Efficacy and safety of daprodustat in Japanese peritoneal dialysis patients.

Daprodustat is a hypoxia-inducible factor-prolyl hydroxylase inhibitor for the treatment of anemia of chronic kidney disease. This phase 3 study evaluated the efficacy and safety of daprodustat in an uncontrolled cohort of 56 Japanese peritoneal dialysis patients with anemia over 52 weeks. Subjects received daprodustat 4 mg orally once daily for 4 weeks and the dose was subsequently adjusted every 4 weeks. Mean baseline hemoglobin was 10.9 g/dL (95% CI 10.59, 11.12). Mean hemoglobin reached the target range (11.0-13.0 g/dL) at week 12 and was maintained until week 52. Mean hemoglobin during weeks 40-52 was 12.1 g/dL (95% CI 12.0, 12.2). The most frequent adverse events included nasopharyngitis (29%), catheter-site infection (18%), peritonitis (16%), diarrhea (14%), and nausea (11%). No deaths were reported. Once-daily oral daprodustat treatment was generally well tolerated and mean hemoglobin was achieved and maintained within the target range in Japanese peritoneal dialysis participants.

Daprodustat Compared with Epoetin Beta Pegol for Anemia in Japanese Patients Not on Dialysis: A 52-Week Randomized Open-Label Phase 3 Trial.

BACKGROUND: Daprodustat is an oral agent that stimulates erythropoiesis by inhibiting the prolyl hydroxylases which mark hypoxia-inducible factor for degradation through hydroxylation. Its safety and efficacy (noninferiority) were assessed in this 52-week, open-label study. METHODS: Japanese patients not on dialysis (ND) (N = 299) with anemia of CKD (stages G3, G4, and G5) with iron parameters of ferritin >100 ng/mL or transferrin saturation >20% at screening were randomized to daprodustat or epoetin beta pegol (continuous erythropoietin receptor activator [CERA], also known as methoxy polyethylene glycol-epoetin beta). After initiation of the study, the daprodustat starting dose for erythropoiesis-stimulating agent (ESA)-naïve participants was revised, and daprodustat was started at 2 or 4 mg once daily depending on baseline hemoglobin. ESA users switched to daprodustat 4 mg once daily. CERA was started at 25 µg every 2 weeks for ESA-naïve patients and 25-250 µg every 4 weeks for ESA users based on previous ESA dose. In both treatment groups, dose was adjusted every 4 weeks based on hemoglobin level and changed according to a prespecified algorithm. The primary endpoint was mean hemoglobin level during weeks 40-52 in the intention-to-treat (ITT) population. ESA-naïve patients who entered before the protocol amendment revising the daprodustat starting dose were excluded from the ITT population. RESULTS: Mean hemoglobin levels during weeks 40-52 were 12.0 g/dL in the daprodustat group (n = 108; 95% confidence interval [CI], 11.8-12.1) and 11.9 g/dL for CERA (n = 109; 95% CI 11.7-12.0); the difference between the groups was 0.1 g/dL (95% CI -0.1 to 0.3 g/dL). The lower limit of the 95% CI of the difference was greater than the prespecified margin of -1.0 g/dL. The mean hemoglobin level was within the target range (11.0-13.0 g/dL) during weeks 40-52 for 92% of participants in both groups. There was no meaningful difference in the frequencies of adverse events. CONCLUSIONS: Oral daprodustat was noninferior to CERA in achieving and maintaining target hemoglobin levels in Japanese ND patients. Daprodustat was well tolerated, with no new safety concerns identified.

RICE SALT SENSITIVE3 forms a ternary complex with JAZ and class-C bHLH factors and regulates jasmonate-induced gene expression and root cell elongation.

Plasticity of root growth in response to environmental cues and stresses is a fundamental characteristic of land plants. However, the molecular basis underlying the regulation of root growth under stressful conditions is poorly understood. Here, we report that a rice nuclear factor, RICE SALT SENSITIVE3 (RSS3), regulates root cell elongation during adaptation to salinity. Loss of function of RSS3 only moderately inhibits cell elongation under normal conditions, but it provokes spontaneous root cell swelling, accompanied by severe root growth inhibition, under saline conditions. RSS3 is preferentially expressed in the root tip and forms a ternary complex with class-C basic helix-loop-helix (bHLH) transcription factors and JASMONATE ZIM-DOMAIN proteins, the latter of which are the key regulators of jasmonate (JA) signaling. The mutated protein arising from the rss3 allele fails to interact with bHLH factors, and the expression of a significant portion of JA-responsive genes is upregulated in rss3. These results, together with the known roles of JAs in root growth regulation, suggest that RSS3 modulates the expression of JA-responsive genes and plays a crucial role in a mechanism that sustains root cell elongation at appropriate rates under stressful conditions.