Positives

• In the PEGASUS trial, 71% of pegcetacoplan-treated PNH patients normalized LDH at week 16 versus 15% on eculizumab, and most reached normal hemoglobin without transfusion NEJM.
  
  
• Patients reported clinically meaningful and durable improvements in fatigue scores through 48 weeks, including those who had previously had only suboptimal results on C5 inhibition PMC.
  
  

Negatives

• Injection-site reactions occurred in roughly 37% of pegcetacoplan-treated patients versus about 3% on eculizumab, with redness, swelling, induration, itching, and pain reported most often PNH News.
  
  
• Patients also commonly reported fever, upper-respiratory infections, cough, and nausea, reflecting the broader immunomodulatory footprint of C3 inhibition FDA.
  
  

Hurdles & Side Effects

• Twice-weekly subcutaneous infusions running 30 to 60 minutes each, plus mandatory pre-treatment meningococcal/pneumococcal/Hib vaccinations, make pegcetacoplan a heavy commitment for any off-label Long COVID trial MedlinePlus.
  
  
• Empaveli is FDA-approved only for PNH and certain glomerulopathies, so a Long COVID patient with microvascular complement activation has no insurance pathway and faces six-figure annual list pricing NCBI Bookshelf.