On June 21, 2012 Dr. Anne Moore and Dr. Linda Vahdat provided a report back from ASCO, the American Society of Clinical Oncologists annual meeting. Dr. Moore kicked off the report stating that many doctors now think of metastatic breast cancer as a chronic disease because there are so many different approaches to treatment where women can live a long time. Dr. Moore stated that breast cancer used to be breast cancer. Now, breast cancer is categorized by its subtype, such as Her2+, ER+, PR+ or Triple Negative, and treated accordingly.
Ten years ago, if a woman who'd previously had breast cancer developed a new tumor, that new tumor would be treated the same as the original cancer. Now, ASCO states new tumors should be re-biopsied to determine their hormone status so they can be treated appropriately. According to a study presented at ASCO, 126 patients with ER+ breast cancer where retested when they developed metastatic breast cancer. Fourteen percent of the patients' cancer was now ER-, and 8% of the patients' status switched from ER- to ER+. In a similar study involving Her2+ patients, 17% of the patients studied had Her2- metastatic cancer after an initial diagnosis of Her2+ cancer.
Dr. Moore also talked about the new drug pertuzumab or Perjeta that was approved by the FDA on June 8, 2012. The combination of pertuzumab (Perjeta) plus trastuzumab (Herceptin) plus docetaxel (taxotere), as compared with placebo plus trastuzumab (Herceptin) plus docetaxel (taxotere), when used as first-line treatment for HER2+ metastatic breast cancer, significantly prolonged progression-free survival, with no increase in cardiac toxic effects in the randomized, double-blind, multinational, phase III CLEOPATRA trial.
Another drug, T-DM1, is also being studied for Her2+ metastatic breast cancer. Herceptin links to T-DM1 and looks for the Her2 receptor. It drags the T-DM1 into the cell and releases it in special locations where it doesn't filter back out of the cell. This enables patients to tolerate chemo well, maintaining a good quality of life. Dr. Moore expressed a lot of excitement about how T-DM1 links to other drugs stating this has never been done before and could open up new combinations of drugs.
Lastly, Dr. Moore discussed the M-Tor inhibitor everolumus or Affinitor. Affinitor together with Aromasin showed complete response, partial response or stable disease for over 6 months in 50% of women in a trial with 724 ER+ metastatic breast cancer patients who have had prior treatment.
Dr. Vahdat focused mostly on Triple Negative Breast Cancer or TNBC. TNBC comprises 15% of all breast cancer while Her2+ breast cancer comprises about 20%. TNBC tends to be more aggressive and there is hope that there will be great progress over the next few years. Dr. Vahdat discussed classic chemotherapy, which includes Avastin, Classic CMF, Ixempra, Eribulin and Platinum drugs. Avastin has been a controversial drug but there is some suggestion it may work well with TNBC. Dr. Vahdat states that even though Avastin is no longer FDA-approved for first-line treatment of metastatic breast, it is not gone yet, and perhaps once they figure out how it works, it can be an effective drug for some types of breast cancer. Ixempra was approved in 2007 and shows good activity in TNBC and other subtypes of cancer. In a review of classic CMF trials, it was shown that CMF is effective in TNBC. Eribulin is a drug derived from marine sponge which works by targeting the scaffolding within a cell. (According to Web MD, "when a cell divides, the scaffolding helps it. What the Eribulin does is interfere with the construction of the scaffolding and stops the cancer cell from dividing.")
Dr. Vahdat said Parp Inhibitors, which are yielding excellent results in treating BRCA1 or 2 related cancers, are still being explored as treatments for TNBC. Parp Inhibitors are drugs that "exploit vulnerability of cells that lack the machinery to repair themselves."
Dr. Vahdat discussed the NCI Trial 8264, which was presented at ASCO 2012. This trial involves ABT-888 (Veliparib) in combination with Carboplatin in patients with stage IV BRCA-associated breast cancer. It's a California Cancer Consortium Trial demonstrating acceptable toxicities and encouraging efficacy.
Glembatumumab vedotin is an antibody-drug conjugate that targets cancer cells expressing a particular protein. This drug has had good results in trials with triple negative metastatic breast cancer.
Dr. Vahdat also spoke about what researchers are currently looking at, including how tumors travel and how they get access to metastatic sites, a phase II study of TM in patients with TNBC and the Optimer Vaccine Trial.
To see slides from the presentations, click HERE.
Christine is the Breast Cancer Program Director at SHARE.