Site-to-site technology transfer: 4 months to a first-attempt PPQ pass

Executive summary

An EU-based marketing authorisation holder needed to move commercial supply of a validated 3-step API synthesis from their existing EU CDMO to Operant Scientific. The move was driven by capacity constraints at the incumbent, not a quality issue — which made the transfer higher-stakes on speed than on remediation.

The transfer completed in four months from kickoff to a first-attempt PPQ pass. Three consecutive PPQ campaigns ran without a critical finding, and the client's regulatory variation cleared without requiring further information from either the sending or receiving site.

The context

Technology transfers driven by capacity — as opposed to remediation — have a specific dynamic. The sending site is often cooperative but not motivated, because the transfer is a loss of business for them. The receiving site has a very tight timeline because commercial supply must not lapse. Any gap in the transfer process becomes a supply-chain risk.

Gap analysis

The engagement opened with a two-week gap analysis phase. We compared SOPs, equipment train, analytical methods, and specifications between the sending site and our own. The output was a written gap list: 47 items in total, of which 12 were material enough to require formal resolution before the engineering run.

• Reactor type differed on step 2 — sending site used a glass-lined 2000 L reactor; we mapped to our 1500 L glass-lined vessel with adjusted mass balance.
• Analytical method for related substances used slightly different HPLC conditions — co-validation exercise commissioned early.
• Cleaning validation on the receiving site needed to include the incoming API in the scope — actioned before the engineering run.
• Nine other material items on process, packaging, and stability protocols, each with a resolution plan and target date.

Signed transfer protocol

We insist on a written, client-signed transfer protocol before any GMP work starts. The protocol names every critical process parameter, its target value, and its acceptance range. It also names the acceptance criteria for the PPQ campaigns and the analytical methods that will be used to evaluate them.

Engineering run

The non-GMP engineering run ran at 500 kg scale — full commercial size but not yet under the validation umbrella. This is where transfers usually surface their real problems: mass balance discrepancies, unexpected impurity profiles, or process-parameter drift that didn't show up in the documentation.

Our engineering run produced material within the impurity acceptance criteria on the first attempt. Two minor deviations were captured and investigated — one on solvent dryness, one on stir rate at crystallisation. Both were resolved with SOP updates before the PPQ campaigns.

PPQ campaigns

Three consecutive PPQ campaigns ran under GMP, back-to-back over a 6-week window. Each campaign was fully documented, released by QA, and audited by the client's representative on-site.

Handover report and steady state

The handover report was jointly signed by the client, our QA head, and the sending site's QA head — an unusual three-party signature that reflected the low-drama nature of the transfer. We took over commercial supply the following quarter and have run steady-state campaigns without a supply-chain incident since.

What made this transfer work

• A written, all-parties-signed transfer protocol before the engineering run.
• A gap analysis that took long enough to be honest — two weeks, not two days.
• Analytical method co-validation at both sites before the first GMP batch.
• Weekly technical review calls including sending site, receiving site, and client on the same line.
• A deviation matrix maintained live across the whole engagement, not reconstructed at the end.