Knowledge and understanding of the molecular pathophysiology of cancer has improved significantly over the last 25 years. This has led to the testing of a large number of new approaches to treating cancer patients. Some of these target oriented approaches have led to impressive benefits for the patients with certain cancers, such as Hodgkin lymphoma or chronic myelogenous leukemia. However, the majority of cancers respond only initially, or become resistant to current targeted therapies or drug combinations.
Fortunately, the technologies available today allow rapid progress in further understanding the mechanistic basis of cancer, as well as the selection and testing of new treatments. The recent identification of tumor stem cells, the importance of the tumor stroma – such as angiogenesis and the dissection of the process of tumor metastasis – and the process leading to cancer spread, all offer many new targets and target combinations. Taken together, the result is a promise for improved treatments for cancer patients in the future.
Actelion’s research programs to identify and develop compounds for cardiovascular and other diseases have provided compounds which can be of potential use in oncology. For instance, endothelin receptors and endothelin are over-expressed on tumor cells and stromal cells in several tumor types, such as melanoma, and contribute to invasion and metastasis. Actelion's endothelin antagonists are therefore being explored for application in cancer therapy.
The test systems Actelion uses will not only analyze effects on the cancer cells, but study the interaction between cancer cells and the tumor stromal elements (vascular cells and inflammatory cells). Besides exploiting compounds in our pipeline from other indication areas, we are using our discovery platform and experience with certain target classes to select novel oncology approaches.
Following excellent preclinical results, a Phase I/Ib open-label study was initiated with macitentan in patients with recurring glioblastoma.