Defining “Good” Early: Idil Arıöz on Reagents, Readiness, and the Hidden Risks in CGT Development
In cell and gene therapy, early technical decisions often carry consequences that only become visible much later in development. Idil Arıöz works across multiple programs and sees how issues around reagent selection, assay design, and scalability tend to repeat. Her perspective highlights common areas where variability can be introduced and where planning early can help reduce downstream rework as programs move toward the clinic.
Where Development Starts to Matter
Across programs, Arıöz sees the greatest impact in early to mid-stage development. This is where teams define their internal standards, often without fully realizing the long-term implications.
“We think that the most impact is early to mid-development, where the teams define what good looks like for them,”
At this stage, assay design and reagent selection are often treated as technical details rather than strategic decisions – yet these choices shape how data is generated and interpreted. If assays rely on inputs with limited characterization or higher variability, it can become harder to establish comparability later. That challenge does not stay contained in preclinical work. It follows programs into regulatory submissions.
A second inflection point comes later, during chemistry, manufacturing, and controls preparation. Here, consistency becomes a requirement rather than a preference. Bridging between lots, demonstrating comparability, and supporting IND-enabling packages all depend on decisions made much earlier.
“Despite the time, the meticulousness, and the whole rigor required for regulatory documentation and quality system alignment, it is not optional.”
About Idil Ariöz
Idil Arıöz is Technical Supervisor for France, Benelux, and Southern Europe at ACROBiosystems. Her role focuses on supporting biopharmaceutical teams with technical solutions, including reagent selection, customization projects, troubleshooting, and regulatory documentation support.
If you are building a cell or gene therapy program, many of your early decisions will not look consequential. They often appear as practical choices about reagents, assays, or timelines. But as Idil Arıöz describes, these decisions tend to resurface later as constraints. Her perspective comes from working across multiple programs, where patterns emerge not in single experiments, but in how development pathways succeed or stall.
Preclinical Signals That Do Not Translate
One recurring issue across programs is the disconnect between in vitro results and in vivo outcomes. This is not always due to biology alone. It often reflects how experiments are designed.
“Another challenge we see is the design of some in vitro assays that may not accurately reflect the mechanism of action,” Arıöz says.
When assays fail to capture the underlying biology, they can produce data that appears strong but lacks predictive value. Teams may advance based on these signals, only to encounter failure in later stages.
A related issue is reagent quality. Inconsistent or poorly characterized materials introduce variability that can obscure true biological effects. This can lead to what Arıöz describes as “misguided decisions of go, no go early in the process.”
If you are evaluating early data, the question is not only whether results are positive, but whether they are reproducible under controlled conditions. Without that foundation, interpretation becomes uncertain.
About ACROBiosystems
ACROBiosystems supports biopharmaceutical development across multiple modalities, including cell and gene therapies, by providing reagents, analytical tools, services, and technical support to drug development teams.
ACROBiosystems
2010
Switzerland
Support across CGT, antibodies, assays, CMC, preclinical
The Transition to Clinical Is Not a Step Change
Moving from preclinical to clinical development is often treated as a milestone. In practice, it is a transition that exposes weaknesses of earlier assumptions.
“The complexity of the whole scaling from lab scale to clinical scale manufacturing, as well as the cost of it, is consistently underestimated,” Arıöz notes.
Processes that work at small scale can fail under GMP requirements. This is not only a technical challenge but also a financial one. Delays at this stage are expensive, both in time and resources.
Documentation is another underestimated area. Regulatory expectations require detailed, consistent records and alignment with quality systems. Teams that delay this work often face rework when preparing for clinical entry.
Supplier strategy also becomes critical. If materials used in preclinical work cannot transition to their GMP-grade equivalents, teams may need to repeat validation work to comply. This creates avoidable delays and increases costs.
Reagent Quality as a System Constraint
Cell and gene therapies rely on complex biological systems, often involving primary cells. In this context, variability is difficult to control and can propagate through the entire workflow.
“Even a small batch-to-batch variability can derail the entire program, and cause a costly delay,” Arıöz says.
Despite this, many teams continue to rely on research-grade reagents without fully accounting for lot-to-lot differences. At early stages, this may not appear critical. But as programs advance, the lack of consistency becomes a barrier to comparability and regulatory acceptance.
Another gap is analytical validation. Without clear methods to define and measure comparability, teams cannot demonstrate that materials perform consistently. This becomes particularly important when transitioning between suppliers or scaling production.
If you are selecting reagents, the question is not only performance in a single experiment, but whether that performance can be maintained across lots, over time, and at scale.
Planning for Scale Before It Is Required
Arıöz emphasizes the importance of thinking ahead without overcommitting resources too early. Her advice focuses on creating continuity between development stages.
“Think about GMP from day one, but don’t pay GMP prices before you need to,” she says.
This approach involves selecting materials that have a defined path from research grade to GMP grade. Intermediate options, such as ACROBiosystems’ premium (pre-GMP) grade, can provide consistency without the full cost of GMP production, allowing teams to generate data that remains usable later.
The goal is to avoid discontinuities. When materials, processes, or assays change significantly between stages, additional validation becomes necessary. By planning for scalability early, teams can reduce the need for requalification and maintain continuity in their data.
Why Idil’s Session Matters
Idil Arıöz offers a perspective shaped by exposure to multiple programs at different stages of development. Rather than focusing on individual technologies, she highlights recurring structural issues in how cell and gene therapy programs are built. Her insights are relevant if you are designing assays, selecting reagents, or preparing for clinical transition. They point to a consistent theme: thoughtful early choices and fit-for-purpose controls can support smoother transitions later, when expectations around comparability, scalability, and documentation increase.
