The oral histone deacetylase inhibitor LBH589 is a potential and promising therapeutic agent in multiple myeloma after at least two lines of chemotherapy including bortezomib or lenalidomide.

Background: Multiple myeloma as the second most common hematological malignancy is characterized by proliferation of monoclonal plasma cells. This entity still remains a non-curable disorder leading, amongst others, to complications as myeloma bone disease, bleeding events, kidney failure and neurological impairment. LBH589 is a histone deacetylase inhibitor with an epigenetic mechanism of action and the potential for treatment in myeloma.

Case Report: We report here about the successful treatment of a 44-year-old woman suffering from progressive myeloma with LBH589 after five different chemotherapies. During the 9 years after first diagnosis of myeloma in April 2000, our patient twice underwent an autologous stem cell transplantation and was also treated with the new substances bortezomib, thalidomide and lenalidomide.

Results: A rapid decline of myeloma activity parameters could be reached, with an approximately exponential decrease of kappa light chains in the 24-h urine. As a consequence, a near-complete remission was determined after about 6 months of LBH589 treatment. Additionally, the adverse event profile was acceptable, and the patient's quality of life showed a considerable advancement of well-being.

Conclusions: LBH589 may be very effective in multiple myeloma after a multitude of preceding treatments that could not induce a long-term anti-myeloma effect. Future trials with LBH589 should search for the specific characteristics of responding patients.