After positive mid-stage trial data suggested earlier this year that it might be able to reshape the treatment of kidney failure in lupus patients, Aurinia Pharmaceuticals (NASDAQ:AUPH) has announced plans for a late-stage study that could eventually allow it to win regulatory OKs in the U.S., Europe, and Japan.

What's going on

Aurinia Pharmaceuticals is working on voclosporin, a drug that could eventually be used alongside CellCept as standard of care in patients diagnosed with lupus nephritis (LN).

Over 500,000 people in the U.S. have systemic lupus erythematosus (SLE), and up to 60% of them develop LN, or inflammation of the kidneys that can lead to end-stage kidney disease. Typically, LN patients are prescribed steroids and CellCept in an attempt to control their disease, but steroids can produce unwanted side effects, and CellCept delivers spotty efficacy.

In a mid-stage phase 2b study, adding voclosporin to CellCept not only improved patient response rates, but it also reduced patients reliance on steroids. The 48-week global study showed that the two-drug combination delivered a complete response rate of 49% at the 23.7 mg dose. That was far better than the 24% complete remission rate observed in the control group, which didn't receive voclosporin.

Adding voclosporin to CellCept therapy also resulted in more patients achieving at least a partial response. In the two-drug combination, the partial response rate was 68% in the 23.7 mg dose arm. The rate in the control arm was just 48%.

Because the remission rates observed in this trial are arguably the best results observed in any previously completed study, they suggest that if similar results are achieved in additional studies, voclosporin could become an important new medicine for doctors treating lupus patients.

What's on deck

The phase 2b study included two doses of voclosporin, a high-dose of 37.5 mg and a low dose of 23.7 mg. Although the high dose provided a higher level of partial responses, the lower dose provided the highest level of complete responses. Importantly, the ability to produce a complete response with the low dose was done with high statistical significance, or a p-value of 0.001. Comparatively, the p-value of the high dose in delivering a complete response was 0.026.

Because the low dose is more statistically significant, it's been chosen as the dose to be used in a newly announced phase 3 study. Although there were concerns that one phase 3 study wouldn't be enough to convince regulators to eventually OK voclosporin, meetings with the various global regulatory agencies have encouraged Aurinia Pharmaceuticals that an approval could be granted following only one late-stage trial.

The company expects to begin enrolling patients in this 52-week phase 3 trial soon, and overall, it plans on including approximately 320 patients, who will be randomized 1:1 to either voclosporin plus CellCept, or CellCept plus placebo.

Looking ahead

Big, late-stage studies aren't cheap, but fortunately, management took advantage of a big-run up in its shares to tap equity investors for $173 million in funding, before fees.

Along with existing cash, that should give Aurinia Pharmaceuticals the wiggle room necessary to pay its expenses until results from its phase 3 trial are available. If the trial's a success, the company will probably have to tap investors again for more money to commercialize voclosporin -- or license it to a company with deeper pockets.

Overall, industry watchers are guessing that voclosporin could be a $1 billion drug someday, but there's no gaurantee this late-stage study will pan out, or if it does, that regulators will green-light voclosporin. Because of this, Aurinia Pharmaceuticals is a high-risk, yet intriguing bet.