What are kidney stones?

Approximately 10% of Americans will suffer from kidney stones (nephrolithiasis) during their lifetime.1 Symptoms of kidney stones include excruciating pain, chills, nausea, and blood in the urine. Nephrolithiasis results from crystal deposits that form when there is an excess of certain substances in the urine, such as oxalate, cystine or calcium. About 70% to 80% of kidney stones are made of calcium oxalate2 and may be due to hyperoxaluria, a metabolic disorder caused by excess oxalate.

Up to 40% of patients experience another kidney stone within 5 years of their first stone,3 and some patients have many kidney stone episodes each year. 

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 is gout?

Gout occurs when uric acid, a normal waste product, builds up in the blood leading to hyperuricemia. Over time the excess uric acid forms crystals in the joints or kidneys, causing pain, inflammation, and stiffness. Crystals that form in the kidney can also lead to painful stones and kidney disease.

What are the long-term consequences of metabolic complications like hyperoxaluria and hyperuricemia?

Oxalate and uric acid are normal byproducts of digestion and metabolism, but patients with hyperoxaluria and hyperuricemia frequently experience the painful consequences of recurrent kidney stones and gout attacks as a result of their build-up over time. Long-term, kidney stones have been associated with adverse health outcomes including an increased risk of kidney failure and cardiovascular disease. 

How do Allena’s technologies affect conditions like kidney stones and gout?

Allena’s technologies support the development of the non-absorbed oral enzymes that target toxic metabolites, including the oxalate and uric acid that can lead to kidney stones and gout.

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 which 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/DevelopingProductsforRareDiseasesConditions/ucm2005525.htm

Are these products available now?

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

How do I get information about participating in clinical trials for ALLN-177?

To find out if you qualify to participate in a trial, please take our short survey.


1. Asplin JR, Favus MJ, Coe FL. Nephrolithiasis. In: Brenner BM, ed. Brenner and Rector's the kidney. 5th ed. Philadelphia: Saunders, 1996: 1893-935.
2. Coe FL, Evan A, Worcester E. Kidney stone disease. Journal of Clinical Investigation. 2005;115(10):2598-2608.
3. Curhan GC. Diagnosis and acute management of suspected nephrolithiasis in adults. In: UpToDate, Forman JP (Ed), UpToDate, Waltham MA.