Recent advances and clinical pharmacology aspects of Chimeric Antigen Receptor (CAR) T-cellular therapy development

Bayesian network analysis of risk classification strategies in the regulation of cellular products

Cell therapy, a burgeoning therapeutic strategy, necessitates a scientific regulatory framework but faces challenges in risk-based regulation due to the lack of a global consensus on risk classification. This study applies Bayesian network analysis to compare and evaluate the risk classification strategies for cellular products proposed by the Food and Drug Administration (FDA), Ministry of Health, Labour and Welfare (MHLW), and World Health Organization (WHO), using real-world data to validate the models. The appropriateness of key risk factors is assessed within the three regulatory frameworks, along with their implications for clinical safety. The results indicate several directions for refining risk classification approaches. Additionally, a substudy focuses on a specific type of cell and gene therapy (CGT), chimeric antigen receptor (CAR) T cell therapy. It underscores the importance of considering CAR targets, tumor types, and costimulatory domains when assessing the safety risks of CAR T cell products. Overall, there is currently a lack of a regulatory framework based on real-world data for cellular products and a lack of risk-based classification review methods. This study aims to improve the regulatory system for cellular products, emphasizing risk-based classification. Furthermore, the study advocates for leveraging machine learning in regulatory science to enhance the assessment of cellular product safety, illustrating the role of Bayesian networks in aiding regulatory decision-making for the risk classification of cellular products.

Getting the Dose Right in Drug Development for Rare Diseases: Barriers and Enablers

In the relentless pursuit of optimizing drug development, the intricate process of determining the ideal dosage unfolds. This involves "dose-finding" studies, crucial for providing insights into subsequent registration trials. However, the challenges intensify when tackling rare diseases. The complexity arises from poorly understood pathophysiologies, scarcity of appropriate animal models, and limited natural history understanding. The inherent heterogeneity, coupled with challenges in defining clinical end points, poses substantial challenges, hindering the utility of available data. The small affected population, low disease awareness, and restricted healthcare access compound the difficulty in conducting dose-finding studies. This white paper delves into critical dose selection aspects, focusing on key therapeutic areas, such as oncology, neurology, hepatology, metabolic rare diseases. It also explores dose selection challenges posed by pediatric rare diseases as well as novel modalities, including enzyme replacement therapies, cell and gene therapies, and oligonucleotides. Several examples emphasize the pivotal role of clinical pharmacology in navigating the complexities associated with these diseases and emerging treatment modalities.

Clinical Pharmacology Considerations for the "Off-the-Shelf" Allogeneic Cell Therapies

Autologous chimeric antigen receptor T-cell (CAR-T) therapies have garnered unprecedented clinical success with multiple regulatory approvals for the treatment of various hematological malignancies. However, there are still several clinical challenges that limit their broad utilization for aggressive disease conditions. To address some of these challenges, allogeneic cell therapies are evaluated as an alternative approach. As compared with autologous products, they offer several advantages, such as a more standardized "off the shelf" product, reduced manufacturing complexity, and no requirement of bridging therapy. As with autologous CAR-T therapies, allogeneic cell therapies also present clinical pharmacology challenges due to their in vivo living nature, unique pharmacokinetics or cellular kinetics (CKs), and complex dose-exposure-response relationships that are impacted by various patient- and product-related factors. On top of that, allogeneic cell therapies present additional unique challenges, including attenuated in vivo persistence and graft-vs.-host disease risk as compared with autologous counterparts. This review draws comparison between autologous and allogeneic cell therapies, summarizing key engineering aspects unique to allogeneic cell therapy. Clinical pharmacology learnings from emerging clinical data of allogeneic cell therapy programs are also highlighted, with particular emphasis on CK, dose-exposure-response relationship, lymphodepletion regimen, repeat dosing, and patient- and product-related factors that can impact CK and patient outcomes. There are specific unique challenges and opportunities arising from the development of allogeneic cell therapies, especially in optimizing lymphodepletion and establishing a regimen for repeat dosing. This review highlights how clinical pharmacologists are well positioned to help address these challenges by leveraging novel clinical pharmacology and modeling and simulation approaches.

Clinical Pharmacology Profile of AMG 119, the First Chimeric Antigen Receptor T (CAR-T) Cell Therapy Targeting Delta-Like Ligand 3 (DLL3), in Patients with Relapsed/Refractory Small Cell Lung Cancer (SCLC)

With the promise of a potentially single-dose curative regimen, CAR-T cell therapies have brought a paradigm shift in the treatment and management of hematological malignancies with 6 approved products in the USA. However, there are no approved CAR-T cell therapies for solid tumors. Herein, we report the clinical pharmacology profile of AMG 119, the first CAR-T cell therapy targeting delta-like ligand 3 (DLL3), in patients with relapsed/refractory (R/R) small cell lung cancer (SCLC). AMG 119 demonstrated robust cellular expansion with long-lasting cell persistence and a favorable exposure-response relationship. AMG 119 has been demonstrated to be clinically safe and well tolerated at the doses tested, with no dose-limiting toxicities (DLTs) reported. This is the first publication of the clinical pharmacology profile of a CAR-T cell therapy in SCLC, with encouraging cellular kinetics data supporting the potential for CAR-T cell therapy in solid tumor space.

New immunotherapy approaches as the most effective treatment for uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Conventional methods of UM treatment are based on chemotherapy and radiotherapy, which have been able to control tumor growth in a limited way. But due to the inadequacy and many side effects of these treatments, many UM patients die during treatment, and approximately 50% of patients develop metastasis. Meanwhile, the 2-year survival rate of these patients from the time of metastasis is 8%. Since immunotherapy has the potential to be the most specific and efficient method in the treatment of tumors, it is considered an attractive and promising research field in the treatment of UM. This review highlights recent advances in UM immunotherapy and provides new immunological approaches on how to overcome the challenges of UM immunotherapy.

Best Practices and Considerations for Clinical Pharmacology and Pharmacometric Aspects for Optimal Development of CAR-T and TCR-T Cell Therapies: An Industry Perspective

With the promise of a potentially "single dose curative" paradigm, CAR-T cell therapies have brought a paradigm shift in the treatment and management of hematological malignancies. Both CAR-T and TCR-T cell therapies have also made great progress toward the successful treatment of solid tumor indications. The field is rapidly evolving with recent advancements including the clinical development of "off-the-shelf" allogeneic CAR-T therapies that can overcome the long and difficult "vein-to-vein" wait time seen with autologous CAR-T therapies. There are unique clinical pharmacology, pharmacometric, bioanalytical, and immunogenicity considerations and challenges in the development of these CAR-T and TCR-T cell therapies. Hence, to help accelerate the development of these life-saving therapies for the patients with cancer, experts in this field came together under the umbrella of International Consortium for Innovation and Quality in Pharmaceutical Development (IQ) to form a joint working group between the Clinical Pharmacology Leadership Group (CPLG) and the Translational and ADME Sciences Leadership Group (TALG). In this white paper, we present the IQ consortium perspective on the best practices and considerations for clinical pharmacology and pharmacometric aspects toward the optimal development of CAR-T and TCR-T cell therapies.

Modeling Patient-Specific CAR-T Cell Dynamics: Multiphasic Kinetics via Phenotypic Differentiation

Chimeric Antigen Receptor (CAR)-T cell immunotherapy revolutionized cancer treatment and consists of the genetic modification of T lymphocytes with a CAR gene, aiming to increase their ability to recognize and kill antigen-specific tumor cells. The dynamics of CAR-T cell responses in patients present multiphasic kinetics with distribution, expansion, contraction, and persistence phases. The characteristics and duration of each phase depend on the tumor type, the infused product, and patient-specific characteristics. We present a mathematical model that describes the multiphasic CAR-T cell dynamics resulting from the interplay between CAR-T and tumor cells, considering patient and product heterogeneities. The CAR-T cell population is divided into functional (distributed and effector), memory, and exhausted CAR-T cell phenotypes. The model is able to describe the diversity of CAR-T cell dynamical behaviors in different patients and hematological cancers as well as their therapy outcomes. Our results indicate that the joint assessment of the area under the concentration-time curve in the first 28 days and the corresponding fraction of non-exhausted CAR-T cells may be considered a potential marker to classify therapy responses. Overall, the analysis of different CAR-T cell phenotypes can be a key aspect for a better understanding of the whole CAR-T cell dynamics.