Open-label, phase 2 study of roxadustat for treatment of anemia in patients receiving chemotherapy for non-myeloid malignancies

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Background: Anemia is prevalent in patients (pts) receiving myelosuppressive chemotherapy (> 60%) and exacerbated by repeated treatment cycles due to cytotoxic agent accumulation. Chemotherapy-induced anemia (CIA) management options are suboptimal. We evaluated the efficacy and safety of roxadustat in pts with anemia receiving myelosuppressive chemotherapy. Methods: This open-label, single-arm, proof-of-concept Phase 2 study included pts with mostly advanced, non-myeloid malignancies and CIA (hemoglobin [Hb] ≤10 g/dL) who had not received red blood cell (RBC) transfusion or erythropoietin-stimulating agents within 4 weeks of enrollment. Patients were treated with oral roxadustat for ≤16 weeks. The primary efficacy endpoint was maximum mean change in Hb within 16 weeks of baseline without RBC transfusion in pts who had received ≥1 dose of roxadustat and who had a baseline and ≥1 post-dose Hb assessment. Hb response and safety data were preliminarily assessed in pts receiving a starting dose of 2.0 mg/kg thrice weekly (TIW) for 4 weeks: doses of 100, 150, and 200 mg were given to pts weighing < 70, 70–100, and > 100 kg, respectively. Following a review of data from these pts, dose was increased to 2.5 mg/kg—150, 200, and 250 mg TIW to pts weighing < 70, 70–100, and > 100 kg, respectively—and adjusted every 4 weeks from Week 5 based on Hb response. Results: Patients were assigned to 2.0 mg/kg (n = 31) and 2.5 mg/kg (n = 61) starting doses, and 89 were assessed for efficacy. The maximum mean Hb change from baseline without RBC transfusion was 2.47±1.51 g/dL and 2.52±1.54 g/dL in the 2.0 mg/kg and 2.5 mg/kg cohorts, respectively. Hb increased by ≥1.5 g/dL in 73% of pts and ≥2.0 g/dL in 61% of pts. Median time to ≥2.0 g/dL Hb increase was 71.0 days. Both cohorts had higher proportions of pts with a Hb increase of ≥1, ≥1.5, or ≥2 g/dL at Week 16 compared with baseline. Median time to ≥1 and ≥2 g/dL Hb increase was shorter in pts who started on 2.5 mg/kg compared with 2.0 mg/kg doses (≥1 g/dL: 30 vs 44; ≥2 g/dL 57 vs 105, respectively). Fewer pts required an RBC transfusion (Week 5 to end of treatment) when starting on 2.5 mg/kg compared with 2.0 mg/kg doses (10.2% vs 20.0%). Subgroup analyses based on major tumor and baseline chemotherapy types demonstrated efficacy of roxadustat at both starting doses. The overall safety profile observed was consistent with the patient population under study. Overall, 92% of pts experienced an adverse event (AE). Most AEs were consistent with the underlying malignancies and chemotherapy regimens used. The incidence of deep vein thrombosis was 15.2% (n = 14) and pulmonary embolism was 9.8% (n = 9). There were 17 deaths (18.5%) during the study; none were attributed to roxadustat, and most were associated with disease progression. Conclusions: Roxadustat increased Hb in CIA regardless of tumor type and chemotherapy regimen. These data support additional clinical study. Clinical trial information: NCT04076943.

The public health significance of latrines discharging to groundwater used for drinking

Faecal contamination of groundwater from pit latrines is widely perceived as a major threat to the safety of drinking water for several billion people in rural and peri-urban areas worldwide. On the floodplains of the Ganges-Brahmaputra-Meghna delta in Bangladesh, we constructed latrines and monitored piezometer nests monthly for two years. We detected faecal coliforms (FC) in 3.3-23.3% of samples at four sites. We differentiate a near-field, characterised by high concentrations and frequent, persistent and contiguous contamination in all directions, and a far-field characterised by rare, impersistent, discontinuous low-level detections in variable directions. Far-field FC concentrations at four sites exceeded 0 and 10 cfu/100 ml in 2.4-9.6% and 0.2-2.3% of sampling events respectively. The lesser contamination of in-situ groundwater compared to water at the point-of-collection from domestic wells, which itself is less contaminated than at the point-of-consumption, demonstrates the importance of recontamination in the well-pump system. We present a conceptual model comprising four sub-pathways: the latrine-aquifer interface (near-field); groundwater flowing from latrine to well (far-field); the well-pump system; and post-collection handling and storage. Applying a hypothetical dose-response model suggests that 1-2% of the diarrhoeal disease burden from drinking water is derived from the aquifer, 29% from the well-pump system, and 70% from post-collection handling. The important implications are (i) that leakage from pit latrines is a minor contributor to faecal contamination of drinking water in alluvial-deltaic terrains; (ii) fears of increased groundwater pollution should not constrain expanding latrine coverage, and (iii) that more attention should be given to reducing contamination around the well-head.

Estimation of biologic gasification potential of arsenic from contaminated natural soil by enumeration of arsenic methylating bacteria

Volatile arsenic species are found in gases released from natural environments as a result of natural ambient-temperature biomethylation of arsenic conducted by yeast, fungi, and bacteria. This process is part of arsenic transport in the arsenic geocycle. It is important to determine the flux of gasified arsenic released by microorganisms to determine the quantitative flux of arsenic cycle clearly and also to understand the effect of microorganisms on the transport and distribution of arsenic in the contaminated environment. In this study, biologic gasification potential of natural soil was determined by enumeration of arsenic methylating bacteria (AsMB). Enumeration of AsMB was conducted for 10 contaminated sites in Bangladesh where AsMB concentration varies from 0.2 x 10(4) to 7.8 x 10(4) most probable number (MPN) kg(-1) dry soil. The specific gasification rate of arsenic by microorganisms was estimated as 1.8 x 10(-7) microg As MPN(-1) d(-1) by incubation of soil in a laboratory soil column setup. Natural biologic gasification potential of arsenic was then calculated by multiplying the specific rate by the number of AsMB in different soils. The attempt of this study is a fundamental step in determining the volatilization flux of arsenic from land surface contributed by microorganisms.

Taxanes from in vitro cultures of the Himalayan yew Taxus wallichiana

Culture conditions have been standardized for initiation of callus cultures of Himalayan yew (Taxus wallichiana) using young stem and needle explants from mature trees. Cultures were established on a modified Murashige and Skoog's medium supplemented with various levels of auxins (2.4-D, NAA) and cytokinin (kinetin). A medium containing 0.25 mg/l kinetin and 5.0 mg/l 2.4-D was optimal for stem callus growth whereas the presence of 0.25 mg/l kinetin along with 3.0 mg/l NAA in the medium supported optimal needle callus growth. Growth of stem callus was faster than needle callus growth. Supplementation of ascorbic acid (30 mg/l) amongst various anti-phenolic agents tested significantly reduced browning of initiated callus. Two taxanes (2-deacetoxytaxinine 1 and 2'-deacetoxyaustrospicatine) known to occur in stem bark, have also been isolated from undifferentiated tissue of T. wallichiana in equal or higher yields, for the first time.