Akebia Therapeutics’ hypoxia-inducible factor (HIF) stabilizer vadadustat hit its primary endpoint in two Japanese phase 3 trials in patients with anemia due to chronic kidney disease (CKD). Though the data aren’t a perfect predictor of what might happen in vadadustat’s global registrational studies, Piper Jaffray analysts called them “a nice proxy” for those trials.
“This morning’s data is of course not a direct read-through to the global PROTECT and INNOVATE programs given some key differences in Japanese patient characteristics,” the analysts wrote in a note on Tuesday. Namely, Japanese patients with anemia due to CKD tend to be healthier and less likely to be diabetic than U.S. or European patients.
“However, we do think this experience provides a decent signal that PROTECT [testing vadadustat innon-hemodialysis dependent patients] and INNOVATE [involving hemodialysis-dependent patients]—which together encompass four separate P3 trials and serve as the drug’s global registration trials, and are expected to read out next year—will be similarly positive,” the analysts wrote.
Akebia also announced data from a pair of single-arm phase 3 studies which include results from patients undergoing peritoneal dialysis.
One of the Japanese trials tested the drug in non-dialysis dependent patients and the second tested it in hemodialysis-dependent patients, with both studies enrolling more than 300 patients. Both are comparing vadadustat against darbepoetin alfa, an Amgen drug sold as Aranesp that is used to treat anemia linked to CKD and cancer chemotherapy.
Topline data at 24 weeks showed that vadadustat was not inferior to darbepoetin alfa, with dialysis-dependent patients’ mean hemoglobin level at weeks 20 and 24 at 10.61 g/dL, compared to 10.65 g/dL. The trend echoed in the non-dialysis dependent group, with vadadustat patients’ mean hemoglobin level at 11.66g/dL at weeks 20 and 24, compared to 11.93 g/dL for darbapoetin alfa patients.
Akebia’s partner Mitsubishi Tanabe is carrying out vadadustat’s clinical program in Japan and will file an NDA in that country later this year.
Cambridge, Massachusetts-based Akebia closed its merger with Keryx Pharmaceuticals last December, creating a kidney disease specialist with an approved drug, the latter’s Auryxia, for the treatment of iron deficiency anemia in patients with CKD. If vadadustat gets approval, Akebia will have a readymade CKD-focused sales team to push the product.
And the commercial opportunity for vadadustat, as the Piper Jaffray analysts see it, is “huge.”
“Our previous nephrologist survey work indicates that the commercial opportunity for the HIF class is considerable, and we continue to model vadadustat WW revenue exceeding $1.5B ... by 2025,” they wrote.