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BIIB059

Phase 3

Subacute Cutaneous Lupus Erythematosus | Small molecule | Immunology |Biogen Inc.|Last Updated: Aug 4, 2026

Target and mechanism

Molecular targetBDCA2
Target classProtein
ModalitySmall molecule

Also known as BIIB059 (litifilimab)

Success Probability

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Market & Valuation

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Trial Design

UNCONTROLLEDDMC
Total Trials1
Total Enrollment306

FDA Designations

No designations recorded

Clinical trial landscape

BIIB059 · 4 trials · 6 indications

Phase 3 1Phase 2 1Phase 1 2
NCT06044337A Long-Term Extension Study to Learn More About the Safety of Litifilimab (BIIB059) Injections and Whether They Can Improve Symptoms of Adult Participants Who Have Active Cutaneous Lupus ErythematosusSubacute Cutaneous Lupus Erythematosus
ENROLLING BY_INVITATION306 Analytics
PHASE3ENROLLING BY_INVITATION
A Long-Term Extension Study to Learn More About the Safety of Litifilimab (BIIB059) Injections and Whether They Can Improve Symptoms of Adult Participants Who Have Active Cutaneous Lupus Erythematosus
Subacute Cutaneous Lupus ErythematosusUnlock trial analytics

Study Endpoints

Primary Endpoints

Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
Up to 232 weeks
Part A: Change From Baseline in Active Joint Count (28-joint Assessment) to Week 24
Baseline to Week 24

An active joint is defined as a joint with pain and signs of inflammation (e.g., tenderness, swelling or effusion). The 28 Joint Count includes assessment of swelling and tenderness in the shoulders, elbows, wrists, metacarpophalangeal joints, proximal interphalangeal joints and knees. The investigator counts how many of the 28 joints are swollen or tender at the given week.

Part B: Percent Change From Baseline in Cutaneous Lupus Erythematosus Disease Area and Severity Index Activity (CLASI-A) Score to Week 16
Baseline to Week 16

The Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) is a clinical tool that quantifies disease activity and damage in cutaneous lupus erythematosus (CLE). The activity scale (CLASI-A) includes measurements of erythema, scale and hypertrophy, and mucous membrane disease. Each part of the body is listed separately, from the scalp to the feet, in addition to sections focusing on mucous membrane involvement and alopecia. Points are given for the presence of erythema, scale, mucous membrane lesions, recent hair loss, and inflammatory alopecia. Composite scores are calculated by summing the individual component scores. CLASI-A scores of 0-9, 10-20, and 21-70 represent disease severity of mild, moderate, and severe, respectively. Higher scores indicate more disease activity.

Percentage of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Up to 20 weeks

An AE is any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not related to the medicinal (investigational) product. An SAE is any untoward medical occurrence that at any dose: results in death; life-threatening event; requires inpatient hospitalization; significant disability; congenital anomaly; medically important event.

Percentage of Participants With Clinically Significant Abnormal Clinical Laboratory Parameters, Vital Signs, 12-Lead Electrocardiograms (ECG), and Physical Examination Findings
Up to 20 weeks
Percentage of Participants With Anti-BIIB059 Antibodies
Up to 20 weeks
Number of Participants that Experience Adverse Events (AEs) and Serious Adverse Events (SAEs)
Up to Week 32

Secondary Endpoints

Percentage of Participants who Achieve a Cutaneous Lupus Erythematosus Disease Area and Severity Index Activity Score (CLASI)-70 Response, Defined as a 70% Decrease in CLASI-A Score From the Baseline Value (Parent Study [NCT05531565])
Up to 232 weeks
Percentage of Participants who Achieve a CLASI-50 Response, Defined as a 50% Decrease in CLASI-A Score From the Baseline Value (Parent Study [NCT05531565])
Up to 232 weeks
Percentage of Participants who Achieve a CLASI-90 Response, Defined as a 90% Decrease in CLASI-A Score From the Baseline Value (Parent Study [NCT05531565])
Up to 232 weeks
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Study Design & Arms

AllocationNA
MaskingNONE
ModelSINGLE_GROUP
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
BIIB059EXPERIMENTALParticipants will receive BIIB059 (litifilimab) subcutaneously (SC), once every 4 weeks up to Week 204 in the LTE period.
Part A: BIIB059 450 mgEXPERIMENTALBIIB059 450 mg administered SC, Q4W with an additional dose at Week 2 for a total of 7 doses (Weeks 0, 2, 4, 8, 12, 16, and 20) in participants with SLE with active skin manifestations and joint involvement.
Part A: PlaceboPLACEBO_COMPARATORBIIB059 matching placebo administered SC, Q4W with an additional dose at Week 2 for total of 7 doses (Weeks 0, 2, 4, 8, 12, 16, and 20) in participants with SLE with active skin manifestations and joint involvement.
Part B: BIIB059 50 mgEXPERIMENTALBIIB059 50 mg administered SC, Q4W with an additional loading dose at Week 2 for a total of 5 doses (Weeks 0, 2, 4, 8, and 12) in participants with active CLE with or without systemic manifestations.
Part B: BIIB059 150 mgEXPERIMENTALBIIB059 150 mg administered SC, Q4W with an additional loading dose at Week 2 for a total of 5 doses (Weeks 0, 2, 4, 8, and 12) in participants with active CLE with or without systemic manifestations.
Part B: BIIB059 450 mgEXPERIMENTALBIIB059 450 mg administered, Q4W with an additional loading dose at Week 2 for a total of 5 doses (Weeks 0, 2, 4, 8, and 12) in participants with active CLE with or without systemic manifestations.
Part B: PlaceboPLACEBO_COMPARATORBIIB059 matching placebo administered SC, Q4W with an additional loading dose at Week 2 for a total of 5 doses (Weeks 0, 2, 4, 8, and 12) in participants with active CLE with or without systemic manifestations.
BIIB059 20 mgEXPERIMENTALParticipants will receive single subcutaneous (SC) dose of 20 milligram (mg) BIIB059 or matching placebo on Day 1.
BIIB059 50mgEXPERIMENTALParticipants will receive single SC dose of 50 mg BIIB059 or matching placebo on Day 1.
BIIB059 150mgEXPERIMENTALParticipants will receive single SC dose of 150 mg BIIB059 or matching placebo on Day 1.
BIIB059 450mgEXPERIMENTALParticipants will receive single SC dose of 450 mg BIIB059 or matching placebo on Day 1.
Part 1, Cohort 1: BIIB059 0.05 mg/kg IVEXPERIMENTALBIIB059 0.05 mg/kg IV dose, Once on Day 1
Part 1, Cohort 2: BIIB059 0.3 mg/kg IVEXPERIMENTALBIIB059 0.3 mg/kg IV dose, Once on Day 1
Part 1, Cohort 3: BIIB059 1 mg/kg IVEXPERIMENTALBIIB059 1 mg/kg IV dose, Once on Day 1
Part 1, Cohort 4: BIIB059 3 mg/kg IVEXPERIMENTALBIIB059 3 mg/kg IV dose, Once on Day 1
Part 1, Cohort 5: BIIB059 10 mg/kg IVEXPERIMENTALBIIB059 10 mg/kg IV dose, Once on Day 1
Part 1, Cohort 6: BIIB059 20 mg/kg IVEXPERIMENTALBIIB059 20 mg/kg IV dose, Once on Day 1
Part 1, Cohort 7: BIIB059 50 mg SCEXPERIMENTALBIIB059 50 mg SC dose, Once on Day 1
Part 1, Cohort 1-6: Placebo IVPLACEBO_COMPARATORMatching placebo IV dose, Once on Day 1
Part 1, Cohort 7: Placebo SCPLACEBO_COMPARATORMatching placebo SC dose, Once on Day 1
Part 2, Cohort 8: BIIB059 20 mg/kg IVEXPERIMENTALBIIB059 20 mg/kg IV dose, Once on Day 1
Part 2, Cohort 8: Placebo IVPLACEBO_COMPARATORMatching placebo IV dose, Once on Day 1
Part 3a, Cohort 9: BIIB059 20 mg SCEXPERIMENTALBIIB059 20 mg SC dose, Every 4 weeks for 2 doses
Part 3a, Cohort 10: BIIB059 50 mg SCEXPERIMENTALBIIB059 50 mg SC dose, Every 4 weeks for 2 doses
Part 3a, Cohort 11: BIIB059 150 mg SCEXPERIMENTALBIIB059 150 mg SC dose, Every 4 weeks for 2 doses
Part 3a, Cohort 12: BIIB059 300 mg or less SCEXPERIMENTALBIIB059 300 mg or less SC dose, Every 2 weeks for 3 doses
Part 3a, Cohort 9-12: Placebo SCPLACEBO_COMPARATORMatching placebo SC dose, Every 4 weeks for 2 doses or every 2 weeks for 3 doses
Part 3b, Cohort 13: BIIB059 50 mg SCEXPERIMENTALBIIB059 50 mg SC dose, Every 4 weeks for 2 doses
Part 3b, Cohort 14: BIIB059 300 mg or less SCEXPERIMENTALBIIB059 300 mg or less SC dose, Every 2 weeks for 3 doses
Part 3b, Cohort 13-14: Placebo SCPLACEBO_COMPARATORMatching placebo SC dose, Every 4 weeks for 2 doses or every 2 weeks for 3 doses

Interventions

NameTypeDescription
BIIB059 (litifilimab)DRUGAdministered as specified in the treatment arm.
PlaceboDRUGAdministered as specified in the treatment arm.
BIIB059DRUGAdministered as specified in the treatment arm
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Eligibility Criteria

Age Range18 Years to N/A
SexALL
Healthy VolunteersNo
Study Sites104

Key Inclusion Criteria: * Participants who completed the parent study (230LE301 \[NCT05531565\], Part A or Part B) on study treatment (received treatment through Week 48 and attended the last study assessment visit at Week 52). * Ability of the participant to understand the purpose and risks of the...

Countries:United StatesArgentinaBrazilBulgariaCanadaChileChinaColombiaFranceGermanyHungaryItalyJapanMexicoPhilippinesPolandPortugalSerbiaSlovakiaSouth KoreaSpainSwedenSwitzerlandTaiwanUnited KingdomIsraelThailand
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Recent Changes (Last 90 Days)

LOWAug 4, 2026NCT06044337lastUpdatePostDate: changed
LOWAug 4, 2026NCT06044337lastUpdatePostDate: changed
LOWJul 13, 2026NCT06044337Enrollment: 322 → 306
LOWJul 13, 2026NCT06044337Enrollment: 322 → 306

Frequently asked questions about BIIB059

What is BIIB059 used for?

BIIB059, also known as litifilimab, is an investigational drug being studied for the treatment of subacute cutaneous lupus erythematosus, systemic lupus erythematosus, and chronic cutaneous lupus erythematosus. It has also been evaluated in healthy subjects. BIIB059 is in clinical development and is not yet approved for any indication.

What does BIIB059 target?

BIIB059 targets BDCA2, a protein found on certain immune cells. By binding to BDCA2, BIIB059 is designed to modulate the immune response involved in lupus. This mechanism is being investigated in clinical trials for cutaneous and systemic lupus erythematosus.

Who makes BIIB059?

BIIB059 is being developed by Biogen Inc., a biotechnology company traded on the NASDAQ under the ticker symbol BIIB. Biogen is conducting clinical trials to evaluate the safety and efficacy of BIIB059 in lupus-related conditions.

What phase is BIIB059 in?

BIIB059 has completed Phase 1 and Phase 2 clinical trials and is currently being evaluated in a Phase 3 long-term extension study. The drug remains investigational and has not received FDA approval. Its development is ongoing across multiple phases.

What clinical trials is BIIB059 in?

BIIB059 has been studied in several clinical trials. NCT02106897 evaluated single and multiple doses in healthy volunteers and participants with systemic lupus erythematosus. NCT02847598 studied BIIB059 in cutaneous lupus with or without systemic lupus. NCT03224793 assessed single doses in healthy Japanese subjects. NCT06044337 is an ongoing Phase 3 long-term extension study in active cutaneous lupus.

Is BIIB059 the same as litifilimab?

Yes, BIIB059 is also known as litifilimab. Both names refer to the same investigational drug being developed by Biogen for lupus-related conditions. Clinical trial records and scientific literature may use either name interchangeably.