📚 Part of the OBX-319 Regulatory Dossier — Reader's Guide. This article shows the live document; edits to the source appear here automatically.

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Module 3 — Device & Combination Product (OBX-319)

Document ID: M3-DEV
Version: 1.0
Change History: 1.0 — Initial issue.
Standard(s): 21 CFR 4; ISO 11608

Device & Combination-Product Information — OBX-319

The subcutaneous presentation of OBX-319 in a prefilled syringe/autoinjector is a combination product (21 CFR Part 4). This section summarises device design controls (design inputs/outputs, verification and validation), human-factors / usability engineering (use-related risk analysis and a validation study), biocompatibility (ISO 10993), and essential performance requirements. 21 CFR 4/820.30; ISO 11608; IEC 62366.

OBX-319 is a humanized, bispecific IgG1 monoclonal antibody (anti-CD19 x anti-CD20) expressed in Chinese hamster ovary (CHO) cell culture and administered subcutaneously for the treatment of moderate-to-severe active Systemic Lupus Erythematosus (SLE). Because the finished product co-packages a biological constituent (drug substance/drug product described in Modules 3.2.S and 3.2.P) with a device constituent (a single-use prefilled syringe and an autoinjector built on the same primary container), it meets the definition of a combination product under 21 CFR 3.2(e). The device is designed to deliver a high-concentration (150 mg/mL) viscous antibody solution reliably by the subcutaneous route, in the clinical setting and for at-home self-administration, while protecting the product-quality attributes on which efficacy and immunogenicity depend. The information below is presented in Module 3.2.R (regional) as the device constituent-part and combination-product record and is cross-referenced to the biologic quality modules and to the risk-management and clinical human-factors documentation.

Regulatory Classification and Combination-Product Framework

The primary mode of action (PMOA) of OBX-319 is that of the biological constituent — B-cell depletion mediated by simultaneous engagement of CD19 and CD20 — so the product is regulated by CDER/CBER as a biologic-led combination product and is submitted in a single Biologics License Application under 21 CFR 601. The current good manufacturing practice (cGMP) obligations are met using the streamlined approach of 21 CFR 4.4: the biologics quality system (21 CFR 210/211 and the 600-series) is operated as the base system, with the device design and production provisions of the Quality System Regulation applied to the device constituent. Specifically, 21 CFR 820.30 (design controls), 820.50 (purchasing/supplier controls), 820.100 (corrective and preventive action), 820.170 (installation, where applicable), and 820.200 (servicing, where applicable) are demonstrated in addition to the biologics base system. The prefilled syringe and autoinjector are needle-based injection systems within the scope of the ISO 11608 series, and the usability engineering process conforms to IEC 62366-1 and the FDA human-factors guidance for combination products.

Constituent Parts and Device Description

Biological constituent. The active is the full-length bispecific humanized IgG1 (approximately 150 kDa) formulated as a sterile, preservative-free aqueous solution at 150 mg/mL for subcutaneous injection; its composition, manufacture, control, container-closure, and stability are described in Module 3.2.P. The OBX-319 High and OBX-319 Low dose levels evaluated in study OBX319-301 share a single formulation and fill concentration and are differentiated by the number of prefilled-syringe/autoinjector units administered per dosing visit rather than by concentration; the composition-matched Placebo is presented in the identical container-closure and device.

Device constituent. The primary container is a pre-sterilized Type I borosilicate glass syringe barrel with a staked stainless-steel needle, rigid needle shield, and fluoropolymer-coated elastomeric plunger stopper, consistent with Module 3.2.P.7. Two presentations are built on this common primary container: (i) a manually operated single-use prefilled syringe (PFS) with a passive needle-safety feature, and (ii) a single-use disposable autoinjector that houses the same PFS and provides automated needle insertion, dose delivery, and end-of-dose indication. The device constituent is characterised against the applicable parts of the ISO 11608 series — 11608-1 (needle-based injection systems: requirements and test methods), 11608-2 (needles), 11608-3 (finished containers), and 11608-5 (automated functions) — and against IEC 62366-1 for usability. The needle geometry (gauge and length) is specified to achieve reliable delivery into the subcutaneous space across the intended-user body-habitus range.

Design Controls and Design History File (21 CFR 820.30)

Development of the device constituent was conducted under a documented design-control process, with a Design History File (DHF) that traces user needs through to verified and validated design outputs:

• Design inputs — derived from the use specification, the intended-user and use-environment definition, the target product profile for subcutaneous delivery of a high-concentration bispecific antibody, essential performance requirements, applicable standards (ISO 11608 series, ISO 10993, IEC 62366-1, ISO 14971), and the outputs of use-related and non-use risk analysis.
• Design outputs — device specifications, drawings, materials, the fluid path, software (where present in the autoinjector actuation/indication logic), labeling, and the Instructions for Use.
• Design verification — objective evidence, generated across the labeled 2-8 C storage condition, after ambient equilibration, and at end of shelf life, that outputs meet inputs (the essential-performance test program below).
• Design validation — confirmation that the finished combination product meets user needs and intended uses under actual or simulated use, including the human-factors validation study and confirmation of dose delivery with the marketed formulation.
• Design reviews, design transfer, and change control — formal reviews at defined stages, qualified transfer of the design to routine assembly, and controlled management of design changes with impact assessment on the biologic constituent, verification status, and human factors.

Risk management (ISO 14971) is integrated throughout the design-control process, and the DHF is maintained under the combination-product quality system.

Essential Performance Requirements and Design Verification

Essential performance requirements were established to ensure that each actuation delivers the intended dose of the viscous, high-concentration bispecific antibody without compromising sterility, container-closure integrity, or the aggregation/subvisible-particle profile that governs immunogenicity and efficacy. Requirements were verified across the storage range, after ambient equilibration prior to injection (viscosity is temperature-dependent), and at the proposed shelf life, using statistically justified sample sizes:

Essential performance attribute	Rationale	Verification
Deliverable/extractable volume and delivered dose accuracy	Correct dose per unit; High/Low delivered by unit count	Gravimetric/volumetric testing per ISO 11608-1
Break-loose and glide (extrusion) force	High-concentration (150 mg/mL) formulation is viscous; force governs deliverability and injection time	Force-displacement testing across temperature and shelf life
Injection time / hold time	Ensures full dose delivery of a viscous solution before device removal	Timed delivery per ISO 11608-1/-5
Needle insertion depth and penetration	Reliable subcutaneous placement across body habitus	Insertion-force and depth verification (ISO 11608-2)
Activation (trigger) and cap-removal force	Operable by intended users, including those with reduced hand strength/dexterity	Force testing linked to human-factors user profile
End-of-dose indication (visual/audible) and needle-shield lockout	Confirms complete delivery and prevents needlestick/reuse	Functional and reliability testing (ISO 11608-1/-5)
Container-closure integrity and sterility of the fluid path	Sterile, preservative-free, single-use product	Physical CCI and sterility assurance (cross-ref 3.2.P.7)
Subvisible particulates and aggregation after actuation	Device shear/interfacial stress must not raise immunogenicity risk	Post-actuation product-quality testing (cross-ref 3.2.P)

Design verification demonstrated that the PFS and autoinjector meet these requirements across the labeled conditions and shelf life, and that device actuation does not adversely affect the monomer, aggregate, and subvisible-particle profile of the drug product.

Human-Factors / Usability Engineering

Usability engineering was conducted per IEC 62366-1 and the FDA human-factors guidance, with a use-related risk analysis (URRA) driving the design and the validation strategy. The use specification defines the intended users (adult patients with moderate-to-severe SLE self-administering at home, lay caregivers, and healthcare professionals), the use environments (home and clinical settings), and the intended use (subcutaneous self-injection of a high-concentration antibody). The user analysis explicitly accounts for SLE-relevant characteristics that can affect device handling — reduced hand strength and dexterity from arthralgia/arthritis, fatigue, and reduced visual acuity — which informed cap-removal and activation-force targets, grip design, needle-safety behaviour, and Instructions-for-Use readability.

Known and foreseeable use problems for needle-based injection systems, and hazard-related use scenarios, were identified and mapped to critical tasks (for example, correct site selection and skin preparation, removing the cap, holding the device against the skin for the full injection/hold time, and confirming end-of-dose). Formative evaluations were performed iteratively during design to identify and mitigate use errors and to refine the Instructions for Use. A human-factors validation (simulated-use) study was then conducted in representative participants — including SLE patients and caregivers, with at least 15 participants per distinct user group — under realistic conditions, with observation of critical-task performance, use errors, close calls, and difficulties, followed by knowledge-task and subjective assessment. Use errors and difficulties were subjected to root-cause analysis; residual use-related risks were evaluated for acceptability in the context of the benefit of B-cell-depleting therapy, and any residual risk was addressed through design or communicated in labeling. The clinical human-factors record supports safe and effective self-administration by the intended-user population.

Biocompatibility (ISO 10993)

Biological safety of the patient- and fluid-contacting materials was evaluated under ISO 10993-1 through a risk-based biological evaluation. The device is categorised as an externally communicating device with a circulating-blood/tissue-communicating fluid path and limited (≤24 h) exposure duration, and only the sterile fluid path contacts the product and, transiently, subcutaneous tissue. The evaluation combined materials characterisation and manufacturing-process information with chemical characterisation of extractables/leachables (ISO 10993-18) and a toxicological risk assessment (ISO 10993-17), supplemented by biological endpoint testing as warranted — cytotoxicity, sensitisation, and irritation/intracutaneous reactivity, with material-mediated pyrogenicity and hemocompatibility considered per the exposure category. Leachables were additionally assessed for the potential to promote protein aggregation or otherwise increase immunogenicity risk for this bispecific antibody, consistent with the container-closure compatibility work in Module 3.2.P.7. The biological evaluation concluded that the fluid-path and patient-contacting materials are acceptable for the intended limited-duration subcutaneous use.

Risk Management, Sterility, and Combination-Product Stability

An integrated risk-management file (ISO 14971) links design, human factors, biocompatibility, and manufacturing hazards to risk controls and residual-risk acceptability, and supports the overall benefit-risk conclusion for the delivery system. Sterility of the fluid path and needle is assured by the sterilisation and aseptic-processing controls described in Module 3.2.P, and container-closure integrity is demonstrated by a validated physical method correlated to microbial ingress. Because device function is temperature- and time-dependent, the essential performance requirements (notably break-loose/glide force and injection time for the viscous 150 mg/mL solution) are verified as part of the combination-product stability program at the labeled 2-8 C storage condition, after qualified transport/temperature excursions, and following ambient equilibration in-use, in alignment with the drug-product stability data in Module 3.2.P.8.

Manufacturing, Design Transfer, and Labeling

Final device assembly, 100% inspection, and functional/dose-delivery verification are performed under the combination-product cGMP framework (21 CFR 4.4), with qualified suppliers of device components (820.50), corrective and preventive action (820.100), and change control spanning both constituents. The design was formally transferred to routine production, and device-constituent lots representative of those used in study OBX319-301 anchor the essential-performance acceptance criteria. Combination-product labeling includes the patient Instructions for Use validated through the human-factors program, symbols per ISO 15223-1, unique device identification as applicable, and the carton/container and patient labeling maintained in Module 1; the labeling reinforces correct storage (2-8 C, protect from light), ambient equilibration before injection, single use, and safe needle handling and disposal.

Governing standards and guidelines: 21 CFR 4; 21 CFR 601; 21 CFR 820.30; ISO 11608; ISO 10993; IEC 62366-1; ISO 14971; ISO 15223-1.