Romidepsin and afatinib combination treatment induce synergistic anti-lymphoma effect in CTCL

Cutaneous T-cell lymphomas (CTCL) are an aggressive group of T-cell lymphomas that present in the skin and are associated with dismal prognosis. Romidepsin is a histone deacetylase (HDAC) inhibitor that is an FDA approved systemic therapeutic indicated for the treatment of CTCL in patients who have received at least one prior systemic therapy. Romidepsin demonstrates promising single agent activity in patients with advanced stages of CTCL, however response is typically low and not durable. One method of overcoming resistance to romidepsin and improving response is through combination therapies. Here, we demonstrate that romidepsin in combination with the epidermal growth factor receptor (EGFR) inhibitor afatinib and afatinib dimaleate produce strongly synergistic anti-tumor effects in CTCL cell lines and an in vivo model of CTCL. Gene expression and western blot analysis further identifies the decreased activation of the JAK-STAT signalling pathway as a key driver of synergy in this combination. These results suggest a potential indication for FDA-approved EGFR inhibitors previously unrecognized in CTCLs as a combination therapeutic with HDAC inhibitors that can be rapidly adopted in the clinic.