In the Cartitude 1 trial, the strongest predictor of long-term remission with Siltacel was a lower burden of disease (measured by bone marrow percentage and soluble BCMA levels), rather than the number of prior treatments. This implies using CAR-T therapy earlier in the disease course is more effective.

T-cell receptor (TCR) therapies offer a significant advantage over monoclonal antibodies by targeting intracellular proteins. They recognize peptides presented on the cell surface, effectively unlocking 90% of the proteome and requiring far fewer target molecules (5-10 copies vs. 1000+) to kill a cancer cell.

To overcome on-target, off-tumor toxicity, LabGenius designs antibodies that act like biological computers. These molecules "sample" the density of target receptors on a cell's surface and are engineered to activate and kill only when a specific threshold is met, distinguishing high-expression cancer cells from low-expression healthy cells.

In follicular lymphoma, the treatment goal is durable remission with manageable toxicity, not necessarily a cure. Therefore, clinicians frequently prefer using a bispecific antibody first, reserving the more complex and toxic CAR-T cell therapy for transformed disease or after a bispecific fails.

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.

Using a BCMA bispecific antibody first can exhaust a patient's T-cells or cause tumors to lose the BCMA target, rendering a subsequent BCMA-targeted CAR-T therapy ineffective. The optimal sequence is CAR-T first, which preserves T-cell function and BCMA expression, leaving bispecifics as a viable later-line option.

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.

Before initiating a CD20-targeting bispecific antibody in patients who have failed CAR-T therapy, a new biopsy is mandatory. Up to 30% of these patients experience CD20 antigen loss, which would render the bispecific therapy ineffective and necessitates choosing a drug with a different target.