It is hard to extrapolate from a measurable "response rate" for a single drug to an improvement in cure rate for large cell lymphoma. There are any number of conventional chemotherapy agents (bleomycin, high dose methotrexate, etoposide...and others) that have measurable response rates in the 37% range. It is reasonable to expect that adding those drugs to CHOP (which was introduced in the 1970's) would improve cure rates. In fact, the entire medical oncology community was burned on just such assumptions for many years. Major centers around the world all created their newest, and latest, combinations based usually on CHOP. These combinations were collectively called 2nd generation combinations, and then 3rd generation, lymphoma regimens. In uncontrolled trials each new regimen seemed better than the last and became the "fashionable" new treatment of the day. Finally, a large controlled, comparative trial looked at the 3 most favored 3rd generation regimens compared to standard CHOP. (I remember Vincent DeVita, at the time the Director of the National Cancer Institute claiming that it was unethical to randomize patients to CHOP, a clearly inferior treatment). Well, it turned out that the newer regimens were far more toxic but no better than CHOP. It was a very humbling event in the Medical Oncology field. Among the developers and promoters of the 3rd generation regimens were the most prominent of oncologists and the major names in Cancer centers: NCI, Stanford, etc.
There is a similar issue, currently, with the addition of high dose chemotherapy (bone marrow transplant) to standard dose therapy for selected patients. While it would seem that adding this therapy to CHOP for high risk patients would make perfect sense, the randomized trials have been inconsistent in showing an improved outcome.
It is only by understanding this kind of history that can you begin to understand why the "established" community is so cautious in embracing new technologies. We all want new treatments for our patients but we all want at least some level of data on which to change our "standard therapy" to something new. There is a joke among medical oncologists that new treatments should be used "while they still work." The comment is, of course, unnecessarily cynical but it speaks to some of the realities of the profession.
Will adding monoclonal antibodies to front line treatments improve outcomes? I certainly hope so but I personally want to see some data. |
