Trial Outcomes & Findings for Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of ANX005 in Participants With Warm Autoimmune Hemolytic Anemia (wAIHA) (NCT NCT04691570)

Last Updated: 2026-06-30

Results Overview

An adverse event (AE) was any untoward medical occurrence in a participant who had been administered a pharmaceutical product. An AE did not necessarily have a causal relationship with the product and therefore could be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a pharmaceutical product. An AE could arise with any use, route of administration, formulation, dose (including an overdose), or when used in combination with another pharmaceutical product. A TEAE was an AE with an onset date/time after the first infusion of ANX005 until the end of the study. A summary of serious and all other non-serious adverse events regardless of causality is located in the Adverse Events module.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

7 participants

Primary outcome timeframe

Day 1 through Day 71

Results posted on

2026-06-30

Participant Flow

Participants with wAIHA who met eligibility criteria were enrolled.

Participant milestones

Participant milestones
Measure	ANX005 Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Overall Study STARTED	7
Overall Study Received at Least 1 Dose of Study Drug	6
Overall Study COMPLETED	6
Overall Study NOT COMPLETED	1

Reasons for withdrawal

Reasons for withdrawal
Measure	ANX005 Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Overall Study Withdrawal by Subject	1

Baseline Characteristics

Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of ANX005 in Participants With Warm Autoimmune Hemolytic Anemia (wAIHA)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Age, Continuous	59.0 years STANDARD_DEVIATION 7.56 • n=20 Participants
Age, Customized In utero	0 Participants n=20 Participants
Age, Customized Preterm newborn infants (gestational age < 37 wks)	0 Participants n=20 Participants
Age, Customized Newborns (0-27 days)	0 Participants n=20 Participants
Age, Customized Infants and toddlers (28 days-23 months)	0 Participants n=20 Participants
Age, Customized Children (2-11 years)	0 Participants n=20 Participants
Age, Customized Adolescents (12-17 years)	0 Participants n=20 Participants
Age, Customized Adults (18-64 years)	5 Participants n=20 Participants
Age, Customized From 65-84 years	1 Participants n=20 Participants
Age, Customized 85 years and over	0 Participants n=20 Participants
Sex: Female, Male Female	5 Participants n=20 Participants
Sex: Female, Male Male	1 Participants n=20 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=20 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	6 Participants n=20 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=20 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=20 Participants
Race (NIH/OMB) Asian	0 Participants n=20 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=20 Participants
Race (NIH/OMB) Black or African American	0 Participants n=20 Participants
Race (NIH/OMB) White	6 Participants n=20 Participants
Race (NIH/OMB) More than one race	0 Participants n=20 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=20 Participants

PRIMARY outcome

Timeframe: Day 1 through Day 71

Population: Safety Population: all participants who received any amount of ANX005.

Outcome measures

Outcome measures
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Number of Participants With Treatment-emergent Adverse Events (TEAEs)	6 participants

PRIMARY outcome

Timeframe: Baseline up to Day 71

Population: Safety Population: all participants who received any amount of ANX005. Number analyzed' = participants evaluable at specified timepoint.

Maximum change from Baseline was calculated as the maximum post-Baseline value observed up to Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Outcome measures

Outcome measures
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Maximum Change From Baseline in Hemoglobin Levels Baseline	9.03 grams/deciliters (dL) Standard Deviation 0.653
Maximum Change From Baseline in Hemoglobin Levels Maximum Change from Baseline	1.30 grams/deciliters (dL) Standard Deviation 0.846

PRIMARY outcome

Timeframe: Baseline, Day 71

Population: Safety Population: all participants who received any amount of ANX005.

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Outcome measures

Outcome measures
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Change From Baseline in Lactate Dehydrogenase Levels at Day 71 Baseline	339.8 units per liter (L) Standard Deviation 84.88 • Interval 84.88 to
Change From Baseline in Lactate Dehydrogenase Levels at Day 71 Change from Baseline	7.8 units per liter (L) Standard Deviation 70.02 • Interval 70.02 to

PRIMARY outcome

Timeframe: Baseline, Day 71

Population: Safety Population: all participants who received any amount of ANX005.

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Outcome measures

Outcome measures
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Change From Baseline in Percentage of Reticulocytes/Total Cells Count at Day 71 Baseline	6.58 percentage of reticulocytes/total cells Standard Deviation 4.706
Change From Baseline in Percentage of Reticulocytes/Total Cells Count at Day 71 Change from Baseline	0.77 percentage of reticulocytes/total cells Standard Deviation 1.607

PRIMARY outcome

Timeframe: Baseline, Day 71

Population: Safety Population: all participants who received any amount of ANX005.

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Outcome measures

Outcome measures
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Change From Baseline in Haptoglobin Levels at Day 71 Baseline	9.0 milligrams (mg)/dL Standard Deviation 14.21 • Interval 14.21 to
Change From Baseline in Haptoglobin Levels at Day 71 Change from Baseline	1.0 milligrams (mg)/dL Standard Deviation 8.99 • Interval 8.99 to

PRIMARY outcome

Timeframe: Baseline, Day 71

Population: Safety Population: all participants who received any amount of ANX005.

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Outcome measures

Outcome measures
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Change From Baseline in Total Bilirubin Levels at Day 71 Baseline	34.43 micromole (µmol)/L Standard Deviation 22.848 • Interval 22.848 to
Change From Baseline in Total Bilirubin Levels at Day 71 Change from baseline	8.55 micromole (µmol)/L Standard Deviation 18.940 • Interval 18.94 to

PRIMARY outcome

Timeframe: Baseline, Day 71

Population: Safety Population: all participants who received any amount of ANX005.

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Outcome measures

Outcome measures
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Change From Baseline in Indirect Bilirubin Levels at Day 71 Change from Baseline	4.75 µmol/L Standard Deviation 11.951 • Interval 11.951 to
Change From Baseline in Indirect Bilirubin Levels at Day 71 Baseline	17.22 µmol/L Standard Deviation 12.008 • Interval 12.008 to

SECONDARY outcome

Timeframe: Baseline, Days 2, 4, 8, 15, 22, 29, 36, 43, 50, 57, and 71

Population: Safety Population: all participants who received any amount of ANX005.Number analyzed' = participants evaluable at specified timepoint.

Change in percent inhibition complement CH50 from Baseline was calculated as the post-Baseline value minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005. A decrease form baseline indicated a better outcome.

Outcome measures

Outcome measures
Measure	ANX005 n=5 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Baseline	27.38 activity percent Standard Deviation 11.481
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 2	-12.50 activity percent Standard Deviation 11.747
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 4	-12.50 activity percent Standard Deviation 11.747
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 8	-12.50 activity percent Standard Deviation 11.747
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 15	-12.50 activity percent Standard Deviation 11.747
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 22	-12.50 activity percent Standard Deviation 11.747
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 29	-11.43 activity percent Standard Deviation 10.722
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 36	-0.13 activity percent Standard Deviation 11.777
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 43	4.95 activity percent Standard Deviation 14.850
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 50	3.20 activity percent Standard Deviation 16.530
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 57	-5.27 activity percent Standard Deviation 5.154
Change in Percent Inhibition Complement CH50 From Baseline Through Day 71 Change from Baseline: Day 71	5.85 activity percent Standard Deviation 19.298

SECONDARY outcome

Timeframe: Baseline, Days 2, 4, 8 (pre-dose and end of infusion), 15, 22, 29, 36, 43, 50, 57, and 71

Population: Safety Population: all participants who received any amount of ANX005. Number analyzed' = participants evaluable at specified timepoint.

Change from Baseline was calculated as the post-Baseline value at Day 71 minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Outcome measures

Outcome measures
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 71	-0.07 mg/dL Standard Deviation 4.507
Change From Baseline in Complement C4 Level Through Day 71 Baseline	9.85 mg/dL Standard Deviation 8.704
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 2 End of Infusion	-6.38 mg/dL Standard Deviation 8.968
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 4	0.00 mg/dL Standard Deviation 9.036
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 8 Pre-dose	-0.47 mg/dL Standard Deviation 8.214
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 8 End of Infusion	-1.54 mg/dL Standard Deviation 9.327
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 15	0.52 mg/dL Standard Deviation 9.383
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 22	0.25 mg/dL Standard Deviation 8.993
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 29	4.42 mg/dL Standard Deviation 7.669
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 36	-1.16 mg/dL Standard Deviation 5.809
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 43	1.26 mg/dL Standard Deviation 2.740
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 50	-0.38 mg/dL Standard Deviation 1.708
Change From Baseline in Complement C4 Level Through Day 71 Change from Baseline: Day 57	-2.00 mg/dL Standard Deviation 2.012

SECONDARY outcome

Timeframe: Baseline, Days 2 (4 hours [hr] after Infusion and end of infusion), 4, 8 (pre-dose, 4 hr after Infusion, and end of infusion), 15, 22, 29, 36, 43, 50, 57, and 71

Population: Safety Population: all participants who received any amount of ANX005. Number analyzed' = participants evaluable at specified timepoint.

Change from Baseline was calculated as the post-Baseline value minus the Baseline value. Baseline was defined as the last non-missing observation recorded before the first dose of ANX005.

Outcome measures

Outcome measures
Measure	ANX005 n=6 Participants Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Change From Baseline in Complement C1q Level Through Day 71 Baseline	125906.7 nanograms/milliliters Standard Deviation 83730.04
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 2 (End of Infusion)	-123406.7 nanograms/milliliters Standard Deviation 83730.04
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 2 (4 hr after Infusion)	-92144.0 nanograms/milliliters Standard Deviation 25572.09
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 4	-120863.3 nanograms/milliliters Standard Deviation 86782.71
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 8 (Pre-dose)	-114658.3 nanograms/milliliters Standard Deviation 95534.57
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 8 (End of Infusion)	-139190.0 nanograms/milliliters Standard Deviation 83036.43
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 8 (4 hr after Infusion)	-139190.0 nanograms/milliliters Standard Deviation 83036.43
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 15	-113278.3 nanograms/milliliters Standard Deviation 97696.09
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 22	-108186.7 nanograms/milliliters Standard Deviation 103427.02
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 29	-73786.0 nanograms/milliliters Standard Deviation 82530.85
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 36	-51298.0 nanograms/milliliters Standard Deviation 43444.46
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 43	-29952.0 nanograms/milliliters Standard Deviation 47280.34
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 50	-4525.0 nanograms/milliliters Standard Deviation 18893.85
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 57	6447.5 nanograms/milliliters Standard Deviation 34873.98
Change From Baseline in Complement C1q Level Through Day 71 Change from Baseline: Day 71	25240.0 nanograms/milliliters Standard Deviation 44201.47

Adverse Events

ANX005

Serious events: 1 serious events

Other events: 6 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	ANX005 n=6 participants at risk Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Blood and lymphatic system disorders Haemolytic anaemia	16.7% 1/6 • Number of events 2 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).

Other adverse events

Other adverse events
Measure	ANX005 n=6 participants at risk Participants were administered intravenous infusion of ANX005 on Day 1 and Day 8.
Blood and lymphatic system disorders Anaemia	33.3% 2/6 • Number of events 2 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Blood and lymphatic system disorders Warm type haemolytic anaemia	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
General disorders Oedema peripheral	33.3% 2/6 • Number of events 2 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
General disorders Face oedema	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
General disorders Pyrexia	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Skin and subcutaneous tissue disorders Rash	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Skin and subcutaneous tissue disorders Rash erythematous	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Skin and subcutaneous tissue disorders Rash maculo-papular	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Gastrointestinal disorders Diarrhea	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Gastrointestinal disorders Hypoaesthesia oral	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Ear and labyrinth disorders Vertigo positional	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Immune system disorders Cytokine release syndrome	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Infections and infestations COVID-19	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Musculoskeletal and connective tissue disorders Arthralgia	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Nervous system disorders Headache	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).
Respiratory, thoracic and mediastinal disorders Dry throat	16.7% 1/6 • Number of events 1 • Day 1 through Day 71 All-cause mortality was assessed for all enrolled participants. AEs were assessed for all participants who received any amount of ANX005 (Safety Population).

Additional Information

Study Coordinator

Annexon, Inc.

Phone: 650-822-5500

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee Written approval from the Sponsor is required before disclosing any information relative to this clinical study, and no publications initiated by Investigators may be published until all protocol-defined results are published in a manuscript. The details and processes of producing and reviewing reports, manuscripts, and presentations based on the data from this study are described in the clinical study agreement between the Sponsor and the institution of the Investigator.
Publication restrictions are in place

Restriction type: OTHER