In vitro and in vivo safety evaluation of Nephure™

Abstract

NephureTM is a proprietary oxalate decarboxylase (OxDC) enzyme being developed as a food ingredient. In this study, the safety of NephureTM was evaluated in a bacterial mutagenicity assay and in a sub-chronic (13-week) oral toxicity study in rats. NephureTM did not show any mutagenic properties in the mutagenicity assay. In the 13-week sub-chronic oral toxicity study in which 10 Sprague Dawley rats per sex were administered 0, 118, 235 and 475 mg/kg bw/day (8260, 16450 and 33,250 Units/kg bw/day, respectively) of NephureTM by gavage, male and female rats did not show any test article-related clinical observations or effects on body weight, body weight gain, food consumption, food efficiency, ophthalmology, functional observational battery parameters or motor activity. Furthermore, there were no changes in coagulation, clinical chemistry, urinalysis or hematology parameters, macroscopic/microscopic findings or organ weights that could be attributed to the test article. Based on these results, NephureTM was not mutagenic and the no-adverse-effect level (NOAEL) in the 13-week study was determined to be 475 mg/kg bw/day (33,250 Units/kg bw/day). Evaluation of the estimated consumption of NephureTM, generation of the metabolite formate, and the current safety studies resulted in a conclusion of a tolerable upper limit of 3450 Units of OxDC activity/day (57.5 Units activity/kg bw/day), when NephureTM is added to food to decrease dietary oxalate.

Biochemical properties and oxalate‐degrading activity of oxalate decarboxylase from bacillus subtilis at neutral pH

“…Up to now, most of the efforts have been directed to decrease intestinal oxalate absorption by oral formulations of OxDC named Nephure™, OxDC CLEC, and Oxazyme. The first is OxDC from Synechococcus elongatus used as a food ingredient , while OxDC CLEC and Oxazyme are forms of OxDC from B. subtilis currently under clinical development, proven to be effective in healthy subjects . These treatments are directed to secondary hyperoxaluria, because in the case of primary hyperoxalurias accumulated oxalate comes from endogenous sources.…”

Recent Advances of Oxalate Decarboxylase: Biochemical Characteristics, Catalysis Mechanisms, and Gene Expression and Regulation

“…Another proprietary oxalate decarboxylase product named as Nephure has been developed as a food ingredient and its safety was evaluated in a bacterial mutagenicity assay and in a 13-week subchronic oral toxicity study in rats. 65 oxalate (CaOx) stone (Figure 7). 66−69 For example, Paul and his colleagues developed food-grade probiotic L. plantarum secreting OXDC using mobile genetic element Ll.LtrB and chromosomal integration, which is capable of degrading intestinal oxalate and preventing CaOx stone formation in experimental rats.…”

“…Recently, two orally administered oxalate degrading enzyme therapy, ALLN-177 and OXDC, have been developed and used in a double-blind, placebo controlled, randomized crossover study in healthy volunteers with diet-induced hyperoxaluria and patients with secondary hyperoxaluria. , The results reveal that ALLN-177 can reduce urine oxalate excretion and is well tolerated. Another proprietary oxalate decarboxylase product named as Nephure has been developed as a food ingredient and its safety was evaluated in a bacterial mutagenicity assay and in a 13-week subchronic oral toxicity study in rats . Although oxalotropic bacterium, O. formigenes , is efficient in oxalate degradation, its probiotic efficiency is still uncertain and not as well established as in lactic acid bacteria.…”

“…Another proprietary oxalate decarboxylase product named as Nephure has been developed as a food ingredient and its safety was evaluated in a bacterial mutagenicity assay and in a 13-week subchronic oral toxicity study in rats. 65 Although oxalotropic bacterium, O. formigenes, is efficient in oxalate degradation, its probiotic efficiency is still uncertain and not as well established as in lactic acid bacteria. Lactic acid bacteria that heterologously express OXDC may be used as potential probiotics for degrading intestinal oxalate to prevent calcium oxalate (CaOx) stone (Figure 7).…”

Perspectives in primary hyperoxaluria — historical, current and future clinical interventions

“…OxDC is available in multiple formulations that have been clinically tested, including Nephure, Oxazyme and reloxaliase. Nephure is purified OxDC from Synechococcus elongatus 77 . To date, enzyme administration therapy with OxDC formulations have only been clinically tested in healthy individuals and patients with secondary hyperoxaluria, which, unlike PH, is not caused by genetic errors of metabolism, but by increased dietary ingestion of oxalate, precursors of oxalate, or alterations in intestinal microflora 78 .…”