Testing the effectiveness of panobinostat in diffuse large B-cell lymphoma
In cells, DNA is wrapped around organizing proteins called histones. Different enzymes interact with the histones to make DNA more or less available to the cell. The histone modifying enzymes are known to be mutated in many diffuse large B-cell lymphoma (DLBCL) tumours, and so inhibitors of one such type of enzyme, histone deacetylases, were suggested to be effective as a treatment. One of these inhibitors, panobinostat, was tested in a Phase II trial with and without another known treatment for DLBCL, rituximab. The study, led by Drs. Assouline, Mann, Greenwood and Johnson, from the experimental therapies axis, found that almost 30% of patients responded to the new treatment, regardless of whether the known treatment was also used. The response to the treatment was durable in most responding patients and the researchers found that responsiveness could be predicted by a mutation in a specific gene (MEF2B) or by a drop in the amount of tumour DNA found in the blood after roughly 2 weeks. Effectively, this study helped identify a new treatment for some types of DLBCL as well as identifying tumour DNA in the blood as a marker or responsiveness.