“My comment on the AFFIRM trial is ‘wow, very impressive.’ The median survival and the declines in PSA levels are impressive, and this is going to change the way we care for patients in our practices,” said Nicholas Vogelzang, MD, medical oncologist with Comprehensive Cancer Centers of Nevada and Chair and Medical Director of the Developmental Therapeutics Committee of US Oncology. Dr. Vogelzang moderated a press briefing on the AFFIRM and ALSYMPCA trials at the 2012 Genitourinary Cancers Symposium.

Since the drugs studied in these two trials—MDV3100 and radium-223—have different mechanisms of action, they will probably be used in sequence or combination. “We would expect survival to be dramatically pushed forward [with use of both drugs]. Thus far, these drugs haven’t been given in sequence, but using them both should bump up survival in the next 2 to 3 years,” Dr. Vogelzang predicted. 

No Regulatory Hurdles Foreseen

“These mechanistically different agents will be combined. We need to see if they have synergy. This is an important step to be taken,” stated Oliver Sartor, MD, Medical Director of the Tulane Cancer Center, New Orleans, and lead investigator for the ALSYMPCA trial in the United States.

Both Dr. Vogelzang and Dr. Sartor said that they foresee no major regulatory hurdles for MDV3100 and radium-223. Neither leukemia nor bone marrow failure (events of concern) has been observed with radium-223, and the seizures in five patients treated with MDV3100 are not perceived as an obstacle to approval.

“With both drugs, adverse events are actually less than with placebo. With this kind of survival benefit and safety profile, both drugs should be approved relatively quickly, Dr. Vogelzang said. Both MDV3100 and radium-223 have received fast-track designation from the FDA.

‘Incredible Achievement’

Adam S. Kibel, MD, Chief of Urology at Brigham and Women’s Hospital/Dana-Farber Cancer Institute, Boston, called MDV3100 “an incredible achievement in rational drug design by Drs. Charles Sawyers and Howard Scher.”

Dr. Kibel continued, “Both of these drugs are advances. We will end up using them extensively, probably earlier in the disease process. There is no reason why we couldn’t use them together, in sequence or in combination, and with other drugs. There is great potential here.” ■

Disclosure: Dr. Vogelzang was an investigator on the radium-223 trial. Dr. Sartor has been a  consultant to Medivation, Algeta, and Bayer, and also an investigator for Algeta and Bayer. Dr. Kibel reported no potential conflicts of interest.