Clinical Trial Intelligence

Which Endpoints Are Measured Most Often in European Lupus Phase II & III Trials?

8 July 2026

Across 56 European CTIS lupus Phase II & III trial records, safety and tolerability endpoints were the most frequent endpoint family, appearing in 35 trials, or 62.5%. The disease-specific endpoint pattern split clearly by lupus subtype: SRI-4 dominated systemic lupus erythematosus, renal response dominated lupus nephritis, and CLASI dominated cutaneous lupus.

56
European Phase II & III lupus trial records
35 / 56
included safety or tolerability endpoints
56 / 412
primary vs secondary endpoint items
95 days
median initial CTIS submission to first authorization

Safety, disease activity scores, PROs, steroids, and flares formed the top lupus endpoint cluster

Safety / tolerability endpoints appeared in 35 of 56 trials, or 62.5%. The next most frequent endpoint families were SLEDAI / PGA / BILAG disease-activity scores in 28 trials, patient-reported outcomes or quality-of-life endpoints in 26 trials, corticosteroid or glucocorticoid reduction in 25 trials, and flare/SFI endpoints in 23 trials.

Endpoint family presence across 56 trials
Safety / tolerability62.5%
SLEDAI / PGA / BILAG activity scores50.0%
Patient-reported outcomes / QoL46.4%
Corticosteroid / glucocorticoid reduction44.6%
Flares / SFI41.1%
PK / PD / immunogenicity39.3%
SRI-4 / SLE responder index28.6%
CLASI / cutaneous response28.6%
Renal function / proteinuria26.8%
LLDAS low disease activity26.8%
Endpoint families are non-mutually exclusive; each trial is counted once per endpoint family.
Interpretation

European lupus endpoint design is not anchored by one universal efficacy measure. Instead, it combines broad safety capture with lupus-specific efficacy scales, patient burden, steroid sparing, and flare prevention.

Primary endpoints concentrated on safety, SRI-4, and renal response; secondary endpoints carried most endpoint breadth

The 56 trials contained 56 primary endpoint items and 412 secondary endpoint items. Safety/tolerability was the most frequent primary endpoint family at 13 of 56 trials, while secondary endpoints were led by safety/tolerability in 29 trials, disease-activity scores in 28 trials, and PRO/QoL endpoints in 26 trials.

Primary vs secondary endpoint families
Endpoint family
Primary
Secondary
Safety / tolerability
13 / 56 · 23.2%
29 / 56 · 51.8%
SRI-4 / SLE responder index
11 / 56 · 19.6%
14 / 56 · 25.0%
Renal function / proteinuria
9 / 56 · 16.1%
14 / 56 · 25.0%
Complete renal response
8 / 56 · 14.3%
13 / 56 · 23.2%
CLASI / cutaneous response
6 / 56 · 10.7%
15 / 56 · 26.8%
Exploratory / other endpoint bucket
0 / 56 · 0.0%
Primary and secondary columns show trials with at least one endpoint in that family.
Interpretation

Primary endpoint selection is subtype- and development-stage dependent, while secondary endpoints are where sponsors usually add steroid sparing, PROs, PK/PD, flare, and biomarker support for CTIS/EU submissions.

Endpoint choice shifted sharply by lupus subtype: SRI-4 for SLE, renal response for LN, CLASI for CLE

Three lupus subgroups were large enough for direct comparison: systemic lupus erythematosus (20 trials), lupus nephritis / renal SLE (19 trials), and cutaneous lupus / CLE (12 trials). In systemic SLE, SRI-4 and steroid-reduction endpoints each appeared in 14 of 20 trials; in lupus nephritis, renal function/proteinuria appeared in 15 of 19 trials; and in CLE, CLASI/cutaneous response appeared in 6 of 12 trials.

Dominant endpoint family by lupus subgroup
Systemic SLE · n=20
70.0%
SRI-4 and steroid-reduction endpoints each appeared in 14 / 20 trials.
Lupus nephritis · n=19
78.9%
Renal function / proteinuria endpoints appeared in 15 / 19 trials.
Cutaneous lupus · n=12
50.0%
CLASI / cutaneous response endpoints appeared in 6 / 12 trials.
Endpoint family
SLE
LN
CLE
Safety / tolerability
55.0%
63.2%
91.7%
SRI-4
70.0%
10.5%
0.0%
Renal function / proteinuria
0.0%
78.9%
0.0%
CLASI / cutaneous response
20.0%
0.0%
50.0%
SLE = systemic lupus erythematosus; LN = lupus nephritis; CLE = cutaneous lupus erythematosus.
Interpretation

For CTIS/EU lupus submissions, the clinically credible endpoint anchor depends on the phenotype: SRI-4/BICLA/LLDAS for systemic SLE, CRR/proteinuria/eGFR for lupus nephritis, and CLASI/CLA-IGA for cutaneous lupus.

Phase II trials were more safety-heavy; Phase III trials more often used SRI-4, flare, steroid, and PRO support

Phase II accounted for 24 of 56 trials and Phase III for 32 of 56. Safety/tolerability appeared in 19 of 24 Phase II trials, or 79.2%, compared with 16 of 32 Phase III trials, or 50.0%; Phase III primary endpoints were led by SRI-4 in 9 of 32 trials, or 28.1%.

Endpoint family presence by phase
Safety / tolerability
Phase II
79.2%
Phase III
50.0%
SLEDAI / PGA / BILAG activity scores
Phase II
54.2%
Phase III
46.9%
SRI-4 / SLE responder index
Phase II
20.8%
Phase III
34.4%
Flares / SFI
Phase II
33.3%
Phase III
46.9%
Phase II denominator: 24 trials. Phase III denominator: 32 trials.
Interpretation

Phase II lupus packages look more exploratory and tolerability-driven, while Phase III packages lean into validated systemic efficacy constructs and confirmatory clinical burden measures.

Monoclonal antibodies and small molecules carried broad endpoint packages; cell therapy emphasized remission and renal response

Three modality groups were large enough for comparison: monoclonal antibody trials appeared in 27 records, small-molecule trials in 22 records, and cell-therapy trials in 12 records. Safety endpoints appeared in 21 of 27 monoclonal-antibody trials, 18 of 22 small-molecule trials, and 8 of 12 cell-therapy trials.

Top endpoint families by modality
Monoclonal antibody · n=27
Safety: 21 / 27 · 77.8%
Activity scores: 19 / 27 · 70.4%
PK/PD: 18 / 27 · 66.7%
Steroid reduction: 18 / 27 · 66.7%
Small molecule · n=22
Safety: 18 / 22 · 81.8%
Activity scores: 13 / 22 · 59.1%
Steroid reduction: 12 / 22 · 54.5%
PRO/QoL: 11 / 22 · 50.0%
Cell therapy · n=12
Safety: 8 / 12 · 66.7%
Activity scores: 7 / 12 · 58.3%
DORIS remission: 6 / 12 · 50.0%
CRR: 6 / 12 · 50.0%
Combination trials can contribute to more than one modality denominator.
Interpretation

The most distinctive modality signal is cell therapy: DORIS drug-free remission and CRR each appeared in 6 of 12 cell-therapy records, suggesting a stronger remission-reset positioning than conventional lupus drug programs.

CTIS submission-to-first-authorization timing was similar between Phase II and Phase III lupus trials

Across the 56 included records, the median interval from initial CTIS submission to first authorization was 95 days, with an interquartile range of 35 to 112 days. Phase II and Phase III were nearly identical: 94.5 days for Phase II and 96.0 days for Phase III.

Median days from initial CTIS submission to first authorization
95
Overall median days
94.5
Phase II median days
96
Phase III median days
55
LN subgroup median days
Cutaneous lupus / CLE86.5 days
Lupus nephritis / renal SLE55 days
Systemic SLE81 days
CTIS = Clinical Trials Information System. Timing uses initial CTIS submission date and first authorization date.
Interpretation

Endpoint complexity did not translate into a clear Phase II versus Phase III timing gap in this cohort. For EU submission planning, lupus nephritis programs showed the shortest median CTIS path among the major lupus subgroups.

Additional answerable signals: endpoint load, evidence layering, and clinical burden coverage

The dataset also answers how heavy lupus endpoint packages are and where sponsors place supportive evidence. Across 56 trials, the cohort contained 468 endpoint items, with a median of 4.5 endpoint items per trial; Phase II and Phase III each contributed 234 endpoint items, but Phase II had the higher median endpoint load per trial at 7.5 versus 4.0 for Phase III.

Adjacent questions answered from the same dataset
How much endpoint content sits outside the primary endpoint?
412 of 468 endpoint items, or 88.0%, were secondary endpoint items.
How often do trials include patient-burden measures?
PRO/QoL endpoints appeared in 26 of 56 trials, or 46.4%, including FACIT, SF-36, EQ-5D, pain, fatigue, LupusQoL, Skindex, and related measures.
How often do trials support efficacy with steroid-sparing or flare endpoints?
Steroid-reduction endpoints appeared in 25 of 56 trials, or 44.6%, and flare/SFI endpoints appeared in 23 of 56 trials, or 41.1%.
Endpoint item counts are raw endpoint entries; endpoint-family counts are trial-level.
Interpretation

A competitive EU lupus protocol should not rely on one headline endpoint alone. The typical evidence package layers primary efficacy or safety with secondary burden, steroid-sparing, flare, PK/PD, and biomarker support.

Definitions used in this report

SRI-4 means Systemic Lupus Erythematosus Responder Index-4. BICLA means BILAG-based Combined Lupus Assessment. SLEDAI means Systemic Lupus Erythematosus Disease Activity Index. PGA means Physician Global Assessment. LLDAS means Lupus Low Disease Activity State. CLASI means Cutaneous Lupus Erythematosus Disease Area and Severity Index. CRR means complete renal response. SFI means SELENA-SLEDAI Flare Index. PK/PD means pharmacokinetics/pharmacodynamics.