A systematic review on the efficacy and safety of PA21 versus sevelamer in dialysis patients

Efficacy and safety of sucroferric oxyhydroxide versus sevelamer carbonate: A systematic review and meta-analysis

INTRODUCTION

Phosphate binders are commonly used in patients receiving kidney replacement therapy (KRT), aiming to reduce and maintain serum phosphorus. Chronic kidney disease-mineral and bone disorder has been linked to reduced lifespan and worsened quality of life. This study aims to examine the efficacy and safety of sucroferric oxyhydroxide versus sevelamer carbonate in patients receiving KRT.

METHODS

The data sources examined were MEDLINE (PubMed), Scopus, and the Cochrane Central Register of Controlled Clinical Trials with a search deadline of October 2023. We examined randomized controlled trials that compared sucroferric oxyhydroxide versus sevelamer carbonate in the adult population receiving KRT. We performed a meta-analysis combining the data from trials, using R-studio.

FINDINGS

Inclusion criteria were met by five randomized trials. There was no statistically significant difference in the reduction of serum phosphorus between the two groups (MD: -0.07 mmol/L, 95% CI-random effects: -0.15 to 0.02). In the same line, a non-statistically significant difference was observed in serum i-PTH reduction between the two drugs (MD = -1.53 mg/dL, 95% CI = (-4.45, 1.4), p = 0.26, random effects model). No statistically significant difference was observed in all adverse events between the two groups (odds ratio: 1.11, 95% CI: 0.65-1.88, random effects model). Further analysis of gastrointestinal adverse events revealed that sevelamer carbonate increases gastrointestinal adverse events by up to 60% (odds ratio: 1.60, 95% CI: 1.31-1.97, common (fixed) effect model).

DISCUSSION

This meta-analysis of randomized trials showed that both drugs, sucroferric oxyhydroxide and sevelamer equally and effectively controlled serum phosphorus levels, whereas sucroferric oxyhydroxide revealed a better profile in terms of gastrointestinal adverse events. Sucroferric oxyhydroxide is a valuable option for patients receiving KRT when sevelamer carbonate is more difficult to tolerate.

Interaction and mechanisms in the phosphate-binding of iron(oxyhydr)oxide core-shell nanoparticles

HYPOTHESIS

The high binding affinity of iron(oxyhydr)oxides for phosphate has recently been used in medicine to treat hyperphosphatemia, an abnormally elevated phosphate concentration in the blood. For iron(oxyhydr)oxide nanoparticles, the composition of the organic shell has a more significant influence on their interaction with phosphate than is often assumed. This study shows different mechanisms in phosphate binding, using the example of two similar new phosphate-binding agents.

EXPERIMENTS

We characterized the phosphate-binding behavior of two iron(oxyhydr)oxide-based nanomaterials with similar composition and particle properties and investigated their binding mechanisms by spectroscopic methods.

FINDINGS

For the often prescribed Velphoro, we demonstrated a phosphate binding capacity of>210 mg/g. A similar active ingredient named C-PAM binds over 573 mg/g. Spectroscopic measurements highlighted differences in the binding mechanism. While Velphoro binds phosphate via surface complexation independent of pH and adsorbent concentration, C-PAM shows a strong concentration dependence. At low concentrations, phosphate is bound via complexation reactions. The iron(oxyhydr)oxide structure was dissolved at higher phosphate concentrations and formed various iron phosphate species. The substances behave differently upon interaction with phosphate, although being very similar in composition and crystal structure. Thus, we demonstrated a crucial influence of the ligands in the shell on the binding mechanism.

The impact of phosphate lowering agents on clinical and laboratory outcomes in chronic kidney disease patients: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Besides reducing hyperphosphatemia in chronic kidney disease (CKD) patients, phosphate lowering agents might provide beneficial effects on clinical and laboratory parameters. This meta-analysis was conducted to comprehensively examine the impact of all phosphate lowering agents on various aspects of clinical and laboratory outcomes in CKD patients.

METHOD

A systematic literature search was performed in MEDLINE, Scopus, and the Cochrane Register of Controlled Trials until July 2020 to identify randomized controlled trials (RCTs) which compared the effects of each phosphate lowering agent with controls, comprising placebo and all other phosphate lowering agents. Various clinical and laboratory outcomes were analyzed. Random effects model was used to compute the standardized mean difference for continuous variables and the risk ratio (RR) for binary variables.

RESULTS

This meta-analysis included 127 RCTs with 20,215 patients. Sevelamer and lanthanum significantly reduced all-cause mortality (RR 0.610, 95% CI 0.401-0.929 and 0.467, 95% CI 0.337-0.647, respectively) but not cardiovascular (CV) mortality or CV events. Hospitalization rates were significantly diminished by sevelamer (RR 0.527; 95% CI 0.308-0.902). Certain phosphate lowering agents improved biochemical parameters including serum phosphate, calcium, coronary artery calcium scores, fibroblast growth factor-23, bone biomarkers, and lipid profiles. Intact parathyroid hormone and bone mineral density were not significantly changed.

CONCLUSIONS

In addition to decreasing serum phosphate levels, various beneficial effects on clinical and laboratory parameters of phosphate lowering agents might play potential roles in diminishing morbidity and mortality in CKD patients.

Changes in serum albumin and other nutritional markers when using sucroferric oxyhydroxide as phosphate binder among hemodialysis patients: a historical cohort study

Background

Elevated serum phosphorus concentrations are common among maintenance hemodialysis patients. Protein is a major source of dietary phosphate, but restriction of protein intake can result in hypoalbuminemia and protein-energy wasting. We hypothesized that sucroferric oxyhydroxide (SO), a potent phosphate binder with a low pill burden, may reduce serum phosphorus levels in hemodialysis patients with hypoalbuminemia without adversely impacting albumin levels or dietary intake of protein.

Methods

We retrospectively examined de-identified data from 79 adult, in-center hemodialysis patients with baseline hypoalbuminemia (≤ 3.5 g/dL) switched to SO as part of routine clinical care for at least 1 year. Temporal changes (3-month intervals from baseline through Q4) in phosphate binder pill burden, serum phosphorous levels, nutritional markers, and equilibrated Kt/V were analyzed. Data from a matched reference group of non-hypoalbuminemic patients (N = 79) switched to SO were also examined.

Results

SO therapy was associated with a mean reduction of 45.7 and 45.1% in daily phosphate binder pill burden, and a mean reduction of 0.4 mg/dL and 0.51 mg/dL in serum phosphorus levels for the hypoalbuminemic and non-hypoalbuminemic patients, respectively. Hypoalbuminemic patients demonstrated significant increases in mean serum albumin levels from 3.50 mg/dL at baseline to 3.69, 3.74, 3.70, and 3.69 mg/dL during Q1 through Q4, respectively (P < 0.0001), whereas serum albumin levels remained unchanged in the non-hypoalbuminemic group.

Conclusions

Both hypoalbuminemic and non-hypoalbuminemic patients switching to SO exhibited significant reductions in serum phosphorus concentrations and daily phosphate binder pill burden. Among hypoalbuminemic patients, the initiation of SO therapy was also associated with increases in serum albumin, suggesting therapy may have allowed patients to increase their dietary intake of protein.