Trial Outcomes & Findings for A Study to Evaluate the Pharmacokinetics, Safety and Immunogenicity of BIIB800 Subcutaneously (SC) Compared to Actemra® in Healthy Male Participants (NCT NCT06262477)

NCT ID: NCT06262477

Last Updated: 2025-10-06

Results Overview

Recruitment status

COMPLETED

Study phase

PHASE1

Target enrollment

300 participants

Primary outcome timeframe

Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Results posted on

2025-10-06

Participant Flow

Healthy male participants were enrolled in this study from 02 January 2024 to 04 October 2024 at investigative sites in the US and UK.

Overall, 342 participants were screened, of which 300 were randomized in the study. Of the 300 participants randomized, 150 participants received a single dose of BIIB800 subcutaneous (SC) injection and 150 participants received a single dose of Actemra SC injection.

Participant milestones

Participant milestones
Measure	BIIB800 Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Overall Study STARTED	150	150
Overall Study COMPLETED	149	148
Overall Study NOT COMPLETED	1	2

Reasons for withdrawal

Reasons for withdrawal
Measure	BIIB800 Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Overall Study Withdrawal by Subject	1	0
Overall Study Adverse Event	0	1
Overall Study Lost to Follow-up	0	1

Baseline Characteristics

A Study to Evaluate the Pharmacokinetics, Safety and Immunogenicity of BIIB800 Subcutaneously (SC) Compared to Actemra® in Healthy Male Participants

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	BIIB800 n=150 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=150 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Total n=300 Participants Total of all reporting groups
Age, Continuous	33.9 years STANDARD_DEVIATION 9.34 • n=99 Participants	34.0 years STANDARD_DEVIATION 9.93 • n=107 Participants	33.9 years STANDARD_DEVIATION 9.62 • n=206 Participants
Sex: Female, Male Female	0 Participants n=99 Participants	0 Participants n=107 Participants	0 Participants n=206 Participants
Sex: Female, Male Male	150 Participants n=99 Participants	150 Participants n=107 Participants	300 Participants n=206 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	20 Participants n=99 Participants	19 Participants n=107 Participants	39 Participants n=206 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	130 Participants n=99 Participants	130 Participants n=107 Participants	260 Participants n=206 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=99 Participants	1 Participants n=107 Participants	1 Participants n=206 Participants
Race/Ethnicity, Customized Race · White	108 Participants n=99 Participants	108 Participants n=107 Participants	216 Participants n=206 Participants
Race/Ethnicity, Customized Race · Black or African American	23 Participants n=99 Participants	25 Participants n=107 Participants	48 Participants n=206 Participants
Race/Ethnicity, Customized Race · Asian	10 Participants n=99 Participants	11 Participants n=107 Participants	21 Participants n=206 Participants
Race/Ethnicity, Customized Race · Multiple	8 Participants n=99 Participants	5 Participants n=107 Participants	13 Participants n=206 Participants
Race/Ethnicity, Customized Race · American Indian or Alaska Native	0 Participants n=99 Participants	1 Participants n=107 Participants	1 Participants n=206 Participants
Race/Ethnicity, Customized Race · Other	1 Participants n=99 Participants	0 Participants n=107 Participants	1 Participants n=206 Participants

PRIMARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Population: The pharmacokinetic analysis set (PKAS) included all randomized study participants with at least one evaluable pharmacokinetic (PK) parameter. 'Overall number of participants analyzed' indicates the number of participants evaluable for the outcome measure.

Outcome measures

Outcome measures
Measure	BIIB800 n=150 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=148 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Maximum Observed Serum Concentration (Cmax) of Tocilizumab	10.5 micrograms per milliter (μg/mL) Geometric Coefficient of Variation 43.3	10.0 micrograms per milliter (μg/mL) Geometric Coefficient of Variation 41.3

PRIMARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Population: The PKAS included all randomized study participants with at least one evaluable PK parameter. 'Overall number of participants analyzed' indicates the number of participants evaluable for the outcome measure.

Outcome measures

Outcome measures
Measure	BIIB800 n=133 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=137 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Area Under the Concentration-Time Curve From Time Zero to Infinity (AUC0-inf) of Tocilizumab	2380 hours (h)*μg/ mL Geometric Coefficient of Variation 44.9	2240 hours (h)*μg/ mL Geometric Coefficient of Variation 41.1

PRIMARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Outcome measures

Outcome measures
Measure	BIIB800 n=150 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=148 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Area Under the Concentration-Time Curve up to the Last Measurable Concentration (AUC0-t) of Tocilizumab	2120 h*μg/ mL Geometric Coefficient of Variation 45.9	2000 h*μg/ mL Geometric Coefficient of Variation 44.0

SECONDARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Outcome measures

Outcome measures
Measure	BIIB800 n=150 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=148 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Time to Reach Cmax (Tmax) of BIIB800 and Tocilizumab	84.0 hours Interval 12.1 to 241.0	96.0 hours Interval 24.0 to 168.0

SECONDARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Outcome measures

Outcome measures
Measure	BIIB800 n=133 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=137 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Apparent Total Body Clearance (CL/F) of BIIB800 and Actemra	0.0680 Liter per hour (L/h) Geometric Coefficient of Variation 44.9	0.0723 Liter per hour (L/h) Geometric Coefficient of Variation 41.1

SECONDARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Outcome measures

Outcome measures
Measure	BIIB800 n=133 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=137 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Apparent Terminal Half-Life (t1/2) of BIIB800 and Actemra	68.5 hours Interval 36.3 to 202.0	68.3 hours Interval 33.0 to 151.0

SECONDARY outcome

Timeframe: From the first dose of study drug up to the end of the study (up to Day 57)

Population: The safety analysis set (SAFS) included all randomized study participants who received the study drug.

An adverse event (AE) is any untoward medical occurrence in a clinical investigation participant who has received a pharmaceutical product, regardless of causal relationship with the product. An AE can therefore be any unfavorable or unintended sign (including an abnormal laboratory finding), symptom, or disease which is temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product. A TEAE was defined as an AE that starts during or after dosing or starts prior to dosing and increases in severity after dosing. An SAE is any untoward medical occurrence that results in death, in the view of the Investigator, places the participant at immediate risk of death, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, results in a congenital anomaly/birth defect, is a medically important event.

Outcome measures

Outcome measures
Measure	BIIB800 n=150 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=150 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment-Emergent Serious AEs (TESAEs) TEAEs	76 Participants	86 Participants
Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment-Emergent Serious AEs (TESAEs) TESAEs	2 Participants	0 Participants

SECONDARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Population: The pharmacodynamics analysis set (PDAS) included all randomized study participants with at least one evaluable pharmacodynamic (PD) parameter i.e., sIL-6R and/or high sensitivity C-reactive protein (hsCRP). 'Overall number of participants analyzed' indicates the number of participants evaluable for the outcome measure.

sIL-6R levels were determined using a validated immunoassay method based on ProteinSimple Ella.

Outcome measures

Outcome measures
Measure	BIIB800 n=150 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=149 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Area Under the Effect-Time Curve (AUE) of Soluble Interleukin-6-Receptor (sIL-6R)	209000 hoursnanograms per milliliter (hng/mL) Standard Deviation 68400	202000 hoursnanograms per milliliter (hng/mL) Standard Deviation 58200

SECONDARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Population: The PDAS included all randomized study participants with at least one evaluable PD parameter i.e., sIL-6R and/or hsCRP. 'Overall number of participants analyzed' indicates the number of participants evaluable for the outcome measure.

Outcome measures

Outcome measures
Measure	BIIB800 n=150 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=149 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Maximum Observed Effect (Emax) of sIL-6R	459 ng/mL Standard Deviation 99.1	452 ng/mL Standard Deviation 90.6

SECONDARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Outcome measures

Outcome measures
Measure	BIIB800 n=150 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=149 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Time to Emax (tEmax) of sIL-6R	336 hours Interval 4.0 to 1370.0	336 hours Interval 144.0 to 1350.0

SECONDARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

hsCRP was determined using a particle enhanced immunoturbidometric assay.

Outcome measures

Outcome measures
Measure	BIIB800 n=142 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=140 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
AUE of High Sensitivity C-Reactive Protein (hsCRP)	1190 hoursmilligrams per liter (hmg/L) Standard Deviation 1480	1780 hoursmilligrams per liter (hmg/L) Standard Deviation 2570

SECONDARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Outcome measures

Outcome measures
Measure	BIIB800 n=142 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=140 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Minimum Observed Effect (Emin) of hsCRP	0.133 milligrams per liter (mg/L) Standard Deviation 0.124	0.131 milligrams per liter (mg/L) Standard Deviation 0.105

SECONDARY outcome

Timeframe: Pre-dose on Day 1 and multiple time points post-dose (up to Day 57)

Outcome measures

Outcome measures
Measure	BIIB800 n=142 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=140 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Time to Emin (tEmin) of hsCRP	72.0 hours Interval 0.0 to 483.0	96.0 hours Interval 0.0 to 338.0

SECONDARY outcome

Timeframe: Day 1 to Day 57

Population: The SAFS included all randomized study participants who received the study drug.

The ADA-positive status was determined as a participant with either a pre-existing ADA-positive status (an ADA-positive sample at baseline \[prior to administration of study treatment\]) or a treatment-induced ADA-positive status (a participant with a negative ADA sample at baseline \[pre-dose\] and at least one ADA-positive sample after the administration of the study treatment. The nAb-positive status was determined in the same manner that of ADA status. ADA and nAb were analyzed in human serum using validated electrochemiluminescence (ECL) assays based on the MesoScale Discovery platform and were measured using validated ECL methods.

Outcome measures

Outcome measures
Measure	BIIB800 n=150 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=150 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Number of Participants With Positive Tocilizumab Anti-drug Antibodies (ADA) and Neutralizing Antibodies (nAb) Status ADA	26 Participants	12 Participants
Number of Participants With Positive Tocilizumab Anti-drug Antibodies (ADA) and Neutralizing Antibodies (nAb) Status nAb	21 Participants	9 Participants

SECONDARY outcome

Timeframe: Pre-dose, Days 15, 29, 57

Population: The SAFS included all randomized study participants who received the study drug. 'Overall number of participants analyzed' indicates the number of participants with positive ADA. 'Number analyzed (n)' signifies the number of participants evaluable for the specified time point.

ADA titre was defined as a quasi-quantitative expression of the level of ADA in a sample.

Outcome measures

Outcome measures
Measure	BIIB800 n=26 Participants Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=12 Participants Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Geometric Mean Titer of Anti-drug Antibodies (ADA) Day 15	—	160.0 titre Geometric Coefficient of Variation 0.0
Geometric Mean Titer of Anti-drug Antibodies (ADA) Day 29	201.6 titre Geometric Coefficient of Variation 41.7	254.0 titre Geometric Coefficient of Variation 94.7
Geometric Mean Titer of Anti-drug Antibodies (ADA) Day 57	477.3 titre Geometric Coefficient of Variation 96.7	452.5 titre Geometric Coefficient of Variation 152.4

Adverse Events

BIIB800

Serious events: 2 serious events

Other events: 75 other events

Deaths: 0 deaths

Actemra

Serious events: 0 serious events

Other events: 86 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	BIIB800 n=150 participants at risk Participants received a single dose of BIIB800 via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.	Actemra n=150 participants at risk Participants received a single dose of Actemra via autoinjector, administered SC in the outer area of the upper arm on Day 1 of the study.
Injury, poisoning and procedural complications Jaw fracture	0.67% 1/150 • From the first dose of study drug up to the end of the study (up to Day 57) The SAFS included all randomized study participants who received the study drug. Treatment-emergent adverse events are reported.	0.00% 0/150 • From the first dose of study drug up to the end of the study (up to Day 57) The SAFS included all randomized study participants who received the study drug. Treatment-emergent adverse events are reported.
Nervous system disorders Paresthesia	0.67% 1/150 • From the first dose of study drug up to the end of the study (up to Day 57) The SAFS included all randomized study participants who received the study drug. Treatment-emergent adverse events are reported.	0.00% 0/150 • From the first dose of study drug up to the end of the study (up to Day 57) The SAFS included all randomized study participants who received the study drug. Treatment-emergent adverse events are reported.

Other adverse events

Additional Information

US Biogen Clinical Trial Center

Biogen

Phone: 866-633-4636

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee Our agreement is subject to confidentiality but generally the PI can publish, for noncommercial purposes only, results and methods of the trial, but no other Sponsor Confidential Information. PI must give Sponsor no less than 60 days to review any manuscript for a proposed publication and must delay publication for up to an additional 90 days thereafter if Sponsor needs to file any patent application to protect any of Sponsor's intellectual property contained in the proposed publication.
Publication restrictions are in place

Restriction type: OTHER