Regulatory Navigation: CDER vs CBER, EMA, and the Nanotechnology Landscape

LNP Regulatory Navigation: FDA CDER vs. CBER Jurisdiction, EMA Guidance, and the Nanotechnology Regulatory Landscape

“The regulatory framework for lipid nanoparticle drug products is still being built in real time. Understanding which regulatory framework applies to your LNP program — and how to navigate the jurisdiction question within FDA — is a foundational strategic decision that must be made before your pre-IND meeting, not discovered during it.”

SECTION 1

The FDA Jurisdiction Question for LNP Programs: CDER vs. CBER and What Determines the Answer

The regulatory framework for lipid nanoparticle drug products is still being built in real time. Understanding which regulatory framework applies to your LNP program — and how to navigate the jurisdiction question within FDA — is a foundational strategic decision that must be made before your pre-IND meeting, not discovered during it.

The mistake that derails LNP programs at the regulatory strategy phase is not a CMC failure — it is an organizational one. Sponsors assume that the payload determines the regulatory center, that siRNA goes to CDER and mRNA goes to CBER, and that the question is settled by chemistry. That assumption is incorrect. Jurisdiction at FDA is determined by the intersection of payload type, clinical indication, mechanism of biological action, and regulatory classification precedent. The same lipid nanoparticle delivery system — identical formulation architecture, same ionizable lipid, same manufacturing platform — can fall under FDA’s Center for Drug Evaluation and Research, under CBER’s Office of Vaccines Research and Review, or under CBER’s Office of Therapeutic Products depending on what the payload does and what disease it is intended to treat. These are not administrative distinctions. They are structural differences in the regulatory pathway, in the CMC depth expected at IND, in the potency assay development requirements, and in the stability program FDA reviewers will expect to see at BLA. Getting this wrong costs programs a year.

The precedent map for CDER jurisdiction begins with patisiran — Onpattro — the siRNA-LNP product approved by FDA CDER in August 2018. The Onpattro BLA established that siRNA-LNP products targeting systemic disease through silencing of a hepatic gene product are New Drug Applications reviewed by CDER, specifically by the Office of Pharmaceutical Quality within CDER. The CMC standard applicable to Onpattro was the small molecule and biological drug product quality framework: ICH Q8(R2) pharmaceutical development, ICH Q9(R1) risk management, ICH Q10 pharmaceutical quality system, with biological drug substance-specific expectations layered in for the RNA payload component. This framework positions the LNP as a drug product with a defined drug substance — the siRNA — and a drug product formulation consisting of the ionizable lipid, phospholipid, cholesterol, and PEG-lipid delivery system. Onpattro’s BLA was not reviewed under the gene therapy framework. It was not reviewed as a biological product subject to the 21 CFR 601 licensure standard for potency assays in the same depth that gene therapy products are reviewed. That distinction has direct consequences for how you design your CMC data package from IND through BLA.

The second CDER precedent is inclisiran — Leqvio — approved by FDA CDER in December 2021 under a New Drug Application. Inclisiran is delivered as a GalNAc-siRNA conjugate, not an LNP formulation — a distinct delivery platform from Onpattro’s lipid nanoparticle — and targets PCSK9 mRNA in hepatocytes for the reduction of LDL cholesterol in patients with cardiovascular disease. Its regulatory path through CDER, under an NDA, confirmed that the Onpattro precedent extends across delivery platforms: both GalNAc-conjugate and LNP-class siRNA therapeutics targeting the liver for chronic systemic disease fall under the same CDER/OPQ jurisdictional framework. For programs developing hepatic siRNA-LNP products, the CDER NDA or BLA pathway — depending on whether the payload is classified as a drug or a biological product — is established by two approved products with complete public approval packages and, critically, with FDA review chemistry team contacts documented in those public-facing approval histories.

CBER jurisdiction divides between two offices, and the division is consequential. CBER’s Office of Vaccines Research and Review claimed jurisdiction over the COVID-19 mRNA-LNP vaccines — Comirnaty (BNT162b2, Pfizer-BioNTech) and Spikevax (mRNA-1273, Moderna) — through the EUA pathway in December 2020 (Comirnaty authorized December 11, 2020; Spikevax authorized December 18, 2020) and the full BLA pathway in 2021 and 2022 respectively. OVRR reviews mRNA-LNP products for infectious disease indication prevention — vaccines. The COVID-19 approvals under OVRR CBER represent the most visible regulatory precedent in the LNP field, but they are also the precedent most commonly misapplied. The Comirnaty and Spikevax approvals under EUA involved compressed CMC datasets that were not equivalent to the full CMC standard that would be required for a therapeutic mRNA-LNP seeking full BLA approval. Stability data packages under EUA were preliminary. Potency assay validation was initiated but not complete. The accelerated CMC standard that enabled COVID-19 vaccine authorization is not transferable to a therapeutic mRNA-LNP seeking approval for a rare disease or oncology indication outside of a genuine public health emergency — and programs that are designing their development plans using Comirnaty’s EUA CMC package as the benchmark for what FDA will accept at BLA are building on a fundamentally miscalibrated foundation.

The third category of CBER jurisdiction — and the one most relevant to therapeutic mRNA-LNP programs in rare disease, genetic disease replacement, and oncology — is CBER’s Office of Therapeutic Products, the “super office” formed in September 2022 when CBER elevated and retitled its former Office of Tissues and Advanced Therapies (itself the successor, since 2016, to the original Office of Cellular, Tissue and Gene Therapies). CBER OTP reviews gene therapy products. Under 21 CFR 312 and the FDA’s 2018 Chemistry, Manufacturing, and Controls Information for Human Gene Therapy Investigational New Drug Applications guidance, gene therapy is defined as a product that mediates its effect through the transcription or translation of transferred genetic material. Therapeutic mRNA-LNP products — products that deliver mRNA encoding a therapeutic protein for gene replacement in an enzyme deficiency, for expression of a tumor antigen for cancer immunotherapy, or for protein replacement in a genetic rare disease — are candidates for classification as gene therapy products under this definition. When CBER OTP claims jurisdiction, it applies the gene therapy CMC framework, and the implications for the development program are substantive. They are not merely administrative.

Pre-IND preparation for a therapeutic mRNA-LNP program must include a written product classification memo — a document, distinct from the briefing document narrative, that explicitly addresses the CBER versus CDER question, states the sponsor’s proposed classification, and presents the regulatory rationale in terms of the payload mechanism of action, the clinical indication, and the applicable precedents. This memo should be included in the pre-IND meeting request package under 21 CFR 312.82 and should form the basis of a formal jurisdictional confirmation request as a discrete agenda item in the pre-IND meeting itself. The goal at the pre-IND meeting is to receive a written FDA statement — in the meeting minutes — confirming or correcting the sponsor’s proposed jurisdiction. Everything downstream in the CMC development plan — the potency assay strategy, the depth of manufacturing process characterization, the starting material controls for the mRNA drug substance, the stability program design — depends on knowing which CMC framework FDA will apply.

The FDA’s treatment of nanotechnology as a regulatory category adds a second layer of complexity to the jurisdictional analysis. FDA’s June 2014 Guidance for Industry: Considering Whether an FDA-Regulated Product Involves the Application of Nanotechnology establishes that FDA considers nanotechnology to apply when a product involves materials with at least one dimension in the range of approximately 1 to 100 nanometers. LNPs are explicitly within this size range. FDA layered a drug-specific companion guidance on top of that threshold definition in April 2022 — Drug Products, Including Biological Products, that Contain Nanomaterials — which addresses quality, nonclinical, and clinical considerations specific to nanomaterial-containing drug and biological products, including abbreviated-pathway considerations not present in the 2014 cross-sector guidance. Neither guidance itself determines which center has jurisdiction — Onpattro, Leqvio, Comirnaty, and Spikevax all involve nanotechnology in the FDA’s definition, and they span three distinct regulatory offices — but it does establish that FDA expects the product’s nanoscale properties to be assessed in the context of product safety and effectiveness, that particle size and surface properties are considered potentially performance-relevant rather than purely characterization data, and that characterization of the nanotechnology dimensions of an LNP product is expected in the CMC submission regardless of which center reviews it. The nanotechnology guidance operationalizes to an expectation that your pharmaceutical development section demonstrates a scientific understanding of how the nanoscale dimensions of your LNP govern drug product performance — not simply that you measured particle size and reported a number.

The regulatory landscape for LNP products at FDA is not static. The CBER OTP gene therapy framework, which governs the most scientifically complex class of therapeutic mRNA-LNP products, has been updated repeatedly since 2018 and continues to evolve. The COVID-19 experience produced policy documentation, EUA-specific guidance, and precedent-setting CMC decisions that are influencing how OVRR and OTP are approaching subsequent mRNA-LNP programs. For development teams navigating this environment, the single most important early-stage action is not drafting the IND CMC section — it is confirming, in writing, from FDA, which regulatory framework governs their specific product. That confirmation, obtained at the pre-IND meeting, is the foundation on which every downstream CMC decision should rest.

SECTION 2

CMC Implications of CBER OTP Jurisdiction: How the GT Guidance Framework Changes Your Development Plan

When CBER OTP claims jurisdiction over a therapeutic mRNA-LNP, the CMC standard that applies is the FDA gene therapy framework — and the depth of manufacturing characterization, potency assay development, and starting material control that FDA’s reviewers expect is materially greater than what the CDER NDA/BLA standard for a siRNA-LNP requires. Understanding this difference before IND — not during BLA readiness review — is the defining factor in whether your development program is resourced correctly.

The first and most operationally consequential implication of CBER OTP jurisdiction is the potency assay expectation. Under FDA’s gene therapy CMC guidance, potency is defined as the specific ability of the product to achieve a defined biological effect, and the expectation is that a cell-based, mechanism-of-action-linked potency assay be developed and validated for inclusion in both lot release testing and the stability program. For a therapeutic mRNA-LNP, this means that an assay measuring protein expression from the delivered mRNA in a relevant cell system — not an in vitro transcription yield assay, not an encapsulation efficiency measurement, not a particle size distribution — must be developed, qualified, and on a validation trajectory by Phase 2. For mRNA-LNP products encoding intracellular proteins, secreted proteins, or membrane-anchored antigens, the cell-based potency assay is the most resource-intensive analytical development activity in the entire CMC program. It requires a relevant cell line, a validated detection method tied to the expressed protein, acceptance criteria derived from the clinical dose-response relationship, and a demonstrated correlation between the in vitro cell-based result and the in vivo efficacy signal. CDER, reviewing a siRNA-LNP under the NDA framework, does not apply this potency assay standard with the same depth. It expects quantitative in vitro activity data, but the gene therapy requirement for a cell-based, MOA-linked assay with full validation under ICH Q2(R2) — Validation of Analytical Procedures, the revised guideline effective June 2024 that explicitly extends validation expectations to biological products and multivariate methods — at BLA is specific to the CBER OTP framework.

The second major CMC implication of CBER OTP jurisdiction is the starting material and raw material control depth expected for the mRNA drug substance. Under the gene therapy CMC framework, the mRNA is classified as the drug substance, and its manufacturing process — from DNA template through in vitro transcription, capping, polyadenylation, purification, and formulation — is subject to detailed characterization and control expectations. The DNA template used for IVT is a starting material that requires identity, purity, and quality documentation consistent with the gene therapy framework’s requirements for genetic materials. Plasmid DNA templates, linearized DNA cassettes, and synthetic DNA templates each carry specific control expectations that are addressed in FDA’s guidance for gene therapy products. For CDER-reviewed siRNA-LNP products, the RNA oligonucleotide drug substance follows a chemical synthesis process with well-established ICH Q3A/Q3B impurity characterization expectations. The IVT-derived mRNA process, reviewed under CBER OTP, introduces biological manufacturing complexity — transcription yield, dsRNA byproduct formation, capping efficiency, polyadenylation heterogeneity, and degradation product profiles — that requires a more extensive drug substance characterization program and more detailed process validation documentation.

The third CMC area shaped by CBER OTP jurisdiction is manufacturing process characterization depth. FDA’s gene therapy guidance documents, including the 2020 Chemistry, Manufacturing, and Controls Information for Human Gene Therapy Investigational New Drug Applications guidance, expect characterization studies demonstrating process understanding at a level consistent with the critical quality attributes of a biological product with complex mechanism of action. For therapeutic mRNA-LNP products, this translates to an expectation that the LNP assembly process — microfluidic mixing parameters, lipid-to-RNA ratio control, ethanol dilution and dialysis conditions — is characterized through multivariate studies demonstrating how critical process parameters affect the particle size distribution, encapsulation efficiency, mRNA integrity within the particle, and potency as measured by the cell-based assay. The characterization depth that FDA reviewers under CBER OTP bring to BLA review of a therapeutic mRNA-LNP is greater than the characterization depth typically applied by CDER reviewers to siRNA-LNP BLA submissions. This is not a speculation — it is a predictable consequence of the gene therapy regulatory tradition, which has from its earliest days applied a detailed process characterization standard to complex biological manufacturing processes for products with irreversible or high-consequence clinical effects.

The stability program for a therapeutic mRNA-LNP under CBER OTP jurisdiction is governed by ICH Q5C — the stability testing guideline for biotechnological and biological products — rather than by ICH Q1A(R2), which applies to chemical drug substances and small molecule drug products. ICH Q5C is not simply a stricter version of Q1A(R2). It imposes different analytical panel requirements — specifically the requirement to monitor potency stability with the cell-based assay at each stability time point — and it requires a stability commitment structure that accounts for the biological complexity of the product. For frozen mRNA-LNP products, the stability program design must address the frozen storage condition at the proposed commercial storage temperature, freeze-thaw cycling studies, real-time and accelerated conditions, and in-use stability for the thawed product in the clinical administration context. The frozen storage stability expectation under ICH Q5C for a CBER OTP-reviewed product requires that cell-based potency be included as a stability-indicating attribute from Phase 1 onward — not introduced at BLA readiness as an afterthought.

The practical development implication of CBER OTP jurisdiction is resource. A therapeutic mRNA-LNP CMC program operating under the gene therapy framework requires a cell-based potency assay development effort that begins before Phase 1 IND filing, a more extensive mRNA drug substance characterization program, a manufacturing process characterization study set with multivariate statistical design, and a stability program anchored to ICH Q5C with potency monitoring from the first time point. Programs that are resourced and timelines that are calibrated for the CDER siRNA-LNP standard — two to three years of CMC development to BLA — will systematically underestimate the timeline and budget for a CBER OTP therapeutic mRNA-LNP program. The difference is not incremental. Confirming CBER OTP jurisdiction early, and calibrating the development program to the gene therapy CMC framework from the beginning, is the strategic decision that separates programs that reach BLA ready from those that arrive at BLA with open CMC commitments and deficiency responses that delay approval by two or three years.

SECTION 3

EMA Navigation for LNP Programs: Scientific Advice, mRNA Analytical Expectations, and COVID Precedent Limitations

EMA does not replicate the FDA jurisdictional complexity for LNP programs. In the European framework, all LNP medicinal products — whether siRNA-LNP, therapeutic mRNA-LNP, or mRNA-LNP vaccines — follow the centralized procedure under Regulation (EC) No 726/2004, with CHMP as the primary scientific committee responsible for the scientific opinion on the marketing authorization application. There is no jurisdictional split equivalent to CDER versus CBER within EMA, and there is no separate gene therapy-specific regulatory office within EMA with independent CMC jurisdiction over mRNA-LNP products in the way that CBER OTP functions at FDA. The CAT — Committee for Advanced Therapies — is involved in the assessment of advanced therapy medicinal products that include gene therapy medicinal products as defined under Regulation (EC) No 1394/2007, and some therapeutic mRNA-LNP products that fall within the ATMP gene therapy definition may be subject to CAT involvement in the CHMP assessment. But for most LNP programs seeking EMA approval, the CHMP centralized procedure is the pathway, and EMA’s Scientific Advice mechanism is the pre-submission engagement mechanism equivalent to FDA’s pre-IND meeting.

EMA Scientific Advice, available under the framework established in Regulation (EC) No 726/2004 and implemented through the CHMP Scientific Advice Working Party, is a formal written procedure in which the sponsor submits a briefing document with specific questions and receives a written EMA scientific opinion. For LNP programs, Scientific Advice is available on CMC questions — and it should be used for any mRNA-LNP program at the CMC strategy stage. EMA’s written Scientific Advice responses are not binding in the legal sense, but they represent the current EMA scientific position on the questions asked and create a documented scientific dialogue record that is directly relevant to the MAA assessment. EMA Scientific Advice on mRNA-LNP CMC questions should address: the analytical approach for mRNA integrity characterization, the capping efficiency methodology, the dsRNA impurity control strategy, the potency assay design, the particle size and encapsulation efficiency specification justification, and the stability program design.

The EMA’s analytical expectations for mRNA-LNP products are grounded in one foundational reflection paper and a purpose-built quality guideline developed specifically in response to the mRNA vaccine experience. The foundational document is the EMA Reflection Paper on Nanotechnology-Based Medicinal Products for Human Use (EMEA/CHMP/79769/2006), which establishes that nanoparticulate medicinal products require specific characterization of physicochemical properties, including particle size, particle size distribution, surface characteristics, and the relationship between these properties and the product’s safety and efficacy. The 2006 nanotechnology reflection paper predates the mRNA-LNP field but remains the foundational EMA policy document establishing that LNP physicochemical characterization must be linked to clinical performance — not simply reported as characterization data in isolation. The second key document is the EMA Guideline on the Quality Aspects of mRNA Vaccines, which CHMP’s Biologics Working Party developed in two stages following the COVID-19 vaccine experience: a June 2023 concept paper (EMA/CHMP/BWP/211968/2023) establishing the need for mRNA-specific quality guidance, followed by the March 2025 draft guideline itself (EMA/CHMP/BWP/82416/2025), released for public consultation through September 2025 and, as of this writing, still moving toward finalization. The draft guideline establishes EMA’s analytical expectations for mRNA-based products in specific, actionable terms: mRNA integrity characterization by capillary electrophoresis or agarose gel electrophoresis with quantitative reporting of intact full-length mRNA as a percentage of total RNA; 5′ capping efficiency by HPLC or enzymatic methods with a defined specification for cap-1 versus cap-0 structures; dsRNA impurity characterization and control through methods capable of detecting double-stranded RNA species formed as IVT byproducts; and poly(A) tail length characterization by methods that can resolve the distribution of polyadenylation lengths around the intended target. Sponsors should treat the draft guideline as the current statement of EMA scientific thinking on these points even while it remains formally in consultation, since CHMP assessors are applying this thinking in Scientific Advice now.

The COVID-19 EMA precedent, like the FDA EUA precedent, carries a critical limitation that must be understood before it is applied to a non-vaccine therapeutic mRNA-LNP MAA. The Comirnaty and Spikevax MAAs under EMA were assessed under exceptional circumstances with compressed review timelines, conditional marketing authorization — not standard marketing authorization — and rolling review mechanisms that allowed assessment of data packages as they became available rather than requiring a complete MAA dossier at submission. The analytical validation datasets, stability data breadth, and process validation documentation that supported conditional marketing authorization for COVID-19 mRNA vaccines are not the standard that EMA will apply to a therapeutic mRNA-LNP seeking standard marketing authorization for a rare disease or oncology indication. Programs benchmarking their EMA CMC package to the COVID-19 conditional MAA standard are systematically underestimating what EMA assessors will require. ICH Q6B specifications for biological medicinal products, ICH Q5C stability requirements for biotechnological products, and ICH Q8(R2) pharmaceutical development section expectations apply in full to a standard MAA for a therapeutic mRNA-LNP — with the addition of EMA’s nanotechnology-specific reflection paper and mRNA-specific quality guideline requirements layered on top.

The CMC differences between an FDA BLA and an EMA MAA for a therapeutic mRNA-LNP are real but manageable if planned for from the outset. EMA assesses the drug substance and drug product quality in the CTD Module 3 format consistent with the ICH eCTD structure. The primary regulatory chemistry assessment standard at EMA for an mRNA-LNP drug substance is ICH Q6B, which applies to biological medicinal products including proteins and nucleic acid-based therapeutics. Impurity characterization for the mRNA drug substance — dsRNA, truncated RNA species, free nucleotides, residual DNA template, and process-related impurities from the IVT reaction — follows the principles of ICH Q6B characterization expectations adapted to the IVT production platform. EMA’s expectations for the mRNA integrity specification are more prescriptive than FDA’s in current practice, driven by the explicit requirement set out in the draft Guideline on the Quality Aspects of mRNA Vaccines (EMA/CHMP/BWP/82416/2025): EMA expects an integrity specification with a defined lower acceptance limit for intact full-length mRNA as a percentage of total RNA, measured by a validated capillary electrophoresis method, and justification of the acceptance limit by reference to stability data and potency correlation studies.

For LNP programs planning global submissions covering both FDA and EMA, the regulatory strategy must account for the jurisdictional and analytical differences from the CMC development planning stage. A single, harmonized CMC data package built to the more demanding of the two standards — gene therapy framework under CBER OTP for FDA where applicable; ICH Q6B and mRNA reflection paper requirements for EMA — will satisfy both agencies more efficiently than a program that designs to one standard and scrambles to add data for the other at submission. The Scientific Advice process at EMA and the pre-IND meeting at FDA serve the same function: to obtain documented regulatory guidance before CMC development commitments are made. Using both mechanisms, early in the program, for both jurisdictional confirmation and CMC strategy alignment, is the most resource-efficient path to a simultaneous FDA BLA and EMA MAA submission.

The XGene LNP Regulatory Strategy Architecture

Step 1 — Jurisdictional Determination at FDA (Before Pre-IND Submission) Define the payload type (siRNA, antisense oligonucleotide, therapeutic mRNA, vaccine mRNA), the clinical indication, and the mechanism of biological action. Map these against the three applicable FDA jurisdictional precedents: CDER/OPQ for siRNA-LNP and ASO-LNP targeting systemic disease (Onpattro 2018 as the LNP-formulation precedent; Leqvio 2021 as the GalNAc-conjugate precedent extending the same jurisdiction to non-LNP hepatic siRNA delivery); CBER/OVRR for mRNA-LNP vaccines for infectious disease prevention (Comirnaty 2021, Spikevax 2022); CBER/OTP for therapeutic mRNA-LNP programs for gene replacement, protein replacement, rare disease, or oncology where the mRNA mediates its effect through transcription or translation of transferred genetic material (21 CFR 312 gene therapy definition). Prepare a written product classification memo documenting the proposed jurisdiction and the regulatory basis for the classification. This memo is a standalone document — not embedded in the briefing document narrative — and must be included in the pre-IND meeting request package.

Step 2 — Pre-IND Meeting Preparation with Jurisdictional Confirmation as a Discrete Agenda Item Structure the pre-IND meeting agenda to include jurisdictional confirmation as a numbered question requiring a written FDA response in the meeting minutes. The meeting briefing document should present the product classification memo, the proposed regulatory pathway (IND under 21 CFR 312 toward BLA or NDA), and the proposed CMC framework. Questions to FDA should explicitly ask: (a) Does FDA agree with the proposed regulatory jurisdiction (CDER vs. CBER OTP vs. CBER OVRR) for this product and indication? (b) Does FDA consider this product to be a gene therapy product subject to the gene therapy CMC guidance framework? (c) Does FDA expect a cell-based, MOA-linked potency assay at IND Phase 1 or at a specified later development stage? Document FDA’s written responses in the meeting minutes and treat them as the authoritative CMC framework reference for the program.

Step 3 — CMC Data Package Requirements from IND Through BLA/MAA by Jurisdiction For CDER NDA/BLA (siRNA-LNP, ASO-LNP): IND CMC — drug substance specification, drug product specification, container closure system description, analytical methods summary, preliminary stability data; Phase 2 — process characterization studies, analytical method qualification, stability data at 6–12 months; BLA — full ICH Q8(R2) pharmaceutical development section, validated analytical methods per ICH Q2(R2), stability data meeting ICH Q1A(R2) requirements, process validation Stage 1 and 2 completion. For CBER OTP BLA (therapeutic mRNA-LNP): IND CMC — all CDER requirements plus cell-based potency assay description and development plan, DNA template starting material controls documentation, mRNA integrity characterization, dsRNA impurity characterization; Phase 2 — cell-based potency assay qualification, ICH Q5C stability program with potency at each time point, multivariate process characterization studies; BLA — all CDER requirements plus fully validated cell-based potency assay, ICH Q6B characterization package for mRNA drug substance, ICH Q5C stability compliance, gene therapy CMC guidance compliance documentation. For CBER OVRR BLA (mRNA-LNP vaccine): Note that EUA CMC standard is NOT equivalent to full BLA standard; full BLA requires complete analytical validation, full stability datasets, complete process validation — do not use EUA CMC package as the BLA benchmark.

Step 4 — EMA vs. FDA CMC Requirement Differences and Global Submission Strategy EMA centralized procedure with CHMP primary committee applies to all LNP programs in the EU regardless of payload type. Use EMA Scientific Advice before CMC development commitments are finalized — target Scientific Advice questions on: mRNA integrity specification and analytical method, capping efficiency specification, dsRNA impurity control strategy, potency assay design, nanotechnology characterization expectations per EMEA/CHMP/79769/2006. Apply EMA’s draft Guideline on the Quality Aspects of mRNA Vaccines (EMA/CHMP/BWP/82416/2025, building on concept paper EMA/CHMP/BWP/211968/2023) requirements to mRNA-LNP drug substance characterization: quantitative mRNA integrity by capillary electrophoresis, cap-1 capping efficiency specification, dsRNA impurity control, poly(A) tail characterization. For global programs, build the CMC data package to the higher of FDA BLA and EMA MAA requirements from the outset: this means cell-based potency assay, ICH Q5C stability, mRNA integrity specification, and dsRNA impurity control strategy in the development plan from Phase 1 IND.