Tackling The Cell & Gene Therapy Sector's Practical Post-Approval Problem

By Megha Sinha, founder and CEO, Kamet Consulting Group

The field of cell and gene therapy (CGT) has achieved something remarkable. Products that would have been theoretical a decade ago are now approved, marketed, and reaching patients, thanks to regulatory pathways — accelerated, conditional, fast-tracked — that represent a genuine achievement of adaptive regulation in the face of significant scientific uncertainty.

Yet there is a consequence to this speed that the industry is only beginning to reckon with. Many of these products were approved with outstanding manufacturing commitments, evolving regulatory frameworks, and supply chains that were never designed to absorb the post-approval change management burden that commercial-stage operation inevitably creates.

Post-approval life cycle change management is difficult for every pharmaceutical product. For CGTs, it is the most acute version of the challenge, for reasons that are structural rather than incidental. The manufacturing processes here are among the most complex in pharmaceutical production. For autologous CAR-T products, the manufacturing process is the patient — a personalized chain of custody from leukapheresis to infusion so tightly coupled to individual patient material that any manufacturing change carries inherent risks absent from off-the-shelf products.

For gene therapies delivered by viral vectors, even incremental changes to the manufacturing process — a scale-up, a change in the viral vector production platform, a modification to the downstream purification process — raise comparability questions of a different order of magnitude than those faced by conventional biologics. Demonstrating that the product made after the change is the same product as the one that was clinically validated, in a modality where potency assays are still maturing and long-term safety data is still being gathered, is a scientific and regulatory challenge that can take years to resolve.

Add to this the fact that regulatory frameworks for CGTs are still actively evolving. Many products were approved through conditional or accelerated pathways that carry post-marketing commitments — confirmatory studies, long-term follow-up requirements, additional CMC data packages — that must be discharged alongside any manufacturing changes the company is implementing. FDA’s CBER is finalizing guidance on manufacturing changes and comparability for CGT products in 2026, one of several regulatory developments that will directly affect how post-approval changes are assessed.

The regulatory landscape that a CGT company is navigating today is not the same one it will be navigating in two years’ time, and post-approval change programs must be planned with continuous regulatory monitoring built in from the start.

A Supply Chain With No Margin For Error

The supply chain dynamics of CGT amplify every one of these challenges. Inventory buffers — the standard mechanism by which conventional pharmaceutical companies protect supply continuity while regulatory approvals are pending — are minimal or nonexistent for autologous therapies. Cold chain requirements are stringent. Production capacity is constrained at most dedicated facilities. And because many of these products target rare diseases or specific oncology indications, the patient populations are small and the impact of a supply disruption is immediately and directly felt.

For allogeneic cell therapies and viral vector-based gene therapies, where some degree of stockpiling is possible, the challenge is different but equally acute. A manufacturing change that would give a conventional pharmaceutical company a two-year runway to manage regulatory approvals and supply transitions in parallel may give a CGT organization three to five years of execution time — and with much higher technical risk at each stage, because the data packages required are more complex and the health authority interactions are more intensive.

The structural challenge facing CGT developers and marketing authorization holders (MAHs) mirrors that of larger pharma: every manufacturing change must be filed separately across every registered market, each with different submission categories, review timelines, and implementation grace periods. For a product approved in the U.S., EU, U.K., and several Asia-Pacific markets, a single process change might require five to eight separate regulatory submissions, each on a different timeline and with different data requirements. Unlike a large small molecule company with a deep regulatory operations bench, many CGT companies are managing this with lean teams that have deep scientific expertise but limited operational infrastructure for multimarket post-approval execution.

The Post-Marketing Commitment Burden

One dimension of post-approval life cycle management that is particularly acute for CGT is the ongoing obligation to fulfill post-marketing commitments made at the time of accelerated or conditional approval. A confirmatory trial that was underway at approval may now have data requiring a label update. Long-term follow-up data from the original registration cohort may be generating safety signals that must be reflected in prescribing information across all markets. These are regulatory obligations, not discretionary activities, and failing to manage them could put the original approval at risk.

What makes this operationally complex is that post-marketing commitments and post-approval manufacturing changes are almost never managed in the same planning framework — the regulatory team tracking CMC changes typically has no visibility into the clinical commitments team’s timeline, and vice versa. In markets where a health authority will not accept a new variation while a prior submission is still under review (there are many such markets), an uncoordinated submission strategy can mean that a manufacturing change is delayed by six to 12 months simply because a post-marketing commitment data submission got there first.

Consider a divestiture requiring transfer of marketing authorization holder status across more than 80 countries — a scenario I have encountered directly. Without a unified view of country-level requirements — which markets required full Type II variations, which accepted notifications, which required local agent appointments and notarization — the company ended up with inconsistent filings, rejected submissions, and a regulatory remediation program that took over two years and cost several million dollars to resolve. For a CGT developer, where the regulatory team is often smaller and the markets fewer, the same failure potential exists — but with less organizational capacity to absorb the remediation cost.

What Good Looks Like, And Why The Time To Build It Is Now

For CGT companies moving from clinical to commercial stage, or scaling approved products into new markets, there are three investments in operational infrastructure that promise immediate dividends.

1. Treat regulatory intelligence as a live operational asset. The country-level requirements for post-approval changes in CGT are not well codified in standard databases, because the frameworks are newer and health authority practices are still developing. Companies that build and maintain their own structured view of these requirements — which markets have established pathways for ATMPs, which require case-by-case engagement, which have no grace period for manufacturing changes — are significantly better positioned to plan and execute changes without costly surprises.
2. Integrate post-marketing commitment management with manufacturing change management in a single planning framework. The submission strategy for any given market should reflect the full picture of what is already in front of that health authority, what commitments are outstanding, and what the authority’s track record is on processing concurrent submissions. In most companies this does not happen because the two workstreams are owned by different teams with no shared visibility.
3. Build the cross-functional governance infrastructure now, before change volumes grow. CGT companies in early commercial stage have a genuine advantage: they are not yet managing 20 or 30 concurrent post-approval change programs. The window to build the organizational structure — clear ownership, shared planning frameworks, defined handoff points between regulatory, manufacturing science, supply chain, and quality — is open now and considerably easier to build in than to retrofit later. AI tools that can encode regulatory intelligence, compute cross-functional dependencies, and flag risks before they materialize are available today, and their ability to give MAHs an aggregate view across programs is exactly what this sector needs as it scales.

The next challenge, having brought these therapies to market, is managing them for the long term — investing in post-approval life cycle management infrastructure with the same seriousness that was invested in achieving approval in the first place. For patients who depend on these therapies, supply continuity is not a back-office concern; it is a clinical one.

References

1. Harris R. et al., “An Evaluation of Postapproval CMC Change Timelines,” ISPE’s Pharmaceutical Engineering journal, September/October 2023. Available at: https://ispe.org/pharmaceutical-engineering/september-october-2023/evaluation-postapproval-cmc-change-timelines
2. Vinther A. et al., “Approaches to Design an Efficient, Predictable Global Post-approval Change Management System,” Therapeutic Innovation & Regulatory Science, 2024. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC11043098/

About The Author:

Megha Sinha is founder and CEO of Kamet Consulting Group, which advises global pharmaceutical and life sciences companies on regulatory operations, quality, and large-scale transformation. With more than 17 years’ experience across the industry, including senior leadership roles at global consulting firm PwC, Sinha has worked with many of the world’s largest pharma organizations, solving their most complex regulatory, supply chain, and life cycle management challenges.