BCL2 Inhibition as a Strategy for Steroid-Refractory GVHD

Amandeep Salhotra, MD, discusses an intriguing in vitro study from the United Kingdom that identifies a specific cellular mechanism behind resistance to standard graft-vs-host disease (GVHD) treatments. The research focused on T cell populations within patients treated with glucocorticoids, uncovering a selective expansion of a unique subset of CD8+ T cells. These cells express a transcription factor known as TCF7, which marks them as a progenitor-like population of effector cells. Notably, when these patients are treated with corticosteroids, this TCF7-positive population expands, and the addition of ruxolitinib (Jakafi) does not eliminate them; instead, they remain detectable in both the systemic circulation and gastrointestinal biopsy specimens.

The most significant finding of this research is that this specific T cell population, which appears refractory to both corticosteroids and ruxolitinib, demonstrates a high expression of the anti-apoptotic protein BCL2. This molecular signature suggests that the cells are “primed” to survive even in the presence of standard immunosuppressive therapies. Dr. Salhotra explains that this discovery opens a compelling new therapeutic pathway: the potential use of BCL2 inhibitors, such as venetoclax, in combination with ruxolitinib.

Although Salhotra notes that these findings are currently speculative and based on early-stage research, the clinical implications are substantial. If the TCF7-positive T cell population is found to be elevated in a patient, it could serve as a biomarker to justify the early introduction of venetoclax (Venclexta). This strategy could be applicable in both the acute and chronic GVHD settings, offering a targeted approach to eliminate the specific cells responsible for treatment resistance. Moving forward, the medical community expects the initiation of clinical trials to formally explore whether BCL2 inhibition can successfully overcome refractory GVHD and provide much-needed options for patients who fail to respond to the current standard of care.