Claes, Kathleen

PURPOSE Hematopoietic stem-cell transplantation–associated thrombotic microangiopathy (HSCT-TMA) is a serious complication with significant mortality and no approved therapy. HSCT-TMA results from endothelial injury, which activates the lectin pathway of complement. Narsoplimab (OMS721), an inhibitor of mannan-binding lectin-associated serine protease-2 (MASP-2), was evaluated for safety and efficacy in adults with HSCT-TMA. METHODS In this single-arm open-label pivotal trial ( NCT02222545 ), patients received intravenous narsoplimab once weekly for 4-8 weeks. The primary end point (response rate) required clinical improvement in two categories: (1) laboratory TMA markers (both platelet count and lactate dehydrogenase) and (2) organ function or freedom from transfusion. Patients receiving at least one dose (full analysis set [FAS]; N = 28) were analyzed. RESULTS The response rate was 61% in the FAS population. Similar responses were observed across all patient subgroups defined by baseline features, HSCT characteristics, and HSCT complications. Improvement in organ function occurred in 74% of patients in the FAS population. One-hundred-day survival after HSCT-TMA diagnosis was 68% and 94% in FAS population and responders, respectively, whereas median overall survival was 274 days in the FAS population. Narsoplimab was well tolerated, and adverse events were typical of this population, with no apparent safety signal of concern. CONCLUSION In this study, narsoplimab treatment was safe, significantly improved laboratory TMA markers, and resulted in clinical response and favorable overall survival.

Background In participants with concomitant chronic coronary disease and advanced chronic kidney disease (CKD), the effect of treatment strategies on the timing of dialysis initiation is not well characterized. Methods and Results In ISCHEMIA‐CKD (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches–Chronic Kidney Disease), 777 participants with advanced CKD and moderate or severe ischemia were randomized to either an initial invasive or conservative management strategy. Herein, we compare the proportion of randomized participants with non–dialysis‐requiring CKD at baseline (n=362) who initiated dialysis and compare the time to dialysis initiation between invasive versus conservative management arms. Using multivariable Cox regression analysis, we also sought to identify the effect of invasive versus conservative chronic coronary disease management strategies on dialysis initiation. At a median follow‐up of 23 months (25th–75th interquartile range, 14–32 months), dialysis was initiated in 18.9% of participants (36/190) in the invasive strategy and 16.9% of participants (29/172) in the conservative strategy (P= 0.22). The median time to dialysis initiation was 6.0 months (interquartile range, 3.0–16.0 months) in the invasive group and 18.2 months (interquartile range, 12.2–25.0 months) in the conservative group (P= 0.004), with no difference in procedural acute kidney injury rates between the groups (7.8% versus 5.4%; P =0.26). Baseline clinical factors associated with earlier dialysis initiation were lower baseline estimated glomerular filtration rate (hazard ratio [HR] associated with 5‐unit decrease, 2.08 [95% CI, 1.72–2.56]; P <0.001), diabetes (HR, 2.30 [95% CI, 1.28–4.13]; P =0.005), hypertension (HR, 7.97 [95% CI, 1.09–58.21]; P =0.041), and Hispanic ethnicity (HR, 2.34 [95% CI, 1.22–4.47]; P =0.010). Conclusions In participants with non–dialysis‐requiring CKD in ISCHEMIA‐CKD, randomization to an invasive chronic coronary disease management strategy (relative to a conservative chronic coronary disease management strategy) is associated with an accelerated time to initiation of maintenance dialysis for kidney failure. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01985360.