In short
Clinical trials are investigating Asfotase Alfa in people with hypophosphatasia. These studies look at safety, effectiveness, immune responses, and treatment-related outcomes in pediatric and other affected participants. The trials also compare Asfotase Alfa with other study treatments in some settings.
Key points
- Clinical trials investigating Asfotase Alfa are focused on hypophosphatasia, including pediatric participants and people who may have lost treatment effect because of immune responses. Both studies in the source data are Phase 3 trials. One completed study looked at immunosuppressive therapy in participants treated with Asfotase Alfa, while the ongoing study compares ALXN1850 with Asfotase Alfa in children with HPP. The trials measure safety, tolerability, immune-related changes, and signs of bone improvement. Overall, the research is aimed at understanding both treatment benefit and treatment-related immune effects.
Clinical trial overview
These studies investigate Asfotase Alfa in people with hypophosphatasia, a rare condition listed in the trial data. Both trials are Phase 3 interventional studies, which means they test treatments in a later stage of research and measure clinical results closely.
Completed Phase 3 immunogenicity study
The completed study, NCT06015750, was designed to evaluate the effect of immunosuppressive therapies in participants treated with Asfotase Alfa who showed immune-mediated loss of effectiveness. The study was completed and enrolled 8 participants.
Its primary outcome was the number and percentage of participants who achieved IST complete response at Week 100. This response was defined by a drop in ADA or NAb titer by at least 2 steps or by becoming negative, plus improvement on radiographic evidence measured by the RSS score by at least 1 point from baseline.
The study interventions included Asfotase Alfa and several immunosuppressive medicines, such as immunoglobulins, rituximab products, bortezomib, and methotrexate. In the source data, these were used as part of the study plan, not as a general treatment guide.
Ongoing Phase 3 pediatric study
The ongoing study, 2023-505674-15-00, is a Phase 3 study of ALXN1850 in pediatric participants with HPP who were previously treated with Asfotase Alfa. It is designed to compare the safety and tolerability of ALXN1850 versus Asfotase Alfa.
This study has an enrollment target of 40 participants and is still ongoing. The intervention list shows ALXN1850 and two Asfotase Alfa formulations used in the comparison.
The primary outcome is the incidence of TEAEs, TESAEs, AESIs, and adverse events that lead to study treatment being stopped or paused. In simple terms, this means the study is watching for any harmful or important medical events during treatment.
Who the studies include
The source data show two main groups of participants. One group includes participants treated with Asfotase Alfa who had immune-mediated loss of effectiveness. The other group includes pediatric participants with HPP who had already been treated with Asfotase Alfa before joining the ongoing study.
These trial descriptions do not provide broad eligibility details such as age limits, lab values, or exact inclusion and exclusion rules. Based on the available data, the target population is narrow and focused on people already connected to Asfotase Alfa treatment.
What the trials measure
The completed study measures whether immune-suppressing therapy can reduce antibody levels and improve bone imaging findings by Week 100. This links the immune response with a clinical sign of improvement.
The ongoing study focuses on safety and tolerability, using event counts such as TEAEs and TESAEs as the main outcomes. These endpoints help researchers understand how often unwanted medical problems occur and whether treatment has to be interrupted.
Key terms in simple language
ADA means anti-drug antibodies, which are antibodies the body may make against a treatment. NAb means neutralizing antibodies, a type of antibody that can block a treatment from working well.
RSS stands for radiographic severity score, a score based on imaging that shows how bones look. IST means immunosuppressive therapy, which is treatment that lowers immune activity.
TEAE means treatment-emergent adverse event, a health problem that starts or gets worse during the study. TESAE means treatment-emergent serious adverse event, which is a more serious health problem. AESI means adverse event of special interest, a problem that researchers watch very carefully.