Prof Dreyling studied human medicine at the Heinrich Heine University of Düsseldorf, the Justus Liebig University Giessen, the Eberhard Karls University Tübingen and the Julius-Maximilians-University Würzburg. After graduating in 1987, he began his internship at the University Hospital Bonn in 1988. In 1990 he received his doctorate. During the same year he moved to Münster, where he worked first at Clemenshospital, then at the University Hospital. He then undertook haematology and oncology research from 1992 to 1995 at the University of Chicago, USA. He returned to Germany and completed his residency at the University Hospital Göttingen and at the Hospital of the Ludwig-Maximilians-University Munich, where he completed his medical exam in 1998. In 2001 he habilitated on "Molecular genetic and functional characterization of the tumour suppressor region of the chromosomal band 9p21 in haematological cell lines and lymphomas and leukemias" and was appointed a senior physician a year later. In October 2007, he received the call to the W2 professorship "Immunotherapy and Molecular Biology" of the Ludwig-Maximilians-University Hospital in Munich.
Currently, he is in charge of the G10B ward at the Medical Clinic III at the University of Munich, Groβhadern, Germany.
Prof Dreyling's clinical research focuses on the development and application of novel therapeutic approaches for patients with haematological or oncological diseases, including malignant lymphomas such as chronic lymphocytic leukaemia and mantle cell lymphoma. He is interested in the development of innovative therapies, (e.g. inhibitors of the B cell receptor pathway) within the German Study Group for low malignant lymphomas, the German Lymphoma Alliance and the European Mantle Cell Lymphoma Network.
Prof Dreyling is a member of various medical societies, he sits, among others, on the Advisory Board of the German Society of Haematology and Medical Oncology (DGHO) and is Member of the ESMO Faculty Group for Haematologic Malignancies.