Paroxysmal Nocturnal Hemoglobinuria
New paroxysmal nocturnal hemoglobinuria research, summarized each month in plain language.
2026 so far: In the months covered (January 2026 to September 2026), complement inhibitors often controlled hemolysis, but anemia and fatigue commonly continued. Real-world studies highlighted access burdens, switch-related hemolysis, and growing evidence for proximal and oral options. Read the 2026 review
We also cover clinical trials.
Yearly update
2026 so far
- Oral and proximal options. Attention moved from lab hemolysis control to ongoing anemia.
- C5 inhibitors in practice. Routine-care data added stability, access burdens, and safety context.
- Pegcetacoplan and crovalimab. More pooled and indirect comparisons, limited direct head-to-head clarity.
- Anemia, fatigue, daily life. Patient-reported burden became more central than single lab targets.
- Clots and switching. Real-world practice variation and switch-period vulnerability became clearer.
New
September 2026
- Treatment access. Complement-blocking drugs were still uncommon in some real-world care.
- Blood thinner report. Low-dose apixaban was reported without clots or bleeding in a small group.
- Ongoing fatigue. Severe fatigue was reported even while taking eculizumab.
August 2026
- Anemia and fatigue. Lower hemoglobin linked to worse daily life, even on treatment.
- Hemolysis labs. One hemolysis lab cutoff did not match quality-of-life scores.
- Treatment comparisons. An indirect comparison estimated fewer transfusions with pegcetacoplan.
- Time to diagnosis. Claims data suggested long delays from symptoms to diagnosis.
July 2026
- Blood thinner practice. Centers differed on using blood thinners to prevent clots.
- Treatment switching. Hemolysis sometimes occurred within 14 days after switching inhibitors.
- AI record screening. An AI screen flagged people and found new PNH diagnoses.
June 2026
- Complement blocker effects. Several complement blockers again improved hemolysis and anemia.
- Crovalimab comparison. Crovalimab looked similar to eculizumab on key blood measures.
- Time spent on dosing. Each treatment day often took hours to complete.
- Blood clot patterns. Blood clots still occurred, especially with higher disease activity.
May 2026
- Haplo transplant survival. In one center’s report, haploidentical stem cell transplant was linked to high engraftment and strong longer-term survival in AA-PNH.
- Early transplant risks. Infections and graft-versus-host disease were common during the transplant period in this experience.
- Flow test can miss PNH. Standard flow cytometry testing can be negative in rare PNH cases, especially early on.
- Multiple immune-escape clones. In aplastic anemia, some patients had more than one immune-escape clone, which may add complexity to lab patterns.
April 2026
- Starting C5 inhibitors. Real-world reports described delays in starting C5 inhibitors and added burdens such as repeated visits and long travel.
- Immune cell changes. On C5 inhibitors, some immune cell measures improved while others showed little or no change.
- Crovalimab results so far. A pooled analysis of crovalimab studies reported hemolysis control but also frequent side effects and differences between studies.
- PNH clones in aplastic anemia. In aplastic anemia, small PNH clones were sometimes seen to expand over time.
March 2026
- Anemia can continue. Anemia may persist even when a C5 blocker keeps LDH (a hemolysis marker) controlled.
- Earlier complement targets. Complement blockers that act earlier in the pathway are being studied for ongoing anemia, but added benefit is not yet proven.
- Ravulizumab in registries. Registry follow-up reports described near-normal LDH and fewer transfusions during ravulizumab treatment.
February 2026
- Hemolysis improves, symptoms can persist. Complement inhibitors continued to link with better blood markers of hemolysis, but many people on long-term C5 blockers still reported anemia and fatigue.
- Switching and add-on evidence is limited. A small switch series reported higher hemoglobin after moving to iptacopan, and modeling work on danicopan supported strong pathway suppression in available datasets.
- PNH can overlap with aplastic anemia. Recent case reports described classic PNH episodes (such as dark urine and severe hemolysis) and highlighted overlap with aplastic anemia, which can affect how the condition is classified.
January 2026
- Switching to ravulizumab. Routine-care reports described stable control of hemolysis after switching from eculizumab to ravulizumab, and one cohort reported lower transfusion needs after the switch.
- Ravulizumab in pregnancy. In a retrospective series, ravulizumab-treated pregnancies all ended in live births, and cord blood testing showed ravulizumab can cross the placenta.
- Tracking fatigue and drug levels. A fatigue questionnaire showed reliable performance and could detect meaningful within-person change, and a separate model estimated eculizumab drug levels from blood samples in many scenarios.
- Early clot-risk biology signals. A small translational study linked MUC4 gene changes to higher reported clot risk, while lab and computer-based work suggested new or repurposed drug ideas that are still unproven in people.
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