A randomized, double-blind, 3-arm, parallel study assessing the pharmacokinetics, safety, tolerability and immunogenicity of AVT04, an ustekinumab candidate biosimilar, in healthy adults

ABSTRACT

Background

This study assessed pharmacokinetic (PK) similarity, safety, and immunogenicity of AVT04, a candidate biosimilar, compared with reference product (RP) ustekinumab (EU-approved and US-licensed Stelara®).

Methods

Healthy subjects (N = 298) were randomized 1:1:1 to receive one 45 mg dose of AVT04, EU-RP, or US-RP. The primary PK parameters were Cmax and AUC0-inf. PK similarity was demonstrated if the 90% confidence intervals (CI) for the ratio of geometric means were all contained within the prespecified margins of 80% and 125%. Additional PK parameters, including AUC0-t, were also assessed. Safety and immunogenicity were also assessed until Day 92.

Results

After pre-specified protein content normalization, the 90% CI for the ratio of geometric means for primary PK parameters were all contained within the pre-specified bioequivalence margins of 80% and 125%, supporting demonstration of PK similarity between AVT04 and both EU- and US-RP. Secondary PK parameters supported the analysis. Safety and immunogenicity profiles were comparable across all three treatment arms, although the study was not powered to detect small differences in these parameters.

Conclusion

Results supported a demonstration of PK similarity between candidate biosimilar AVT04, US-RP and EU-RP. Similar safety and immunogenicity were also shown.

Clinical trial registration: www.clinicaltrials.gov identifier is NCT04744363.

KEYWORDS:

• AVT04
• bioequivalence
• biosimilar
• immunogenicity
• pharmacokinetic similarity
• pharmacokinetics
• Phase I
• ustekinumab

1. Introduction

Ustekinumab is a fully human immunoglobulin G1 kappa monoclonal antibody that inhibits the bioactivity of human interleukin (IL)-12 and IL-23 by preventing p40 from binding to the IL-12 Rβ1 receptor protein expressed on the surface of immune cells, thereby disrupting the IL-12- and IL-23-mediated cellular responses [1,2].

Reference product (RP) ustekinumab (Stelara®; Janssen Biotech, Inc) was originally approved in the European Union (EU) in January 2009, in the United States (US) in September 2009 [1,2]. In both the EU and US, RP ustekinumab is indicated for a variety of anti-inflammatory conditions.

The high cost of RP ustekinumab may preclude some patients from being able to access the treatment, especially considering prolonged use is required to treat the chronic conditions indicated for this product. A similar product that provides comparable safety and efficacy at reduced cost would fulfill a broader medical need as a more cost-effective treatment. There are currently no approved biosimilar medicines to RP ustekinumab.

Alvotech is developing AVT04 as a proposed biosimilar to RP ustekinumab. Demonstration of biosimilarity requires that no clinically meaningful differences in quality, safety, or efficacy are shown compared to the RP [3–5]. The primary amino acid sequences of ustekinumab in AVT04 are identical to those of the RP. Physiochemical analytical methods and in vitro functional assays support the demonstration of analytical similarity between AVT04 and the RP. This study aimed to establish three-way pharmacokinetic (PK) similarity between AVT04 and the RP (EU-approved and US-licensed) in healthy volunteers, that represents part of the demonstration of clinical similarity.

AVT04 is an investigational product and has not received regulatory approval in any country as a biosimilar. The final US prescribing information will include the specific uses for which the product is indicated in the US.

2. Patients and methods

2.1. Study design and participant population

This phase I study was a multicenter, randomized, double-blind, 3-arm, parallel-group study of AVT04 compared with EU-approved and US-licensed RP (EU-RP and US-RP, respectively) when administered as a single dose in healthy adult subjects. It was conducted in two sites in New Zealand and two sites in Australia. While ethnicity has been shown to have no impact on ustekinumab pharmacokinetics, the study aimed to enroll approximately 10% Japanese volunteers, in order to meet regulatory requirements [6]. Clinical trial registration: www.clinicaltrials.gov identifier is NCT04744363.

The study duration per completed subject was approximately 17 weeks, comprising a 4-week screening period (‘Screening’), a 13-week treatment and assessment period, and an end-of-study (EOS) visit on Day 92. Healthy male or female participants aged 18 to 55 years old were eligible for the study. Subjects were required to have a body mass index (BMI) of between 17.0 and 30.0 kg/m² inclusive. Participants of Japanese origin were defined as either a second-generation Japanese person living abroad and both parents and grandparents being of Japanese origin, or having been born in Japan and both parents and grandparents of Japanese origin. Key exclusion criteria were previous exposure to IL-12 and/or IL-23 inhibitor molecules including ustekinumab, previous or concurrent clinically relevant pathologies (e.g. malignancies or demyelinating disorders), presence of chronic obstructive pulmonary disease (excluding childhood asthma), a current active infection, including localized infections, or any recent history (within the week prior to study drug administration) of active infections, cough or fever, or a history of recurrent or chronic infections, subjects who had a positive test for tuberculosis (TB) or a known history of active or latent inadequately treated TB, and subjects with clinically significant lab abnormalities.

A computer-generated randomization schedule was created by an unblinded statistician prior to study start and uploaded into the electronic data capture (EDC) system (Viedoc™). Randomization to AVT04, EU-RP, or US-RP treatment groups was performed in a 1:1:1 ratio and stratified as follows: Japanese, non-Japanese ≤80 kg, and non-Japanese >80 kg. As a double-blind study, apart from prespecified unblinded individuals, the Investigator, site staff, Sponsor, Sponsor’s delegates (if applicable) and all subjects were blinded to treatment. Appropriate study drug blinding techniques were implemented during the study as per the sites’ standard operating procedures.

Subjects were confined to the study site from Day −1 until after collection of the 24-hour postdose samples and study assessments on Day 2. Subjects received a single dose of 45 mg/0.5 mL of either AVT04, EU-RP, or US-RP on Day 1 as a subcutaneous (SC) injection in the abdomen (preferred site) or thigh (secondary site) according to the predetermined randomization schedule. Only authorized study site staff could administer the IP. No dose modification was allowed in the study. After Day 2, measurements were assessed during ambulant visits on Days 3 to 15 inclusive, then on Days 22, 29, 36, 43, 50, 57, 64, and 78, with a final EOS visit on Day 92.

The study was conducted in accordance with the protocol, the ethical principles derived from international guidelines including the Declaration of Helsinki, applicable International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) Good Clinical Practice (GCP) guidelines, New Zealand Medicines and Medical Devices Safety Authority (Medsafe) regulations, Australia Therapeutic Goods Administration (TGA) regulations, and all other applicable laws and regulations. In addition, the study was approved by two independent ethical committees: Central Health and Disability Ethics Committee (New Zealand) and The Alfred (Australia).

2.2. PK analysis

Serum ustekinumab concentrations were listed for all subjects in the safety population. Summaries of serum ustekinumab concentrations, PK parameters and PK similarity assessment were undertaken with the PK population, which comprised all randomized subjects who received any amount of the investigational product (IP) and had at least 1 evaluable PK parameter (n = 287). An evaluable profile allowed the determination of one or more PK parameters and was determined at the discretion of the pharmacokineticist. Subjects were analyzed according to the treatment they received, if this differed from that to which the subject was randomized. Subjects with dosing deviations that could potentially affect the PK profile were excluded from the PK Population, at the discretion of the blinded pharmacokineticist prior to analysis as defined in the study protocol. This population was used for summaries of all PK data.

Blood from participants was collected pre-dose (within the hour prior to dosing), and at the following time points post-dose: 8 hours, 12 hours, and at Days 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 22, 29, 36, 43, 50, 57, 64, 78, and 92. PK samples for AVT04 and RP were analyzed using a sandwich assay on 96-well microtiter plates using Meso Scale Discovery (MSD) electrochemiluminescence (ECL) technology, an appropriate validated bioanalytical method with AVT04 as reference material in a one-assay-approach [7–9]. The lower limit of quantification was 25 ng/mL.

Serum ustekinumab concentrations were listed for each subject and summarized with descriptive statistics (N, mean, standard deviation [SD], coefficient of variation as a percent [CV%], median, minimum, maximum, geometric mean, and geometric CV%) by treatment and nominal PK sampling time point. All serum ustekinumab concentrations that were below the limit of quantification (BLQ) were labeled as such in the concentration data listings. Serum concentrations of ustekinumab that were BLQ were designated a value of half of Lower Limit of Quantification (LLOQ) for the summary of concentration-time data except for pre-dose which was assigned zero. Individual and arithmetic mean (per treatment) concentration-time profiles were plotted with the concentration axis displayed on a linear scale (arithmetic mean ±SD) and on a logarithmic scale (arithmetic mean). Individual subject concentration-time plots were overlaid by treatment/strata combination and nominal time post dose was used. For mean concentration-time plots, nominal (i.e. protocol specified) sampling time was used. For individual subject concentration-time plots, BLQ values were set to half of LLOQ. PK parameters were generated using WinNonLin version 9.4 (Certara, LP Princeton, New Jersey, US).

2.3. Safety evaluations

Safety endpoints comprised incidence, type, and severity of adverse events (AEs; including adverse drug reactions), injection-site reactions (ISRs), clinical laboratory assessments, vital signs, electrocardiogram (ECG), and physical examination findings. The safety population comprised all randomized subjects who received any amount of the study drug (n = 294) and was analyzed according to the treatment actually received, if this differed from that to which the subject was randomized.

All AEs were recorded from the time of study drug administration (Day 1) until the end of the subject’s participation in the study. Any AEs that occurred after obtaining informed consent but before IP administration were recorded as medical history. All serious AEs (SAEs), whether related or unrelated, were recorded from the time of Screening (signing the Informed Consent Form) and submitted to the Alvotech Swiss AG Sponsor and/or designee within 24 hours of site awareness. Adverse events were coded using MedDRA Version 24.0.

Based on their clinical judgment, each Investigator made an assessment of severity for each AE and SAE reported during the study and assigned it to one of the following categories: mild (the AE is easily tolerated by the subject, causes minimal discomfort, and does not interfere with everyday activities), moderate (the AE is sufficiently discomforting to interfere with normal everyday activities; intervention may be needed), or severe (the AE prevents normal everyday activities; treatment or other intervention usually needed) as well as assessing the relationship between the study drug and the occurrence of each AE/SAE using the WHO-Uppsala Monitoring Centre classification of causal relationship: certain, probable, possible, or unlikely.

Injection site evaluations were made by clinical staff following administration of study drug. Injection sites were monitored for pain, tenderness, erythema/redness, and swelling. The severity of each injection site reaction was graded using the FDA Toxicity Grading Scale: Grade 0 (absent), Grade 1 (mild), Grade 2 (moderate), Grade 3 (severe), and Grade 4 (potentially life-threatening). If an injection site reaction of at least Grade 1 was observed, a physician was to characterize and document the reaction as an AE and AE of special interest (AESI). Review of the injection site continued until the AE was resolved. The severity of each resulting AE was also recorded.

Study enrollment was to be halted if more than two subjects experienced a suspected unexpected serious adverse reaction (SUSAR), or if the Sponsor or Investigator considered there to be an unfavorable benefit-risk ratio based on the emerging safety data.

2.4. Immunogenicity

Immunogenicity endpoints comprised the time of onset, frequency and titer of anti-drug antibodies (ADAs), as well as the time of onset and frequency of neutralizing antibodies (NAbs) in ADA-positive samples. The immunogenicity population comprised randomized subjects who received any amount of the IP and had at least 1 evaluable postdose immunogenicity result (n = 294). Subjects were analyzed according to the treatment they received, if this differed from that to which the subject was randomized.

Blood from participants was collected pre-dose (within the hour prior to dosing), and at the following time points post-dose: 12 hours, and at Days 9, 15, 29, 57, 78, and 92. Immunogenicity samples for AVT04 and RP were analyzed using validated, highly sensitive ECL methods (ADA: one bridging assay using labeled AVT04 as capture/detection reagent; NAb: one competitive ligand binding assay using AVT04 as capture reagent [10]) and the titer of confirmed positive samples was reported. Antibodies were further characterized and/or evaluated for their ability to neutralize the activity of the study drug. All samples collected for detection of antibodies to ustekinumab were also evaluated for ustekinumab serum concentrations to enable interpretation of the antibody data.

Individual immunogenicity sample collection and ADA results (including NAb results, if available) were listed for all subjects. Detection of ADAs and NAbs were summarized with frequency counts by treatment group and scheduled time point. The titer/concentration values were also summarized if >20% of subjects within a single treatment group had positive results.

2.5. Statistical analysis

All derivations, statistical analyses, summaries, and listings were generated using SAS® Version 9.4 (SAS Institute, Inc., Cary, North Carolina). The PK parameters were generated using Phoenix® WinNonlin® Version 9.4 (Certara, LP Princeton, New Jersey, U.S.A).

To achieve a power of at least 90% for the three pairwise comparisons of each coprimary endpoints maximum serum concentration (C_max) and area under the plasma concentration curve extrapolated to infinite time (AUC_0-inf), the individual pairwise comparisons had to be powered at 96.6%. For C_max, assuming a true geometric ratio of 1.05, the required sample size was 168 subjects for each pairwise comparison. For AUC_0-inf, assuming a true geometric ratio of 1.05, the required sample size was 176 subjects for each pairwise comparison. With a sample size of 176 subjects (88 per group) for each pairwise comparison, the evaluation of C_max would have a power of 97.4% for each of these comparisons, resulting in an overall power of at least 83.1% for the study (all pairwise comparisons and both PK parameters). Taking into consideration a nonevaluable/dropout rate of up to 10%, the sample size was 294 subjects in total (98 per group).

An Analysis of Covariance (ANCOVA) on the logarithmic scale (i.e. using natural log-transformed values of C_max and AUC_0-inf) was used and included fixed effects for treatment and body weight at baseline as the covariates.

For each primary PK parameter and pairwise comparison, the least squares (LS) means (for Test [T] and Reference [R]), LS treatment difference (i.e. difference between the corresponding LS means), and 90% confidence intervals (CIs) for the treatment differences on a logarithmic scale (i.e. derived from the log-transformed parameter values) were obtained. The LS treatment differences, and corresponding CIs were back transformed to the original scale, resulting in point estimates of the T/R ratios of geometric LS means (geometric mean ratios [GMRs]) and 90% CIs for each comparison.

The PK similarity of AVT04 versus EU-RP, AVT04 versus US-RP, and US-RP versus EU-RP was demonstrated if, for all pairwise comparisons, the 90% CIs of the GMRs for both C_max and AUC_0-inf were entirely contained within the prespecified equivalence margin of 0.8 to 1.25 (ie, 80% to 125% when the ratio was expressed as a percentage).

As prespecified in the study protocol and Statistical Analysis Plan (SAP), if differences were identified in the drug protein content between AVT04, EU-RP, and USRP, statistical analysis was to be performed using PK parameters normalized by protein content. Protein-normalized PK parameters were to be summarized and the ANCOVA model was to be presented with the body weight at baseline as a covariate. PK parameters were to be protein-adjusted as follows:

$AdjustedPKparameter=originalPKparameter\times \left(\frac{expectedproteincontent\left[mg\right]}{actualinjectedvolume\left[mL\right]\times proteinconcentration\left[mg/mL\right]}\right)$

The analyses of PK similarity of the primary PK endpoints were also performed for the subgroups based on randomization strata and immunogenicity subgroups. These subgroup analyses were considered exploratory, and no formal statistical inference was made.

3. Results

3.1. Participant disposition

The study was conducted between 9 June 2021 and 14 March 2022. Of 563 participants screened, 265 were screen failures and 298 were randomized in a 1:1:1 ratio (Figure 1). Four participants were not dosed and withdrawn, and 294 were dosed (AVT04 treatment, n = 98; EU-RP treatment, n = 99; US-RP, n = 97). Overall, 278 participants completed the study (92 in AVT04 group, 96 in EU-RP group, and 90 in US-RP group) and 16 participants discontinued (6 in AVT04 group, 3 in EU-RP group, and 7 in US-RP group). There were no discontinuations due to AEs.

Figure 1. Disposition of study participants.

The demographics and baseline characteristics were well-balanced across groups: age (mean 31.5 ± 9.89 years), weight (mean 70.93 ± 9.254 kg), and gender (60.9% female) were similar across the three treatment groups (Table 1). In the PK population, the demographic and baseline characteristics were also well balanced across treatment groups and were consistent with those of the safety population. An additional 7 participants were excluded from the PK population; of these, 6 were excluded due to too many missing PK samples and 1 was excluded due to early termination (withdrawal of consent) on Day 7. Therefore, a total of 287 (96.3%) participants were included in the PK population; the number of participants in this population was comparable across groups.

Table 1. Demographic and baseline characteristics (safety population).

	Statistic	AVT04 (N = 98)	EU-RP (N = 99)	US-RP (N = 97)	Overall (N = 294)
Age (years)	n	98	99	97	294
	Mean	32.0	30.5	32.0	31.5
	SD	10.09	9.65	9.96	9.89
Gender
Male	n (%)	41 (41.8)	34 (34.3)	40 (41.2)	115 (39.1)
Female	n (%)	57 (58.2)	65 (65.7)	57 (58.8)	179 (60.9)
Females of Childbearing Potential
Yes	n (%)	54 (94.7)	61 (93.8)	51 (89.5)	166 (92.7)
No	n (%)	3 (5.3)	4 (6.2)	6 (10.5)	13 (7.3)
Race
Asian	n (%)	13 (13.3)	12 (12.1)	23 (23.7)	48 (16.3)
Black or African American	n (%)	1 (1.0)	1 (1.0)	0 (0.0)	2 (0.7)
Caucasian/White	n (%)	71 (72.4)	73 (73.7)	64 (66.0)	208 (70.7)
American Indian or Alaska Native	n (%)	2 (2.0)	1 (1.0)	3 (3.1)	6 (2.0)
Native Hawaiian or other Pacific Islander	n (%)	1 (1.0)	4 (4.0)	3 (3.1)	8 (2.7)
Australian Aborigine/Torres Strait Islander	n (%)	1 (1.0)	0 (0.0)	0 (0.0)	1 (0.3)
Multiple	n (%)	5 (5.1)	4 (4.0)	2 (2.1)	11 (3.7)
Other	n (%)	4 (4.1)	4 (4.0)	2 (2.1)	10 (3.4)
Ethnicity
Japanese	n (%)	7 (7.1)	7 (7.1)	6 (6.2)	20 (6.8)
Non-Japanese	n (%)	91 (92.9)	92 (92.9)	91 (93.8)	274 (93.2)
Height (cm)	n	98	99	97	294
	Mean	170.67	169.74	169.96	170.12
	SD	8.851	7.464	8.131	8.148
Weight (kg) at screening	n	98	99	97	294
	Mean	70.76	70.49	71.56	70.93
	SD	9.133	9.293	9.399	9.254
Weight Group^a at screening
≤80 kg	n (%)	80 (81.6)	81 (81.8)	80 (82.5)	241 (82.0)
>80 kg	n (%)	18 (18.4)	18 (18.2)	17 (17.5)	53 (18.0)
Strata at randomization
Non-Japanese ≤80 kg	n (%)	73 (74.5)	73 (73.7)	73 (75.3)	219 (74.5)
Non-Japanese >80 kg	n (%)	18 (18.4)	19 (19.2)	18 (18.6)	55 (18.7)
Japanese	n (%)	7 (7.1)	7 (7.1)	6 (6.2)	20 (6.8)
BMI (kg/m^2)	n	98	99	97	294
	Mean	24.34	24.45	24.77	24.52
	SD	2.942	2.683	2.804	2.808

Note: % = percentage of subjects in each category calculated relative to the total number of subjects in the relevant population; BMI = body mass index; n = number of subjects in each category; N = total number of subjects in the relevant population for each Strata (where relevant); RP = reference product; SD = standard deviation.

Percentage of females of childbearing potential calculated relative to the total number of female subjects in the relevant population.

Age (years) is relative to the date informed consent form was signed.

a. Weight Group is derived from measured weight rather than the assigned stratum for each subject. There may be instances where the weight is different to the assigned strata.

The distribution of dosed participants according to the pre-defined randomization groups was also well-balanced across the treatment groups. Overall, 74.5% of participants were non-Japanese weighing ≤80 kg, 18.7% were non-Japanese weighing >80 kg, and 6.8% were Japanese.

3.2. PK results

In the PK population, following a single SC dose of 45 mg/0.5 mL, the mean serum ustekinumab concentration-time profiles for AVT04, EU-RP, and US-RP were similar, all showing a slowly increasing absorption phase up to approximately 168 hours post dose (Days 9 to 10), followed by a slowly declining phase at higher concentrations and then faster elimination at lower concentrations in a mono-exponential manner (Figure 2). The mean serum ustekinumab concentrations in the EU-RP group were slightly lower than those observed in the AVT04 and US-RP groups across the majority of sampling time points.

Figure 2. Mean (± standard deviation) serum ustekinumab concentration over time by treatment group (PK population). All predose BLQ values were substituted by zeros. Thereafter BLQ values between evaluable concentrations and terminal BLQ were set to 0.5 × LLOQ.

In all 3 groups, the CV% of mean serum ustekinumab concentrations was ≥50% during the initial drug absorption phase up to at least Day 2 (24 hours post dose), then reduced to a range of 30% to 50% for the majority of time points, and then increased again to ≥50% from Day 78 to Day 92.

The geometric mean C_max value in the AVT04 group (4019.2 ng/mL) was similar to that in the US-RP group (4046.4 ng/mL), both of which were higher than in the EU-RP group (3681.7 ng/mL; Table 2). A similar pattern was seen with the geometric mean AUC in the AVT04 group (AUC_0-inf: 35 11,612 h·ng/mL; AUC_0-t: 32 86,173 h·ng/mL), which were similar to the US-RP group (AUC_0-inf: 33 44,427 h·ng/mL; AUC_0-t: 31 71,230 h·ng/mL) both of which treatment groups were slightly higher than the EU-RP group (AUC_0-inf: 30 14,505 h·ng/mL; AUC_0-t: 28 72,578 h·ng/mL). The geometric CV% for all three exposure PK parameters were comparable across treatment groups (32% to 39%).

Table 2. Summary of serum ustekinumab pharmacokinetic parameters by treatment (PK population).

	Median (Range)	Geometric Mean (Geometric CV%)
	Tmax (h)	Cmax (ng/mL)	AUC0-inf (ng·h/mL)	AUC0-t (ng·h/mL)	Kel (1/h)	t1/2 (h)	CL/F (mL/h)	Vz/F (L)	CL/F/ BW (L/h/kg)	Vz/F/ BW (L/kg)
AVT04 (N = 96)	168.0 (46.4–504.0)	4019.2 (33%)	3511612 (33%)	3286173 (32%)	0.0015 (24.9%)	477.9 (24.9%)	0.01 (33.1%)	8.76 (31.6%)	0.00018 (30.6%)	0.12 (29.5%)
EU-RP (N = 97)	167.7 (47.8–503.6)	3681.7 (38%)	3014505 (39%)	2872578 (38%)	0.0016 (27.8%)	431.94 (27.8%)	0.02 (39.2%)	9.30 (36.6%)	0.00021 (36.2%)	0.13 (32.9%)
US-RP (N = 94)	168.1 (48.0–339.5)	4046.4 (31%)	3344427 (36%)	3171230 (34%)	0.0016 (39.9%)	438.17 (39.9%)	0.01 (36.3%)	8.46 (33.9%)	0.00019 (33.3%)	0.12 (33.6%)

Note: AUC_0-inf = Area under the serum of the concentration-time curve from time zero (predose) extrapolated to infinity; AUC_0-t = Area under the serum concentration-time curve from time zero (predose) to the time of the last quantifiable concentration; BLQ = below the lower limit of quantification (25 ng/mL); BW = body weight adjusted; CL/F = apparent total serum clearance; C_max = maximum serum concentration; CV% = coefficient of variation as a percent; K_el = terminal elimination rate constant; LLOQ = lower limit of quantification; N = Total number of subjects in the relevant population; RP = reference product; t_½ = apparent terminal half-life; T_max = time to C_max; V_z/F = apparent volume of distribution.

All predose BLQ values were substituted by zeros. Thereafter BLQ values between evaluable concentrations and terminal BLQ were set to 0.5 × LLOQ.

It was noted that there were fewer evaluable subjects for determination of AUC_0-inf than AUC_0-t as not all subjects met the requirement for AUC_0-inf (and associated parameters CL/F, t_1/2, V_z/F). The PK parameters were determined by noncompartmental analysis methods using WinNonLin version 9.4 (Certara, LP Princeton, New Jersey, U.S.A).

The protein content for EU-RP was found to deviate from the nominal and expected value of 90 mg/mL. The mean actual protein content of the dose administered was slightly higher than the nominal 45 mg dose in the AVT04 and US-RP groups and lower in the EU-RP group, resulting in a dosing bias of 104.3% and 104.5% in the AVT04 and US-RP groups, respectively, and 97.9% in the EU-RP group. The impact of this deviation on ustekinumab exposure was assessed. As pre-specified in the study protocol and SAP, protein content normalization was implemented for dose-dependent PK parameters. Following protein content normalization, the exposure PK parameters for ustekinumab were similar across the 3 treatment groups: C_max (ranging from 3761.3 to 3876.0 ng/mL) and the AUC (AUC_0-inf ranging from 30 79,700 to 33 69,848 h·ng/mL; AUC_0-t ranging from 29 34,704 to 31 53,938 h·ng/mL; Table 3).

Table 3. Summary of serum ustekinumab protein content-normalized exposure pharmacokinetic parameters by treatment (PK population).

	Geometric Mean Ratio (90% CI)^a
	Cmax (ng/mL)	AUC0-inf (ng·h/mL)	AUC0-t (ng·h/mL)
AVT04 (N = 96)	3857.5 (34%)	3369848 (34%)	3153938 (32%)
EU-RP (N = 97)	3761.3 (38%)	3079700 (39%)	2934704 (38%)
US-RP (N = 94)	3876.0 (32%)	3204580 (37%)	3037712 (35%)

Note: AUC_0-inf = area under the serum concentration-time curve from time zero (predose) extrapolated to infinity; AUC_0-t = Area under the serum concentration-time curve from time zero (predose) to the time of the last quantifiable concentration; BLQ = below the lower limit of quantification (25 ng/mL); CL/F = apparent total serum clearance; C_max = maximum serum concentration; CV% = coefficient of variation as a percent; LLOQ = lower limit of quantification; N = Total number of subjects in the relevant population; PK = pharmacokinetic(s); t_½ = apparent terminal half-life; RP = reference product; V_z/F = apparent volume of distribution.

All predose BLQ values were substituted by zeros. Thereafter BLQ values between evaluable concentrations and terminal BLQ were set to 0.5 × LLOQ.

Protein content-normalized PK parameter = original PK parameter × (45/actual injected volume [mL] × protein concentration [mg/mL])

It was noted that there were fewer evaluable subjects for determination of AUC_0-inf than AUC_0-t as not all subjects met the requirement for AUC0-inf (and associated parameters CL/F, t_1/2, V_z/F). The PK parameters were determined by noncompartmental analysis methods using WinNonLin version 9.4 (Certara, LP Princeton, New Jersey, USA).

A statistical analysis of PK similarity after protein content normalization was performed, in which the 90% CIs of the GMRs for both primary parameters C_max and AUC_0-inf, as well as key secondary endpoint AUC_0-t, were entirely contained within the prespecified margins of 80% and 125% for each of the 3 pairwise comparisons, supporting the demonstration of PK similarity between AVT04 and both EU-RP and US-RP Table 4 , Figure 3

Figure 3. PK similarity assessment of serum ustekinumab protein content-normalized exposure PK parameters by treatment (PK population). It is noted that there are fewer subjects assessed by AUC_0-inf than AUC_0-t as not all subjects met the requirements for AUC_0-inf (and associated parameters: CL/F, t_1/2, V_z/F). Treatment comparison by analysis of covariance of log-transformed protein content-normalized parameters using SAS proc GLM with model: <parameter≥ Treatment + body weight at baseline as the covariate. A 90% CI for the LS mean ratio was constructed from the one-sided lower 5% CL and one-sided upper 5% CL. Protein content-normalized PK parameter = original PK parameter x (45/actual injected volume [mL] x protein concentration [mg/mL]).

Note: * PK similarity was demonstrated if, for each pairwise comparison, the 90% CIs for the geometric LS means ratios were entirely contained within the equivalence margin 80% to 125%.

Table 4. PK similarity assessment of serum ustekinumab protein content-normalized exposure pharmacokinetic parameters by treatment (PK population).

		Test		Reference		Ratio of Geometric LS Means (%)	90% Confidence Interval for Ratio of Geometric LS Means^a
Comparison (Test/Reference)	Protein content-normalized parameter	n	LS Mean	n	LS Mean	Test/Reference
AVT04/EU-RP	Cmax (ng/mL)	96	3848.8	97	3742.9	102.8	95.5	110.7
	AUC0-inf (ng·h/mL)	93	3360604.3	97	3060788.2	109.8	101.5	118.8
	AUC0-t (ng·h/mL)	96	3146295.4	97	2919171.0	107.8	100.0	116.2
AVT04/US-RP	Cmax (ng/mL)	96	3848.8	94	3904.7	98.6	91.5	106.2
	AUC0-inf (ng·h/mL)	93	3360604.3	93	3234105.1	103.9	95.9	112.6
	AUC0-t (ng·h/mL)	96	3146295.4	94	3061970.0	102.8	95.3	110.8
US-RP/EU-RP	Cmax (ng/mL)	94	3904.7	97	3742.9	104.3	96.8	112.4
	AUC0-inf (ng·h/mL)	93	3234105.1	97	3060788.2	105.7	97.6	114.4
	AUC0-t (ng·h/mL)	94	3061970.0	97	2919171.0	104.9	97.3	113.1

Note: AUC_0-inf = Area under the serum of the concentration-time curve from time zero (predose) extrapolated to infinity; AUC_0-t = Area under the serum concentration-time curve from time zero (predose) to the time of the last quantifiable concentration; CL = confidence limit; CL/F = apparent total serum clearance; C_max = maximum serum concentration; GLM = general linear model; LS = Least-Squares; n = number of subjects used in calculation; PK = pharmacokinetic(s); t_½ = apparent terminal half-life; RP = reference product; V_z/F = apparent volume of distribution during the terminal phase after SC administration.

It was noted that there were fewer subjects for determination of AUC_0-inf than AUC_0-t as not all subjects met the requirement for AUC_0-inf (and associated parameters CL/F, t_1/2, V_z/F).

Treatment Comparison by analysis of covariance of log-transformed protein content-normalized parameters using SAS proc GLM with model: <parameter≥ treatment + body weight at baseline as the covariate. 90% confidence interval for the ratio of LS mean was constructed from the one-sided lower 5% CL and one-sided upper 5% CL.

Protein content-normalized PK parameter = original PK parameter × (45/actual injected volume [mL] × protein concentration [mg/mL]).

a. Pharmacokinetic similarity was demonstrated if, for each pairwise comparison, the 90% confidence intervals for the ratios of geometric LS means were entirely contained within the prespecified equivalence margins of 80% to 125%. Values in bold text indicate that the PK similarity criteria were met.

Additional secondary mean PK parameters in the AVT04 group were comparable with the EU-RP and US-RP treatment groups (Table 2). The median T_max was 168 hours in all 3 treatment groups and the geometric CV% for T_max was moderate across groups (37.5% to 49.2%), with values ranging from 46.4 to 504.0 hours. Systemic elimination of ustekinumab showed slow clearance, a long half-life and low volume of distribution in all 3 treatment groups. The geometric mean terminal half-life (t_1/2) in the AVT04 group (477.9 hours) was slightly longer than that in the EU-RP (438.2 hours) and US-RP (431.9 hours) groups. The geometric mean CL/F ranged from 0.01 to 0.02 L/h and geometric mean V_z/F ranged from 8.46 to 9.30 L; the values were similar across groups.

Systemic exposure to ustekinumab was body weight dependent as expected (Table S1). The body weight-adjusted geometric mean apparent total serum clearance (CL/F; ranging from 0.00018 to 0.00021 L/h/kg) and apparent volume of distribution (V_z/F; ranging from 0.12 to 0.13 L/kg) were also similar across groups. The geometric CV% values for the elimination PK parameters and body weight-adjusted parameters were moderate (24.9% to 39.2%) and comparable across groups. Following the same approach as for the overall PK population, in the Japanese subgroup, for all pairwise comparisons between AVT04, EU-RP, and US-RP, the point estimates of GMRs for C_max, AUC_0-inf, and AUC_0-t were contained within the prespecified margins of 80% to 125% (Table S2), thus demonstrating consistency of the results in the Japanese subgroup (n = 20) and the overall PK population (n = 287) with any observed differences likely due to the small sample size.

3.3. Immunogenicity

The immunogenicity profile AVT04 was generally similar across treatment groups, with the frequency of ADAs and NAbs being lower in AVT04 than in EU-RP and US-RP treatment groups at all time points (Table 5). Across treatment groups, there was a similar trend in the formation of ADAs with the highest positivity rates at Day 92 (EOS visit; 27.6% in AVT04 group, 48.5% in EU-RP group, 45.4% in US-RP group). The frequency of participants with at least 1 positive ADA result was lower in the AVT04 group (36.7%) compared with the EU-RP (59.6%) and US-RP groups (53.6%). The frequency of ADA-positive participants with at least 1 positive NAb result was also lower in the AVT04 group (33.3%) compared with the EU-RP (42.4%) and US-RP groups (53.8%). As expected, the formation of NAb lagged behind the positive detection of ADA in all treatment groups.

Table 5. Summary of detection of antidrug antibodies and neutralizing antibodies (immunogenicity population).

Treatment group		Day 1 pre-dose	Day 1 12 h postdose	Day 9	Day 15	Day 29	Day 57	Day 78	Day 92/ EOS	Any positive
Antidrug Antibody Positivity
AVT04 (N = 98)	n (%)	1 (1.0)	0 (0.0)	11 (11.2)	14 (14.3)	9 (9.2)	13 (13.3)	21 (21.4)	27 (27.6)	36 (36.7)
EU-RP (N = 99)	n (%)	3 (3.0)	1 (1.0)	30 (30.3)	19 (19.2)	14 (14.1)	30 (30.3)	43 (43.4)	48 (48.5)	59 (59.6)
US-RP (N = 97)	n (%)	1 (1.0)	2 (2.1)	19 (19.6)	15 (15.5)	14 (14.4)	33 (34.0)	37 (38.1)	44 (45.4)	52 (53.6)
Neutralizing Antibody Positivity
AVT04 (N = 98)	n (%)	0 (0.0)	0 (0.0)	0 (0.0)	1 (2.8)	0 (0.0)	2 (5.6)	7 (19.4)	11 (30.6)	12 (33.3)
EU-RP (N = 99)	n (%)	0 (0.0)	0 (0.0)	5 (8.5)	3 (5.1)	1 (1.7)	10 (16.9)	14 (23.7)	20 (33.9)	25 (42.4)
US-RP (N = 97)	n (%)	0 (0.0)	0 (0.0)	2 (3.8)	2 (3.8)	4 (7.7)	20 (38.5)	19 (36.5)	22 (42.3)	28 (53.8)

Note: % = percentage of subjects in each category calculated relative to the total number of subjects in the relevant population. For NAb positivity rates, percentages are based on the total number of subjects with any ADA positive result; ADA = antidrug antibody; EOS = end of study; n = number of ADA or NAb positive subjects at the relevant time point; N = total number of subjects in the relevant population; NAb = neutralizing antibody; RP = reference product.

A NAb test was only performed when ADA titer was ‘Positive.’

At Day 92, the median ADA titer was higher in the AVT04 group (16.0) compared with the EU-RP (8.0) and US-RP (12.0) groups (Table S3).

In the ADA-positive subgroup, values for systemic exposure to ustekinumab were lower compared with those observed in ADA-negative participants across treatment groups. While, in general, the same pattern was observed for data from systemic exposure to ustekinumab in NAb-positive subgroups compared with NAb-negative participants, values in the AVT04 NAb-positive subgroup were higher than in NAb-negative participants. These results should be interpreted with caution due to the very small numbers of participants with NAbs in the AVT04 group (n = 12).

3.4. Safety

Of the 294 participants who received ustekinumab, 203 (69.0%) reported at least one treatment-emergent AE (TEAE; Table 6). The frequency of participants with TEAEs was similar across treatment groups (68.4% in AVT04 group, 67.7% in EU-RP group, 71.1% in US-RP group); however, the US-RP group (190 events) had a higher number of events compared with the AVT04 (151 events) and EU-RP (155 events) groups. Over one-third (37.8%) of participants had at least 1 treatment-related TEAE. The frequency of participants who reported treatment-related TEAEs in the AVT04 group (34.7%) was similar to the EU-RP group (34.3%), and lower than in the US-RP group (44.3%). The majority (67.3%) of participants experienced mild TEAEs. Six participants (2.0%) reported at least 1 severe TEAE (2 in AVT04 group, 3 in EU-RP group, and 1 in US-RP group). One of the these was considered to be treatment related (grade 3 neutropenia), which occurred in the EU-RP group. Three severe events were considered as SAEs; one in each treatment group (anaphylactic reaction, abdominal pain, and cerebrovascular accident), none of which were judged to be treatment-related. Adverse events of special interest were reported by 10.5% of participants overall; the frequency of participants with events was similar across groups. Most participants had mild AESIs and no severe AESI were reported during the study. The majority of AESI were considered treatment-related (reported by 9.5% of participants), with no notable differences across groups. There were no TEAEs leading to discontinuation of the study, and there were no deaths.

Table 6. Treatment-emergent adverse events (safety population).

	AVT04 N = 98		EU-RP N = 99		US-RP N = 97		Overall N = 294
Adverse event category	Subjects, n (%)	Events, n	Subjects, n (%)	Events, n	Subjects, n (%)	Events, n	Subjects, n (%)	Events, n
Any TEAE	67 (68.4)	151	67 (67.7)	155	69 (71.1)	190	203 (69.0)	496
Treatment-related TEAEs	34 (34.7)	46	34 (34.3)	59	43 (44.3)	61	111 (37.8)	166
TEAEs of special interest	10 (10.2)	11	9 (9.1)	9	12 (12.4)	13	31 (10.5)	33
Treatment-related TEAEs of special interest	9 (9.2)	9	8 (8.1)	8	11 (11.3)	12	28 (9.5)	29
TEAEs of laboratory abnormality of at least CTCAE Grade 3	3 (3.1)	3	5 (5.1)	5	2 (2.1)	2	10 (3.4)	10
Treatment-related TEAEs of laboratory abnormality of at least CTCAE Grade 3	0 (0.0)	0	1 (1.0)	1	0 (0.0)	0	1 (0.3)	1
Local administration site reactions	10 (10.2)	10	8 (8.1)	8	11 (11.3)	12	29 (9.9)	30
TESAEs	1 (1.0)	1	1 (1.0)	1	1 (1.0)	1	3 (1.0)	3
Treatment-related TESAEs	0 (0.0)	0	0 (0.0)	0	0 (0.0)	0	0 (0.0)	0
TEAEs leading to death	0 (0.0)	0	0 (0.0)	0	0 (0.0)	0	0 (0.0)	0
TEAEs leading to early withdrawal	0 (0.0)	0	0 (0.0)	0	0 (0.0)	0	0 (0.0)	0
Maximum severity of TEAEs
Mild	67 (68.4)		65 (65.7)		66 (68.0)		198 (67.3)
Moderate	3 (3.1)		8 (8.1)		7 (7.2)		18 (6.1)
Severe	2 (2.0)		3 (3.0)		1 (1.0)		6 (2.0)
System organ class MedDRA-preferred term
Infections and infestations	24 (24.5)	28	26 (26.3)	33	26 (26.8)	35	76 (25.9)	96
Upper respiratory tract infection	11 (11.2)	12	19 (19.2)	19	17 (17.5)	21	47 (16.0)	52
Gastroenteritis	3 (3.1)	3	1 (1.0)	1	5 (5.2)	5	9 (3.1)	9
Nervous system disorders	25 (25.5)	30	19 (19.2)	23	28 (28.9)	34	72 (24.5)	87
Headache	19 (19.4)	23	14 (14.1)	18	19 (19.6)	23	52 (17.7)	64
General disorders and administration site conditions	20 (20.4)	20	17 (17.2)	21	27 (27.8)	36	64 (21.8)	77
Injection site erythema	4 (4.1)	4	4 (4.0)	4	5 (5.2)	5	13 (4.4)	13
Fatigue	2 (2.0)	2	2 (2.0)	2	6 (6.2)	6	10 (3.4)	10
Musculoskeletal and connective tissue disorders	12 (12.2)	12	13 (13.1)	14	12 (12.4)	14	37 (12.6)	40
Back pain	4 (4.1)	4	5 (5.1)	5	2 (2.1)	2	11 (3.7)	11
Injury, poisoning, and procedural complications	15 (15.3)	20	8 (8.1)	9	13 (13.4)	17	36 (12.2)	46
Vaccination complication	6 (6.1)	8	1 (1.0)	1	2 (2.1)	2	9 (3.1)	11
Gastrointestinal disorders	7 (7.1)	9	15 (15.2)	21	13 (13.4)	14	35 (11.9)	44
Nausea	0 (0.0)	0	6 (6.1)	7	3 (3.1)	3	9 (3.1)	10

Note: % = Percentage of subjects in each category calculated relative to the total number of subjects in the relevant population; AE = adverse event; E = Number of TEAEs in each category; IP = investigational product; MedDRA = Medical Dictionary for Regulatory Activities; TEAE = treatment-emergent AE; n = Number of subjects in each category (subjects with multiple events in each category are counted only once per category); N = Total number of subjects in the relevant population.

A TEAE was defined as any AE which commence or worsened in severity on or after IP administration. Adverse events were coded using MedDRA Version 24.0.

TEAEs occurring in at least 5% of participants are also reported in Table 6. The most frequently-reported events per System Organ Class (SOC) were infections and infestations (25.9%), nervous system disorders (24.5%) and general disorders and administration site conditions (21.8%), with similar frequencies across treatment groups. At the Preferred Term (PT) level, the most frequently reported TEAEs were upper respiratory tract infection (16.0%) and headache (17.7%). Fewer participants in the AVT04 group (11.2%) reported upper respiratory tract infections compared with the EU-RP (19.2%) and US-RP (17.5%) groups. No notable differences across groups were observed for the other frequently reported PTs.

Overall, the frequency of participants with treatment-related TEAEs in the AVT04 group (34.7%) was similar to the EU-RP group (34.3%), and lower than in the US-RP group (44.3%). The most frequently-reported treatment-related TEAEs per SOC were nervous system disorders (11.9%), general disorders and administration site conditions (11.6%), and infections and infestations (8.8%). Based on the injection site assessments, 6.1% of participants reported at least 1 local injection site reaction. The frequency of participants with these events was comparable between groups (7.1% in the AVT04 group, 4.0% in the EU-RP group, and 7.2% in the US-RP group). All reported reactions were Grade 1 to 2 in severity; no Grade ≥3 reactions were reported.

There were no clinically meaningful changes in mean values for hematology, coagulation, or clinical chemistry over time, and no treatment group differences were noted. Ten participants (3.4%) had TEAEs of Grade ≥3 laboratory abnormalities; 3 in the AVT04 group, 5 in the EU-RP group, and 2 in the US-RP group. The most frequently reported Grade ≥3 laboratory abnormality was blood creatinine phosphokinase increased (7 participants). The other Grade ≥3 events were blood triglycerides increased (2 participants) and neutropenia (1 participant). The majority of these events were mild in intensity. The event of neutropenia (EU-RP group) was severe and also considered treatment-related. Except for 2 events (blood creatine phosphokinase increased in the AVT04 and US-RP groups) with an unknown outcome, all Grade ≥3 events had resolved by the end of the study.

There were no clinically relevant findings or observations of note in vital signs or physical examinations. Analyses of ECG parameters did not reveal any clinically relevant effect of the treatment in healthy participants.

4. Discussion

Demonstration of biosimilarity requires that no clinically meaningful differences in quality, safety, or efficacy are shown compared to the reference product [3–5]. Physiochemical analytical methods and in vitro functional assays support the demonstration of analytical similarity between AVT04 and RP ustekinumab. Clinical assessment of a proposed biosimilar is necessary for establishing biosimilarity, with demonstration of PK similarity typically the first step at this stage. This study sought to assess PK similarity between candidate biosimilar AVT04 and RP ustekinumab to support an assessment of biosimilarity. Such data may also support the scientific justification to extrapolate from the studied indication to additional ustekinumab indications for a biosimilar [4].

Healthy adult subjects were selected as the study population in accordance with global regulatory guidelines to effectively assess the study objectives while avoiding potential interference associated with concomitant treatments or medical conditions [3,4,11]. Healthy volunteers were judged to be adequately sensitive to detect any PK differences between drug products, as well as differences in common AEs and immunogenicity.

In alignment with the EMA and FDA guidelines [3,11], the SC route of administration was evaluated in this study, as the SC route represents the main approved route of administration for RP ustekinumab. Furthermore, the SC route was expected to be the most sensitive in detecting differences in immunogenicity, and SC administration (in contrast to the intravenous route) could provide insight into potential PK differences during the absorption phase, in addition to the distribution and elimination phases (ie, it covers both absorption and elimination phases).

The proposed dose for the study (45 mg/0.5 mL SC) was considered the most relevant dose level as it represents one of the approved doses for the RP. Furthermore, both 45 mg/0.5 mL and 90 mg/1.0 mL SC doses fall within the linearity range [12,13]. Previous studies using the RP in healthy subjects showed an approximately linear PK of ustekinumab following the single SC injection at the dose levels studied (45 mg/0.5 mL and 90 mg/1.0 mL), with systemic exposure increasing in a dose-proportional manner. According to the body weight range allowed by the protocol for the current study (between 50 and 90 kg), a dose of 45 mg/0.5 mL would result in a weight-adjusted dose between 0.50 and 0.90 mg/kg, which would fall in the steep part of the exposure-response curve. Moreover, while both 45 mg/0.5 mL and 90 mg/1.0 mL doses were well tolerated in healthy subjects [12,13], the 90 mg/1.0 mL dose was considered to be less immunogenic than 45 mg/0.5 mL; therefore, differences in PK parameters and in the immunogenic response (if any) would be better detected by using the 45 mg/0.5 mL dose.

Mean serum concentration-time profiles were similar for AVT04, EU-RP, and US-RP. As prespecified in the protocol, differences identified in the drug protein content between AVT04, EU-RP, and US-RP led to analysis being performed using PK parameters normalized by protein content. Following protein content normalization, the 90% CIs of the geometric mean ratios for C_max and AUC_0-inf were contained within the prespecified margins of 80% and 125% in all six pairwise comparisons, supporting the demonstration of PK similarity. All secondary endpoints supported this result, including key secondary endpoint AUC_0-t.

Subgroup analysis showed that systemic exposure to ustekinumab was body weight dependent, with geometric mean C_max, AUC_0-inf, and AUC_0-t values being lower in the non-Japanese >80 kg subgroup compared with the non-Japanese ≤80 kg subgroup. This trend was consistently observed in all 3 treatment groups.

Analysis stratified by ethnicity was evaluated in the Japanese subgroup (n = 20; 6.8%). Across treatment groups, the geometric mean C_max, AUC_0-inf, and AUC_0-t, values in the Japanese subgroup were consistent with the overall PK population, indicating no notable impact of ethnicity differences on ustekinumab PK.

Treatment with a single dose of AVT04 45 mg/0.5 mL was safe and well tolerated in healthy subjects during this study, with a safety profile similar to EU-RP and US-RP. Overall, 69% of subjects reported at least 1 TEAE during the study. The frequency of subjects with TEAEs was similar across treatment groups; however, the US-RP group had a higher number of events compared with the AVT04 and EU-RP groups. The most-frequently-reported drug reactions (incidence ≥5%) were upper respiratory infection and headache, which was consistent with data from studies involving the RP. The most-frequently-reported treatment-related TEAE was headache, which was likewise consistent with the known profile for RP ustekinumab.

Comparable immunogenicity for a candidate biosimilar is essential to support a demonstration of biosimilarity with the RP, since ADAs and NAbs can reduce exposure to the drug and thereby affect efficacy and safety [14]. While both presentations of RP have been shown to be well tolerated in healthy volunteers [12,13], the 45 mg/0.5 mL dose was considered more immunogenic than the 90 mg/1.0 mL, and therefore more suitable for detecting any differences in immunogenic response in this study. Across treatment groups, there was a similar trend in the time of onset of ADAs and NAbs, with the highest positivity rates at Day 92 (end-of-study visit).

The ongoing approval of biosimilars can bring more competition to the market, thereby helping to lower costs and potentially increasing patient access to treatment [15,16]. These data support the assessment of PK similarity of AVT04 and RP, forming a critical part of the clinical assessment of AVT04 as a candidate biosimilar. The study was powered to assess differences in PK profile between the three groups, and small differences in safety and immunogenicity could have been missed in the relatively small sample size.

The clinical development program of AVT04 continues with a patient study assessing therapeutic equivalence of AVT04 and EU-RP (NCT04930042), data from which are intended to further support a demonstration of biosimilarity. Preliminary results from both AVT04 studies were recently presented at the 2023 Annual Meeting of the American Academy of Dermatology [17,18].

5. Conclusions

This study supported the finding of PK similarity between AVT04, US-licensed- and EU-approved-reference product ustekinumab. The safety, tolerability, and immunogenicity profiles were comparable across all three treatment arms.

Declaration of interest

C Wynne is an employee of, and holds shares in, New Zealand Clinical Research that received payment for carrying out the study. P Hamilton was an employee at New Zealand Clinical Research at the time of the study. K McLendon is an employee of Nucleus Network Pty Ltd that received payment for carrying out the study. H Stroissnig, M Smith, P Duijzings, R Ruffieux, H Otto, A Sattar, HN Haliduola, S Leutz, and F Berti are employees at Alvotech.

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

C Wynne, H Stroissnig, M Smith, P Duijzings, R Ruffieux, H Otto, A Sattar, HN. Haliduola, and F Berti were involved in the conception and design of the study. C Wynne, P Hamilton, K McLendon, M Smith, and P Duijzings were involved in the provision of study materials and patients and acquisition of the data. C Wynne, H Stroissnig, H Otto, A Sattar, HN Haliduola, S Leutz, and F Berti did the analysis and/or the interpretation of the data. All authors revised the report critically. All authors approved the final version.

Acknowledgments

The authors thank the participants who volunteered in the study and all the investigators who contributed. The authors additionally thank Joseph McClellan of Alvotech for strategic guidance, and Lorna Rettig of Alvotech for medical writing assistance.

Data availability statement

The datasets generated and/or analyzed during the current study are available from thecorresponding author, [Fausto Berti, [email protected]], upon reasonable request.

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/13543784.2023.2215426

Additional information

Funding

This study was funded by Alvotech Swiss AG, Zürich, Switzerland