No Universal Winner in rAAV Manufacturing Economics, Study Finds

The cheapest way to make a recombinant adeno-associated virus (rAAV) therapy depends on which metric you use: on a per-batch basis, baculovirus infection beats transient transfection and producer cell lines (PCLs), but when costs are normalized to vector titer, transient transfection becomes the lowest-cost platform. That reversal sits at the center of a new economic analysis by researchers at Thermo Fisher Scientific, published in Gene Therapy.

Study author Seyed Pouria Motevalian, PhD, and co-authors compared the three dominant rAAV manufacturing methods and concluded that platform selection is a genuinely hard call. "Optimal platform choice depends on indication prevalence, dose requirements, desired serotype flexibility, development timelines, and willingness to invest in process intensification," Motevalian writes.

For R&D managers, the practical message is that raw material and reagent costs should not drive the decision alone. The target patient population belongs in the equation from the start.

What drives cost on each platform?

Each manufacturing route carries what the authors call a distinct "economic fingerprint" — a different distribution of spend across the process:

• Transient transfection: costs concentrate in plasmids, transfection reagent, media, and endonuclease.
• PCL perfusion processes: media and perfusion-related single-use hardware dominate.
• Baculovirus platform: a greater share of cost shifts into downstream operations, particularly affinity capture.

These fingerprints matter for budget planning. A team optimizing upstream yield on a baculovirus platform may find the real cost lever sits downstream in affinity capture, while a transfection-based program should scrutinize plasmid supply contracts before it tunes cell culture conditions.

Which platform fits which patient population?

The study's core recommendation is to match the manufacturing method to the commercial footprint of the therapy. For products intended for smaller patient populations, transient transfection — in which vector genes are introduced into producer cell lines — may be the best approach, despite the high cost of the DNA plasmids it requires. Plasmid expense is tolerable when batch volumes stay modest.

For mass-market gene therapies, the calculus changes. Baculovirus infection or PCL-based manufacturing becomes the more cost-effective option, particularly when paired with optimized upstream and downstream processes. The authors do not crown either approach outright; they frame the choice as a function of scale, indication prevalence, and dose requirements.

The analysis also factors in serotype flexibility and development timelines as selection criteria, alongside the developer's appetite for investing in process intensification. A platform that looks expensive at launch may pay off if it supports multiple serotypes or compresses time to clinic.

What should developers do differently?

The authors argue that gene therapy firms must bring these economic dynamics into process development as early as possible, rather than treating cost modeling as a late-stage commercial exercise. Waiting until Phase III to confront manufacturing economics invites expensive retrofits.

"Integrating quantitative cost modeling into platform selection and process development decisions early in program design will be essential for making rAAV therapies economically sustainable and expanding global patient access," they write.

The framing acknowledges an industry-wide pressure point: viral vector production costs have a disproportionate influence on final gene therapy prices, and several approved therapies have carried price tags that limit patient uptake. The study, authored by Thermo Fisher Scientific researchers, comes from a company that sells manufacturing technologies across these platforms — a relationship readers should weigh when evaluating the comparison. The core finding, however, is one of restraint rather than promotion: there is no universally best rAAV platform, and any vendor or developer claiming otherwise is overselling.

The work points toward cost-modeled platform selection becoming a standard discipline in gene therapy program design, as developers weigh pipeline decisions against the patients those therapies are meant to reach.