Up to one-third of patients with paroxysmal nocturnal hemoglobinuria (PNH) receiving complement component 5 (C5) inhibitors may experience breakthrough hemolysis due to suboptimal inhibition of the terminal complement pathway. |
Evidence-based data for managing patients who may benefit from switching to proximal complement component 3 (C3) from terminal C5 inhibition are lacking. |
A Delphi-like process, systematic review, real-world experience in Central Europe, and expert opinion were used to develop recommendations for using complement Inhibitors in specific populations of patients with PNH. |
Five consensus recommendations for switching from C5 to C3 anti-complement agents were developed by 11 PNH experts from Central European. |
These recommendations may help physicians across Central Europe and worldwide in their treatment decisions in managing patients with PNH using complement inhibitors. |
Introduction
PNH Classification and Clinical Manifestations
Anti-Complement Treatment Options
C5 Inhibition
Study (ClinicaTrials.gov identifier) | Study design (population characteristics) | Trial duration | Patients, n; median age | Primary efficacy and safety endpoints | Key outcomes | Ref | |
---|---|---|---|---|---|---|---|
Efficacy and safety outcomes | Transfusion independence achieved | ||||||
Eculizumab (C5 inhibition) | |||||||
TRIUMPH (NCT00122330) | Double-blind, multicenter randomized trial of ECU vs. PBO in transfusion-dependent PNH pts (pts had undergone ≥ 4 transfusions in prior 12 months) | 26 weeks | 87 (n = 43 ECU and n = 44 PBO); 38 years | Coprimary efficacy endpoints: stabilization of Hb levels and no. PRBC units transfused | Efficacy: Hb stabilization: 49.0% vs. 0.0% (p < 0.001) for pts in the ECU and PBO groups, respectively; number of PRBC units transfused: 0 in the ECU group vs. 10 in the PBO group (p < 0.001) | 51.0% | Hillmen et al. 2006 [8] |
Safety: AEs, laboratory findings, ECG and vital signs | Safety: no deaths; SAEs reported in 4 ECU patients and 9 PBO pts; no SAE was deemed treatment-related | ||||||
SHEPHERD (NCT00130000) | Open-label, single-arm (PNH pts with minimal transfusion requirements and with evidence of TCP) | 52 weeks | 97 (ITT); 41 years | Efficacy: hemolysis assessed by LDH AUC | Efficacy: hemolysis reduction: 87.0% of patients (p < 0.001) | 51.0% | Brodsky et al. 2008 [30] |
Safety: AEs, laboratory findings, ECG and vital signs | Safety: SAEs in 44 pts, 7 were possibly drug-related, including pyrexia (2), headache (1), abdominal distension (1), viral infection (1), anxiety (1), and renal impairment (1). The majority (96.4%) of AEs were mild to moderate in intensity. TEAEs in 2 pts. Vital signs, physical examination, and ECG data did not reveal temporally associated AEs. No clinically significant laboratory abnormalities were seen | ||||||
Ravulizumab (C5 inhibition) | |||||||
301 (NCT02946463) | Active-controlled, multicenter, randomized open-label study (complement inhibitor-naïve pts) | 26 weeks | 246 (n = 125 RAV and n = 121 ECU); 45.5 years | Coprimary efficacy endpoints: transfusion avoidance and hemolysis assessed by LDH normalization | Efficacy: transfusion avoidance achieved for 73.6% and 66.1% of pts receiving RAV and ECU, respectively, with a between-group difference of 6.8% (95% CI, − 4.7, 18.1; Pinf < 0.0001); The adjusted prevalence of LDH normalization was 53.6% for the RAV group and 49.4% for the ECU group | NR | Lee et al. 2019 [32] |
Safety: AEs | Safety: headache occurred in 36.0% of RAV and 33.1% of ECU pts. SAEs in 11 RAV and 9 ECU pts. No deaths or cases of meningitis were reported in either treatment group. SAEs in 2.1% RAV and 1.0% ECU pts | ||||||
302 (NCT03056040) | Active-controlled, multicenter, randomized, open-label study (complement inhibitor-experienced pts stable for ≥ 6 months on ECU) | 26 weeks | 191 (n = 96 RAV and n = 95 ECU); mean age 35.5 years | Efficacy: percentage change in hemolysis assessed by LDH from baseline to Day 183 | Efficacy: percentage change in LDH: difference, 9.2% (95% CI, 20.4 to 18.8; p = 0.058 for superiority), showing RAV was non-inferior to ECU | NR | Kulasekararaj et al. 2019 [33] |
Safety: AEs | Safety: headache occurred in 26.8% of RAV and 17.3% of ECU pts. SAEs in 4 RAV and 8 ECU pts. No cases of meningitis were reported in either treatment group. SAE—pyrexia in 1 RAV and 2 ECU pts | ||||||
Pegcetacoplan (C3 inhibition) | |||||||
PEGASUS (NCT03500549) | Active-controlled, multicenter, randomized, open-label study (complement inhibitor-experienced pts stable for ≥ 3 months on ECU with Hb < 10.5 g/dL at screening) | 16 weeks | 80 (n = 41 PGC and n = 39 ECU); mean age 48.8 years | Efficacy: percentage change in Hb level from baseline to Week 16 during the randomized, controlled period | Efficacy: improvement in adjusted means of 3.8 g/dL of Hb at week 16 (p < 0.001), showing superiority of PGC to ECU | 85.0% vs. 15.0% (p < 0.001) for PGC and ECU-treated pts, respectively | Hillmen et al. 2021 [37] |
Safety: AEs, TEs, laboratory and ECG variables | Safety: AEs occurred in 88.0% PGC and 87.0% ECU patients. Most common AEs: injection-site reactions (37.0% vs. 3.0%), diarrhea (22.0% vs. 3.0%), BTH (10.0% vs. 23.0%), headache (7.0% vs. 23.0%), and fatigue (5.0% vs. 15.0%). SAEs occurred in 17.0% of PGC and 15.0% of ECU patients. Infections were reported in 29.0% PGC and 26.0% ECU pts; meningitis was not reported in either treatment group. No TEs in either group. BTH in 10.0% PGC and 23.0% ECU pts | ||||||
48 weeks | 77 (n = 38 PGC-to-PGC and n = 39 ECU to PGC) | Efficacy and safety endpoints were as per the 16-week study (see above) | Efficacy: Patients in the PGC-to-PGC group maintained a high mean [Hb] between 16 weeks (11·5 g/dL) and 48 weeks (11·3 g/dL; p = 0·140). Patients in the ECU-to-PGC group had significantly greater mean [Hb] at 48 weeks (11·6 g/dL) versus 16 weeks (8·6 g/dL; p < 0·0001). Clinically meaningful improvements in FACIT-Fatigue scores: mean change from baseline for all patients receiving PGC of 9·9 points (SD 9·6), for patients in the PGC-to-PGC group mean 10.1 points (9.1), and for patients in the ECU-to-PGC group mean 9.6 points (10·3) | 73.0% vs. 72.0% in the PGC-to-PGC and ECU-to-PGC groups, respectively | De Latour et al. 2022 [38] | ||
Safety: 16.0% of patients discontinued treatment (7.0% through to week 16 due to BTH, and 13.0% due to severe treatment-emergent adverse events) and 18 patients (n = 8 PGC-to-PGC, n = 10 ECU-to-PGC) had at least one serious TEAE during the OL period, four of which were considered to be related to PGC treatment. The most common TEAEs (in ≥ 10.0% patients) among both PGC-treated groups during the OL period were injection site reactions (26.0%), hemolysis (19.0%), nasopharyngitis (16.0%), and diarrhoea (13.0%). No treatment-related deaths occurred throughout the study | |||||||
PRINCE (NCT04085601) | Multicenter, randomized, open-label trial of PGC vs. SOC (excluding complement-inhibitors) in complement-inhibitor-naïve PNH pts | 26 weeks | 53 (n = 35 PGC and n = 18 SOC); mean age 48.8 years | Coprimary efficacy endpoints: Hb stabilization (avoidance of a > 1.0 g/dL decrease in Hb levels in the absence of transfusions) and change from baseline (CFB) in LDH level from baseline to Week 26 | Efficacy: PGC was superior to SOC in both co-primary endpoints. Hb stabilization was achieved by 85.7% (n = 30) of PGC-treated patients and 0.0% of SOC patients through Week 26 (p < 0.0001). PGC-treated patients demonstrated superior reductions in mean LDH levels from baseline to Week 26 compared to SOC patients (least-squares mean CFB: PGC, −1870.5 U/L; SOC, −400.1 U/L; p < 0.0001), and mean LDH levels in PGC-treated patients at Week 26 (mean level: 204.6 U/L) were below the ULN for LDH (226.0 U/L) | NR | Wong et al. 2021 [39] |
Safety (secondary endpoint): incidence of AEs | Safety: serious AEs were reported by 8.7% (n = 4) of PGC-treated patients and 16.7% (n = 3) of SOC patients through Week 26. Two deaths (PGC, 2.9%, n = 1, septic shock related to medullary aplasia; SOC, 5.6%, n = 1, respiratory failure), both deemed unrelated to treatment, occurred. No events of meningitis or thrombosis were reported in either group. The most common AEs reported during the study were injection site reaction (PGC, 30.4%, n = 14; SOC, 0.0%), hypokalemia (PGC, 13.0%, n = 6; SOC, 11.1%, n = 2), and fever (PGC, 8.7%, n = 4; SOC, 0.0%). There were no AEs leading to discontinuation of PGC |
C5 inhibition | C3 inhibition | |
---|---|---|
Advantage(s) | ∙ Several years of real-world data/experience ∙ Clinically effective in a large proportion of patients ∙ Very well tolerated, few side effects | ∙ aSuperior efficacy compared to C5 eculizumab in improving Hb and improvements in clinical and hematologic outcomes in patients with PNH (PEGASUS trial) ∙ Current C3 inhibitor available as SQ treatment; option for self-administration ∙ Well tolerated, few side effects |
Disadvantage(s) | ∙ Not effective in all patients ∙ Accentuates C3-related extravascular hemolysis ∙ Current C5 inhibitors available as IV treatments ∙ Neisseria meningitidis vaccination required ∙ High direct cost ∙ High indirect cost (e.g., breakthrough hemolysis and loss of work/school productivity due to treatment regimen) | ∙ Only one approved treatment is available in the EU ∙ Twice weekly applications ∙ Limited clinical and real-world data/experience ∙ Neisseria meningitidis, Streptococcus pneumoniae and Hemophilus influenzae vaccination required ∙ High direct cost ∙ Indirect cost unknown |
C3 Inhibition
Novel Therapies in Late-Stage Clinical Development
Methods
Procedures
Expert Panel
Literature Review and Expert Recommendations
Results
Use of Complement Inhibitors in Classic PNH (Hemolytic Anemia)
Use of Complement Inhibitors in PNH in the Setting of Bone Marrow Failure
Use of Complement Inhibitors in Subclinical PNH
Switching from Eculizumab to Ravulizumab
Other Considerations
Expert Panel Recommendations for Switching from C5 to C3 Inhibition in Special Patient Populations with PNH Relevant to Real-World Practice
Special patient populations with PNH | Proportion of patients with PNH (%) | Expert recommendation(s) | Consensus (n = 11) n (%) |
---|---|---|---|
1. Patients with BT IVH during regular C5 inhibitor treatment for ≥ 3 months | Occurs in 11.0–27.0% patients with PNH on C5 inhibitor [9] | ∙ Consider a clinical trial if available ∙ For recurrent PK BTHa (typically 10.0–15.0% of patients) [87], consider a clinical trial; alternatively, increase the dose of ECU to 1200 mg or decrease dosing interval to 10 daysc [88] ∙ Alternatively switch to RAVc ∙ For sporadic PD BTHb, do not switch therapy [87]. Treat the triggering condition | 11 (100) |
2. Patients with clinically relevant C3-mediated EVH on C5 inhibitor treatment for ≥ 3 months | 100.0% of patients treated with ECU show some degree of EVH [11] | ∙ Consider a clinical trial if available | 11 (100) |
3. Patients with unprovoked TE while on C5 inhibitor for ≥ 3 months (a rare event) | The rate of both venous and arterial TE during ECU treatment is 1.1 events per 100 PY [31] | ∙ Consider a clinical trial if available ∙ Consider secondary thrombo-PPX with anticoagulants unless contraindicated [91] ∙ Alternatively, switch to PGCd and treat with anticoagulants; strongly consider switching if the TE event occurs on thrombo-PPX. Note: all patients should be examined for additional thrombophilic markers | 11 (100) |
4. Patients with severe fatigue and impaired QoL despite ≥ 3 months of C5 inhibitor treatmente | Mean change in FACIT-F score from BSL to Week 16 was 10.3 vs. −1.2 in the PGC and ECU treatment groups, respectively [84] | ∙ Consider a clinical trial if available | 9 (72) |
5. Patients with PNH and rare C5 polymorphisms (mostly of Japanese ethnicity) non-responsive to C5 inhibition | ∙ Consider a clinical trial if available | 11 (100) |