If COVID-19 made mRNA a household name, you could call the lipid nanoparticle (LNP) delivery technology behind those groundbreaking SARS-Cov-2 vaccines the unsung hero. During this time, nanomedicine was identified as the perfect solution for delivering delicate mRNA cargo to cells, and its safety was proved on a huge scale. Many scientists were already interested in mRNA-LNP before the pandemic, but the COVID-19 vaccines reignited that fire.

According to GlobalData’s Drugs database, there are currently approximately 92 mRNA-based LNP drugs in the preclinical stage of development plus an additional 70 in discovery. There are around 32 in Phase I trials, 27 in Phase II, and 10 in Phase III. While drug registration is not expected to happen anywhere near as quickly as it did during the pandemic, it will be critical for these companies to prepare for clinical and GMP manufacturing early in the journey, prioritising patient safety from the beginning.

Ahead of each development team will be a series of challenges as they scale-up laboratory processes for manufacturing and brace themselves for unforeseen recipe issues.

Meanwhile, the move from lab-scale batches to clinical supply can put pressure on some all-too-familiar nanomedicine challenges. These include the difficulty of attracting talent with sufficient RNA-LNP expertise and the hefty investments required to equip those scientists with the right tools for clinical manufacturing.

Due to the complexities of LNP formulations and the specialized instrumentation required for their manufacture, such challenges have pushed many companies towards outsourcing.

“LNP is not rocket science, but I sometimes say it is like building a rocket,” says Dr Jagbir Singh, Director of Pre-clinical Services at Precision NanoSystems. “There are multiple components that need to come together in the right configuration to form these particles. You have the RNA, you have the ionizable lipid needed to encapsulate this RNA and then you have different helper lipids needed to form tightly packed stabile particles. Each component has an important role in stability, protection and release of RNA for efficient delivery.”

Strictly speaking, developing and manufacturing LNPs may not be rocket science, but much trial and error can be expected for teams who lack nanomedicine experience.

According to Dr Lloyd Jeffs, Senior Director of Biopharma Services at Precision NanoSystems, failure to approach process scale-up with extreme caution can have repercussions, followed by extensive troubleshooting and subsequent delays.

“First, we have to consider whether the process equipment we’re using is scale-up appropriate,” Dr Jeffs says. “You can make a batch of LNP on the bench in about 30 minutes – maybe using a Precision NanoSystems instrument – but that doesn’t necessarily mean you can scale-up and make sufficient quantities of the appropriate quality for tox studies and clinical trials.

“If we use new, larger equipment, we need to show that the process and drug product is still the same and biological activity is retained.”

Appropriate analytical methodologies are critical for gaining a comprehensive view of any changes to the investigational medicinal product (IMP) during this transition. But scale is not the only consideration. The new process may take longer to complete, with new instruments potentially generating more heat. Both of these parameters  can have severe consequences for payloads that are not stable at room temperature – a well-known challenge with mRNA.

“There are many considerations, so having the full picture and taking a very cautious approach to scale-up is essential. We don’t want to gloss over the rough bits. We want to understand what the issues are and address those,” he says.

Eye-opening analytics

Robust analytical methods are essential across every stage of development, from the early definition of the drug’s critical quality attributes (CQAs) to batch-to-batch comparisons during process scale-up and the release of the drug product.

“You can’t do formulation development unless you have the eyes to do that, and your eyes are your comprehensive set of analytical methods,” says Jeffs. “That’s the data you need to develop a drug, rather than just saying, ‘we’ve done a couple of tests and it looks good.’”

Due to the multiple components that make up an RNA-LNP drug, Dr Singh explains that a wide array of techniques are essential for robust characterization.

“We have to not only take a holistic view in order to characterize and understand the particle itself, but we also have to understand each individual component and make sure they come together in the right way,” he says.

At Precision NanoSystems, he says characterization of the RNA itself is performed using a bioanalyzer and an ultra-performance liquid chromatography (UPLC) system. Capillary electrophoresis is used to assess the integrity, purity and length of the RNA.  For looking at the purity and integrity of lipids, a combination of UPLC, charged aerosol detector (CAD) and mass spectrometry techniques are used.

Taking a deeper dive

Since these are nanoparticles, dynamic light-scattering techniques are needed to look at particle size and distribution. Measurements for determining particle charge are also necessary. Other broad capabilities at Precision NanoSystems include plate reading, ELISA and Western blot, and everything needed for drug product release, such as pH, osmolality and endotoxin.

“Many times, what we find is that we have to go beyond those CQAs and those minimal analytics needed for drug product release,” says Singh. “We have access to high-resolution mass spectrometry techniques to take a deeper dive, in case we see some challenges in the product.”

Through third-party collaborations, the biopharma services team can perform bioburden testing, sterility testing and residual solvent checks. Cryo-TEM is another option for further understanding particle characteristics.

Many other techniques are also possible, Singh says, adding that the key is to discuss your chosen analytics for both drug product characterization and product release in a pre-IND meeting with the regulatory body to make sure the methodology is deemed appropriate, thus avoiding any delays later down the line.

Then, when a downstream process is locked in for clinical manufacturing, the importance of standardising those methods to ensure reproducible experiments and consistent LNP production cannot be underestimated.

“I’ve been in research labs where you’ve got four people, all running the same assay, but they each have their own procedures for doing it,” Jeffs says. “Standardisation of methods, getting them verified and making sure they’re suitable is very important.”

Flexible collaborations

Due to the challenges involved in LNP development and production and the expertise required to overcome them, there is often a compelling argument  to outsource process development and clinical manufacturing to a specialist contract development and manufacturing organisation (CDMO).

When outsourcing RNA-LNP production, it is critical to select a partner with the necessary experience to guide you through the process step by step. 

“From my experience, there is never a linear path to process development,” says Singh. “It is very important to ask the question, ‘does your CDMO have the right experience, the right expertise and the right technologies to troubleshoot any problems?’”

Vancouver-based Precision NanoSystems has supported biotechnology companies on more than 180 LNP projects, with the ability to take a compound right from discovery all the way to the clinic if needed.

“We want to basically take that trial and error out of the equation, and get the clients what they need to move forward with their drug development programs,” says Jeffs.

It isn’t just about providing solutions, however. Jeffs says the company also spends a lot of time explaining solutions to clients, enabling them to build their own LNP expertise in-house.

“It does take time to gain that experience. We fill that need near-term, but we can also continue to support that client all the way through if they don’t have an interest in building an internal LNP process-development team,” he says.

Perhaps the key to successful partnerships, then, is this flexibility, driven by the desire to provide the right level of support for each individual client. Flexibility is also essential when you consider that plans often change. Whether it’s a modification to the payload, a different LNP formulation or a switch in the desired storage conditions, changes in direction are common in the still emerging nanomedicine field, and it is important to partner an agile CDMO that can keep up.

But there is one more vital component of a successful outsourcing model and that’s collaboration.

“Everything we do here is about providing solutions within budget in the shortest possible timeframe, so we work with our clients to understand their needs, and then we use our experience and expertise to guide them in the right direction,” concludes Singh.

“We work very collaboratively and closely with our customers. We leverage each other’s strengths to accelerate this technology.”

To learn more about how to monitor the physiochemical characteristics of your RNA-LNP drug product and substance, and the importance of high-throughput tools and workflows during process development, please download  the technical poster below.