At the Annual European Congress of Rheumatology conference in Madrid this week, Aurinia Pharmaceuticals (NASDAQ:AUPH) presented new duration-of-remission data from a mid-stage study that's good enough to suggest it could eventually change how doctors treat kidney failure in lupus patients.

Improving standard care

Aurinia Pharmaceuticals is a clinical-stage biotechnology company, and its lead product candidate is voclosporin, a drug designed for use alongside CellCept in patients diagnosed with lupus nephritis (LN).

Scientists in white coats and goggles working together in a lab

IMAGE SOURCE: GETTY IMAGES.

In the United States, there are over 500,000 people with systemic lupus erythematosus (SLE), and up to 60% of these patients will develop LN, or inflammation of the kidneys that can lead to end-stage kidney disease.

Today, patients with LN are treated with steroids and CellCept, but for many patients this approach falls short. Steroids can result in unwanted side effects, and CellCept's efficacy can be hit-and-miss.

Because current treatments are inadequate, there's an important need for new treatments, and based on Aurinia Pharmaceuticals' trial data, that need may be addressed by voclosporin.

Earlier this year, the company reported that adding voclosporin to CellCept improved patient response rates and reduced patients' need for steroids. Specifically, 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 trial's control group. Also, 68% of patients in the 23.7 mg dose arm had a partial response, versus 48% in the control arm of the study.

At the conference this week, management reaffirmed those results, and noted that 100% of patients in complete remission at the 24-week mark remained in complete remission at week 48. Patients not only responded more quickly when using voclosporin, but also had a duration of remission nearly twice that of CellCept alone.

Management thinks this data, combined with results from a phase 3 study that began enrolling patients last month, can support eventually filing for voclosporin's approval from the U.S. Food and Drug Administration.

Getting to the finish line

The ability to produce so many complete responses with high statistical significance, or a p-value of 0.001, bodes well for a positive outcome in late-stage trials, but it doesn't guarantee success. Clinical-trial failure rates are historically high, and that means that investors need to keep some of their optimism in check.

If the company's recently started 52-week phase 3 trial confirms mid-stage results, then it could represent a lucrative market opportunity for Aurinia Pharmaceuticals. Guessing at peak sales is notoriously risky (and usually industry-watchers' predictions miss the mark), but estimates suggest that a U.S. approval could translate into a billion-dollar blockbuster market opportunity for the company. Additionally, management estimates that an additional $300 million opportunity exists in Europe, plus another $80 million in Japan. Whether it can successfully realize that opportunity is anyone's guess.

Todd Campbell has no position in any stocks mentioned. His clients may have positions in the companies mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.