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Study of DAXDILIMAB for the Treatment of Moderate-to-Severe Alopecia Areata

A Phase 2A, Open Label, Proof of Concept Trial of Daxdilimab for the Treatment of Moderate To Severe Alopecia Areata

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05368103
Enrollment
30
Registered
2022-05-10
Start date
2022-04-27
Completion date
2024-01-26
Last updated
2025-01-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Alopecia Areata

Brief summary

The purpose of this study is to assess the preliminary efficacy, safety, tolerability, PK, and PD of Daxdilimab in participants with moderate to severe AA, with ≥50% and ≤95% total scalp hair loss as defined by the SALT score at Screening and Day 1.

Detailed description

Approximately 30 participants will be enrolled to receive daxdilimab administered subcutaneously over 32 weeks. The maximum trial duration per participant is approximately 52 weeks, including up to 30 days for the screening period, 32 weeks for the open-label treatment period where participants will receive daxdilimab and approximately 16 weeks for the follow-up period. Safety evaluations will be performed regularly throughout the course of the study. Study acquired from Horizon in 2024.

Interventions

BIOLOGICALDaxdilimab

Daxdilimab will be administered subcutaneously as two injections for each dose.

Sponsors

Amgen
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

1. Willing and able to give informed consent. 2. Willing and able to comply with the prescribed treatment protocol and evaluations for the duration of the trial. 3. Adult men or women 18 to 65 years of age. 4. Willing to keep the same hair style and color (eg, hair products, process, and timing for hair appointments) for the duration of the trial. 5. Clinical diagnosis of moderate-to-severe AA - defined as meeting the following criteria: * Presence of ≥ 50% and ≤ 95% total scalp hair loss at screening and baseline (Day 1) defined by the SALT score. * Duration of current episode of hair loss \>3 months but \<7 years at screening and Day 1, along with investigators' assessment that hair regrowth is possible. * No evidence of active regrowth present at baseline and no known history of significant regrowth, as per investigator's judgement, over the last 6 months.

Exclusion criteria

1. Individuals involved in the conduct of the trial, their employees, or immediate family members of such individuals. 2. Any clinically significant medical condition or physical/laboratory/ECG/vital signs abnormality that would, in the opinion of the investigator, put the participant at undue risk or interfere with the evaluation of the IP or interpretation of trial results. 3. History of allergy, hypersensitivity reaction, or anaphylaxis to any component of the IP or to a previous monoclonal antibody (mAb) or human immunoglobulin (Ig) therapy. 4. Participant has had excessive sun exposure, is planning a trip to a sunny climate, or has used tanning booths within 4 weeks prior to Day 1 or is not willing to minimize natural and artificial sunlight exposure during the trial. Use of sunscreen products and protective apparel are recommended when sun exposure cannot be avoided. 5. Known history of a primary immunodeficiency or an underlying condition such as known human immunodeficiency virus (HIV) infection, a positive result for HIV infection, splenectomy, or any underlying condition that in the opinion of the investigator significantly predisposes the participant to infection. 6. Confirmed positive test for hepatitis B serology defined as: * Hepatitis B surface antigen (HBsAg), or * Hepatitis B core antibody (HBcAb or anti-HBc) 7. Positive test for hepatitis C virus antibody. 8. Active tuberculosis (TB), or a positive TB test at Screening. Participant will be evaluated for latent TB infection with a purified protein derivative (PPD) test or a QuantiFERON-TB Gold test. Participants who demonstrate evidence of latent TB infection (either PPD ≥5 mm of induration or positive QuantiFERON-TB Gold test, irrespective of bacille Calmette-Guérin vaccination status will not be allowed to participate in the trial, unless documented history of appropriate treatment for active or latent TB. Participants with an indeterminate test result can repeat the test, but if the repeat test is also indeterminate, they are excluded. 9. Any severe herpes virus family infection (including Epstein-Barr virus, cytomegalovirus \[CMV\]) at any time prior to Day 1, including, but not limited to, disseminated herpes, herpes encephalitis, recent recurrent herpes zoster (defined as 2 episodes within the last 2 years), or ophthalmic herpes. 10. Any herpes zoster, CMV, or Epstein-Barr virus infection that was not completely resolved 12 weeks prior to Day 1. 11. Any of the following within 30 days prior to signing the ICF and though Day 1: * Clinically significant active infection in the opinion of the investigator, including ongoing, and chronic infection requiring antibiotics or antiviral medication (chronic nail infections are allowed). Note: Participant with a limited recurrence of a cold sore or herpes genitalis between ICF signature and Day 1 could be eligible based on the investigator's judgement. * Any infection requiring hospitalization or treatment with intravenous (IV) anti-infectives. * A participant with a documented positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test may be rescreened at least 2 weeks after a positive test if the participant is asymptomatic and at least 3 weeks after resolution of symptomatic Coronavirus Disease 2019 (COVID-19) illness. 12. Opportunistic infection requiring hospitalization or parenteral antimicrobial treatment within 2 years prior to Day 1. 13. Any acute illness or evidence of clinically significant active infection, such as fever ≥ 38.0°C (≥ 100.5°F) on Day 1. 14. History of clinically significant cardiac disease including unstable angina; myocardial infarction within 6 months prior to Day 1; congestive heart failure; arrhythmia requiring active therapy, except for clinically insignificant extra systoles, or minor conduction abnormalities; or presence of clinically significant abnormality on ECG if, in the opinion of the investigator, it would increase the risk of trial participation. 15. History of cancer or lymphoproliferative disease within 5 years prior to Day 1, except as follows: * In situ carcinoma of the cervix treated with apparent success with curative therapy \> 12 months prior to Screening, or * Nonmetastatic cutaneous basal cell or squamous cell carcinoma of the skin treated with apparent success with curative therapy. 16. Active forms of other inflammatory skin disease(s) or evidence of other skin conditions (eg, psoriasis, seborrheic dermatitis, lupus) at the time of the Screening and through Day 1, that in the opinion of the investigator might interfere with evaluation of AA and the assessment of the activity measures. 17. Presence of another form of alopecia (except for androgenic alopecia). 18. History of male or female pattern hair loss \> Hamilton stage III or \> Ludwig stage II. 19. History or presence of hair transplants. 20. History or presence of micropigmentation of the scalp (Note: microblading of the eyebrows is permitted). 21. Use of steroids (systemic and intralesional), anthralin, squaric acid, diphenylcycloprophenone (DPCP), dinitrochlorobenzene (DCNB), protopic, minoxidil, or any other medication which in the opinion of the investigator may affect hair regrowth within 4 weeks of Day 1 visit. Note: Intranasal and inhaled corticosteroids are allowed, eye and ear drops containing corticosteroids are also allowed. 22. Use of platelet-rich plasma injections in the last 12 weeks prior to Day 1. 23. Topical medicated treatment that could affect AA including, but not limited to, topical corticosteroids, calcineurin inhibitors, antimicrobials, medical devices within 2 weeks of Day 1 visit. Note: Topical corticosteroids are permitted outside of the scalp, eyebrows, and eyelids. 24. Participants who have had previous treatment with any biologic B-cell-depleting therapy (eg, rituximab, ocrelizumab, or ofatumumab) or other B-cell targeting therapy (eg, belimumab) within 12 months before Day 1. 25. Participants who have received previous treatment with pDC inhibiting therapies (eg, anti-ILT7, anti-blood dendritic cell antigen 2 \[BDCA2\]). 26. Inadequate response to adequate trial of oral Janus Kinase (JAK) inhibitors. Previous exposure to topical JAK inhibitors is acceptable, regardless of response. 27. Any biologic or conventional disease-modifying antirheumatic drugs (DMARD), immunosuppressant (eg, cyclosporine, methotrexate, or azathioprine), JAK-inhibitors, interferon (IFN) blocking therapies, or antiproliferative agents, if last dose was taken: a. within 8 weeks prior to Day 1 or b. drug-specific 5 half-lives elimination period (if longer than 8 weeks). 28. Participant has received any marketed or investigational biological agent within 12 weeks or 5 half-lives (whichever is longer) prior to Day 1. 29. Currently receiving a nonbiological IP or device or has received one within 4 weeks prior to Day 1 or within 5 published half-lives, whichever is longer. 30. Participant has received any ultraviolet (UV)-B phototherapy (including tanning beds), has had psoralen-UV-A (PUVA) treatment, or excimer laser within 4 weeks prior to Day 1.

Design outcomes

Primary

MeasureTime frameDescription
Percent Change From Baseline in SALT Score at Week 24Baseline to Week 24The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Secondary

MeasureTime frameDescription
Percentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 12, 16, 20, 24, 28, 32, and 36Baseline to Weeks 12, 16, 20, 24, 28, 32, and 36The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 12, 16, 20, 24, 28, 32, and 36Weeks 12, 16, 20, 24, 28, 32, and 36The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 12, 16, 20, 24, 28, 32, and 36Weeks 12, 16, 20, 24, 28, 32, and 36The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 12, 16, 20, 24, 28, 32, and 36Weeks 12, 16, 20, 24, 28, 32, and 36The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 12, 16, 20, 24, 28, 32, and 36Weeks 12, 16, 20, 24, 28, 32, and 36The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percent Change From Baseline in SALT Score at Weeks 40, 44, and 48Baseline to Weeks 40, 44, and 48The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 40, 44, and 48Baseline to Weeks 40, 44, and 48The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 40, 44 and 48Weeks 40, 44 and 48The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percent Change From Baseline in SALT Score at Weeks 12, 16, 20, 28, 32, and 36Baseline to Weeks 12, 16, 20, 28, 32, and 36The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 40, 44 and 48Weeks 40, 44 and 48The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Percentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 40, 44 and 48Weeks 40, 44 and 48The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.
Serum Concentration of DaxdilimabBaseline: 2 hours post-dose; Weeks 4-32: Pre-dose; Weeks 36-48: Any time during the visit.Blood samples were collected at the visits and time points specified. All post-baseline concentrations below the limit of quantification (BLQ) were imputed as half of the lower limit of quantification value.
Percent Change From Baseline in Plasmacytoid Dendritic Cell (pDC) LevelsBaseline to Weeks 4, 12, 24, 32, 36 and 48Blood samples were collected at the visits and timepoints specified and analyzed using flow cytometry.
Number of Participants Who Experienced an Anti-drug Antibody (ADA) ResponseBaseline and Weeks 4, 8, 12, 24, and 36: Pre-doseThe number of participants who experienced an ADA response was defined as participants with ADA positive post-baseline only or boosted their preexisting ADA during the study.
Number of Participants Who Experienced a Treatment-emergent Adverse Event (TEAE)Day 1 to Week 48A TEAE was any untoward medical occurrence in a participant that was not present prior to treatment but appeared following treatment, was present at treatment initiation but worsened during treatment, or was present at the treatment initiation but resolved and then reappeared while the participant was on treatment and did not necessarily have a causal relationship with the treatment. A serious TEAE was defined as any medical occurrence that had any of the following consequences: * Resulted in death. * Was life-threatening. * Required in-patient hospitalization or prolongation of existing hospitalization. * Resulted in persistent or significant disability/incapacity. * Was a congenital anomaly/birth defect.
Number of Participants Who Experienced an Adverse Event of Special Interest (AESI)Day 1 to Week 48An AESI was defined as a serious or non-serious adverse event of scientific and medical interest specific to understanding the treatment and may have required close monitoring and collection of additional information by the investigator. The following were defined as AESIs: * Hypersensitivity reaction, including anaphylaxis. * Severe viral infection/reactivation. * Opportunistic infection. * Malignancy (except non-melanoma skin cancer).
Percentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 40, 44 and 48Weeks 40, 44 and 48The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Countries

Canada, United States

Participant flow

Recruitment details

A total of 30 participants were enrolled at 5 trial centers located in the United States and 7 trial centers in Canada between 27 April 2022 and 26 January 2024.

Pre-assignment details

Of the 55 participants who were screened for enrolment in the trial, 25 were screen failures. A total of 30 participants were enrolled and received daxdilimab.

Participants by arm

ArmCount
Daxdilimab 300 mg
Participants received 300 mg daxdilimab as two subcutaneous (SC) injections every 4 weeks (Q4W) for 32 weeks. Participants were followed-up until Week 48.
30
Total30

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyLack of Efficacy3
Overall StudyLost to Follow-up1
Overall StudyWithdrawal by Subject4

Baseline characteristics

CharacteristicDaxdilimab 300 mg
Age, Continuous42.7 years
STANDARD_DEVIATION 13.83
Ethnicity (NIH/OMB)
Hispanic or Latino
2 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
28 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Race/Ethnicity, Customized
Asian
6 Participants
Race/Ethnicity, Customized
Black or African American
2 Participants
Race/Ethnicity, Customized
Other
2 Participants
Race/Ethnicity, Customized
White
20 Participants
Severity of Alopecia Tool (SALT) Score74.4 score on a scale
STANDARD_DEVIATION 15.72
Sex: Female, Male
Female
20 Participants
Sex: Female, Male
Male
10 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
0 / 30
other
Total, other adverse events
17 / 30
serious
Total, serious adverse events
0 / 30

Outcome results

Primary

Percent Change From Baseline in SALT Score at Week 24

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Baseline to Week 24

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureValue (MEAN)Dispersion
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Week 24-12.6 percent change in score on a scaleStandard Deviation 35.15
Secondary

Number of Participants Who Experienced an Adverse Event of Special Interest (AESI)

An AESI was defined as a serious or non-serious adverse event of scientific and medical interest specific to understanding the treatment and may have required close monitoring and collection of additional information by the investigator. The following were defined as AESIs: * Hypersensitivity reaction, including anaphylaxis. * Severe viral infection/reactivation. * Opportunistic infection. * Malignancy (except non-melanoma skin cancer).

Time frame: Day 1 to Week 48

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Daxdilimab 300 mgNumber of Participants Who Experienced an Adverse Event of Special Interest (AESI)2 Participants
Secondary

Number of Participants Who Experienced an Anti-drug Antibody (ADA) Response

The number of participants who experienced an ADA response was defined as participants with ADA positive post-baseline only or boosted their preexisting ADA during the study.

Time frame: Baseline and Weeks 4, 8, 12, 24, and 36: Pre-dose

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Daxdilimab 300 mgNumber of Participants Who Experienced an Anti-drug Antibody (ADA) Response1 Participants
Secondary

Number of Participants Who Experienced a Treatment-emergent Adverse Event (TEAE)

A TEAE was any untoward medical occurrence in a participant that was not present prior to treatment but appeared following treatment, was present at treatment initiation but worsened during treatment, or was present at the treatment initiation but resolved and then reappeared while the participant was on treatment and did not necessarily have a causal relationship with the treatment. A serious TEAE was defined as any medical occurrence that had any of the following consequences: * Resulted in death. * Was life-threatening. * Required in-patient hospitalization or prolongation of existing hospitalization. * Resulted in persistent or significant disability/incapacity. * Was a congenital anomaly/birth defect.

Time frame: Day 1 to Week 48

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Daxdilimab 300 mgNumber of Participants Who Experienced a Treatment-emergent Adverse Event (TEAE)TEAEs23 Participants
Daxdilimab 300 mgNumber of Participants Who Experienced a Treatment-emergent Adverse Event (TEAE)Serious TEAEs0 Participants
Secondary

Percentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 12, 16, 20, 24, 28, 32, and 36

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Baseline to Weeks 12, 16, 20, 24, 28, 32, and 36

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 12, 16, 20, 24, 28, 32, and 36Week 123.3 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 12, 16, 20, 24, 28, 32, and 36Week 1610.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2013.3 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2420.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2820.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3220.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3620.0 percent of participants
Secondary

Percentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 40, 44, and 48

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Baseline to Weeks 40, 44, and 48

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 40, 44, and 48Week 4020.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 40, 44, and 48Week 4426.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Achieved a ≥ 50% Reduction in SALT Score From Baseline at Weeks 40, 44, and 48Week 4823.3 percent of participants
Secondary

Percentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 12, 16, 20, 24, 28, 32, and 36

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Weeks 12, 16, 20, 24, 28, 32, and 36

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 120.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 160.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 200.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 243.3 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 286.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3210.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3613.3 percent of participants
Secondary

Percentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 40, 44 and 48

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Weeks 40, 44 and 48

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 40, 44 and 48Week 4010.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 40, 44 and 48Week 4410.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 10 at Weeks 40, 44 and 48Week 4813.3 percent of participants
Secondary

Percentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 12, 16, 20, 24, 28, 32, and 36

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Weeks 12, 16, 20, 24, 28, 32, and 36

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 120.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 160.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 206.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2413.3 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2816.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3216.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3616.7 percent of participants
Secondary

Percentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 40, 44 and 48

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Weeks 40, 44 and 48

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 40, 44 and 48Week 4016.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 40, 44 and 48Week 4416.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 20 at Weeks 40, 44 and 48Week 4816.7 percent of participants
Secondary

Percentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 12, 16, 20, 24, 28, 32, and 36

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Weeks 12, 16, 20, 24, 28, 32, and 36

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 126.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 1610.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2010.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2416.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2816.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3216.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3620.0 percent of participants
Secondary

Percentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 40, 44 and 48

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Weeks 40, 44 and 48

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 40, 44 and 48Week 4020.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 40, 44 and 48Week 4420.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 30 at Weeks 40, 44 and 48Week 4816.7 percent of participants
Secondary

Percentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 12, 16, 20, 24, 28, 32, and 36

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Weeks 12, 16, 20, 24, 28, 32, and 36

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 1216.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 1623.3 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2026.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2426.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 2830.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3230.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 12, 16, 20, 24, 28, 32, and 36Week 3630.0 percent of participants
Secondary

Percentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 40, 44 and 48

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Weeks 40, 44 and 48

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (NUMBER)
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 40, 44 and 48Week 4026.7 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 40, 44 and 48Week 4430.0 percent of participants
Daxdilimab 300 mgPercentage of Participants Who Had an Absolute SALT Score ≤ 50 at Weeks 40, 44 and 48Week 4823.3 percent of participants
Secondary

Percent Change From Baseline in Plasmacytoid Dendritic Cell (pDC) Levels

Blood samples were collected at the visits and timepoints specified and analyzed using flow cytometry.

Time frame: Baseline to Weeks 4, 12, 24, 32, 36 and 48

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab. Only participants with evaluable data at each time point were included.

ArmMeasureGroupValue (MEDIAN)
Daxdilimab 300 mgPercent Change From Baseline in Plasmacytoid Dendritic Cell (pDC) LevelsWeek 4-88.89 percent change in pDC levels
Daxdilimab 300 mgPercent Change From Baseline in Plasmacytoid Dendritic Cell (pDC) LevelsWeek 12-87.50 percent change in pDC levels
Daxdilimab 300 mgPercent Change From Baseline in Plasmacytoid Dendritic Cell (pDC) LevelsWeek 24-85.71 percent change in pDC levels
Daxdilimab 300 mgPercent Change From Baseline in Plasmacytoid Dendritic Cell (pDC) LevelsWeek 32-85.71 percent change in pDC levels
Daxdilimab 300 mgPercent Change From Baseline in Plasmacytoid Dendritic Cell (pDC) LevelsWeek 36-82.86 percent change in pDC levels
Daxdilimab 300 mgPercent Change From Baseline in Plasmacytoid Dendritic Cell (pDC) LevelsWeek 48-40.00 percent change in pDC levels
Secondary

Percent Change From Baseline in SALT Score at Weeks 12, 16, 20, 28, 32, and 36

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Baseline to Weeks 12, 16, 20, 28, 32, and 36

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (MEAN)Dispersion
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Weeks 12, 16, 20, 28, 32, and 36Week 12-5.4 percent change in score on a scaleStandard Deviation 21.57
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Weeks 12, 16, 20, 28, 32, and 36Week 16-8.1 percent change in score on a scaleStandard Deviation 26.58
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Weeks 12, 16, 20, 28, 32, and 36Week 20-10.0 percent change in score on a scaleStandard Deviation 30.1
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Weeks 12, 16, 20, 28, 32, and 36Week 28-16.2 percent change in score on a scaleStandard Deviation 34.35
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Weeks 12, 16, 20, 28, 32, and 36Week 32-17.2 percent change in score on a scaleStandard Deviation 37.16
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Weeks 12, 16, 20, 28, 32, and 36Week 36-18.2 percent change in score on a scaleStandard Deviation 37.22
Secondary

Percent Change From Baseline in SALT Score at Weeks 40, 44, and 48

The SALT score determined the degree of hair loss based on the percentage of scalp surface area involved on the top, back, and each side of the scalp for AA. The Investigator determined the percent scalp hair loss in a given quadrant, multiplied this by the total scalp area delineated by that quadrant, and summed the resultant numbers for each quadrant to give the total percent scalp hair loss with a range of 0-100. Higher scores indicated more severe AA symptoms. A decrease in SALT score from baseline indicated a reduction in AA symptoms. Baseline indicates last non-missing valid observation prior to the first dose of daxdilimab.

Time frame: Baseline to Weeks 40, 44, and 48

Population: Safety Analysis Set: Included all participants who received any dose of daxdilimab.

ArmMeasureGroupValue (MEAN)Dispersion
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Weeks 40, 44, and 48Week 40-19.4 percent change in score on a scaleStandard Deviation 37.72
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Weeks 40, 44, and 48Week 44-20.6 percent change in score on a scaleStandard Deviation 40.67
Daxdilimab 300 mgPercent Change From Baseline in SALT Score at Weeks 40, 44, and 48Week 48-22.1 percent change in score on a scaleStandard Deviation 41.43
Secondary

Serum Concentration of Daxdilimab

Blood samples were collected at the visits and time points specified. All post-baseline concentrations below the limit of quantification (BLQ) were imputed as half of the lower limit of quantification value.

Time frame: Baseline: 2 hours post-dose; Weeks 4-32: Pre-dose; Weeks 36-48: Any time during the visit.

Population: Pharmacokinetic (PK) Analysis Set: Included all participants who received any dose of daxdilimab and had at least one measurable PK concentration post-dose. Only participants with evaluable data at each timepoint were included.

ArmMeasureGroupValue (MEAN)Dispersion
Daxdilimab 300 mgSerum Concentration of DaxdilimabBaseline0.640 ng/mLStandard Deviation 1.354
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 46.698 ng/mLStandard Deviation 3.514
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 88.823 ng/mLStandard Deviation 4.439
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 129.978 ng/mLStandard Deviation 5.569
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 169.582 ng/mLStandard Deviation 5.41
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 209.473 ng/mLStandard Deviation 5.616
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 2410.322 ng/mLStandard Deviation 6.154
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 2810.595 ng/mLStandard Deviation 6.663
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 3210.638 ng/mLStandard Deviation 6.549
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 3610.480 ng/mLStandard Deviation 6.074
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 403.543 ng/mLStandard Deviation 2.878
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 441.309 ng/mLStandard Deviation 1.218
Daxdilimab 300 mgSerum Concentration of DaxdilimabWeek 480.430 ng/mLStandard Deviation 0.465

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026