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