ASP015K at the ACR 2012 in Washington

I've just written a blogpost concerning the data from EULAR 2013, which isn't as positive as the one below: http://rheumatologe.blogspot.de/2013/06/asp015k-at-eular-2013-meeting.html

"ASP015K is an oral Janus kinase (JAK) inhibitor with selectivity for JAK1/3 in development for treatment of rheumatoid arthritis (RA) and other autoimmune diseases."

T. Zhu et al. presented: "Coadministration of ASP015K, a Novel Janus Kinase Inhibitor with Methotrexate Demonstrates Tolerability and Lack of Pharmacokinetic Interactions in Patients with Rheumatoid Arthritis" (Abstract No. 1322). The study had two parts: 1. In vitro experiments on the “inhibitory potency of ASP015K on human multidrug resistance-associated protein 2/4 (MRP2/4) and organic anion transporter 1/3 (OAT1/3).” And a phase 1 study, which was open-labeled and single-sequenced, “to confirm the in vivo effect of ASP015K on the PK of MTX, a substrate of MRP2/4 and OAT1/3.” Conclusions: " Coadministration of ASP015K and MTX was well tolerated in this short-term study exhibiting no clinically significant effect on the PK profile of either drug. Efficacy and safety of ASP015K/MTX combination therapy is being assessed in ongoing phase 2 trials in RA patients."
According to the design of the study there wasn’t more to be expected.

Shunji Yamazaki and colleagues presented a seond study (Abstract No. 2084): “ASP015K: A Novel JAK Inhibitor Demonstrated Potent Efficacy in Adjuvant-Induced Arthritis Model in Rats.” They could show in this rat model, that ASP015K “potently inhibits human JAK enzymes with moderate selectivity against JAK1/3 over JAK2/2, which may translate to less hematological side effects observed in the clinic such as anemia.” Further conclusions: “The data suggests that ASP015K has the potential to reduce clinical signs and symptoms as well as prevent disease progression in RA patients warranting further clinical investigation.”

ASP015K is an interesting small molecule as it may be efficacious against rheumatoid arthritis with less adverse events when compared to other small molecules. The data is preliminary and there’s still a long way to go. It would be nice, if Astellas Pharma could give the compound a name. Good luck from my side!