Reports from ASCO 2012
The American Society of Clinical Oncology (ASCO) Annual Conference was held in Chicago this year from June 1-5. This is the preeminent clinical cancer conference in the world with over 30,000 attendees, at least half of whom come from countries outside of the United States. There were more than 50 posters and a dozen oral sessions focused on kidney cancer. The following summaries represent reports from some of the significant conference sessions. More reports will be added over the course of the summer.
One of the studies that we are following are the results of a Phase III tivozanib versus sorafenib (Nexavar) trial. Tivozanib is destined to be added to the current half dozen targeted therapies used to treat metastatic rcc. However, while tivozanib targets only VEGF (a promoter of angiogenesis), there are additional targets such as MET pathways that also promote the growth of blood vessels instrumental in supporting tumor growth. Unfortunately, combining an agent that attacks one target with another agent that homes in on a different target has so far proven to be too toxic. On the bright side, however, there are newer trends in drug development aimed at overcoming the resistance of the cancer.
One simple device being used is to titrate up (increase) the dosage of a therapy to the maximum tolerated by the patient. This has been tried, with some success, with axitinib and may also be an option for tivozanib, both of which are highly potent drugs. Another choice is to develop a single drug that inhibits multiple pathways instead of trying to combine two drugs. For example, cabozantinib targets both the VEGF and MET pathways, and it has shown early promising results in rcc, although it was initially developed for prostate cancer. Finally, immunotherapies are making a comeback with companies developing antibodies to combat rcc. For example, the anti-PD-1 drug originally developed by the biotech company Medarex as MDX-1106 and currently being developed and marketed by Bristol-Myers Squibb as BMS-936558, has also shown good results in rcc in early trials. The PD-1 complex is thought to put a break on killer T-cells, one of the body’s immune cells that would otherwise defend it against tumors.
Currently, since the approval of the first targeted therapy at the end of 2005, the best targeted therapy (so far), sunitinib (Sutent), has only increased overall median survival of metastatic kidney cancer patients by 14 months over the previous standard of care. We still have a long way to go. However, as long as research continues in kidney cancer treatment, we are hopeful that the efficacy of the therapies will increase.
The chart below represents the therapies approved by the US Food and Drug Administration (FDA) for the treatment of metastatic kidney cancer. Throughout this summer, will be adding our reports of the relevant ASCO session to our website. The following reports are available now.