Hexasodium fytate for the treatment of calciphylaxis: a randomised, double-blind, phase 3, placebo-controlled trial with an open-label extension.

Background: In the CALCIPHYX trial, we investigated hexasodium fytate, an inhibitor of vascular calcification, for the treatment of calcific uraemic arteriolopathy (calciphylaxis), a rare condition characterised by painful, non-healing skin lesions. Methods: In this international, phase 3, randomised, double-blind, placebo-controlled trial, adults with an ulcerated calciphylaxis lesion and pain visual analogue scale (VAS) score ≥50/100 were randomised 1:1 to hexasodium fytate 7 mg/kg or placebo intravenously during maintenance haemodialysis. Primary efficacy outcomes were an 8-item modification of the Bates-Jensen Wound Assessment Tool (BWAT-CUA) and Pain VAS in the intention-to-treat population. ClinicalTrials.gov number: NCT04195906. Findings: Overall, 34/37 patients randomised to hexasodium fytate and 26/34 patients randomised to placebo completed the 12-week randomised treatment period. At Week 12, both groups (hexasodium fytate versus placebo) showed similar improvements in BWAT-CUA (mean [standard deviation (SD)], -5.3 [5.2] versus -6.0 [6.2]; least squares mean difference, 0.3 [96% confidence interval (CI): -2.5, 3.0]; p = 0.88) and Pain VAS (mean [SD], -19.5 [26.9] versus -32.2 [38.5]; least squares mean difference, 11.5 [96% CI: -4.8, 27.8]; p = 0.15). One patient randomised to placebo briefly received hexasodium fytate in error. Serious adverse events through Week 12 included: calciphylaxis-related events leading to hospitalisation (2/38 [5%] versus 11/33 [33%]) and death (1/38 [3%] versus 5/33 [15%]). During the subsequent 12 weeks of open-label hexasodium fytate and 4 weeks of follow-up, there were no additional calciphylaxis-related events leading to hospitalisation. Over the course of the entire trial, deaths were 2/38 [5%] for the hexasodium fytate group and 7/33 [21%] for the placebo group. Interpretation: In patients with calciphylaxis, BWAT-CUA and Pain VAS improved similarly in hexasodium fytate- and placebo-treated patients; over the course of the entire trial, there were fewer deaths and calciphylaxis-related events leading to hospitalisation in the hexasodium fytate group. Funding: Funded by Sanifit, a CSL Vifor company.

Calciphylaxis, A Case Series: The Importance of Early Detection.

Introduction: Calciphylaxis is a rare disorder that involves the formation of cutaneous, subcutaneous, and vascular calcifications. Although it is predominantly seen in patients with end-stage renal disease (ESRD), it has also been reported in patients without chronic kidney disease. The presence of multiple risk factors, a poorly understood mechanism, high mortality, and the lack of standardized treatment make calciphylaxis an important subject. Case Presentation: We describe the clinical presentation, disease course, and management of 3 patients with calciphylaxis and also provide a literature review. In all 3 patients, the diagnosis was confirmed histologically, and the management involved the continuation of renal replacement therapy, pain medication, wound debridement, and intravenous (IV) sodium thiosulphate. Conclusion: Calciphylaxis should be suspected in ESRD patients presenting with painful areas of cutaneous induration, and the early recognition of these findings allows for prompt diagnosis and management.

Successful treatment of severe calciphylaxis in a renal transplant patient with previous total parathyroidectomy.

Calciphylaxis is a rare dermatological condition strongly associated with chronic kidney disease. The pathophysiology and optimum treatment remain uncertain. Calciphylaxis is known mostly to affect dialysis patients but is less frequently reported in renal transplant recipients. We report the case of a renal transplant recipient who had undergone previous total parathyroidectomy.

The Role of Iron in Calciphylaxis-A Current Review.

Calcific uraemic arteriolopathy (CUA), also known as calciphylaxis, is a rare and often fatal condition, frequently diagnosed in end-stage renal disease (ESRD) patients. Although exact pathogenesis remains unclear, iron supplementation is suggested as a potential risk factor. Iron and erythropoietin are the main stay of treatment for anaemia in ESRD patients. Few observational studies support the role of iron in the pathogenesis of calciphylaxis although data from the pivotal trial was not strongly supportive of this argument, i.e., no difference in incidence of calciphylaxis between the low-dose and high-dose iron treatment arms. Elevated levels of vascular cell adhesion molecules in association with iron excess were postulated to the pathogenesis of CUA by causing inflammation and calcification within the microvasculature. In-addition, oxidative stress generated because of iron deposition in cases of systemic inflammation, such as those seen in ESRD, may play a role in vascular calcification. Despite these arguments, a direct correlation between cumulative iron exposure with CUA incidence is not clearly demonstrated in the literature. Consequently, we do not have evidence to recommend iron reduction or cessation in ESRD patients that develop CUA.

Calciphylaxis after kidney transplantation: a rare but life-threatening disorder.

Calciphylaxis is a rare disorder characterized by vascular calcification and thrombosis of the subcutaneous microcirculation, leading to painful necrotic skin lesions and bearing a dreadfully high mortality rate. This syndrome is frequently also termed uraemic calcific arteriolopathy, since most cases are observed in patients with kidney failure. However, it is increasingly clear that calciphylaxis may also affect patients with normal or only slightly impaired renal function, including kidney transplant recipients. A precise definition of the characteristics and risk factors of calciphylaxis developing after kidney transplantation has been hindered by the extreme rarity of this condition, which also hampered the development of effective therapeutic strategies. In the present issue of CKJ, Guillén and colleagues report the largest case series of calciphylaxis in kidney transplant recipients to date, outlining several features that are apparently specific to this population. In this editorial, we briefly present the epidemiology and pathogenesis of calciphylaxis in different patient populations and discuss recent findings for its therapeutic management.

Development of calciphylaxis in kidney transplant recipients with a functioning graft.

Background: Calciphylaxis is not uniquely observed in uraemic patients, as some cases have also been reported in patients with normal renal function or moderate chronic kidney disease (CKD), in association with severe vasculopathy or systemic inflammation. A particular subset worthy of studying is represented by those patients who develop calciphylaxis after kidney transplantation (KT). Methods: Analysis of the local series of calciphylaxis after KT (n = 14) along with all the other cases reported in the literature from 1969 to 2019 (n = 31), for a total population of 45 patients, is presented. Demographic data, CKD history, risk factors, immunosuppression, clinical presentation and management have been analysed both as a whole and according to the time period (before or after the year 2000). Results: Calciphylaxis developed during the first year after KT in 43.2% of patients and median (interquartile range) creatinine at diagnosis was 2.4 (1.25-4.64) mg/dL. The most frequent presentation included distal purpura or ulcers in one-third of cases and 39.1% of patients were receiving vitamin K antagonists. PTH values were above 500 pg/mL and below 100 pg/mL in 50.0% and 25.0% of cases, respectively. Whole population mortality was 55.6%. As expected, clinical presentation, immunosuppression and management varied depending on the time period. Patients diagnosed after 2000 were older, with longer dialysis vintage, and treatment was usually multimodal; on the contrary, in patients diagnosed before 2000, parathyroidectomy was the treatment of choice in 61.9% of cases. Conclusions: Calciphylaxis can still occur after KT, in many cases during the first year and in patients with a good renal function. Risk factors and management varied according to the time period studied.

Vascular calcification in skin and subcutaneous tissue in patients with chronic and end-stage kidney disease.

BACKGROUND: Vascular calcification (VC) is well described in large- and medium-sized vessels in patients with chronic kidney disease (CKD), especially in those with end-stage kidney disease (ESKD) on dialysis. Medial calcification is particularly prevalent in this population and contributes to arterial stiffness and increased cardiovascular mortality and morbidity. Apart from in the setting of calciphylaxis, few studies have assessed skin and subcutaneous calcification and associations with abnormalities of bone and mineral metabolism in patients with CKD. METHODS: We performed a single-centre observational study to evaluate incisional skin tissue samples from three anatomical sites in patients with different stages of CKD undergoing elective surgery. We compared these samples to skin samples of a control cohort without CKD. Staining for calcification was performed with von Kossa method. A subgroup of skin samples were assessed by RT-PCR for upregulation of pro-calcific gene transcripts for tissue non-specific alkaline phosphatase (TNAP) and Runt-related transcription factor 2 (RUNX2). RESULTS: Forty-five patients were evaluated, 34 with CKD (including ESKD) and 11 control patients. VC was identified in 15 skin samples (13 CKD/ESKD and 2 controls). VC was present in the dermal and subcutaneous tissues of the neck, abdomen and arm samples. Two different histological types of VC were identified: speckled medial calcification and internal elastic lamina calcification. Presence of perieccrine calcification was identified in 14 samples, 10 with concurrent VC. There were no significant differences in serum parathyroid hormone, phosphate or calcium in patients with or without VC. Expression of TNAP or RUNX2 was not increased in samples from patients with ESKD or those with histological evidence of calcification. CONCLUSION: This study reports the novel finding of dermal and subcutaneous calcification in multiple anatomical locations in 38% of patients with advanced CKD/ESKD undergoing elective surgery but free from calciphylaxis.

Mechanism of action of SNF472, a novel calcification inhibitor to treat vascular calcification and calciphylaxis.

BACKGROUND AND PURPOSE: No therapy is approved for vascular calcification or calcific uraemic arteriolopathy (calciphylaxis), which increases mortality and morbidity in patients undergoing dialysis. Deposition of hydroxyapatite (HAP) crystals in arterial walls is the common pathophysiologic mechanism. The mechanism of action of SNF472 to reduce HAP deposition in arterial walls was investigated. EXPERIMENTAL APPROACH: We examined SNF472 binding features (affinity, release kinetics and antagonism type) for HAP crystals in vitro, inhibition of calcification in excised vascular smooth muscle cells from rats and bone parameters in osteoblasts from dogs and rats. KEY RESULTS: SNF472 bound to HAP with affinity (KD ) of 1-10 µM and saturated HAP at 7.6 µM. SNF472 binding was fast (80% within 5 min) and insurmountable. SNF472 inhibited HAP crystal formation from 3.8 µM, with complete inhibition at 30.4 µM. SNF472 chelated free calcium with an EC50 of 539 µM. Chelation of free calcium was imperceptible for SNF472 1-10 µM in physiological calcium concentrations. The lowest concentration tested in vascular smooth muscle cells, 1 µM inhibited calcification by 67%. SNF472 showed no deleterious effects on bone mineralization in dogs or in rat osteoblasts. CONCLUSION AND IMPLICATIONS: These experiments show that SNF472 binds to HAP and inhibits further HAP crystallization. The EC50 for chelation of free calcium is 50-fold greater than a maximally effective SNF472 dose, supporting the selectivity of SNF472 for HAP. These findings indicate that SNF472 may have a future role in the treatment of vascular calcification and calcific uraemic arteriolopathy in patients undergoing dialysis.

The use of cinacalcet for the treatment of calciphylaxis in patients with chronic kidney disease: A comprehensive review.

Calciphylaxis is a rare but life-threatening condition, most commonly affecting patients with stage 4 or 5 chronic kidney disease. No universally accepted therapy exists so far. In an attempt to avoid surgical intervention with parathyroidectomy, which is of questionable efficacy and carries several risks, a number of noninvasive treatments have been trialled with variable success. These treatments are aimed at modifying risk factors for calciphylaxis, in particular hypercalcaemia, hyperphosphataemia and hyperparathyroidism. The aim of this review was to summarise the available evidence to determine the potential role of cinacalcet in the treatment of calciphylaxis in patients with chronic kidney disease. Demographic, clinical and laboratory data were retrospectively collected from the available English and non-English literature. Overall, there was a very high response rate (partial or complete) of calciphylaxis lesions to both cinacalcet monotherapy and cinacalcet as part of a combination therapy (83.4% and 82.8%, respectively). When examining complete response to treatment specifically, combination therapy with cinacalcet proved more efficacious than monotherapy (62.1% versus 41.7%). There was also an associated rapid reduction of intact parathyroid hormone over a period of 2-33 months in both groups. While there are limitations as to how our data can be interpreted due to the heterogeneity of the methods and follow-up of the included case reports and case series, prompt and consistent therapy including cinacalcet may help improve the disease outcome. Additional research needs to be performed in this area, to further define the optimal use of cinacalcet for the treatment of calciphylaxis.

Multimodal treatment of calcific uraemic arteriolopathy (calciphylaxis): a case series.

BACKGROUND: This is an incident series of five dialysis patients with late-diagnosed calcific uraemic arteriolophathy (CUA), severe uncontrolled hyperparathyroidism and infected skin ulcerations. METHODS: A multimodal intervention was based on wound care, antibiotics, surgical debridement, sodium thiosulphate and cinacalcet and associated with regression of skin disease in four cases after varying treatment time periods ranging from 4 to 33 months. RESULTS: Multimodal treatment including sodium thiosulphate and cinacalcet was associated with very favourable local outcomes and survival. This series further confirms that the diagnosis of CUA is rarely made at the nodular, non-ulcerative phase of the disease. CONCLUSIONS: This series contributes to the build-up of case series reporting on the treatment of CUA, and will hopefully serve as a basis of well-conceived comparative effectiveness studies investigating the value of the combined interventions applied so far in this severe condition.

Blueprint for a European calciphylaxis registry initiative: the European Calciphylaxis Network (EuCalNet).

Calcific uraemic arteriolopathy (CUA) is a rare disease and continues to be a clinical challenge. The typical course of CUA is characterized by painful skin discolouration and induration evolving to necrotic ulcerations. Medial calcification of cutaneous arterioles and extensive extracellular matrix remodelling are the hallmarks of CUA. The epidemiology and risk factors associated with this disease are still not fully understood. Moreover, CUA treatment strategies vary significantly among centres and expert recommendations are heterogeneous. Registries may provide important insights and information to increase our knowledge about epidemiology and clinical aspects of CUA and may help to optimize its therapeutic management. In 2006, we established an internet-based registry in Germany (www.calciphylaxie.de) to allow online notification of patients with established or suspected CUA. The registry includes a comprehensive database with questions covering >70 parameters and items regarding patient-related and laboratory data, clinical background and presentation as well as therapeutic strategies. The next phase will be to allow international patient registration via www.calciphylaxis.net as part of the multinational EuCalNet (European Calciphylaxis Network) initiative, which is supported by the ERA-EDTA scientific working group 'CKD-MBD'. Based on the valuable experience with the previous German CUA registry, EuCalNet will be a useful tool to collect data on the rare disease CUA and may become a basis for prospective controlled trials in the near future.

Use of sodium thiosulphate in a multi-interventional setting for the treatment of calciphylaxis in dialysis patients.

BACKGROUND: Calciphylaxis is a life-threatening complication in patients with end-stage renal disease (ESRD). No established therapy exists so far. The aim of the present study was to determine the therapeutic response to a multi-interventional treatment regimen with consistent use of sodium thiosulphate (STS) in an Austrian cohort of calciphylaxis patients. METHODS: We retrospectively collected demographic, clinical and laboratory data on 27 calciphylaxis patients treated with STS at seven Austrian dialysis centres between June 2004 and November 2010. RESULTS: Twenty-seven dialysis patients (68 ± 12 years) were treated with STS for a median (25th, 75th percentile) of 96 (54, 133) days. Seven patients (26%) suffered from proximal-type, and 20 patients (74%) from distal-type calciphylaxis. Fourteen patients (52%) showed a complete remission, five patients (19%) a partial remission and eight patients (30%) progression that resulted in amputation in four patients. During a median follow-up of 101 (79, 273) days, 14 patients died (52%). Non-survivors were older (P = 0.04), showed higher CRP values (P = 0.04), presented more frequently with proximal-type calciphylaxis (P = 0.03), had a higher disease severity score at diagnosis (P = 0.01), were treated more often with antibiotics (P = 0.01) and cinacalcet (P = 0.03) and had a lower remission rate during treatment (P = 0.004) than did survivors. The use of antibiotics and cinacalcet, disease severity at diagnosis and remission rates were found to be significant survival predictors in logistic regression analysis. CONCLUSIONS: Calciphylaxis remains a serious complication with high mortality. Early and consistent therapy including STS may help to improve the disease outcome.

Secondary hyperparathyroidism: Uncommon cause of a leg ulcer.

INTRODUCTION: Most leg ulcers are vascular based. Only if vascular therapy fails other causes are considered. We report the case of a female with incapacitating leg ulcers caused by a rare condition which was only diagnosed after failing treatment. PRESENTATION OF CASE: The female had an extensive previous history including diabetes, renal insufficiency and cardiovascular disease and presented with three large and painful ulcers on her left lower leg. Standard treatment with antibiotics, wound excision and additional treatment with hyperbaric oxygen were ineffective. One month post hospital-admission calciphylaxis cutis caused by renal failure induced secondary hyperparathyroidism was diagnosed. Surgical treatment by a parathyroidectomy induced rapid regeneration of the ulcers. DISCUSSION: Our patient's vast comorbidity and previous history had expanded differential considerations causing a delay in diagnosis. Our patient's previous history led us to believe her ulcers were vascular based, however her chronic renal failure appeared responsible for her condition. CONCLUSION: Although less probable than venous insufficiency and concomittant leg ulcers or other differential considerations, calciphylaxis cutis should be part of the differential diagnosis in any end stage renal disease-patient with unexplained ulcers as an effective therapy is readily available.