For organisations outside Europe, the role of the Qualified Person (QP) is often unfamiliar. In the EU and UK, however, a QP is legally required to certify every batch of investigational or commercial medicinal product before it can be released for use in patients. This certification confirms that manufacture and testing comply with Good Manufacturing Practices (GMP), documentation is complete, and the batch aligns with the relevant clinical trial or marketing authorisation. For conventional small molecules and biologics this is already a significant responsibility. However, with the steady rise in gene therapies, QPs are facing a new level of complexity in both risk assessment and regulatory oversight.
Mike Jentsch is a Qualified Person at Sharp Clinical in the Netherlands, overseeing both commercial and clinical batch certification across a wide range of products, including ATMPs and gene therapies, and leading quality, risk, and supply chain oversight under EU GMP and clinical trial regulations. He combines this role with an academic background as a PhD in medical sciences/biological psychiatry, with expertise in biomarkers, analytical method development and neuroscience.
“Gene therapy can sound frightening,” notes Jentsch. “Someone is ‘messing with your genes’ — but they only target diseased cells to make them better. It doesn’t affect germline cells, and there are many people, especially QPs, making sure the product is as safe as possible before it ever reaches a patient.”
Over the past decade, cell and gene therapies (CGTs) have emerged as one of the fastest‑growing biopharma areas. They are now a major industry trend, with accelerated regulatory approvals and strong expansion in clinical research and manufacturing. As of August 2025, there were 45 FDA-approved CGTs in the US alone, with seven greenlit in 2024.
According to GlobalData’s Sales and Forecast database, the genomics drugs market is set for rapid expansion, with sales rising from just over US$20 billion in 2024 to almost $90 billion in 2030 – representing a CAGR exceeding 28%. Gene therapies specifically are expected to spike at a CAGR of over 50%, growing from around $2.6 billion in 2024 to reach nearly $31 billion by 2030. Oncology is predicted to remain the leading application area, with cancer-related indications expected to account for 44% of the market by 2029. However, gene therapies are increasingly targeting a broader range of diseases, including rare genetic, metabolic, and neurological disorders, demonstrating their growing role.
Implications for QP work in the EU
When it comes to clinical research, gene therapies fall within the EU category of advanced therapy medicinal products (ATMPs), alongside cell therapies and certain combined products. These therapies typically involve viral vectors or other complex biological systems and are often developed for serious, genetically driven conditions in very sick patients.
“Gene therapy is one of the three subtypes of ATMPs – the most complex type of drugs – so they are under more scrutiny,” explains Jentsch. “It’s a biologic, so you have additional safety testing, as you’re working with viruses.”
For QPs, this means applying all of the expectations associated with biologics, plus additional ATMP-specific requirements. Crucially, the regulatory framework is still evolving; scientific and industrial practice in areas such as vector design, analytics and manufacturing can move faster than formal guidance, leaving QPs with interpretive work to do when assessing compliance and risk.
Compared with many traditional products, gene therapy batches are also significantly more resource-intensive to certify. Additional safety testing is required, including viral vector–specific assays, checks for replication-competent virus, and infectivity assessments. Manufacturing processes are more complex, with multiple steps to construct, modify and handle viral vectors, each step generating extra batch records and supporting documentation. The issue is not only the volume of documentation but also the depth of technical understanding required to interpret data and evaluate residual risk, explains Jentsch.
“For ATMPs, a batch release typically takes me around two weeks,” he says. “Every day I work at least three to four hours on a batch… it’s definitely twice as much work as many traditional products.”
Alongside this, storage and distribution conditions introduce additional considerations. Drug products are typically stored at around –80°C, and vectors may be held in liquid nitrogen. QPs must be confident that facilities and logistics partners have appropriate controls, monitoring and contingencies in place so that quality is maintained through to the point of use.
Import testing and regulatory misalignment
For ATMPs manufactured outside the EU, import testing is one of the most significant practical challenges. “For ATMPs… it is specifically stated that if it is manufactured outside of the EU, you need to perform import testing when you want to bring it into the EU,” Jentsch says. “For all other traditional drugs, you don’t need import testing for clinical products, but for ATMPs there is this specific requirement for both commercial and clinical gene therapy products.”
For sponsors manufacturing in regions such as the US and supplying EU clinical trials, transferring complex, bespoke analytical methods to an EU laboratory can extend timelines by six to twelve months. In early-phase development this can influence decisions on where to run studies. So, in selected cases, QPs may seek risk-based exemptions and rely on original release data rather than repeating all tests in the EU. This requires audits of non-EU manufacturing and testing sites to confirm EU-GMP–equivalent standards, as well as detailed risk assessments that can withstand regulatory inspection. “[For us] these documents take time to draft, and it’s a joint effort between the Sharp QPs and the customer,” Jentsch notes. “There’s a lot of time and effort involved in making sure the documentation is robust enough to withstand regulatory scrutiny.”
QP product-specific training and risk management
To address the growing number and complexity of gene therapy projects, Sharp has adapted its internal QP framework. For conventional products, QPs are trained and authorised at the product-type level, however, for ATMPs, Sharp has introduced a product-specific authorisation layer.
“When we started working with gene therapies, we needed to adjust our internal QP framework,” Jentsch explains. “We set up an additional level to make sure that only a QP who is trained on that product can perform a batch certification.” This training, delivered with the client, covers the manufacturing process, analytical strategy, risk assessments and clinical use of the product. QPs are also required to undertake annual external training, including ATMP-focused topics and regulatory updates.
A substantial part of the role is systematic risk analysis across the full lifecycle of each batch. “You have to be a scenario thinker,” Jentsch says. “Sometimes, when people ask me what I do, I just say, I’m doing risk assessment the entire day for five days a week.”
On top of this analytical work, Jentsch also highlights the QP’s accountability for quality across the entire supply chain. Ensuring adherence at every step requires deep visibility and close collaboration with multiple partners during manufacturing, testing and logistics – often under intense time pressure, given that many patients are living with rare or orphan diseases. In this environment, the QP is constantly balancing urgency against risk, safeguarding those patients in need while refusing to compromise on standards.
Jentsch concludes: “When we certify a batch, we make sure that every important stage – from starting material to the final syringe – is compliant and supports an acceptable risk profile for the patient. We only sign if we’re fully confident it is safe to use.”
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