Trial Outcomes & Findings for A Study to Investigate DSA Rebound in Patients Treated With Imlifidase Prior to Transplantation (NCT NCT05049850)

NCT ID: NCT05049850

Last Updated: 2025-10-21

Results Overview

The recurrence of DSA may cause AMR and increased risk of graft loss. Due to the early termination of the trial the primary endpoint was assessed as the incidence of DSA rebound of either immunodominant or total DSA to a mean fluorescence intensity (MFI) level that was ≥50% of the pre-imlifidase value up to 3 months after transplantation (trial day 91).

• Recruitment status: TERMINATED
• Study phase: PHASE2
• Target enrollment: 3 participants
• Primary outcome timeframe: Up to 3 months after transplantation
• Results posted on: 2025-10-21

Participant Flow

The Sponsor decided to prematurely terminate the trial after 3 of the 12 patients had been treated and transplanted in the trial due to prioritization of internal resources. This decision was unrelated to either safety or efficacy, no safety issues were raised during the conduct of the trial.

Participant milestones

Measure	Imlifidase Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Overall Study STARTED	3
Overall Study COMPLETED	3
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

A Study to Investigate DSA Rebound in Patients Treated With Imlifidase Prior to Transplantation

Baseline characteristics by cohort

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	3 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants
Sex: Female, Male Female	2 Participants n=5 Participants
Sex: Female, Male Male	1 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	1 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants
Race (NIH/OMB) White	2 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Region of Enrollment United States	3 participants n=5 Participants

PRIMARY outcome

Timeframe: Up to 3 months after transplantation

The recurrence of DSA may cause AMR and increased risk of graft loss. Due to the early termination of the trial the primary endpoint was assessed as the incidence of DSA rebound of either immunodominant or total DSA to a mean fluorescence intensity (MFI) level that was ≥50% of the pre-imlifidase value up to 3 months after transplantation (trial day 91).

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Proportion of Patients With DSA Rebound	0 Participants

SECONDARY outcome

Timeframe: Up to 6 months after transplantation

The standardized international Banff classification 2019 for assessment of renal allograft biopsies will be used to assess AMRs reported from the study based on for cause and protocol biopsies.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Proportion of Patients With Kidney Biopsy Proven AMR	1 Participants

SECONDARY outcome

Timeframe: Up to 6 months after transplantation

See description to primary outcome measure

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Proportion of Patient With DSA Rebound	0 Participants

SECONDARY outcome

Timeframe: Up to 24 hours after imlifidase treatment

Imlifidase is highly efficacious in converting a positive crossmatch to a negative

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Proportion of Patients With Negative FCXM	3 Participants

SECONDARY outcome

Timeframe: Within 4 hours before imlifidase until Day 181

Population: Only 2 of 3 patients had data for DSA collected at the Day 181 timepoint, for patient 2 data from an unscheduled visit at day 139 is presented.

Analysis of DSAs before and after imlifidase will be done. The mean fluorescence intensity (MFI) will be presented for the individual patients' DSAs.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Levels of DSA Patient 1, pre-dose	22311 MFI
Levels of DSA Patient 1, Day 181	8619 MFI
Levels of DSA Patient 2, pre-dose	8526 MFI
Levels of DSA Patient 2, Day 139	2172 MFI
Levels of DSA Patient 3, pre-dose	9994 MFI
Levels of DSA Patient 3, Day 181	149 MFI

SECONDARY outcome

Timeframe: Within 4 hours before imlifidase until Day 181

Population: Samples for assessment of DSA, including Cq1 DSA, were collected. However, the central laboratory assigned to Cq1 DSA analyzes was never activated due to the premature trial termination, hence analysis of Cq1 DSA was not performed.

Analysis of C1q DSAs before and after imlifidase will be done. The mean fluorescence intensity (MFI) will be presented for the individual patients' C1q DSAs.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 6 months after transplantation

Graft survival will be summarized by end of trial.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Number of Participants With Graft Survival	3 Participants

SECONDARY outcome

Timeframe: 6 months after transplantation

Patient survival will be summarized by end of trial.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Patients Survival	3 Participants

SECONDARY outcome

Timeframe: Up to 6 months after transplantation

Population: Results for adverse events is presented in the section Reported Adverse Events.

Safety is assessed as type, frequency and intensity of adverse events (AEs)/serious adverse events (SAEs) including clinically relevant changes in clinical laboratory tests, vital signs and ECG)

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Number of Participants With Adverse Events (AEs)	3 Participants

SECONDARY outcome

Timeframe: Up to 6 months after transplantation

P-creatinine is a measure of kidney function.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Kidney Function Assessed by Creatinine Pre-dose	506 μmol/L Interval 305.0 to 682.0
Kidney Function Assessed by Creatinine Day 181	180 μmol/L Interval 91.0 to 184.0

SECONDARY outcome

Timeframe: Up to 6 months after transplantation

Estimated glomerular filtration rate (eGFR) is a measure of kidney function. eGFR will be calculated as described by the modification of diet in renal disease (MDRD) equation.

eGFR for a kidney with normal function is 90 mL/min/1.73m2. Kidney disease is characterized by a decreased eGFR value.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Kidney Function Assessed by Estimated Glomerular Filtration Rate (eGFR) Pre-dose	11 mL/min/1.73m2 Interval 6.0 to 14.0
Kidney Function Assessed by Estimated Glomerular Filtration Rate (eGFR) Day 181	35 mL/min/1.73m2 Interval 26.0 to 60.0

SECONDARY outcome

Timeframe: Up to 6 months after transplantation

Population: Only 2 of the 3 patients had data collected at the Day 181 timepoint.

The protein/creatinine ratio in urine is a measure of kidney function. Will be measured unless patients are anuric.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Kidney Function Assessed by Protein/Creatinine Ratio in Urine 24h post-dose	2158 mg/g Interval 1900.0 to 120025.0
Kidney Function Assessed by Protein/Creatinine Ratio in Urine Day 181	1233 mg/g Interval 470.0 to 1996.0

SECONDARY outcome

Timeframe: Within 4 hours before imlifidase dose until Day 15

AUC = Area under the imlifidase plasma concentration versus time curve

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Imlifidase Pharmacokinetics (AUC)	71.9 h×μg/mL Interval 65.6 to 119.0

SECONDARY outcome

Timeframe: Within 4 hours before imlifidase dose until Day 15

Cmax = Maximum observed plasma concentration of imlifidase following dosing

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Imlifidase Pharmacokinetics (Cmax)	3.70 μg/mL Interval 3.2 to 4.1

SECONDARY outcome

Timeframe: Within 4 hours before imlifidase dose until Day 15

tmax = Time point for maximum observed plasma concentration of imlifidase following dosing

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Imlifidase Pharmacokinetics (Tmax)	1.13 h Interval 1.0 to 1.25

SECONDARY outcome

Timeframe: Within 4 hours before imlifidase dose until Day 15

t1/2 = Terminal half-life of imlifidase, the time taken for concentration of imlifidase to decrease from its maximum concentration (Cmax) to half of Cmax in the blood plasma.

t1/2 alpha = alpha phase (distribution/elimination) half-life, an initial phase of rapid decrease in plasma concentration.

t1/2 beta = beta phase (elimination) half-life, a phase of gradual decrease in plasma concentration after the alpha phase.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Imlifidase Pharmacokinetics (t1/2) t1/2 alpha	6.40 h Interval 1.05 to 9.29
Imlifidase Pharmacokinetics (t1/2) t1/2 beta	28.3 h Interval 26.7 to 37.2

SECONDARY outcome

Timeframe: Within 4 hours before imlifidase dose until Day 15

CL = Clearance of imlifidase

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Imlifidase Pharmacokinetics (CL)	3.48 mL/h/kg Interval 2.11 to 3.81

SECONDARY outcome

Timeframe: Within 4 hours before imlifidase dose until Day 15

Vz = Apparent volume of distribution during terminal phase

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Imlifidase Pharmacokinetics (Vz)	0.142 L/kg Interval 0.081 to 0.205

SECONDARY outcome

Timeframe: Within 4 hours before imlifidase dose until Day 10

Concentration of IgG in patient serum will be measured. Scoring of IgG fragments will be done.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Pharmacodynamics Pre-dose	11.6 g/L Interval 5.2 to 15.7
Pharmacodynamics Day 10	1.0 g/L Interval 0.6 to 3.4

SECONDARY outcome

Timeframe: Up to 6 months after imlifidase

Immunogenicity towards imlifidase will be assessed by the measurement of ADA levels in patient serum using a customized ImmunoCAP analysis.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Anti-drug Antibodies (ADA) Levels Day 181	20.5 mg/L Interval 13.7 to 30.2
Anti-drug Antibodies (ADA) Levels Pre-dose	4.1 mg/L Interval 2.4 to 82.9

SECONDARY outcome

Timeframe: At screening and Day 181

Population: PROMIS-SF-8 sores are calculate using the PROMIS® Short Form v2.0-Ability to Participate in Social Roles and Activities 8a scoring manual. The total scale raw score was translated into a T-score for each participant. The T-score rescales the raw score into a standardized score with a mean of 50 and a standard deviation (SD) of 10, i.e. a T-score of 40 is one SD below the mean. The lowest possible T-score is 25.9 and the highest possible score is 65.4, a higher score means a better outcome.

The PROMIS Social Health domain "Ability to participate in social roles & activities PROMIS-SF-8" will be used as a measure of the patients' health related quality of life.

Outcome measures

Measure	Imlifidase n=3 Participants Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Change in Patient-reported Life Participation, as Measured PROMIS-SF-8a Screening	53.6 score on a scale Interval 44.0 to 54.6
Change in Patient-reported Life Participation, as Measured PROMIS-SF-8a Day 181	65.4 score on a scale Interval 60.2 to 65.4

Adverse Events

Imlifidase

Serious events: 2 serious events

Other events: 3 other events

Deaths: 0 deaths

Serious adverse events

Measure	Imlifidase n=3 participants at risk Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Gastrointestinal disorders Abdominal pain	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Injury, poisoning and procedural complications Post procedural discharge	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Infections and infestations Wound evisceration	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Investigations Donor specific antibody present	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Investigations International normalised ratio increased	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Vascular disorders Hypotension	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.

Other adverse events

Measure	Imlifidase n=3 participants at risk Imlifidase is administered intravenously as one dose of 0.25 mg/kg over 15 minutes within the 24-hour period prior to transplantation. (A second dose may be given if the crossmatch test at 4 hours after the first dose remains positive.)
Blood and lymphatic system disorders Anaemia	66.7% 2/3 • Number of events 2 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Blood and lymphatic system disorders Thrombocytopenia	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Gastrointestinal disorders Abdominal pain	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Gastrointestinal disorders Haemorrhoids	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Gastrointestinal disorders Small intestinal obstruction	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Infections and infestations Abdominal infection	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Injury, poisoning and procedural complications Delayed graft function	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Injury, poisoning and procedural complications Infusion related reaction	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Investigations Alanine aminotransferase increased	66.7% 2/3 • Number of events 2 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Investigations Aspartate aminotransferase increased	66.7% 2/3 • Number of events 2 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Investigations Neutrophil count decreased	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Investigations White blood cell count decreased	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Metabolism and nutrition disorders Hypokalaemia	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Musculoskeletal and connective tissue disorders Arthralgia	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Nervous system disorders Headache	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Nervous system disorders Paraesthesia	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Renal and urinary disorders Renal infarct	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.
Vascular disorders Deep vein thrombosis	33.3% 1/3 • Number of events 1 • AEs were collected on the AE CRF for each patient, from the time of signing of the informed consent and throughout the trial including the follow-up period. 35 Days in screening phase plus 181 Days in trial, a total of 216 Days.

Additional Information

Study Director

Hansa Biopharma AB

Phone: +46 46 16 56 70

Email: clinicalstudyinfo@hansabiopharma.com

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place