ADC manufacturing.

Antibody-drug conjugate manufacturing joins a biological intermediate with a highly potent small-molecule linker-payload through conjugation, purification, formulation and often sterile fill. The record has to preserve both source lineages, the reaction and purification course, containment, analytical control and the downstream product population, frequently across a sponsor and more than one CDMO.

Seal connects antibody and linker-payload lots, suites, equipment, electronic batch execution, process data, pools, samples, drug-to-antibody ratio (DAR) and impurity testing, potent-material balance, cleaning, deviations, partner custody, fill and disposition in one genealogy.

Why teams choose Seal for ADC manufacturing

ADC programmes usually track product quality in a LIMS and batch record, containment in EHS systems, potent-material balance in spreadsheets and cleaning in logbooks, often across a sponsor and more than one CDMO, so a single released flag can stand in for all of them and authorise work that is unsafe or incomplete. Seal keeps these as separate, connected states on the same lot, and each execution step names the combination it requires before work begins. A deviation then identifies both the product population and the safety population it affects.

1Keep product state and hazard state separate but connected.

The approved product has three linked definitions: the antibody intermediate, the linker-payload or conjugation reagent, and the conjugated product. Each has its own specifications, storage, methods, stability, suppliers or sites and change history. Their effectivity stays synchronised, so a material or method change cannot enter production under an incompatible process version.

Readiness is rarely one state. An antibody lot can be GMP released but not yet accepted at the conjugation site. A linker-payload can be analytically approved but unavailable because the receiving suite lacks the required containment state. A conjugated pool can meet in-process criteria while its potent-material reconciliation is still open. Seal keeps material quality, occupational handling, facility containment, equipment cleaning, custody, analytical evidence and disposition as distinct states. Safety response and product-quality investigation can then run under their own procedures while sharing the same material, place, people, time and batch context.

2Carry both source lineages into conjugation.

The antibody lot keeps its cell bank, production culture, harvest, purification, viral-safety, formulation, testing and disposition evidence, either managed in Seal or received from the supplying partner as authoritative evidence with source references. Receipt, identity, custody, condition and container-level issue connect the physical intermediate to the conjugation batch.

The linker-payload is both a GMP material and a potent hazard. It carries chemical identity, supplier, lot, potency or assay, impurities, storage, expiry, occupational classification and handling controls. Access, transfer, dispensing, PPE, spill, waste and reconciliation rules derive from the approved material and area controls.

Facility and equipment state enforce containment. Suite classification, pressure or containment state, isolator, cleaning status, campaign, monitoring and equipment qualification determine eligibility, and the batch step checks the actual room and asset state before potent material is opened or transferred. An alarm or containment breach identifies the active people, materials, batches, equipment and time window for response and impact assessment.

3Account for every quantity of potent material.

Receipt quantity, potency correction, tare and gross weights, issue, return, residue, samples, spills, destruction and waste reconcile for the potent material. Identity is verified by barcode and independent check at the point of use, and tolerances and calculations are versioned. An unexplained difference blocks closure and opens an investigation; the record is never balanced by altering the issued quantity afterwards.

Yield and balance describe unlike quantities. Antibody mass, protein concentration, potency-corrected payload input, theoretical conjugate, pool mass, DAR, hold-up and waste measure different aspects of the operation, and one percentage cannot reconcile them all. Seal keeps approved definitions and units for material accountability, step yield, process recovery and product yield, each with its inputs, corrections, precision, rounding and version. A discrepancy may come from weighing, transfer, sampling, residue, spill or recording, and the investigation starts from the physical objects rather than forcing a neat answer before the evidence supports one.

4Record conjugation and purification with their context.

The electronic batch record defines antibody preparation, linker-payload solution, addition sequence and rate, molar or mass relationships, mixing, temperature, pH, time, sampling, quench and exception paths. Actual lots, containers, equipment, calculations, values, alarms, interventions and signatures accumulate against the reaction; automation can keep high-frequency control while Seal captures the accountable events and source references.

Chromatography, tangential-flow filtration, diafiltration and filtration create fractions and pools with their source, quantity, yield, column or membrane identity, process data and samples. Column and membrane use history, cleaning, prior products, cycle count and retirement limits gate selection. Holds travel with every reaction mixture, intermediate and bulk, pools inherit their sources’ exposure, and scheduling sees the time remaining before assigning suites, laboratory work or fill.

DAR is a distribution with method context, not one release number. Average DAR, distribution, unconjugated antibody, free payload, aggregates, fragments and potency depend on method and sample stage, so each result links to its source pool, reaction, purification step, method version, instrument acquisition, standards, calculations and review. In-process results can gate quench, pooling, buffer exchange or formulation through approved decision tables. Reprocessing creates controlled execution and new pool genealogy rather than modifying the first result.

5Treat cleaning as containment and cross-contamination control.

Cleaning procedures, executions, swab and rinse results and equipment release follow written procedures.¹ Product and equipment matrices, toxicological inputs, residue limits and worst-case rationale belong to the same lifecycle. In the EU, measures to prevent cross-contamination rest on a documented risk assessment that includes toxicological evaluation.² Potent-material cleaning also connects to waste routes and occupational controls, and maintenance respects residual state. A failed result contains the equipment and assesses every use since the last known acceptable condition.

6Keep accountability clear across partners and release.

Antibody supply, payload manufacture, conjugation, testing and fill may span sponsors and CDMOs. Each handoff defines identity, containers, quantity, condition, custody, documents, samples, status, acknowledgement and discrepancy handling, and quality agreements define who owns execution, raw data, deviations, change and disposition. Tech transfer carries containment as well as process intent: potent-material classification, enclosure requirements, closed-transfer assumptions, cleaning limits, waste routes and emergency response, each with an explicit equivalency or change assessment at the receiving site.

Where the ADC is filled as a sterile product, bulk, filters, fill line, environmental evidence, interventions, inspection and reconciliation stay downstream of the conjugation lot. A fill deviation traces back to both sources; a linker-payload concern traces forward to filled lots, shipments and markets. A deviation opens with its physical objects and time attached, and quality impact, worker safety, environmental response and product disposition proceed as connected but separately accountable workflows.

Disposition sees approved sources, material balance, suite and equipment state, conjugation, pools, results, holds, cleaning, deviations, fill evidence, partner approvals and final reconciliation. Review by exception brings missing evidence, corrections, alarms, OOS results, balance differences and open partner obligations forward while keeping the complete record.

7Prove one antibody-and-payload-to-vial lineage.

Trace approved antibody and linker-payload lots through receipt, containment, dispensing, conjugation, purification, analytical decisions, holds, cleaning, partner handoffs, sterile fill and release. Include a material mismatch, a containment alarm, a balance discrepancy, a reaction excursion, an atypical DAR result, extra purification, a cleaning failure and missing partner evidence.

The system is ready when every issue identifies both the exact product population and the exact safety population it affects.