The journey from laboratory discovery to clinical application is rarely a simple one, and tumor-infiltrating lymphocyte (TIL) therapy is no exception. What began as an observation of tumors regressing through natural immune response has evolved into a promising personalized biotherapeutic strategy for advanced melanoma and other solid cancers.
In February 2024, this field reached a significant milestone with the FDA approval of Lifileucel, the first commercially available TIL therapy. This breakthrough offers an option for treatment of advanced melanoma in patients who have exhausted other avenues. A Phase 3 trial conducted by the Netherlands Cancer Institute has demonstrated that TIL therapy can outperform standard immunotherapy approaches for advanced melanoma [1]. But the potential for TILs goes far beyond melanoma.
There are currently over 180 active clinical trials investigating TILs across a wide spectrum of solid tumors. In addition to melanomas, there is growing interest in more complex and prevalent cancers. Trials are actively recruiting patients for non-small cell lung cancer (NSCLC), colorectal cancer, breast cancer, gynecologic cancers, and head and neck cancers, underscoring the strong momentum to utilize TILs to address unmet needs in many cancer treatments.
For more background on TIL therapies and their clinical applications, check out this article.
Despite the promise of TIL therapy, it faces substantial manufacturing challenges and lengthy production times (4 to 6 weeks) that may leave some patients too ill to receive treatment by the time it’s ready. Additionally, TIL population within a tumor can vary and harvesting is manual, therefore subject to human error. These variables make strategies to automate, standardize, and optimize manufacturing processes critical to achieving large scale success and faster delivery of TIL therapy.
The remarkable efficacy of TIL therapy in cases where traditional treatment has failed drives research to find solutions to these challenges. This article explores some TIL manufacturing hurdles, solutions on the market today, and end-to-end process development strategies for clinical trials.
Critical TIL manufacturing challenges: variability and risk factors
TIL therapy is a type of adoptive cell transfer where cells are collected from a patient, expanded, then infused back without genetic modification. TILs are not typically present in high amounts within tumor tissue, and harvesting samples require labor-intensive protocols by skilled surgeons and technicians.
The location of the tumor, the patient’s condition, and the handling of the sample during and after collection influences TIL population and activity. On top of that, a single tumor sample can contain many different types of tumor-infiltrating lymphocytes that vary in their tumor reactivity and ability to grow, which poses further challenges on batch-to-batch consistency.
After tumor samples are harvested, the tissue undergoes disaggregation to extract TIL cells—traditionally a manual process that poses contamination risks. While methods exist to select more active populations for subsequent expansion steps, they require further manual processing that extends the already-lengthy manufacturing timeline.
To learn more about challenges and strategies associated with TIL sample processing, check out this article.
Adding to the complexity of these procedures, the total loss or poor performance of a TIL therapy batch can mean that the patient may never receive their treatment. Since repeating the invasive tumor extraction is rarely feasible, especially in advanced cases, a failed batch could delay or eliminate the opportunity for therapy altogether. For patients who have already exhausted other treatment options, this can be devastating—both physically and emotionally—as it may represent their last viable chance at disease control or remission.
Improving TIL manufacturing: speed, consistency, and automation
Transitioning to a closed and automated manufacturing process reduces the risk of contamination, decreases operator intervention, and can speed up manufacturing timelines. Standardizing procedures through automated, integrated workflows enable rapid process optimization and support regulatory compliance—key factors to further advancing TIL therapy for solid tumor treatment.
Next, we’ll take a look at TIL manufacturing steps ready for a transition to closed, automated systems using existing cell therapy equipment: cell expansion through to formulation and cryopreservation. Unlike traditional open and manual workflows that are vulnerable to variability and risk, a closed and automated platform using modular cell therapy manufacturing systems enables consistent, GMP-compliant manufacturing with reduced operator intervention.
Automation in TIL therapy manufacturing
Closed and automated cell therapy manufacturing systems from Cytiva are engineered to be flexible and adaptable to a variety of workflows, including TILs manufacturing.
To help us navigate the TILs workflow, we talked to Simon Quenneville, a cell therapy field application specialist, and Sabrina Carmichael, Global Technical Leader of our Cell Therapy Fast Trak™ services, including process development. Combined, these two have over 10 years of experience supporting researchers to automate, scale, and optimize cell manufacturing workflows.
Fig. 1 A TIL therapy manufacturing workflow starting with optional thawing and washing of tumor sample, followed by cell expansion the Xuri™ cell expansion system W25, cell harvest and formulation with the Sefia Select™ system, then cryopreservation with the VIA Freeze™ controlled-rate freezer.
Cell expansion
The Xuri™ cell expansion system is particularly well-suited for the rapid expansion phase (REP) of TIL manufacturing thanks to its scalability, automation capabilities, and support for culture intensification. “TIL processes require a much larger cell dose than CAR T therapies, which makes having a robust and scalable platform absolutely critical,” explains Simon.
While the early (pre-REP) expansion phase still heavily relies on manual techniques, many teams turn to static vessels as a practical solution. “As soon as you’re scaling up or looking at clinical readiness, transitioning to a Xuri™ system becomes the natural next step,” says Simon.
He notes that many customers choose to pump cells directly from a static vessel into the Xuri™ system to begin REP. “That’s where the Xuri™ system really shines—you’re getting process control, closed-system operation, and the ability to easily monitor and adjust parameters in real time,” he adds. Cytiva has established parameters to support high-yield, high-viability expansion on Xuri™ system, providing a streamlined, GMP-aligned platform for advancing TIL therapies.
Cell expansion in a Xuri™ system is fully closed and automated with standardized protocols. Not only does this minimize the risk of contamination but it also reduces the demand on operators, freeing them to focus on the early manual stages. In previous studies, TILs expanded in the Xuri™ system had high CD62L+/CD45RO+ cell populations, further underscoring its role in providing consistent, high-quality therapeutic products.
Fig. 2 TILs show increased percentage of central memory-like T cells (CD62L+, CD45RO+) at the end of the rapid cell expansion protocol compared to the TIL cells prior to expansion.
There’s two key features the Xuri™ cell expansion system brings to the table for cell expansion, Sabrina explained. First, its ability to perform perfusion, also termed culture intensification, which “helps your cells grow quickly and stay happy.” The Xuri™ system also enables sterile sampling, allowing you to monitor expansion progress and take action as soon as you notice something might be off. That can mean the difference between batch failure and a successful patient dose.
Harvest and formulation
As an integrated platform, you can directly take the closed bag of expanded cells from the Xuri™ cell expansion system and hook it onto the Sefia™ S-2000 cell processing instrument, or a complete Sefia Select™ system, for automated harvest and formulation.
The flexibility of the Sefia™ S-2000 cell processing instrument has been a powerhouse for CAR T therapies and is fully capable of supporting TILs manufacturing in the same way. Process parameters can simply be enabled or disabled as needed to suit various workflows.
The major difference between TILs and CAR T processes is that you need three to four times more cells for a complete dose, explained Simon. “The TIL customers I interact with are typically working with five liters of cell culture, whereas CAR T customers might be working with just one liter.”
The Sefia™ S-2000 cell processing instrument can perform automated concentration, washing, and formulation of up to 10 L of cellular product using the FlexCell protocol software. Simon noted that concentrating 5 L of product takes 30 to 45 minutes. Following our reported manufacturing process, cell viability and recovery rate post wash and formulation were 94.1% and 89.5%, respectively.
Formulated TILs products can move directly from the Sefia™ S-2000 cell processing instrument to a VIA Freeze™ controlled rate freezer for cryopreservation. This range of freezers provide precise and automated cooling procedures to support GMP-compliant cryopreservation.
A digitally integrated workflow
Chronicle™ automation software digitally integrates the VIA Freeze™ freezer together with the Xuri™ cell expansion system and Sefia™ instruments, proving one digital platform to digitize batch records, reduce operator time and error with electronic standard operating procedures (eSOPs), and monitor the status of all connected instruments.
Check out the Mastering TIL therapy manufacturing eBook to learn more about our TIL workflow.
Scaling out TIL manufacturing and evolving needs
Given TILs is an autologous therapy, Simon notes there’s less of a focus on scaling up than there is on scaling out. “An established manufacturing facility might consist of several Xuri™ cell expansion systems, a Sefia™ S-2000 cell processing instrument or the Sefia Select™ system, then a few VIA Freeze™ freezers.” In other words, scaling out is as straightforward as adding units to meet demand.
Scaled-out workflows allow operators to run parallel cell expansions and only occupy the Sefia™ instrument for less than a day for the harvesting and formulation.
Sabrina added that the process described here can be adapted to accommodate various needs thanks to the modularity of our cell therapy manufacturing equipment. For example, “if there is a logistical need to freeze down cells prior to expansion, additional components, such as cryoprotectant, can be added without disrupting the closed, integrated process.” In this case, the Sepax™ C-Pro cell processing system can wash cells, and the VIA Freeze™ and VIA Thaw™ instruments support automated freezing and thawing procedures.
This flexible TILs manufacturing workflow offers a closed process from cell expansion to cryopreservation that can be performed using integrated, automated systems. These measures reduce the risk of contamination and human error—crucial safeguards given that repeating the initial tumor sampling is rarely feasible.
Fast Trak™ services: End-to-end support for TIL process development
If that’s all seems like a lot to navigate, the Fast Trak™ services team provides training and process development services to support customers early in their process scale-up journey. Sabrina gave us an inside look into how the Fast Trak™ service team works with customers to put them on the right track for success with TILs manufacturing.
Building a TIL manufacturing process from concept to execution
“Potential customers get referred to us when they are looking for details about how our portfolio might fit their needs. So we sit down and get to know their specific project and goals. One of the things we bring to these conversations that often surprise people is that we also provide third party systems. We want to support them in their end-to-end workflow, and I think they really appreciate that,” explained Sabrina.
She notes that this would be the case for the tissue disaggregation step in a TIL process. “Although we don’t offer equipment for this step, we do give advice on what third-party components could fit best in a customer’s process. It’s one of those ‘ask and you shall receive’ sort of things that I think many people don’t expect to get from the ones selling equipment.”
From there, Sabrina and the team build out a “bare bones” statement of work (SOW) that details what the project will look like, how long it will take, and approximate costs. Once agreed upon, the SOW gets detailed. “We’re talking media types, cytokine combinations, rock rates—every single step of every phase is written out.” Going forward, it’s an iterative process, “we want to build a collaborative relationship, so there’s plenty of back and forth.”
In addition to the closed and automated features of Cytiva instruments that support GMP compliance, the Fast Trak™ team works to make sure media, reagents, and other components will also enable GMP-compliance. Sabrina described often talking with our global regulatory team to make sure they’re working within guidelines of whatever country the project is located in.
Executing the TIL manufacturing plan and beyond
“Once details are agreed upon by everyone, we’ll get started. Timelines can vary greatly depending on what they want to accomplish, but throughout any project we’ll have continuous meetings to let them know we’re on track or if any changes need to be made,” Sabrina explained.
To wrap up the project, there’s a final meeting to hand over any deliverables such as SOPs or compiled data sets—then it’s time for technology transfer training where they run through all the processes to bring teams up to speed. From there, the Fast Trak™ team as well as local FAS team members like Simon are available to support any other needs that come up later down the line.
In closing, “Cytiva doesn’t make cell therapies, but we have all the tools to do it. What we do is help others make cell therapies,” said Sabrina. There’s a large network of people here experienced in every stage of the process that can be looped in when support is needed.
References
- Rohaan MW, Borch TH, van den Berg JH, et al. Tumor-Infiltrating Lymphocyte Therapy or Ipilimumab in Advanced Melanoma. New England Journal of Medicine. 2022;387(23):2113-2125. doi: 10.1056/nejmoa2210233