Development of the BWAT-CUA Scale to Assess Wounds in Patients with Calciphylaxis

Calcific uremic arteriolopathy (CUA; calciphylaxis) is a severe form of vascular calcification with no approved therapies. A standardized wound assessment tool is needed to evaluate changes in calciphylaxis wounds over time. A prospective, single-arm study of 14 patients with calciphylaxis reported improvement for the primary endpoint of wound healing using the 13-item Bates-Jensen Wound Assessment Tool (BWAT), although that tool was developed for assessment of pressure ulcers. This report describes development of BWAT-CUA, an 8-item modification of BWAT focusing on prototypical features of calciphylaxis lesions. The BWAT-CUA has a range of 8 (best) to 40 (worst) and was used ad hoc to analyze BWAT data collected in the prospective study. Using BWAT-CUA, relative improvement in calciphylaxis wounds was 30% overall (from 21.2 to 14.9; p = 0.0016) and 34% in the subset of 12 patients with ulceration at baseline (from 23.3 to 15.3; p = 0.0002). BWAT-CUA is a primary endpoint in an ongoing randomized, placebo-controlled phase 3 study of SNF472 recruiting patients with end-stage kidney disease and at least one ulcerated calciphylaxis lesion. BWAT-CUA, a newly developed tool for assessment of calciphylaxis wound severity and improvements over time, may be used in clinical research and in clinical practice.