What is oxalate?

Oxalate is endogenously produced as an end product of normal cellular metabolism and is also absorbed from a typical diet. Oxalate is present in many foods, especially healthy foods like plants, including green leafy vegetables, fruits and nuts, because plants utilize oxalate to store calcium. Humans lack the innate capacity to digest oxalate and primarily depend on renal excretion to eliminate it from the body. Although oxalate has no identified biological function, it is known to damage the kidney when present in excess amounts, a condition called hyperoxaluria.

What causes hyperoxaluria?

Hyperoxaluria has two main causes. Secondary hyperoxaluria is caused by increased intestinal oxalate absorption associated with underlying gastrointestinal conditions such as inflammatory bowel disease, Crohn’s disease, and short bowel syndrome or bariatric surgery (enteric hyperoxaluria). Secondary hyperoxaluria may also occur without an identified cause (idiopathic hyperoxaluria). 

Primary hyperoxaluria is an orphan genetic disease that leads to increased endogenous oxalate production by the liver due to genetic defects in certain enzymes involved in carbohydrate metabolism.  

What causes hyperuricemia?

Hyperuricemia, or elevated levels of uric acid in the blood, results from overproduction or insufficient excretion of urate, or often a combination of the two. Humans lack urate oxidase, an enzyme that degrades uric acid in other animals. Hyperuricemia can be a predisposing condition for gout and kidney stones, and is also intricately linked with various metabolic disorders, including hypertension, chronic kidney disease or CKD, glucose intolerance, dyslipidemia, insulin resistance and obesity.

What is an orphan designation?

The Orphan Drug Designation Program is administered by the FDA's Office of Orphan Products Development, which grants orphan status to drugs that are intended to treat rare diseases that affect fewer than 200,000 people in the U.S., or diseases that affect more than 200,000 persons in the U.S., in circumstances where there is not expectation of recovering the costs of developing and marketing a therapeutic drug. The program provides incentives for sponsors and has enabled the development and marketing of more than 400 products for rare diseases since 1983. For more information, please visit http://www.fda.gov/ForIndustry/DevelopingProductsforRareDiseasesConditio...

Are these products available now?

Reloxaliase (formerly ALLN-177), Allena’s lead product candidate that targets oxalate, is currently being studied in clinical trials. It is not commercially available now. For information about clinical trials, please see www.clinicaltrials.gov.