Rather than expecting cell therapies (CAR-T, TIL) to eradicate every cancer cell, Dr. Radvanyi reframes them as powerful adjuvants. Their role is to inflict initial damage, kill tumor cells, and release antigens, creating an opportunity to prime a broader, secondary immune response with other modalities like vaccines or checkpoint inhibitors.
Related Insights
Future cancer vaccines may target antigens derived not from standard coding regions, but from the "dark genome." Dr. Radvanyi highlights that retro-transposable elements and endogenous retroviruses, activated in cancer, represent a vast, untapped source of tumor-specific antigens for novel immunotherapies.
The drug exhibits a multimodal mechanism. It not only reverses chemoresistance and halts tumor growth but also 'turns cold tumors hot' by forcing cancer cells to display markers that make them visible to the immune system. This dual action of direct attack and immune activation creates a powerful synergistic effect.
An innovative strategy for solid tumors involves using bispecific T-cell engagers to target the tumor stroma—the protective fibrotic tissue surrounding the tumor. This novel approach aims to first eliminate this physical barrier, making the cancer cells themselves more vulnerable to subsequent immune attack.
Dr. Radvanyi emphasizes that foundational discoveries in immunotherapy arose from basic immunology and serendipitous observations, like his own unexpected T-cell proliferation with an anti-CTLA-4 antibody. This highlights the risk of over-prioritizing translational research at the expense of fundamental, curiosity-driven science.
Despite exciting early efficacy data for in vivo CAR-T therapies, the modality's future hinges on the critical unanswered question of durability. How long the therapeutic effects last, for which there is little data, will ultimately determine its clinical viability and applications in cancer versus autoimmune diseases.
The efficacy of Siltacel stems from a powerful initial expansion that eliminates cancer upfront. The CAR-T cells are often undetectable beyond six months, indicating their curative potential comes from an overwhelming initial response rather than persistent, long-term immune policing of the disease.
The future of medicine isn't about finding a single 'best' modality like CAR-T or gene therapy. Instead, it's about strategic convergence, choosing the right tool—be it a bispecific, ADC, or another biologic—based on the patient's specific disease stage and urgency of treatment.
While the field focuses heavily on T-cells and myeloid-derived suppressor cells, Dr. Radvanyi argues that dendritic cells have not received enough attention. Better understanding how to activate these primary antigen-presenting cells is crucial for priming effective and durable anti-tumor immune responses, especially within tertiary lymphoid structures.
Dr. Radvanyi advocates for a paradigm shift: treating almost all cancers with neoadjuvant immunotherapy immediately after diagnosis. This "kickstarts" an immune response before standard treatments like surgery and chemotherapy, which are known to be immunosuppressive, can weaken the patient's natural defenses against the tumor.
The success of CAR-T therapy hinges on the quality of the patient's own lymphocytes. Procuring T-cells earlier in the disease course, before they become exhausted from numerous prior therapies, results in a higher proportion of naive T-cells, leading to better CAR-T cell manufacturing and clinical outcomes.