Overview

Duke iGEM is dedicated to using synthetic biology for good. Recognizing CAR T-cell therapy's potential in immunotherapy, especially against solid tumors, our team sought to comprehend and mitigate risks associated with optimizing CAR-T. To ensure ICARUS was socially responsible, we consulted experts in medical oncology, industry, and policy. Through interviews, we identified key social, moral, and scientific values and incorporated them into our project design process.

Our stakeholder analysis can be divided into two key areas: understanding the technical demands and the ethical implications of our project. We implemented feedback from stakeholders that assisted us with responsible design throughout the project. The stakeholders whose work focused more on medical ethics helped us frame how we intend to proceed with our project in the future.

Responsible Project Design

We believe the power of synthetic biology comes from using innovative design to address unmet needs, in turn creating positive change in the world. True innovation in design means bringing new ideas and insights to the realm of synthetic biology, as opposed to simply echoing what has been done before. In addition, crafting an effective, tailored solution requires recognizing and understanding existing shortcomings in current approaches. With this in mind, our approach to responsibly designing our project was centered around guaranteeing our project’s novelty and relevance to the evolving needs of the field.

We consulted expert stakeholders from a variety of backgrounds to characterize the existing oncology treatment landscape, identify gaps in the research, and understand where we are best poised to contribute. Read on to understand how we chose our stakeholders and integrated their feedback into our project.

Stakeholder Selection

We chose to focus our human practices approach principally on clinicians and researchers. Doctors are key stakeholders for two primary reasons: they possess knowledge of the standard of care we aimed to understand, and they are bound by an oath to uphold ethical practices in medicine. Additionally, we chose to consult with researchers to better understand the current state of research and learn about cutting-edge innovations in the field of cancer immunotherapy.

Round 1: Exploration

Nelson Chao, MD

Graft rejection in allogeneic CAR-Ts

Nelson Chao is a doctor and researcher at the Duke University School of Medicine with a keen interest in graft rejection and immune reconstitution. We met with Dr. Chao to discuss how the immune system responds to allogeneic CAR T-cell therapies, which offer a promising direction toward a more affordable and universally available treatment option. A significant challenge is graft rejection, where the patient's native T-cells identify the donor-derived CAR T-cells as invaders and initiate an immune response against them. For these allogeneic therapies to be clinically successful, it is crucial to mask the CAR T-cells from the host's immune system. A promising strategy being explored is the alteration or removal of class one and class two human leukocyte antigens, which effectively reduces the risk of recognition and rejection. Ultimately, preventing graft rejection would bring us one step closer to a safer allogeneic CAR T-cell therapy.

Dr. Chao offered key priorities to keep in mind when designing immunotherapies. He explained that researchers must not only target the cancer cells themselves but also consider targeting the tumor microenvironment. He emphasized a need to identify targets that will allow adoptive T-cells to target tumor cells specifically. Dr. Chao also touched on challenges with treating cold tumors, which are solid tumors that lack or possess few tumor-infiltrating lymphocytes (TILs) and cannot be treated with checkpoint inhibitors and instead require a strong antigen. This insight shaped our interest in using antigens and leveraging the tumor microenvironment in our project.

Mitchell Horwitz, MD

Obstacles in solid tumor treatment

Dr. Horwitz is a specialist in cellular therapy with a research focus on preventing graft-versus-host disease (GvHD). GvHD is a major issue in oncology trials that parallels a problem we seek to address within our research, cytokine release syndrome (CRS). Both complications involve the immune system producing an undesired response to receiving new T-cells in the body.

Dr. Horwitz shared thoughts on adoptive T-cell therapies potentially replacing bone marrow transplants but noted the challenge due to cancers lacking specific targets and oftentimes resembling healthy tissue.

In recent years the development of allogeneic T-cells designed to target specific cancer cells have presented a promising solution to this issue. Another large issue lies in the uncertainty of whether the re-engineered T-cells will be able to do their job before the patient rejects them. Overall, immunotherapies hold promise, but overcoming tumor resistance and harnessing the power of the patient's own immune systems are critical challenges.

Scott Antonia, MD, PhD

Identifying targets in solid tumors

Dr. Antonia gave us an overview of the immunotherapy landscape and the challenges of addressing solid tumors. As the field of immunotherapy has developed, nearly 20% of patients survive long-term after treatment. Among the remaining patients, Dr. Antonia sees a need to evaluate why only a limited number of T-cells are reactive, as well as how adaptive resistant mechanisms and variety in the tumor microenvironment shape patient outcomes. He sees potential for engineering circuits in the T-cells to drive the T-cell state into one that is more suitable and functional.

In addition, Dr. Antonia highlighted two key issues with targeting solid tumors: finding an appropriate target and navigating the heterogeneity of targets. Isolating a target that is attached to malignant cells, but not to other cells, is essential to prevent toxicity. This is not a problem in lymphomas that are B-cell derived, for example, because eliminating B-cells from a patient is not lethal. Yet, even when a suitable target is found, it is rare that all tumor cells express that target. Dr. Antonia cites that roughly 20-30% of cells might have a common, appropriate target, but this is not nearly enough. With all of this in mind, Dr. Antonia sees a promising future for CAR T-cell therapies in solid tumors once they have good targets for which to make CARs.

Andrew Nixon, PhD, MBA

Cancer biomarkers and eligibility for CAR T-cell therapies

Dr. Nixon is the Director of the Phase I Biomarker Laboratory, where he develops biomarkers to identify mechanisms of sensitivity, resistance, and toxicity in different drug classes, particularly anti-angiogenic agents. We interviewed Dr. Nixon to gain insight into how biomarkers are driving innovation and can lead to safer CAR T-cell administration. Dr. Nixon emphasized the importance of measuring biomarkers to get “the right patient, the right treatment, at the right time.” Biomarkers can be used to identify patients who may have better outcomes or fewer adverse effects, in turn shaping the design of clinical trials.

While sequencing and mutation identification in tissue samples is common, this approach can be greatly expanded to address CAR T-cell therapies. In the future, biomarkers could play a pivotal role in making CAR T-cell therapies safer by identifying patients vulnerable to cytokine surges. Dr. Nixon sees potential in assessing biomarkers from both the product and the host. For example, Dr. Nixon's lab conducted a study that pioneered the discovery of a connection between CD3/CD8 antigens and cytotoxicity, enhancing our knowledge of patient responses to CAR T-cell therapies. Finally, Dr. Nixon emphasized the importance of working in immunosuppressive tissues like the liver and managing the tumor microenvironment, a large focus of our own iGEM project.

Round 2: Insight

Beth Shaz, MD 12w3

Manufacturing of cell therapies

Dr. Shaz, director of Robertson GMP Laboratory for cell and tissue therapies and Co-Director of Duke's Stem Cell Lab, discussed the challenges of manufacturing cell therapies and their ethical implications. She highlighted the need for FDA and Investigational New Drug (IND) approval, as well as GMP compliance when working with patient-derived cells. Ensuring sterility and purity of substance is crucial to preventing potential adverse patient reactions.

Regarding CAR T-cell therapies in oncology, Dr. Shaz noted their current use in only severe cases typically when limited alternative treatments are available due to their novelty. However, she expressed hope that with time, CAR T-cell therapies might become more common. CAR T-cell therapy presents unique challenges when applied to solid tumor cancers, “currently solid tumor CAR-T cell therapies have not been successful at all because they do not have the needed antigen profile.” According to Dr. Shaz, solid tumor therapies are polyclonal, have more antigens, and selecting one target alone won’t work.

Another obstacle hindering CAR T-cell from becoming a primary treatment option is cost. Dr. Shaz explained, "manufacturing expenses pose a significant challenge for companies. These costs are driven up by the need for FDA regulation, rigorous quality control testing, qualification of source control materials, environmental monitoring, and facility maintenance...there are numerous factors to take into account”.1

Jeffrey Clarke, MD

HER2 receptor in lung cancer

Dr. Clarke, a lung cancer specialist, focuses on evaluating the safety and effectiveness of autologous T-cells. He believes that immunotherapies have the potential to replace current treatments providing a more targeted approach. Fundamentally, solid tumors pose greater challenges than lymphomas; currently, there are no adoptive T-cell therapies for them due to complex targets. Identifying targets for T-cell therapies, especially internal ones, is challenging particularly in identifying cells non-essential to preserving life. Identifying universally expressed solid tumor targets poses unique challenges.

HER2, a protein receptor found in both healthy and mutated tissue, is a key focus in lung cancer. Targeted therapies for HER2-mutated lung cancer are crucial, aiming to halt tumor growth by removing the mutated receptor, sparing normal ones. Novel compounds target the mutated form specifically.

The goal is to target tumor-specific molecules, minimizing side effects. The challenge lies in identifying targets with minimal crossover and addressing rare mutations that can restrict treatable patient populations.

Finally, in our conversation with Dr. Clarke, we inquired about how clinical trials are conceptualized with a specific focus on the recruitment of lung cancer patients to which he admitted “in adult oncology we do a poor job of designing clinical trials and enrolling broadly across our patient populations.” He explains that novel treatments have various criteria which pose barriers to getting patients on these clinical trials and granting them access to therapies they likely otherwise wouldn't have had access to. “Only a small portion of our patients can make it onto clinical trials and this is one of the major challenges of clinical research.”

Georgia Beasley, MD

Immunotherapy in Melanoma

We began our research with a vision of developing a novel immunotherapy that could prove efficacious for solid tumor cancers. To delve deeper into this project concept, we consulted Dr. Georgia Beasley. Dr. Beasley is a surgical oncologist at the Duke University Hospital who engages in both patient care and research regarding interactions between treatments and the immune system to better understand how strategic manipulation of the immune system can enhance its efficacy against various cancer types.

In our conversation with Dr. Beasley, we gained valuable insights into the factors that determine the effectiveness of different therapies. She underscored the significance of tumor engagement in treatment efficacy and made a critical distinction between solid tumor targets versus those in blood-based cancers. This distinction highlighted a notable challenge in making CAR T-cell therapy a viable option for solid tumors, as the targets in solid tumors are vital for the patient's survival, in contrast to those in blood-based tumors. This aspect of safety emerged as a pivotal consideration for our team as we moved forward.

Confronted with this newfound challenge, we returned to the lab to brainstorm solutions to incorporate into project design with the aim to comprehensively grasp the risks associated with the development of a novel therapy for solid tumors, particularly considering the characteristics of solid tumor targets compared to other cancer types.

Bruce Thompson, PhD

Closing the gap between innovation and manufacturing

Dr. Thompson of Kincell Bio discussed various aspects of cell therapy manufacturing in a recent interview. Kincell serves as a manufacturing partner for innovator companies that help turn research into viable cell therapy products, which requires a lot of problem-solving in the Phase 1 space. While much attention is given to CAR T-cell research in academic settings, there's often less focus on the manufacturing process. Kincell, however, emphasizes the need to consider the product profile required to bring immunotherapies to a large scale efficiently. Dr. Thompson notes that a lot of the cost and efficacy of the new drug is determined by how the material is produced and how the target mechanism is delivered. This poses a challenge for manufacturing companies as once innovators set up a process, it is a huge regulatory burden to change viral editing to gene editing to edit the target mechanism, even if one is more efficient. Thus, it is important to focus on the most efficient editing mechanism much earlier on in trials, as it would help drugs actually get out on a large scale.

Kincell's strategy for closing the gap between lab research and delivering cell therapies focuses on narrowing their expertise to immune cell therapies in oncology. By building expertise equipment in a narrow part of the field, they hope to find a common denominator in the therapies and apply strategies across the immunology space.

Balancing safety and innovation in cell therapy requires extensive patient data and a thorough understanding of the risk-benefit ratio, especially in cases where there are no alternative therapies. Dr. Thompson believes that patient education is one of the most important parts of helping CAR T-cell therapy become more widely used as it is not just the research and manufacturing that matters in patient care, but also the mental comfort that people feel with infusions that is important. Dr. Thompson also touched on the challenges of getting insurance companies to cover cell therapies, emphasizing the importance of collecting long-term data to demonstrate the value of these treatments.

Brent Hanks, MD, PhD

Tumor microenvironment and immunotherapy

Dr. Brent Hanks leads a lab at Duke University to investigate the mechanisms of how cancers develop adaptive or acquired resistance to immunotherapy and to explore methods to overcome immunotherapy resistance and toxicities. Dr. Hanks emphasized to us a need for major changes in CAR T-cell therapies' design and treatment regimen. He argued that one of the most important weaknesses of CAR T-cell therapies is their selectiveness: patients that enter clinical trials for CAR T-cell therapies have passed through stringent selection criteria. He admitted the therapy can be effective—but only for a small proportion of cancer patients. He pointed out that the heterogeneity of solid tumors is what renders CAR T-cell therapy ineffective against them. He also noted that the six weeks between isolation of a patient's tissue and reinfusion could mean that a patient is no longer able to undergo treatment.

Round 3: Implementation

Following the design of the ICARUS system, we returned to some of our key stakeholders to seek feedback on our developed model.

Dr. Clarke Follow-up Interview

During our discussion with Dr. Clarke, we delved into one of the most significant challenges in CAR T-cell engineering: the reduction of CRS to minimize systemic side effects, particularly in the context of solid tumor treatments. Dr. Clarke mentioned that CRS can be managed with adequate support but emphasized that severe consequences, including mortality, often stem from CRS involvement, leading to inflammation and capillary leakage. This prompted our follow-up question about the necessity of re-engineering CAR T-cells to reduce CRS risk, to which Dr. Clarke stressed the significance of optimizing dosing and minimizing toxicity. Mentioning our work to develop a library of soluble antigens, including HER2 in a soluble form, he recognized the potential impact of this work in the field of lung cancer and immunotherapy in general. Dr Clarke says “HER2 mutations could be a fascinating target,” targeting tumor-specific antigens, like HER2, is an attractive therapeutic strategy, although tumor toxicity considerations are vital.

Shifting to the ethical and social dimensions of our project, we explored the broader implications of CAR T-cell therapy. We raised concerns about potential misuse in certain scenarios, and Dr. Clarke introduced the concept of "off-label use," a common practice in oncology where a specific drug is employed with evidence of efficacy even without FDA approval. The issue of high pricing for these innovative therapies was also discussed, and Dr. Clarke emphasized that “the price should match the benefit.”

Additionally, we examined the possible misrepresentation and negative impact of CAR T-cell therapy on specific communities. Dr. Clarke highlighted the example of HLA-restricted cell therapies, which are more frequently compatible with the genotypes of Caucasian patients and less so with minority patients. This selection bias in clinical trials poses a significant threat to equal access and appropriate representation. These complex factors underscore the importance of addressing economic and racial disparities in cell therapies.

Dr. Shaz and Dr. Antonia Follow-up Interview

We reconnected with Dr. Shaz and Dr. Antonia to delve deeper into two significant challenges that CAR T-cell therapies are currently facing: antigen escape and CRS. After presenting our model and sharing our experimental results, Dr. Antonia expressed concern about the potential failure of our system when a patient experiences a complete loss of antigen expression. This phenomenon often leads to patients being excluded from clinical trials due to their antigens becoming masked, which poses a considerable ethical dilemma.

When we inquired about the possibility of our system addressing this challenge, they discussed its potential in mitigating CRS, but noted that the activation of the CAR would still result in the secretion of IL-6. This conversation served as a catalyst for motivating Duke iGEM to persist in enhancing our system, with the aim of making it more ethically sound and finding innovative solutions to overcome the existing barriers that hinder CAR T-cell therapy from becoming a primary treatment option for solid tumor cancers.

Future Ethical Considerations

Our project arose from the desire to meet an unmet need: there is no safe and effective therapeutic option to treat solid tumors in the CAR T-cell space. In addition to offering new hope for patients with solid tumors, we also sought to make CAR T-cell therapies safer by mitigating the risk of CRS. CRS is a key issue in administering cell therapies, often causing patients to drop out of clinical trials.

We approached our project with a desire to improve patients’ lives and make the world a better place, but we recognize good intentions are not enough to produce an ethical and responsible project. This motivated us to consult clinicians, lawyers, and hospital systems to better understand the ethical implications of our work.

Analysis from our expert stakeholders led us to narrow in on three key values: equity, safety, and innovation. We translated these into design requirements for our project in the future, as detailed below:

We have identified two key risks for misuse of our project and have outlined potential methods to mitigate them below:

• Limited access to ICARUS because of high cost:
  • Value-based payment: Implementing a payment model based on the value and outcomes achieved can provide more equitable access and ensure that pricing reflects the benefits delivered to users.
  • Scale up production: Increasing our production capacity can lead to economies of scale, reducing the overall production costs and the price for patients.
  • Open-access licensing: Offering open-access licensing can facilitate wider dissemination and use of ICARUS, ensuring that cost is not a barrier to access.
• Patenting of soluble antigens might restrict innovation and access to our work:
  • Collaborative agreements: Establishing collaborations with those who own the patents on the scFv antibody fragments can ensure we do not infringe on their work while still making it available.

References

1. Frey, N., & Porter, D. (2019). Cytokine release syndrome with chimeric antigen receptor T cell therapy. Biology of Blood and Marrow Transplantation, 25(4). https://doi.org/10.1016/j.bbmt.2018.12.756
2. Mitri, Z., Constantine, T., & O’Regan, R. (2012). The HER2 receptor in breast cancer: Pathophysiology, clinical use, and new advances in therapy. Chemotherapy Research and Practice, 2012, 1-7. https://doi.org/10.1155/2012/743193
3. Saukshmya, T., & Chugh, A. (2009). Commercializing synthetic biology: Socio-ethical concerns and challenges under Intellectual Property Regime. *Journal of Commercial Biotechnology*, *16*(2), 135-158. https://doi.org/10.1057/jcb.2009.28