Researchers at the American Society of Clinical Oncology (ASCO) in Chicago this week have unveiled data on several promising new cancer treatments - and FDA regulators have offered some innovative thinking with respect to how the agency can offer faster approval for the most promising breast cancer treatments.
Bloomberg reports that Bayer's experimental cancer drug regorafenib has proven an effective treatment for patients with a rare type of stomach cancer (gastrointestinal stromal tumors or GIST) whose tumors have developed resistance to existing medications. There are only two drugs approved to treat this type of cancer, Sutent and Gleevec, and 85 percent or more of these cancers will eventually become resistant to those drugs. So adding another effective option for patients will (hopefully) both extend overall patient survival and buy time to come up with more powerful therapies that can slow the development of drug resistance.
Two other drugs discussed at ASCO appear to be promising new treatment options for metastatic melanoma, a deadly form of skin cancer. The targeted drugs, trametinib and dabrafenib, developed by GlaxoSmithKline, were both significantly more successful at sustaining life and preventing disease progression than standard chemotherapy treatment. And a smaller study of the drugs suggests that they be may be even more effective when used in combination, as they block two different cancer growth mechanisms (BRAF and MEK).
A new approach in cancer therapy is to use combinations of targeted therapies that attempt to shut down multiple cancer growth pathways at the same time, slowing cancer growth and (hopefully) making it harder for the cancer to develop drug resistance to targeted therapies.
Apart from targeted therapies, the Wall Street Journal also reports some promising data from the field of cancer immunotherapy, once considered a therapeutic dead end. Researchers have gained a much better understanding of how cancer shields itself from the body's immune system, escaping detection and destruction.
The biggest challenge in immunotherapy treatment has been to train the body's immune system to attack cancer cells while leaving normal, healthy tissue unharmed. Though much work remains to be done in terms of making immunotherapy widely effective, new research has shown that at least some late-stage cancer patients (across several different cancer sub-types) can enjoy significant sustained benefits from immunotherapy treatment with relatively limited side effects.
Thankfully, innovation is not only occurring in the development of new drugs and treatments for cancer. FDA regulators have announced a new approach to cancer drug testing. The Chicago Tribune reports that in an effort to "spur innovation and get more effective drugs to the patients who need them," the FDA will now allow drug companies to test their medications on women with "highly aggressive" breast cancers before their tumors fully develop and metastasize.
This breaks from the traditional FDA policy of testing new breast cancer drugs (which may have less well understood safety profiles) in patients suffering from very advanced, metastatic cancers, where the prognosis is extremely poor to begin with. According to a new FDA guidance targeted at breast cancer, any drug that is found to eradicate cancer in early stage patients will be granted "accelerated approval," providing companies a fast-track to market.
Finally, The Scientist recently noted a provocative article published in Nature by cancer researcher Patricia Steeg. Steeg argues that FDA regulators have forced drug companies to focus exclusively on combating cancer growth, rather than preventing metastasis, to the detriment of patient health. Steeg argues that any cancer drug that prevents metastasis should be regarded as life-prolonging and hence should meet the FDA's standards for drug effectiveness, even if those same drugs fail to reduce tumor size after metastasis has occurred. Steeg specifically believes that the FDA should create a new type of randomized clinical trial to test whether cancer drugs successfully prevent metastasis, and argues that those that do should be granted FDA approval and be rapidly offered to patients at high risk for metastasis.