Bispecific T-cell Engagers versus CAR-Ts: The Race to Market Adoption

Key Points

The rising adoption of advanced cancer therapeutics in clinical stages is fueling growth in the cancer immunotherapy market. While Immune Checkpoint Inhibitors (ICIs) have been approved for a wide range of solid tumors, T-cell directed therapies like Chimeric Antigen Receptor-T cells (CAR-Ts) and T-cell redirecting Bispecific T-cell Engagers (BiTEs) are now available for the treatment of hematologic malignancies. Encouraging results for using CAR-Ts and BiTEs in liquid tumors have created interest in expanding these therapies to solid tumors.

While both CAR-Ts and BiTEs present structural similarities, they constitute different therapeutic classes and modes of action. CAR-T cell therapies rely on ex-vivo activation and expansion of T-cells, whereas BiTEs count on the patient’s endogenous T-cells. CAR-Ts are usually administered as a single intravenous infusion, whereas most BiTEs are injected intravenously or subcutaneously once a week, owing to their short half-life. Clinical data gathered so far suggests that BiTEs have a more favorable safety profile in terms of common adverse reactions. At the same time, the efficacy appears to be comparable for both in relapsed / refractory settings.

A looming competition exists between these two modalities, especially in hematological cancers. The success of future market launches will depend on how the treatment paradigm shifts in the years to come. With recent drug approvals and the presence of multiple assets in the late clinical stages, patients may soon have multiple treatment options. The available products will then compete for patient and physician preference at each point in the treatment journey. Hence, it is important to evaluate the risks and benefits of each therapy and optimize the sequence of administration.