A 35 year old Chinese female with classical presentation of paroxysmal nocturnal haemoglobinuria is reported. The various aspects of these conditions are discussed.
Iptacopan (LNP023) is a novel, oral selective inhibitor of complement factor B under clinical development for paroxysmal nocturnal hemoglobinuria (PNH). In this ongoing open-label phase 2 study, PNH patients with active hemolysis were randomized to receive single-agent iptacopan twice daily at a dose of either 25 mg for 4 weeks followed by 100 mg for up to 2 years (cohort 1) or 50 mg for 4 weeks followed by 200 mg for up to 2 years (cohort 2). At the time of interim analysis, of 13 PNH patients enrolled, all 12 evaluable for efficacy achieved the primary endpoint of reduction in serum lactate dehydrogenase (LDH) levels by ≥60% by week 12 compared with baseline; mean LDH levels dropped rapidly and durably, namely by 77% and 85% at week 2 and by 86% and 86% at week 12 in cohorts 1 and 2, respectively. Most patients achieved a clinically meaningful improvement in hemoglobin (Hb) levels, and all but 1 patient remained transfusion-free up to week 12. Other markers of hemolysis, including bilirubin, reticulocytes, and haptoglobin, showed consistent improvements. No thromboembolic events were reported, and iptacopan was well tolerated, with no severe or serious adverse events reported until the data cutoff. In addition to the previously reported beneficial effect of iptacopan add-on therapy to eculizumab, this study showed that iptacopan monotherapy in treatment-naïve PNH patients resulted in normalization of hemolytic markers and rapid transfusion-free improvement of Hb levels in most patients. This trial was registered at www.clinicaltrials.gov as #NCT03896152.
Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired haemopoietic stem cell disorder arising from somatic mutation of the X-linked PIG-A gene which leads to deficiency of the glycosylphosphatidylinositol (GP1) membrane anchor proteins such as CD 59 (MIRL: membrane inhibitor of reactive lysis) and CD 55 (DAF: decay accelerating factor). Allogeneic peripheral blood stem cell transplant (PBSCT) is a curative mode of treatment in symptomatic PNH patients. Assessment of donor chimerism for PBSCT can be performed by various methods including short tandem repeat loci (STR) and variable number of tandem repeats (VNTR). Flow cytometry, which is much cheaper and faster, also can be used to assess engraftment in patients with PNH. Engrafted patients will show the presence of CD 55 and CD 59 on their red cells and white cells. We describe here the usefulness of flow cytometry in the assessment of donor chimerism following allogeneic PBSCT, in a case of PNH.
Ravulizumab (ALXN1210), a new complement C5 inhibitor, provides immediate, complete, and sustained C5 inhibition. This phase 3, open-label study assessed the noninferiority of ravulizumab to eculizumab in complement inhibitor-naive adults with paroxysmal nocturnal hemoglobinuria (PNH). Patients with lactate dehydrogenase (LDH) ≥1.5 times the upper limit of normal and at least 1 PNH symptom were randomized 1:1 to receive ravulizumab or eculizumab for 183 days (N = 246). Coprimary efficacy end points were proportion of patients remaining transfusion-free and LDH normalization. Secondary end points were percent change from baseline in LDH, change from baseline in Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score, proportion of patients with breakthrough hemolysis, stabilized hemoglobin, and change in serum free C5. Ravulizumab was noninferior to eculizumab for both coprimary and all key secondary end points (Pinf < .0001): transfusion avoidance (73.6% vs 66.1%; difference of 6.8% [95% confidence interval (CI), -4.66, 18.14]), LDH normalization (53.6% vs 49.4%; odds ratio, 1.19 [0.80, 1.77]), percent reduction in LDH (-76.8% vs -76.0%; difference [95% CI], -0.83% [-5.21, 3.56]), change in FACIT-Fatigue score (7.07 vs 6.40; difference [95% CI], 0.67 [-1.21, 2.55]), breakthrough hemolysis (4.0% vs 10.7%; difference [95% CI], -6.7% [-14.21, 0.18]), and stabilized hemoglobin (68.0% vs 64.5%; difference [95% CI], 2.9 [-8.80, 14.64]). The safety and tolerability of ravulizumab and eculizumab were similar; no meningococcal infections occurred. In conclusion, ravulizumab given every 8 weeks achieved noninferiority compared with eculizumab given every 2 weeks for all efficacy end points, with a similar safety profile. This trial was registered at www.clinicaltrials.gov as #NCT02946463.
Paroxysmal nocturnal haemoglobinuria (PNH) also known as 'Marchiafava Micheli syndrome' is a rare condition which can lead to both acute and chronic forms of renal failure through renal tubular haemosiderin deposition. A 45-year-old lady with underlying PNH, presented with complaints of fever, productive cough followed by dark coloured urine. Investigations revealed pancytopenia with a markedly raised creatinine from her baseline (from 65 mmol/L to 385 mmol/L) consistent with acute kidney injury (AKI). Renal biopsy confirmed the diagnosis of haeme nephropathy. The renal impairment improved rapidly and normalised over a period of 5 days with alkaline diuresis (AD). The patient did not require haemodialysis unlike most other reported cases of AKI secondary to haeme nephropathy in PNH. This is the second reported case of AKI in PNH which was successfully treated with AD alone emphasizing the role of AD as a promising therapeutic strategy in this condition.