Exacerbation of Diabetic Retinopathy following Hypoxia-Inducible Factor-Prolyl Hydroxylase Inhibitor Administration: A Case Report

Introduction

Hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) inhibitors, used in the treatment of renal anemia, hold the potential to increase the production of vascular endothelial growth factors. Therefore, HIF-PH inhibitors may exacerbate retinal hemorrhage in diseases such as diabetic retinopathy. Here, we present a case involving the administration of an HIF-PH inhibitor, resulting in the exacerbation of retinal hemorrhage in a patient with diabetic retinopathy.

Case Presentation

A 32-year-old man with diabetes mellitus and renal anemia caused by diabetic nephropathy was referred to our department for ophthalmic examination, revealing diabetic retinopathy with scattered retinal hemorrhages, exudates, and diabetic maculopathy in both eyes. Darbepoetin alfa was initially administered and switched to the HIF-PH inhibitor roxadustat on day 74. By day 88, fresh retinal hemorrhage was observed in the right eye. On day 132, the retinal hemorrhage had further worsened, with new preretinal hemorrhage in both eyes. Roxadustat was discontinued, replaced with darbepoetin alfa, resulting in retinal hemorrhage improvement by day 181 (49 days post-roxadustat cessation). On day 201, fundus hemorrhage further improved, optical coherence tomography showed no macular edema or subretinal fluid, and the retina was thinning. Fluorescein angiography showed neovascular vessels, active fluorescein leakage, and extensive avascular areas in both eyes, prompting pan-retinal photocoagulation. Visual acuity remained stable throughout treatment.

Conclusion

Patients with advanced diabetic retinopathy taking HIF-PH inhibitors should be aware of retinal hemorrhage exacerbations. If observed, the treatment plan, including discontinuation of the HIF-PH inhibitor or switching to another agent, should be discussed with a diabetologist, nephrologist, and ophthalmologist.

Resistance to Erythropoiesis-Stimulating Agents among Patients on Hemodialysis Is Typically Transient

INTRODUCTION

This study examines factors associated with erythropoiesis-stimulating agent (ESA) hyporesponsiveness, the duration of ESA hyporesponsiveness, the frequency of new episodes, and variation across countries.

METHODS

We used international Dialysis Outcomes and Practice Patterns Study data from 2015 to 2018 (N = 26,656) to investigate changes in ESA Resistance Index (ERI), calculated as epoetin dose divided by [hemoglobin × body weight] in patients on hemodialysis. We illustrated the proportion of patients who moved to other ERI quintiles over 12 months, and we studied the incidence and duration of ESA resistance. We examined case-mix factors associated with quintiles of ERI.

RESULTS

Most patients migrated out of their original ERI quintile within 4 months. Only 22% of patients in the top quintile of ERI at baseline (4.4% of all patients) remained in the top quintile during all 12 months of follow-up. A total of 42% of patients manifested an upper-quintile ERI during at least 1 month. Median duration of a new episode of ESA resistance was 2 months. Catheter hemoaccess, elevated C-reactive protein, lower transferrin saturation, lower serum albumin concentration, and recent hospitalization occurred more frequently among patients in the highest ERI quintile at baseline. ERI values were highest in the USA, Italy, and Mideastern nations and lowest in Russia and Japan.

DISCUSSION/CONCLUSION

It is a misconception to envision a sizable, fixed segment of the population with permanent resistance to ESA - resistance fluctuates frequently. The implications of these findings for prescription of ESAs and of hypoxia-inducible factor-prolyl hydroxylase inhibitors are discussed.

The Effect of Roxadustat on Transfusion-Dependent Myelodysplastic Syndrome Complicated by Chronic Kidney Disease

Haematopoietic insufficiency is the treatment target of lower-risk myelodysplastic syndrome (MDS). Although erythropoiesis-stimulating agents (ESAs) are generally effective for treating anaemia, resistance can develop. Hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) improves renal anaemia by promoting endogenous erythropoietin production and normalizing iron metabolism. HIF-PH inhibitors could be used to treat MDS, but their efficacy and safety have not been studied. A 78-year-old female patient with essential thrombocythemia gradually developed anaemia and was diagnosed with therapy-related MDS 4 years later. The anaemia temporarily improved with ESAs, but the patient became transfusion dependent. At the same time, anaemia and chronic renal failure due to nephrosclerosis progressed, and the patient was diagnosed with MDS with renal anaemia. After switching from ESAs to roxadustat, an HIF-PH inhibitor, anaemia improved, and the patient was no longer transfusion dependent. No progression of the underlying disease or any adverse events was observed 4 months after initiating roxadustat.

A Phase 3 Study of Enarodustat (JTZ-951) in Japanese Hemodialysis Patients for Treatment of Anemia in Chronic Kidney Disease: SYMPHONY HD Study

INTRODUCTION

Enarodustat (JTZ-951) is a new oral hypoxia-inducible factor-prolyl hydroxylase inhibitor for the treatment of anemia in chronic kidney disease (CKD). We conducted a phase 3 study to compare the efficacy and safety of enarodustat with darbepoetin alfa (DA) in Japanese anemic patients with CKD receiving maintenance hemodialysis.

METHODS

Subjects receiving maintenance hemodialysis were randomly assigned at a 1:1 ratio to receive oral enarodustat once daily or intravenous DA every week for 24 weeks with dose adjustment every 4 weeks to maintain hemoglobin (Hb) within a target range (≥10.0 to <12.0 g/dL). The primary efficacy endpoint was difference in mean Hb level between arms during the evaluation period defined as weeks 20-24 (noninferiority margin: -1.0 g/dL). Intravenous iron preparations were prohibited during the screening period and during weeks 0-4.

RESULTS

The mean Hb level of each arm during the evaluation period was 10.73 g/dL (95% confidence interval [CI]: 10.56, 10.91) in the enarodustat arm and 10.85 g/dL (95% CI: 10.72, 10.98) in the DA arm. The difference in the mean Hb level between arms was -0.12 g/dL (95% CI: -0.33, 0.10), confirming the noninferiority of enarodustat to DA. The mean Hb level of each arm was maintained within the target range during the treatment period. Increased total iron-binding capacity and serum iron and decreased hepcidin were observed through week 4 in the enarodustat arm albeit after switching from erythropoiesis-stimulating agents. No apparent safety concerns of enarodustat were observed compared with DA.

DISCUSSION/CONCLUSION

Enarodustat was noninferior to DA for the treatment of anemia in CKD patients receiving maintenance hemodialysis and was generally well tolerated over 24 weeks.