Trial Outcomes & Findings for A Trial to Learn How Well REGN7508 Works for Preventing Blood Clots After a Knee Replacement in Adult Participants (NCT NCT06454630)
NCT ID: NCT06454630
Last Updated: 2026-03-02
Results Overview
Composite endpoint that includes asymptomatic deep DVT (deep venous thrombosis) detected by unilateral venography of the operated leg; confirmed symptomatic DVT of either leg; confirmed fatal or nonfatal pulmonary embolism (PE) including unexplained death for which PE cannot be ruled out.
COMPLETED
PHASE2
179 participants
Through day 12
2026-03-02
Participant Flow
Of 201 participants screened, 179 participants met eligibility criteria and were randomized. All 179 randomized participants received study intervention.
Participant milestones
| Measure |
REGN7508
Administered by single intravenous (IV) infusion
|
Enoxaparin
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Overall Study
STARTED
|
120
|
59
|
|
Overall Study
COMPLETED
|
116
|
58
|
|
Overall Study
NOT COMPLETED
|
4
|
1
|
Reasons for withdrawal
| Measure |
REGN7508
Administered by single intravenous (IV) infusion
|
Enoxaparin
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Overall Study
Lost to Follow-up
|
1
|
0
|
|
Overall Study
Withdrawal by Subject
|
3
|
1
|
Baseline Characteristics
A Trial to Learn How Well REGN7508 Works for Preventing Blood Clots After a Knee Replacement in Adult Participants
Baseline characteristics by cohort
| Measure |
REGN7508
n=120 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=59 Participants
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
Total
n=179 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
66.3 years
STANDARD_DEVIATION 7.50 • n=41 Participants
|
66.6 years
STANDARD_DEVIATION 7.53 • n=35 Participants
|
66.4 years
STANDARD_DEVIATION 7.49 • n=76 Participants
|
|
Sex: Female, Male
Female
|
92 Participants
n=41 Participants
|
44 Participants
n=35 Participants
|
136 Participants
n=76 Participants
|
|
Sex: Female, Male
Male
|
28 Participants
n=41 Participants
|
15 Participants
n=35 Participants
|
43 Participants
n=76 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
4 Participants
n=41 Participants
|
1 Participants
n=35 Participants
|
5 Participants
n=76 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
115 Participants
n=41 Participants
|
58 Participants
n=35 Participants
|
173 Participants
n=76 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
1 Participants
n=41 Participants
|
0 Participants
n=35 Participants
|
1 Participants
n=76 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=41 Participants
|
0 Participants
n=35 Participants
|
0 Participants
n=76 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=41 Participants
|
0 Participants
n=35 Participants
|
0 Participants
n=76 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=41 Participants
|
0 Participants
n=35 Participants
|
0 Participants
n=76 Participants
|
|
Race (NIH/OMB)
Black or African American
|
0 Participants
n=41 Participants
|
0 Participants
n=35 Participants
|
0 Participants
n=76 Participants
|
|
Race (NIH/OMB)
White
|
120 Participants
n=41 Participants
|
59 Participants
n=35 Participants
|
179 Participants
n=76 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=41 Participants
|
0 Participants
n=35 Participants
|
0 Participants
n=76 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=41 Participants
|
0 Participants
n=35 Participants
|
0 Participants
n=76 Participants
|
PRIMARY outcome
Timeframe: Through day 12Population: Modified Intention to Treat Population (mITT): Randomized participants that had either an evaluable venogram, a confirmed episode of venous thromboembolism, or both.
Composite endpoint that includes asymptomatic deep DVT (deep venous thrombosis) detected by unilateral venography of the operated leg; confirmed symptomatic DVT of either leg; confirmed fatal or nonfatal pulmonary embolism (PE) including unexplained death for which PE cannot be ruled out.
Outcome measures
| Measure |
REGN7508
n=113 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=58 Participants
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Percentage of Participants With Confirmed, Adjudicated Venous Thromboembolism (VTE)
|
7.1 percentage of participants
|
17.2 percentage of participants
|
SECONDARY outcome
Timeframe: Through day 12Population: mITT population
International Society on Thrombosis and Hemostasis (ISTH) criteria for Major Bleeding and CRNM Bleeding as described in the protocol
Outcome measures
| Measure |
REGN7508
n=113 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=58 Participants
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Number of Participants With Major Bleeding and Clinically Relevant Non-major (CRNM) Bleeding
Major bleeding
|
0 Participants
|
0 Participants
|
|
Number of Participants With Major Bleeding and Clinically Relevant Non-major (CRNM) Bleeding
CRNM bleeding
|
0 Participants
|
0 Participants
|
SECONDARY outcome
Timeframe: Through day 75Population: Safety Analysis Set (SAF): All randomized participants who received any study drug; it is based on the treatment received (as treated).
A TEAE is any untoward medical occurrence in a participant administered a pharmaceutical product, which does not necessarily have a causal relationship with this treatment.
Outcome measures
| Measure |
REGN7508
n=120 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=59 Participants
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Percentage of Participants With at Least One Treatment Emergent Adverse Event (TEAE)
|
21.7 percentage of participants
|
28.8 percentage of participants
|
SECONDARY outcome
Timeframe: Through day 12Population: mITT population
Major VTE is a composite endpoint that includes: proximal DVT; confirmed symptomatic DVT of either leg; confirmed fatal or nonfatal PE including unexplained death for which PE cannot be ruled out.
Outcome measures
| Measure |
REGN7508
n=113 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=58 Participants
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Percentage of Participants With Major VTE
|
0 percentage of participants
|
1.7 percentage of participants
|
SECONDARY outcome
Timeframe: Through day 12Population: mITT population
DVT measured by venography of the operated leg
Outcome measures
| Measure |
REGN7508
n=113 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=58 Participants
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Percentage of Participants With Deep Venous Thrombosis (DVT)
|
7.1 percentage of participants
|
17.2 percentage of participants
|
SECONDARY outcome
Timeframe: Days 1, 5, 10, 30 and 75Population: All participants in the REGN7508 treatment group who received study drug and who had at least 1 non-missing result following the first dose of study drug and who were evaluable at time points specified for this outcome measure.
Outcome measures
| Measure |
REGN7508
n=120 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Concentrations of Total REGN7508 in Serum
Day 1 (1 hour post REGN7508 dose)
|
54.3 milligrams per liter (mg/L)
Standard Deviation 15.1
|
—
|
|
Concentrations of Total REGN7508 in Serum
Day 5
|
29.2 milligrams per liter (mg/L)
Standard Deviation 9.94
|
—
|
|
Concentrations of Total REGN7508 in Serum
Day 10
|
20.9 milligrams per liter (mg/L)
Standard Deviation 6.46
|
—
|
|
Concentrations of Total REGN7508 in Serum
Day 30
|
6.82 milligrams per liter (mg/L)
Standard Deviation 3.28
|
—
|
|
Concentrations of Total REGN7508 in Serum
Day 75
|
0.696 milligrams per liter (mg/L)
Standard Deviation 0.556
|
—
|
SECONDARY outcome
Timeframe: Days 1, 5, 10, 30, 75Population: All randomized participants who received any study drug and who had at least 1 non-missing pharmacodynamic (PD) result following the first dose of study drug and who were evaluable at time points specified for this outcome measure.
aPTT was used to measure the anticipated anticoagulant effect of REGN7508. Fold change is based on the follow-up value/baseline value within an arm.
Outcome measures
| Measure |
REGN7508
n=117 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=58 Participants
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Fold Change From Baseline in Activated Partial Thromboplastin Time (aPTT)
Day 75
|
1.01 Fold Change
Standard Deviation 0.190
|
1.04 Fold Change
Standard Deviation 0.214
|
|
Fold Change From Baseline in Activated Partial Thromboplastin Time (aPTT)
Day 1
|
2.80 Fold Change
Standard Deviation 0.620
|
—
|
|
Fold Change From Baseline in Activated Partial Thromboplastin Time (aPTT)
Day 5
|
3.24 Fold Change
Standard Deviation 0.753
|
1.15 Fold Change
Standard Deviation 0.265
|
|
Fold Change From Baseline in Activated Partial Thromboplastin Time (aPTT)
Day 10
|
3.10 Fold Change
Standard Deviation 0.856
|
1.06 Fold Change
Standard Deviation 0.123
|
|
Fold Change From Baseline in Activated Partial Thromboplastin Time (aPTT)
Day 30
|
1.39 Fold Change
Standard Deviation 0.612
|
1.07 Fold Change
Standard Deviation 0.227
|
SECONDARY outcome
Timeframe: Days 1, 5, 10, 30, 75Population: All randomized participants who received any study drug and who had at least 1 non-missing pharmacodynamic (PD) result following the first dose of study drug and who were evaluable at time points specified for this outcome measure.
PT is a measure of extrinsic and/or common pathway function. Fold change is based on the follow-up value/baseline value within an arm.
Outcome measures
| Measure |
REGN7508
n=117 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=58 Participants
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Fold Change From Baseline in Prothrombin Time (PT)
Day 1
|
1.11 Fold Change
Standard Deviation 0.707
|
—
|
|
Fold Change From Baseline in Prothrombin Time (PT)
Day 5
|
0.97 Fold Change
Standard Deviation 0.092
|
0.95 Fold Change
Standard Deviation 0.077
|
|
Fold Change From Baseline in Prothrombin Time (PT)
Day 10
|
0.96 Fold Change
Standard Deviation 0.086
|
0.94 Fold Change
Standard Deviation 0.066
|
|
Fold Change From Baseline in Prothrombin Time (PT)
Day 30
|
0.96 Fold Change
Standard Deviation 0.125
|
1.02 Fold Change
Standard Deviation 0.265
|
|
Fold Change From Baseline in Prothrombin Time (PT)
Day 75
|
0.94 Fold Change
Standard Deviation 0.084
|
0.97 Fold Change
Standard Deviation 0.198
|
SECONDARY outcome
Timeframe: Through end of study; approximately Day 75Population: Participants who received any REGN7508 and who had at least 1 non-missing anti-REGN7508 antibody result following the first dose of study drug.
Immunogenicity characterized by anti-drug antibody (ADA) status
Outcome measures
| Measure |
REGN7508
n=116 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Number of Participants With Anti-REGN7508 Antibodies by Status
Negative
|
112 Participants
|
—
|
|
Number of Participants With Anti-REGN7508 Antibodies by Status
Pre-existing Immunoreactivity
|
2 Participants
|
—
|
|
Number of Participants With Anti-REGN7508 Antibodies by Status
Treatment-Boosted Response
|
0 Participants
|
—
|
|
Number of Participants With Anti-REGN7508 Antibodies by Status
Treatment-Emergent Response
|
2 Participants
|
—
|
SECONDARY outcome
Timeframe: Through end of study; approximately Day 75Immunogenicity characterized per by ADA status
Outcome measures
| Measure |
REGN7508
n=2 Participants
Administered by single intravenous (IV) infusion
|
Enoxaparin
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Number of Participants With Treatment-Emergent or Treatment-Boosted Anti-REGN7508 Antibodies by Maximum Titer
Low (<1,000)
|
1 Participants
|
—
|
|
Number of Participants With Treatment-Emergent or Treatment-Boosted Anti-REGN7508 Antibodies by Maximum Titer
Moderate (1,000 to 10,000)
|
1 Participants
|
—
|
|
Number of Participants With Treatment-Emergent or Treatment-Boosted Anti-REGN7508 Antibodies by Maximum Titer
High (>10,000)
|
0 Participants
|
—
|
Adverse Events
REGN7508
Enoxaparin
Serious adverse events
| Measure |
REGN7508
n=120 participants at risk
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=59 participants at risk
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Infections and infestations
Diverticulitis
|
0.83%
1/120 • Number of events 1 • From signing of informed consent to end of study (up to Day 75)
|
0.00%
0/59 • From signing of informed consent to end of study (up to Day 75)
|
|
Injury, poisoning and procedural complications
Joint dislocation
|
0.83%
1/120 • Number of events 1 • From signing of informed consent to end of study (up to Day 75)
|
0.00%
0/59 • From signing of informed consent to end of study (up to Day 75)
|
Other adverse events
| Measure |
REGN7508
n=120 participants at risk
Administered by single intravenous (IV) infusion
|
Enoxaparin
n=59 participants at risk
Administered by daily subcutaneous (SC) injections through the time of venography (or day 12, whichever was earlier)
|
|---|---|---|
|
Gastrointestinal disorders
Nausea
|
1.7%
2/120 • Number of events 2 • From signing of informed consent to end of study (up to Day 75)
|
5.1%
3/59 • Number of events 3 • From signing of informed consent to end of study (up to Day 75)
|
|
Infections and infestations
Respiratory tract infection viral
|
0.00%
0/120 • From signing of informed consent to end of study (up to Day 75)
|
5.1%
3/59 • Number of events 3 • From signing of informed consent to end of study (up to Day 75)
|
|
Injury, poisoning and procedural complications
Anaemia postoperative
|
5.0%
6/120 • Number of events 6 • From signing of informed consent to end of study (up to Day 75)
|
0.00%
0/59 • From signing of informed consent to end of study (up to Day 75)
|
Additional Information
Clinical Trials Administrator
Regeneron Pharmaceuticals, Inc.
Results disclosure agreements
- Principal investigator is a sponsor employee The investigator has the right to independently publish study results from the investigator's site after a multi-center publication, or a defined period after the completion of the study by all sites. The investigator must provide the Sponsor a copy of any such publication derived from the study for review and comment in advance of any submission, and delay publication, if requested, to allow the Sponsor to preserve its proprietary rights.
- Publication restrictions are in place
Restriction type: OTHER