Chugai Pharmaceutical Co., Ltd. announced that its wholly-owned subsidiary, Chugai Pharma Taiwan Ltd. (CPT), has received an orphan drug import license from the Taiwan Food and Drug Administration (TFDA) for PiaSky. The approval, granted on May 19, 2025, is for the treatment of patients 13 years and older with paroxysmal nocturnal hemoglobinuria (PNH) who weigh at least 40 kg.
This milestone marks PiaSky as the first PNH treatment in Taiwan that can be administered subcutaneously every 4 weeks during the maintenance period, offering a significant advancement for patients living with this rare blood disorder.
"We are very pleased that Chugai-originated PiaSky has been approved in Taiwan," said Yuji Habara, President of CPT. "Paroxysmal nocturnal hemoglobinuria is a disease with limited treatment options in Taiwan and high unmet medical needs for patients and their families. We expect that this drug will be widely useful for patients, their families, and healthcare professionals."
Innovative Technology Behind PiaSky
PiaSky is an anti-C5 recycling antibody created with Chugai's proprietary Recycling Antibody technology. This innovative approach enables pH-dependent antigen binding, allowing a single antibody molecule to bind with the antigen multiple times. This results in longer efficacy compared to conventional antibodies.
The drug also incorporates surface charge modification technology, which increases the clearance rate of the antigen from the blood. This enables more efficient neutralization compared to conventional recycling antibodies, thereby reducing the required dosage.
By targeting C5, a key component of the complement system, PiaSky effectively controls complement activity. Notably, PiaSky binds to complement C5 at a different site from existing antibody drugs, making it an effective treatment option for PNH patients with a specific C5 gene mutation reported in Asia (appearing in approximately 3.2% of Japanese PNH patients), which renders existing antibody drugs ineffective.
Clinical Evidence Supporting Approval
The Taiwan approval is based on results from three Phase III clinical trials:
- The global COMMODORE 2 study in PNH patients who had not been previously treated with C5 inhibitors
- The global COMMODORE 1 study in PNH patients switching from currently approved C5 inhibitors
- The COMMODORE 3 study conducted in China in PNH patients who had not been previously treated with C5 inhibitors
The COMMODORE 2 study was a Phase III, randomized, open-label global trial evaluating the efficacy and safety of PiaSky versus eculizumab in people with PNH who had not been previously treated with C5 inhibitors. The study's co-primary efficacy endpoints measured transfusion avoidance and control of hemolysis (the ongoing destruction of red blood cells measured by lactate dehydrogenase levels).
Adult participants were randomized in a 2:1 ratio to receive either subcutaneous PiaSky every four weeks or intravenous eculizumab every two weeks. Participants under 18 years old were included in a descriptive arm and received subcutaneous PiaSky every four weeks.
Patient Benefits and Reduced Treatment Burden
A key advantage of PiaSky is its subcutaneous administration route and extended dosing schedule. Patients can receive treatment every 4 weeks with a small volume of medicine, compared to the biweekly intravenous administration required for existing treatments like eculizumab.
This represents a significant reduction in treatment burden for people with PNH and their caregivers, potentially improving quality of life and treatment adherence.
Global Regulatory Status
PiaSky has been steadily gaining regulatory approvals worldwide:
- First approved in China in February 2024 for adults and adolescents (12 years and above) with PNH who have not been previously treated with complement inhibitors
- Approved in Japan in March 2024 for PNH treatment and launched in May 2024
- Received approval in the US in June 2024
- Gained European approval in August 2024
Future Therapeutic Applications
Beyond PNH, clinical trials for PiaSky are ongoing for atypical hemolytic uremic syndrome (aHUS). Additionally, Roche is conducting trials for sickle cell disease (SCD) outside of Asia.
The approval of PiaSky in Taiwan represents an important advancement in the treatment landscape for PNH, offering patients a more convenient treatment option with potentially broader efficacy across patient populations, including those with genetic mutations that limit the effectiveness of existing therapies.
