Signal transduction inhibitor therapy for Lymphoma

DESCRIPTION (provided by applicant): Treatment advances for non-Hodgkin Lymphoma (NHL) and Hodgkin Disease (HD) over the last several decades have improved the survival of patients with these common malignancies. However, nearly 40% of patients with large cell NHL, 80% with indolent NHL, and 20% with HD are not cured and die of their disease. It is clear that new agents with unique mechanisms of action based on knowledge of signal transduction pathways in lymphoma cells are needed to advance lymphoma treatment. This proposal focuses on the phosphatidylinositol-3 kinase (PI3K) and Raf kinase pathways in lymphoma cells. We have demonstrated single agent activity in patients with NHL/HD using inhibitors of the PI3K pathway (temsirolimus/everolimus) and inhibitors of farnesyl transferase (tipifarnib). Preliminary in vitro studies demonstrate activity of the Raf kinase/VGFR inhibitor sorafenib against lymphoma cells that is synergistic with the PI3K pathway inhibitors. The overall hypothesis of this proposal is that a combination of chemotherapy agents with one or more of the signal transduction inhibitors (STIs) will improve the response rate and survival of patients with NHL/HD. To test this hypothesis, this project includes clinical trials that assess rational combinations of STIs with each other and with conventional chemotherapy agents, investigational biomarkers in lymphoma cells from patients participating in these trials, and in vitro studies of new agents and combinations in primary tumor cells that will lead to the next generation of clinical trials. This work is organized in 3 specific aims: Aim 1, to investigate the safety and efficacy of PI3K/Akt/mTOR pathway inhibitors in combination with Raf- kinase inhibitors and conventional chemotherapy agents. Aim 2, to assess the action of combinations of STIs on the targeted pathways and identify potential markers of anti-tumor efficacy using malignant B-cells from patients entered on the trials in Aim 1. Aim 3, to investigate novel combinations containing agents targeting the PI3K/Akt/mTOR pathway and other STIs or conventional agents in malignant B-cells in vitro to provide the rationale for the next generation of clinical trials. Our initial studies will focus on drugs that target PI3K/Akt/mTOR pathway components or those of pathways known to connect with the PI3K/Akt/mTOR pathway. Combinations with substantial clinical activity will then move to large-scale testing in the cooperative groups such as NCCTG or ECOG. Lay Language Statement: Lymphoma cells respond to signals that are transmitted from the outside to the inside of the cell resulting in cell growth. This project focuses on new drugs for patients with lymphoma that interfere with those signals. Preliminary studies with several of these drugs are promising and the goal of this project will be to combine these agents together and with other common chemotherapy agents to advance the treatment of lymphoma.