APPLY-PNH: Anti-C5 Treatment Experienced Patients With PNH

The efficacy of FABHALTA administered orally in adults with PNH was evaluated in a multi-center, open-label, 24-week, active comparator-controlled trial (APPLY-PNH; NCT04558918).

The study enrolled adults with PNH and residual anemia (hemoglobin < 10 g/dL) despite previous treatment with a stable regimen of anti-C5 treatment (either eculizumab or ravulizumab) for at least 6 months prior to randomization. 

Ninety-seven patients were randomized in an 8:5 ratio to switch to FABHALTA 200 mg orally twice daily (n = 62) or to continue anti-C5 treatment (US-approved and non-US-approved eculizumab product n = 23 or US-approved and non-US-approved ravulizumab product n = 12) throughout the duration of the 24-week randomized controlled period. Randomization was stratified based on prior anti-C5 treatment and transfusion history within the last 6 months. Following completion of the 24-week randomized controlled period, all patients were eligible to enroll in a 24-week treatment extension period and receive FABHALTA monotherapy. Subsequently, patients were eligible to enter a separate long-term extension study.

Patients were required to be vaccinated against Neisseria meningitidis and recommended to be vaccinated against Streptococcus pneumoniae and Haemophilus influenzae type b. If the patient had not been previously vaccinated or if a booster was required, vaccination was administered at least 2 weeks prior to the first dose of study medication. If FABHALTA treatment was initiated earlier than 2 weeks after vaccination, antibacterial drug prophylaxis was administered.

Demographics and baseline disease characteristics were generally well balanced between treatment groups (see Table 3). The mean time on prior anti-C5 treatment was 3.8 and 4.2 years for the FABHALTA and anti-C5 groups, respectively. The baseline mean PNH RBC clone size (Type II + III) was 64.6% for the FABHALTA group and 57.4% for the anti-C5 group.

Efficacy was established based on demonstration of superiority of switching to FABHALTA compared to continuing on anti-C5 therapy in achieving hematological response after 24 weeks of treatment, without a need for transfusion, by assessing the proportion of patients demonstrating: 1) sustained increase of ≥ 2 g/dL in hemoglobin levels from baseline (hemoglobin improvement) and 2) sustained hemoglobin levels ≥ 12 g/dL. Additional efficacy endpoints included transfusion avoidance, change from baseline in hemoglobin levels and change from baseline in absolute reticulocyte counts.

The efficacy results from the APPLY-PNH trial are provided in Table 4.

APPOINT-PNH: Complement Inhibitor Naïve Patients with PNH

Study APPOINT-PNH (NCT04820530) is a single arm study in adults with PNH who were not previously treated with a complement inhibitor. This study enrolled a total of 40 adults with PNH (RBC clone size ≥ 10%), hemoglobin < 10 g/dL, and LDH > 1.5 times upper limit of normal (ULN). All 40 patients received FABHALTA 200 mg orally twice daily during the 24-week open-label core treatment period. Subsequently, patients were eligible to enroll in a 24-week treatment extension period and continue to receive FABHALTA, followed by a separate long-term extension study.

The mean age of the patients was 42.1 years and 42.5% were female. The mean disease duration was 4.7 years. The baseline mean PNH RBC clone size (Type II + III) was 42.7%, mean baseline hemoglobin was 8.2 g/dL, and approximately 70% of patients required a transfusion in the 6 months prior to treatment. The baseline mean LDH level was 1,699 U/L and the mean absolute reticulocyte count was 154 X 109/L. About 13% of patients had a history of MAVEs. No patients discontinued from the core treatment period of the study.

In total, 77.5% (95% CI: 61.5%, 89.2%) of patients (31/40) achieved a sustained increase (between Day 126 and Day 168) in hemoglobin levels from baseline of ≥ 2 g/dL in the absence of RBC transfusions, based on central laboratory hemoglobin values. In a sensitivity analysis, 87.5% (95% CI: 73.2%, 95.8%) of patients (35/40) achieved a sustained increase (between Day 126 and Day 168) in hemoglobin levels from baseline of ≥ 2 g/dL in the absence of RBC transfusions, including local laboratory hemoglobin values when central laboratory hemoglobin values were not available.