Practice-Changing Developments in Treatment of Metastatic NSCLC

Immune checkpoint inhibitor drugs that target the proteins PD-1 and PD-L1 are by now well established in the treatment of non-small cell lung cancer (NSCLC). In 2015, the U.S. Food and Drug Administration (FDA) approved nivolumab (Opdivo), an anti-PD-1 drug, for treatment of patients with metastatic NSCLC who progressed or relapsed after platinum-based chemotherapy. Atezolizumab (Tecentriq), an anti-PD-L1 drug, was approved in 2016 for treatment of NSCLC patients in the same situation. In October 2016, the FDA approved Pembrolizumab (Keytruda), a competing anti-PD-1 antibody, as first-line treatment in metastatic NSCLC patients whose tumors have high expression levels of the PD-L1 protein.

With these approvals, the stage was set to move these drugs into combination treatments that may increase their efficacy. Not surprisingly, combinations with chemotherapy have now been explored, among other possibilities. Continue reading…

Predicting If an Immune Checkpoint Drug Will Work

Drugs that activate the immune system to attack cancer in a process known as immune checkpoint blockade (ICB) are a focus of intense investigation. A number of them are already approved by the U.S. Food and Drug Administration (FDA) for various cancers; namely, the anti-CTLA4 antibody ipilimumab (Yervoy), two anti-PD-1 antibodies: pembrolizumab (Keytruda) and nivolumab (Opdivo), and three anti-PD-L1 drugs: atezolizumab (Tecentriq), avelumab (Bavencio) and durvalumab (Imfinzi). These ICB drugs have the potential to induce durable cancer regressions, but the majority of cancer patients just do not respond to them at all.

Biomarkers, signature molecules in the blood or other tissue, can sometimes be used to predict a patient’s response to a given treatment. But no reliable biomarkers exist for ICB, and this is a serious concern. Patients who may really benefit from ICB could be overlooked, and patients who are not likely to respond may receive useless (and very expensive) ICB treatment.

Most potential response predictors that have already been identified are not yet useful for one or all of the following reasons: they are not extensively validated, their significance is still uncertain and may differ from one cancer (or even one patient) to another, or they are technically challenging for routine use. These markers are addressed below. Continue reading…

Targetable Mutations in NSCLC: More Testing Needed!

Diagnosis of adenocarcinoma of the lung, a major subtype of non-small lung cancer (NSCLC), nowadays triggers mandatory testing of tumor tissue for alterations in four genes: EGFR, ALK, ROS1, and more recently, BRAF. If present, these alterations predict sensitivity to specific targeted drugs approved by the U.S. Food and Drug Administration (FDA) that work better and often longer than standard chemotherapy, and are better tolerated.

However, there are many more targetable/actionable genomic alterations (also known as “drivers”) in NSCLC. This blog post will briefly discuss most of them, with the goal of promoting molecular testing for more than the four “usual suspects” mentioned above. Some patients with these alterations may benefit from FDA-approved drugs or from enrollment in clinical trials that are testing additional drugs and drug combinations. Continue reading…

A Gut Feeling: Bacteria in Your Gut May Affect Cancer Treatment

The human gut contains hundreds of species bacteria, which are known to contribute to various bodily functions (such as digestion, of course!) but they also shape our immune system. Now, recent research has revealed how our microbiomes (the abundant bacteria living in our bodies) may affect the efficacy of immune checkpoint blockade (ICB) in cancer treatment.

How it started: about two years ago, an American group of scientists led by Thomas Gajewski of the University of Chicago noticed that melanoma (and some other cancers’) growth in mice was influenced heavily by the type of bacteria found in the mouse gut. They worked with mice purchased from two different vendors, and realized that mice from one vendor had consistently slower-growing tumors. Bifidobacterium bacteria present in the mouse gut were pinpointed to be the culprit, because transfer of Bifidobacterium to mice that did not have it was able to slow down melanoma growth. Treatment with an immune anti-PD-L1 drug was effective in mice that had the bacteria, but not in mice lacking it. Continue reading…

EGFR-mutant NSCLC: Choice of First-Line Treatment May Get More Complicated

Medical guidelines for treatment of newly diagnosed non-small cell lung cancer (NSCLC) mandate upfront testing of tumor tissue for mutations in the EGFR gene (as well as ALK and ROS gene translocation). EGFR mutations are found in 10 to 15% of white patients, but in patients of East Asian origin such mutations are in encountered in approximately 48%. However, with new data and drugs entering the playing field, newly diagnosed patients’ treatment decisions could become more complex.

There is a good reason to test for EGFR mutations: the accumulated data show that, compared to first-line chemotherapy, treatment with drugs that inhibit the activity of EGFR in patients with activating EGFR mutations improves patients’ median progression-free survival (PFS) time from 4.6 to 6.9 months to 9.6 to 13.1 months, and has a higher objective response rate (ORR). Moreover, EGFR inhibitors are associated with a significantly lower incidence of adverse effects and better control of disease symptoms. Continue reading…

Super ASK Patient: Phil Kauffman Finds Peace in a Pragmatic Approach to Lung Cancer Treatment

In November of 2014, Phil Kauffman went to his primary care doctor with what he thought was a broken rib. The doctor advised him to let it heal on its own—a standard approach for such maladies.

Phil, a retired engineering consultant who lives near San Diego, California, with his wife (their two daughters are grown), went home and waited for his rib to heal, but the pain stuck around for months.

In March of 2015 his doctor ordered an X-ray, but instead of a broken rib, it revealed suspicious spots in Phil’s lung. A CT scan found five lesions characteristic of lung cancer. His rib pain was caused by pleural effusion (liquid) in his right lung, which was extracted, and an examination of that liquid confirmed a diagnosis of stage IV non-small cell lung cancer (NSCLC).

Phil remembers that during the first week after his diagnosis he was paralyzed with fear. His brother in law, a physician, helped him snap out of it, assuring him that his treatment options guaranteed a survival period of at least a few years or maybe more, and that cancer research was progressing at such a fast rate that the prospect of extending his lifetime beyond a couple of years was good. Continue reading…

The Trouble With KRAS

Mutations in the gene that encodes the KRAS protein are frequently encountered in various human cancers. They are found in about 30% of non-small cell lung cancers (NSCLCs), making KRAS the single most common gene mutated in this cancer. The rate of KRAS mutations in other cancers, such as pancreatic or colorectal, is even higher.

A mutant KRAS protein that is always in the “on” position activates many signaling pathways, many of which lead to unrestrained growth and proliferation of cancer cells. This makes KRAS an appealing treatment target. However, challenges abound, and researchers are exploring several different approaches to treating KRAS-mutant cancers.

Unlike mutations in proteins known as receptor tyrosine kinases, like EGFR or ALK, mutated KRAS is a very difficult protein to target with cancer drugs. (So much so that the National Institutes of Health (NIH) has undertaken a special effort to intensify the effort towards successful targeting of mutant KRAS, known as the RAS Initiative.) Continue reading…

Testing for Tumor Mutations: Liquid Biopsy Versus Traditional Biopsy

Liquid biopsies, virtually unknown even a year or two ago, are becoming common tools in precision diagnostics for cancer. Here, I will try to explain some of the more important differences between liquid and “traditional” tumor biopsies.

Biopsies of solid tumors (e.g., lung, breast, or brain tumors) involve surgically removing a small part of a tumor and sending it to pathology lab. In the last few years, doctors have also started to send some tumor samples to special service labs that analyze tumor DNA for the presence of cancer-related mutations.

By definition, regular biopsies can be intrusive and are sometimes associated with side effects, such as bleeding or infection. However, they provide some really essential information; i.e., the histology and grade of the tumor and other tumor characteristics necessary to determine the best choice of treatment. For lung cancer, for example, a biopsy determines the type of tumor—adenocarcinoma, squamous cancer, small-cell lung cancer, or another, less common type. For breast cancer, a routine test will determine if the tumor expresses estrogen, progesterone receptors, and a protein called HER2. These tests are critically important in guiding treatment choices. If mutational analysis of cancer-related genes is also performed (which doesn’t always happen, unfortunately), it may guide treatment with targeted drugs. Continue reading…

War of the Checkpoint Inhibitors: Anti-PD-1 Drugs Move into First-Line Treatment in NSCLC

Last year, the U.S. Food and Drug Administration (FDA) approved two anti-PD-1 checkpoint inhibitors, a type of immunotherapy, for treatment of non-small cell lung cancer (NSCLC) in patients whose cancer has progressed after first-line treatment with chemotherapy. Now, the manufacturers of both drugs, pembrolizumab (made by Merck) and nivolumab (made by Bristol-Myers Squibb; BMS) are intent on expanding the indications for use of their drugs. To this end, they have conducted clinical trials testing each as a first-line treatment (i.e., in previously untreated patients), comparing them to standard chemotherapy. Continue reading…