Aeterna Zentaris Inc. said Monday it reached an agreement with the U.S. Food and Drug Administration that will enable the Canadian company to complete a late-stage trial of its potential diagnostic test for adult growth hormone deficiency.

The company is developing Solorel, which could become the first oral test for adult growth hormone deficiency, giving patients an alternative to current injectable tests. Solorel works by stimulating a patient's growth hormone secretion after which a healthcare provider measures how well the body responds to that stimulation based on the patient's growth hormone levels over a period of time.

Low GH levels, despite giving an effective stimulating agent, confirm a diagnosis of AGHD. The condition affects 35,000 adult Americans, with 6,000 new adult patients diagnosed each year. AGHD is usually characterized by low energy levels, decreased strength and exercise tolerance, increased weight or difficulty losing weight, emotional changes, anxiety and impaired sleep.

The company's study was initiated some years ago to compare the performance of Solorel against the then-available standard test, Geref Diagnostic + Arginine. However, that test was withdrawn from the market, worldwide, in 2008. At the time of withdrawal, the trial included 42 patients with AGHD and ten control subjects. In 2009, Aeterna Zentaris regained the rights to Solorel and worked with the FDA to establish the best way forward to complete this registration study and continue to use the data it had already compiled, in light of the loss of the original test it was comparing Solorel against.

The agreement with the FDA modifies the original study, but does not alter the basic study design so that the completed portion of the study will work with the new part to provide one, complete, Phase 3 study involving about 100 patients.

Aeterna Zentaris said in a statement it looks forward to completing the trial and submitting a new drug application for approval next year.

Aeterna Zentaris shares climbed 4 cents to $1.88 in Monday morning trading.