Akebia Therapeutics President & CEO John Butler presenting at the American Kidney Fund

What: After reporting positive phase 2 trial results for its anemia drug, shares in Akebia Therapeutics (NASDAQ:AKBA) jumped by 53% earlier today.

So what: Akebia Therapeutics is developing vadadustat for the treatment of anemia in patients with chronic kidney disease receiving dialysis.

Anemia is common in these patients, and it's frequently treated with Epogen, an erythropoiesis-stimulating agent manufactured by Amgen.

In a 16-week phase 2 trial, Akebia Therapeutics patients that were converted from Epogen to vadadustat didn't see any drop-off in hemoglobin levels. Hemoglobin levels were similar across all three dosing options, including 300 mg daily, 450 mg daily, and 450 mg three times weekly. Importantly, there were no serious safety concerns associated with taking vadadustat.

Now what: Akebia Therapeutics plans to design and launch a phase 3 study soon, and if that study confirms earlier stage findings, then it could result in a needle-moving FDA approval.

That's because Epogen was a multibillion dollar blockbuster drug for Amgen prior to losing patent protection, and even though Epogen faces off against biosimilars overseas, it's still selling at an annualized $2 billion clip.

Vadadustat's oral dosing could give it an important advantage over Epogen, which is injected, but safety is actually the biggest reason why vadadustat could win away market share from Epogen. Epogen has been associated with increasing the risk of cardiac events and with shortening overall survival in certain cancer patients -- risks that haven't been seen in vadadustat's trials to date. 

For that reason, I think that if Akebia Therapeutics skates through its final stage of trials, eases its way through regulators, and nets a favorable prescribing label, then investors could be smart for buying shares of the company now.