New Drug Combining Herceptin, Maytansine Shows Improved Survival and Fewer Side Effects
The annual San Antonio Breast Cancer Symposium (SABCS), held last month, is the premier scientific symposium in the world for breast oncologists, breast cancer researchers, and associated healthcare professionals. Last year’s session included the presentation of over 1,000 scientific papers related to breast cancer; this year’s agenda was similar.
The majority of these papers detail the results of ongoing breast-cancer research – much of it nearly unintelligible to the typical breast cancer survivor. And the majority of the research is years from being translated into anything actionable for patients.
Still, sifting through the online abstracts and summaries from SABCS, I came up with a few nuggets I’d like to share.
The first, regarding Herceptin, is being treated in the press as the “big news” to come out of this year’s conference. The second, centered on drugs used to treat osteoporosis, is an eye-opener for those of us dutifully taking our Fosamax or Boniva – or considering whether we should.
About 25% of all breast cancers are HER2-positive, which is a more aggressive type of breast cancer. The first-line defense in these cancers is Herceptin, an antibody that helps prevent cancer cells from growing. If you’re one of the many women taking Herceptin – or about to – here’s some news that’ll interest you.
New hope for women with metastatic disease
Herceptin is one of the drugs women with metastatic breast cancer rely on. And not just women with HER2-positive cancer; Herceptin is used to treat all kinds of metastatic breast cancer.
Problem is, it often loses its effectiveness as time goes by; women become resistant to it. And to Tykerb, Xeloda, and many other drugs used to treat “mets.”
Now a new agent – T-DM1, which combines Herceptin with maytansine, derived from sea sponges – has been shown in Phase II clinical trials to significantly improve length of survival, without the dangerous cardiovascular side effects so often present in prolonged chemo.
“A response this good didn’t even seem possible,” noted José Baselga, MD, of the Vall d'Hebron University Hospital in Barcelona, Spain, who moderated the SABCS session where the results were presented.
The study, led by Ian Krop, MD, PhD, of the Dana-Farber Cancer Center in Boston, is based on Phase II clinical trial results. Typically, a new treatment has to progress through Phase III to be considered for FDA approval. But based on its surprising results, and the desperate needs of the population it treats, T-DM1 might be put on the fast track for approval.
Phase III trials are set to being in May, with possible approval sometime in 2010, according to Krop.
Don’t wait - start Herceptin with your chemo
Edith Perez, M.D., working from the Mayo Clinic in Jacksonville, Florida, reported results of a study showing that women who began taking Herceptin midway through their ACT chemotherapy – when AC ends, and T begins – had a 25% better chance of disease-free survival at 5 years than women who waited till chemo was over before starting Herceptin.
The majority of American doctors recommend this concurrent treatment, but not all. If your oncologist recommends Herceptin, but says you don’t need to start it till after chemo, point to this study – and ask him why.
Bisphosphonates – for once, a positive side effect
Bisphosphonates – Boniva, Fosamax, et. al. – are drugs commonly prescribed for women with osteoporosis, or at significant risk of it. Now it appears these drugs may have benefits beyond bone health.
Two different studies presented at SABCS indicate that women taking oral bisphosphonates have a 30% lower risk of getting breast cancer than women who don’t take them.
Studies involving IV-administered bisphophonates presented at last year’s SABCS showed similar positive results.
In addition to reducing the risk of breast cancer, bisphosphonate use seems to be associated with less serious breast cancer, where it occurs. Women taking bisphosphonates were less likely to have invasive breast cancer, and more likely to have hormone-receptive breast cancer, which is more easily and successfully treated.
Are you on the fence about taking a bisphosphonate for osteopenia? This news might help you make up your mind.