Bevacizumab In Colon Cancer – “A Shot Across The Bowel”

Colon2 130320.01 lo resAn E-Publication article in the February Journal of Clinical Oncology analyzes the cost efficacy of Bevacizumab for colon cancer. Bevacizumab, sold commercially as Avastin, has become a standard in the treatment of patients with advanced colorectal cancer. Indeed, Bevacizumab plus FOLFOX or FOLFIRI, are supported by NCCN guidelines and patients who receive one of these regimens are usually switched to the other at progression.

A Markov computer model explored the cost and efficacy of Bevacizumab in the first and second line setting using a well-established metric known as a Quality-Adjusted Life Year (QALY). In today’s dollars $100,000 per QALY is considered a threshold for utility of any treatment. To put this bluntly, the medical system values a year of yavastinour life at $100,000. The authors confirmed that Bevacizumab prolongs survival but that it does so at significantly increased costs. By their most optimistic projections, Bevacizumab + FOLFOX come in at more than $200,000 per QALY. Similar results were reported for Canadian, British and Japanese costs. Though more favorable, the results with FOLFIRI + Bevacizumab still came in above the $100,000 threshold.

No one doubts that Bevacizumab provides improved outcomes. It’s the incremental costs that remain an issue. Society is now confronting an era where the majority of new cancer agents come in at a cost in excess of $10,000 per month. Where and how will we draw the line that designates some treatments unaffordable? On the one hand, clinical therapies could be made available only to the “highest bidder.” However, this is contrary to the western societal ethic that holds that medical care should be available to all regardless of ability to pay. Alternatively, increasingly narrow definitions could be applied to new drugs making these treatments available to a shrinking minority of those who might actually benefit; a form of “evidence-based” rationing. A much more appealing option would be to apply validated drug predication assays for the intelligent selection of treatment candidates.
Avastin-MOA-Overview
In support of the latter, the authors state, “Bevacizumab potentially could be improved with the use of an effective biomarker to select patients most likely to benefit.” This is something that genomic (DNA) profiling has long sought to achieve but, so far, has been unable to do. This conceptual approach however is demonstrably more attractive in that all patients have equal access, futile care is avoided and the costs saved would immediately provide highly favorable QALY’s as the percentage of responders improved.

Similar to the recent reports from the National Health Service of England, the American public now confronts the challenge of meeting the needs of a growing population of cancer patients at ever-higher costs. It is only a matter of time before these same metrics described for colon cancer are applied to lung, ovarian and other cancers for which Avastin is currently approved.

At what point will the American medical system recognize the need for validated predictive platforms, like EVA-PCD analyses, that have the proven capacity to save both money and lives? We can only wonder.

Is Rationed or Rational Medical Care In Our Future?

We are witness to a sea change in medicine. Doctors and nurses are being replaced by “healthcare providers;” medical judgment is being phased out in favor of therapeutic algorithms; and the considered selection of treatments is giving way to rigid therapy guidelines. All the while, the regulatory environment increasingly precludes the use of “off label” drugs. It is understandable why insurers, governmental entities and hospital chains might welcome these changes. After all, once therapies have been reduced to standardized formulae, one can predict costs, resource allocations and financial exposures to the twentieth decimal place. For many medical conditions, these approaches will provide adequate care for the majority of patients.

But, what of the outliers? What of those complicated disease entities like cancer, whose complexity and variability challenge even the best minds? How do we bang the round peg of cancer therapy into the square hole of formulaic care?

There are several answers. The first is the least attractive: In this scenario, predicated upon cancer’s incidence in an older population, at the end or beyond their productive (and reproductive) years, we simply don’t allocate resources. Most civilized modern societies haven’t the stomach for such draconian measures and will seek less blunt instruments.

The second is a middle of the road approach. In this scenario, standardized guidelines that provide the same treatment to every patient with a given diagnosis are developed. Every medical oncologist knows the drill: FOLFOX for every colon cancer, Cytoxan plus Docetaxel for every breast cancer and carboplatin plus paclitaxel for ovarian cancer. The treatments work adequately well, the schedules are well established, the toxicities are well known and no one is cured. The beauty of this approach is that the average patient has an average outcome with the average treatment. By encompassing these regimens into standardized algorithms, we may soon be able to eliminate physicians entirely — first, with nurse practitioners and physician’s assistants and, ultimately, with computers. What is perhaps most surprising about this scenario has been the willingness of the medical oncology community to embrace it, a sort of professional self-induced extinction. At the time of this writing, this is the predominant model and is becoming increasingly entrenched under the auspices of NCCN and related guidelines. The operative term being guidelines, in as much as these “guidelines” are rapidly becoming “dictates.”

The final approach, and the one I find most appealing, is that which utilizes the clinical, scientific, laboratory and technical acumen of the physician to the maximum. Combining diagnostic skill with scientific insight, the physician becomes the captain of the ship, who must assume control from the autopilot once the vessel has entered the tempest and use his/her experience and training to guide the patient to a soft landing. This requires the capacity to think and demands an up-to-date knowledge of many disciplines. The judicious application of laboratory-directed approaches can further enhance the skillset, introducing objective data that is then used to guide drug and treatment selections. Predicated upon an understanding of the patient’s tumor biology, cancer therapy becomes an intellectual exercise that draws upon literature, and a knowledge of pharmacology and physiology. Adding the wealth of newly developed signal inhibitors to the mix only enhances the odds of a good outcome.

This approach improves responses and eliminates futile care. It provides patients the opportunity to participate in their own management. Correctly delivered, it would make available to every patient any FDA-approved drug. While it would seem to some that this would open the floodgates of drug use, I would strenuously disagree. It would instead limit drug administration to those patients most likely to respond, a goal currently pursed by virtually every major institution, yet accomplished by none. While a handful of targeted approaches have come to fruition in the last few years — erlotinib for EGFR mutation, and sunitinib in kidney cancers — most of the molecular profiling being done today doesn’t aid in the selection of therapy but instead provides negative information (e.g. RAS in colon cancer, ERCC1 over expression in lung) enjoining the physician against the use of a given agent but then leaving the unfortunate patient to fend for themselves amidst a panoply of randomly chosen options.

This is the approach that I have chosen to adopt in my own care of cancer patients. Our rapidly growing successes in ovarian, breast, lung, melanoma, leukemias and other diseases could and should serve as a model for others.

There is More to Gastrointestinal Cancer Management Than FOLFOX

Several months ago, I was introduced to a 58-year-old gentleman with a very bad diagnosis — a bout of gastrointestinal bleeding that had lead to an upper GI endoscopy. It wasn’t an ulcer, or even gastric cancer, but a very rare form of cancer arising in the duodenum. Adenocarcinoma of the duodenum is very uncommon.

This patient was in trouble.

In addition to the bleeding, he had lost a substantial amount of weight, was in pain and had a very large tumor that was nearly obstructing his upper GI tract. After getting the patient stabilized in September 2010, he was referred to a surgeon who conducted an aggressive surgical resection. The recovery was difficult, prolonged and accompanied by additional GI bleeding. By the time the patient had recovered adequately enough to consider additional therapy, his PET scan revealed extensive re-growth.

If you were to ask medical oncologists in the United States what to give such a patient, 99 percent would recommend FOLFOX or some variation thereof. But, FOLFOX wasn’t the right treatment for this patient. Instead, he had a strong signal for Irinotecan, which was further enhanced by the addition of an EGFR inhibitor. Based on this, I elected to treat the patient with Erbitux + Irinotecan. Before starting therapy, his CA 19-9 was 354. Although his signal for the EGFr inhibitor was very favorable in our analysis, I screened him for K-ras mutation. It seemed evident from his dose response curves and clear synergy between Irinotecan and the EGFR inhibitors that he would be K-ras wild type, but in this era of evidenced-based medicine one must be politically correct.

Indeed, he was K-ras wild type and we started treatment with Erbitux + Irinotecan. Other than the rash associated with the Erbitux, the tolerance was good. The bleeding stopped immediately, the CA plummeted with the first dose to 71 and the patient then returned every other week for therapy.

On February 11, 2011, three cycles later, we repeated the PET/CT. The phrase “marked interval regression” of measurable disease caught my eye. I also noted the normalization of his CA 19-9. The patient had gained weight and returned to normal activities. With the exception of a small and diminishing rash, he looks quite normal. In fact, with the rather modest dose of Irinotecan used in his schedule, he hasn’t even suffered any hair loss. What I find most interesting about this patient is that FOLFOX, the most widely used regimen in this setting, wasn’t anywhere on the radar screen. It wasn’t active, it wasn’t recommended and I feel confident it wouldn’t have worked. However popular FOLFOX may have come to be in patients like this, it doesn’t fit everyone.