Breast Cancer and Avastin, the Ongoing Saga

As many are now aware, in November of 2011, the United States FDA withdrew approval for bevacizumab (Avastin) for the treatment of breast cancer. Medicare and the National Comprehensive Cancer Network  (NCCN) are now re-examining their guidelines. In the interim, reimbursement for Avastin is a patchwork of approvals and denials across the country.

Into this mix comes an interesting concept apparently floated by Roche’s European affiliates. Described in a brief press release was the suggestion that Roche might be prepared to attach Avastin reimbursement to its efficacy. That is – Roche would only demand payment from patients and third party payers if the treated patient revealed objective evidence of response. This is an interesting idea!

The concept of conditional reimbursement is extremely intriguing. Contrary to contemporary reimbursement policy, the purveyors of therapy would only receive compensation if they could prove benefit, not mind you, benefit in the broad brush Phase III tiny statistically significant result (e.g. the FDA approval of erlotinib plus gemcitabine in pancreatic cancer for a median survival advantage of 10.6 days!), but instead very real benefit on a patient-by-patient basis.

We use erlotinib plus gemcitabine, as well as Avastin combinations, to great benefit for many of our patients and applaud the availability of these drugs and combinations. But we never, just give them. Were the federal government, major payers or HMOs to be prepared to reimburse novel therapies predicated on their efficacy, we might envisage a meaningful advance in cancer therapeutics.

Today, few small laboratories, start-up companies and early stage biotech firms have the resources to marshal multi-million dollar clinical trials to test new therapies. This may in part be why advances in cancer therapy are moving so slowly forward.  The barriers to entry are insurmountable, causing many good ideas to fall by the wayside for lack of the hundreds of millions of dollars required to achieve FDA approval and Medicare reimbursement. But what if on an individual basis, reimbursement policies reflected the most meaningful of all endpoints – individual patient response and survival. Even the largest pharmaceutical companies are now coming to realize that despite their clout they too are suffering under the guidelines forced upon drug developers in this era of ever increasing regulation.

This is a concept worth pursuing. Let’s see where it goes.

English Patients Denied Access to Ipilimumab

Among the more interesting discoveries in recent years have been two breakthroughs in the management of malignant melanoma. One drug, vemurafenib, a tyrosine kinase inhibitor, acts specifically in patients who carry the BRAF (V600E) mutation. The second drug ipilimumab, offered commercially from Bristol-Meyers Squibb as Yervoy, is a monoclonal antibody that acts by blocking CTLA-4, thereby enhancing T-cell response to tumor antigens. While vemurafenib has a somewhat narrow target population, ipilimumab targets may extend to a broader range of melanoma patients and will likely find a role in other cancers.

The data supporting ipilimumab’s use in advanced melanoma was reported in a 2010 Phase III trial, which provided a superior median survival for those treated with the drug over those who received a placebo. Superior one and two-year survivals were also reported. Unfortunately, this did not rise to the level that met the standards of the English watchdog organization, National Institute for Health and Clinical Excellence (NICE). The chief executive of NICE did admit that the drug could “potentially be very effective for a small percentage of patients.” Unfortunately, under current NICE guidelines, that small percentage of patients will not have access to the drug.

This is not the first time that a drug, found effective for the treatment of a subpopulation of patients has been denied approval based upon cost efficacy and the comparatively limited population of patients who stand to gain.

The role of Avastin in breast cancer represents a similar dilemma for those patients who might benefit but cannot afford the out-of-pocket expenses. Indeed, NICE originally denied approval to bortezomib, a highly active drug for the treatment of multiple myeloma, based upon similar cost considerations.

What ipilimumab, Avastin and bortezomib have in common is that they are harbingers of the coming conflict between patients-in-need and society’s capacity to cover the increasing costs of cancer therapy. Cost efficacy questions will only be resolved when we have the capacity to identify likely responders prior to therapy, enabling us to use drugs only in those patients with the highest expectations of response. Marginal overall benefits that come at high price will continue to fail until we redouble our efforts to refine the process of drug selection for individual patients. Janet Woodcock, MD, from the FDA once said, that we need “a critical path” from bench to bedside to guide clinical decisions. The human tumor primary culture functional analyses that we employ can provide that critical path and we would hope limit the need for the broad-brush policy decisions that are being handed down by NICE and similar entities both here in the U.S. and abroad.

The Avastin Saga Continues

We previously wrote about bevacizumab (Avastin) and its approval for breast cancer. The early clinical trials revealed evidence of improved time to disease progression. This surrogate measure for survival benefit had, over recent years, gained popularity, as time to disease progression is a measure of the impact of a given treatment upon the patient’s response durability. It was hoped and believed that time to progression would be an early measure of survival.

Unfortunately, the survival advantage for the Avastin-based therapies in breast cancer has not met statistical significance. As such, careful review by the oncology drug committee of the FDA lead to a unanimous decision to remove Avastin’s indication in breast cancer. Avastin has not been removed from the market, but instead, cannot be promoted or advertised, nor do insurers necessarily reimburse it. This decision, however, will have a very big impact on Medicare patients and many others who are in managed care programs (HMOs).

There are no villains here. Instead, dedicated physicians empowered to scrutinize the best data could not prove beyond any doubt that the drug improved survival. The time to progression data was favorable and the survival data also trended in a favorable direction. But, the final arbiter of clinical approval — statistically significant survival — was not met.

The physicians who want to provide this for the patients, the company that produces the drug and the patients who believe it offers benefit all have legitimate positions. As Jerome Groopman, MD, once said, in a similar situation with regard to the FDA approval of interleukin 2 (a biological agent with profound activity in a small minority of melanoma and renal cell cancer patients), “I am confronted with a dilemma of biblical proportions, how to help the few at the expense of the many.”

The Avastin saga is but one example of what will occur repeatedly. The one-size-fits-all paradigm is crumbling as individual patients with unique biological features confront the results of the blunt instrument of randomized clinical trials. Our laboratory has been deeply involved in these stories for 20 years. When we first observed synergy for purine analogs (2CDA and fludarabine) with cytoxan, and then recommended and used this doublet in advanced hematologic malignancies (highly successfully, we might add) we were a lone voice in the woods. Eventually, clinical trials conducted at M.D. Anderson and other centers confirmed the activity establishing these treatments as the standards of care for CLL and low-grade lymphoma.

The exact same experience occurred in our solid tumor work when we combined cisplatin plus gemcitabine in pancreatic, ovarian, breast, bladder, lung and other cancers. While our first patient (presumably the first patient in the world) received cisplatin plus gemcitabine for drug-resistant recurrent ovarian cancer in 1995 — providing her an additional five years of life — it wasn’t until 2006 that the FDA approved the closely related carboplatin plus gemcitabine for this indication.

We now confront an even greater hurdle. With our discoveries, using novel combinations of targeted agents, we are years (perhaps decades) ahead of the clinical trial process. We know that patients evaluated in our laboratory with favorable profiles can respond to some of the newest drugs, many of which have already completed Phase I of clinical trials. It is our fervent belief that we could accelerate the drug development process if we could join with the pharmaceutical companies and the FDA to put these hypotheses to a formal test.

Again, there are no villains here. Patients want, and should, receive active drugs. Doctors should be allowed to give them. The drug companies want to sell their agents and the FDA wants to see good therapies go forward.

The rancor that surrounds these emotionally charged issues will best be resolved when we introduce techniques that match patients to active therapies. We believe that the primary culture platform used in our laboratory, and a small number of dedicated investigators like us, may be the answer to this dilemma.

We will redouble our efforts to apply these methods for our patients and encourage our patients to lobby their health care insurers and representatives to sponsor these approaches. To date, we have been unsuccessful in convincing any cooperative group to test the predictive ability of these selection methodologies. In response, I reiterate that I will gladly participate and, to the best of my ability, support at least the laboratory component of any fair test of our primary culture methodologies.

We stand at the ready for the challenge.

Not Responding to the Standard Cancer Treatment? Maybe You’re an Outlier

In a recent reply to a blog comment, I mentioned the term “outlier” to describe a woman with breast cancer who had an excellent response to bevacizumab-based therapy. This was part of a discussion about the drug and its role in cancer treatment. The term outlier was utilized to describe this woman’s excellent response to a drug combination that has not achieved statistically significant survival advantage in the general population of breast cancer patients.

While outliers may connote strangeness or removal from the norm, in contemporary cancer therapies being removed from the norm can be a very, very good thing. After all, a minority of cancer patients benefit durably from chemotherapy. Those patients fortunate enough to have long-term responses are the happy outliers who populate the scientific community’s grab bag of anecdotes.

However, to the individual patient, a good response is much more than an anecdote, it is a life saving experience, an experience that every cancer patient richly deserves. While clinical trials are designed to identify average improvements for average patients, virtually every trial conducted has patients who live much longer than average. They constitute the tail on the survival curve and almost every trial has several.

Our job should be to identify those true responders and treat them appropriately rather than denying them active treatments based on the failure of the average patient paradigm. In statistics, the term applied for these failures are “beta errors,” meaning that the investigators missed the benefit of a given treatment. By identifying active treatments in small subsets of patients, functional analytic tools (like the Rational Therapeutics EVA-PCD platform) enable us to select those small subsets for treatment regardless of average expectations.

A Tale of Two Lung Cancers

I was recently asked to speak at a community outreach mixer to describe our work in lung cancer. I invited two patients to join me:

1. A woman in her early 50s who presented to medical attention with metastatic adenocarcinoma of the lung with brain involvement.
2. A woman in her early 60s, also with metastatic adenocarcinoma with brain involvement.

Under the microscope their tumors appeared almost identical. But, in the laboratory, the profiles were distinctly different. Patient no. 1 revealed a highly sensitive profile to the EGFR-TKI erlotinib (Tarceva) that was demonstrably enhanced by VEGF inhibition (e.g. Bevacizumab, Avastin). The second patient was resistant to erlotinib and VEGF inhibition, but was highly sensitive to the doublet of platinum plus gemcitabine.

Both patients attended the mixer and spoke to the crowd. They both looked the picture of health, sporting their own hair with no significant toxicities from therapy. Both had completed Cyberknife brain radiation and had gone on to exactly the right treatment for them. Despite their similarities in presentation and histology, their treatments were extremely different. Yet, both have had excellent and durable responses.

Every lung cancer patient has the capacity to do well. It is our job to find out which drugs and combinations are most likely to achieve that end. Functional profiling provided both of these patients exactly the right treatment for them. With the Rational Therapeutics EVA-PCD platform, every patient is treated as an individual.

What’s Wrong with Avastin?

Nothing really. It’s a wonderful drug that incorporates the brilliant insights originally articulated by Judah Folkman, MD, at Harvard University. Dr. Folkman reasoned that:

1. Cancers require oxygen and nutrients
2. These would need to be delivered by a blood supply
3. Tumors would avidly seek their own blood supply via humoral factors.

His groundbreaking work ultimately lead to the discovery of VEGF, as well as the FDA approval of Avastin, the monoclonal antibody that binds and inactivates circulating VEGF in patients. The problem isn’t with Avastin, it’s with the practice of oncology – the clinical trial process and the muddied waters that surround clinical utility of any drug, new or old.

There are no perfect drugs. There are simply drugs that work for certain patients. VEGF down-regulation is an attractive and highly appropriate therapy for a subset of cancer patients with many different diagnoses whose tumors use the VEGF pathway to their advantage. Avastin combined with carboplatin and taxol has improved the survival of lung cancer patients. Avastin plus folfox has improved survival for colon cancer patients. Avastin plus chemotherapy improves the survival of some breast cancer patients. The problem is that it doesn’t improve the survival of all breast cancer patients.

When the FDA rules on the clinical utility of a drug, they use a broad-brush approach that looks at the global outcomes of all patients, determining whether these glacial trends reflect a true climate change. The problem is that while Bethesda, Maryland may not be noticing significant changes in ocean levels, people who live on the Maldives are having a very different experience. As these scientists ponder the significance of Avastin, some breast cancer patients are missing out on a treatment that could quite possibly save their lives.

One breast cancer patient’s life saving therapy is another’s pulmonary embolism without clinical benefit. Until such time as cancer patients are selected for therapies predicated upon their own unique biology, we will confront one Avastin after another. Our solution to this problem has been to investigate the VEGF targeting agents in each individual patient’s tissue culture, alone and in combination with other drugs, to gauge the likelihood that vascular targeting will favorably influence each patient’s outcome. Our results to date in patients with non-small cell lung cancer, colorectal cancer and even rare tumors (like medullary carcinoma of the thyroid) suggest this to be a highly productive direction for future development.