of the knee, showing a significant improvement in symptoms following direct injection into the affected joint. The phase 3 trial is enrolling patients with arthritis of the hip, ankle, elbow and shoulder as well.

Describing the current deal as a "basic agreement", the two companies said they are now in discussions about firming up the terms into a definitive licensing deal.

The prospect of signing up larger pharma group Ono is a boost for Seikagaku, which started pivotal trials of the drug in Japan earlier this year but has made no secret of its ambition to bring it forward onto the global stage. That would prove tough for the small drugmaker without the help of a larger partner.

If the phase 3 trial proves the worth of SI-613, the drug could emerge as a new treatment option in the osteoarthritis market, which is valued at around $3.5 billion a year in the seven countries with the largest pharma markets, according to GlobalData.

Why so little? Despite millions of sufferers around the world—around 9 million in Japan alone—osteoarthritis treatment still largely relies on cheap generic drugs that have been around for decades. SI-613 could provide a shakeup in the market, although the need for injections into the joints may reduce its use in patients with less severe symptoms who may prefer to take tablets.

In the meantime, after years of stagnation there are some emerging biologic drugs for osteoarthritis that for the first time promise to affect the underlying disease process, rather than simply alleviating symptoms.

One of these is TissueGene's Invossa, a cell-based disease-modifying osteoarthritis drug that requires a single injection into the affected joint and has been filed for approval in South Korea by licensee Kolon Life Sciences. It is currently in phase 3 trials in the U.S., and was recently licensed in Japan to Mitsubishi Tanabe in a $434 million deal last November.

GlobalData also tips Nordic Bioscience/Merck KGaA's sprifermin as another candidate to watch. The drug, a recombinant form of fibroblast growth factor 18 (FGF18), is in phase 2 testing for osteoarthritis and is thought to stimulate joint repair.