The Changing Landscape in Non-small Cell Lung Cancer (NSCLC)

In October 2012, we published a study of patients with metastatic NSCLC whose treatment was guided by EVA-PCD laboratory analysis. The trial selected drugs from FDA approved, compendium listed chemotherapies and every patient underwent a surgical biopsy under an IRB-approved protocol to provide tissue for analysis.

The EVA-PCD patients achieved an objective response rate of 64.5 percent (2-fold higher than national average, P < 0.0015) and median overall survival of 21.3 months (nearly 2-fold longer than the national average of 12.5 months).

Non-small cell lung cancer

Non-small cell lung cancer

The concept of conducting biopsies in patients with metastatic NSCLC was not only novel in 2004, it was downright heretical. Physicians argued forcefully that surgical procedures should not be undertaken in metastatic disease fearing risks and morbidity. Other physicians were convinced that drug selection could not possibly improve outcomes over those achieved with well-established NCCN guidelines. One oncologist went so far as to demand a formal inquiry. When the hospital was forced to convene an investigation, it was the co-investigators on the IRB approved protocol and the successfully treated patients who ultimately rebuffed this physician’s attempt to stifle our work.

With the publication of our statistically superior results and many of our patients surviving more than 5 years, we felt vindicated but remain a bit battle scarred.

I was amused when one of my study co-authors (RS) recently forwarded a paper authored at the University of California at Davis about surgical biopsies and tumor molecular profiling published by The Journal of Thoracic and Cardiovascular Surgery. This single institution study of twenty-five patients with metastatic NSCLC reported their experience-taking patients with metastatic disease to surgical biopsy for the express purpose of selecting therapy. Sixty four percent were video assisted thoracic (VATS) wedge biopsies, 16 percent pleural biopsies, 8 percent mediastinoscopies, 12 percent supraclavicular biopsies and 8 percent rib/chest wall resections. Tissues were submitted to a commercial laboratory in Los Angeles for genomic profiling.

The authors enthusiastically described their success conducting surgical procedures to procure tissue for laboratory analysis. Gone was the anxiety surrounding the risk of surgical morbidity. Gone were the concerns regarding departure from “standard” treatment. In their place were compelling arguments that recapitulated the very points that we had articulated ten years earlier in our protocol study. While the platforms may differ, the intent, purpose and surgical techniques applied for tissue procurement were exactly the same.

What the Cooke study did not describe was the response rate for patients who received “directed therapy.” Instead they provide the percent of patients with “potentially targetable” findings (76 percent) and the percent that had a “change in strategy” (56 percent) as well as those that qualified for therapeutic trials (40 percent). Though, laudable, changing strategies and qualifying for studies does not equal clinical responsiveness. One need only examine the number of people who are “potential winners” at Black Jack or those who “change their strategies” (by changing tables/dealers for example) or, for that matter, those who qualify for “high roller status” to understand the limited practical utility of these characterizations.

Nonetheless, the publication of this study from UC Davis provides a landmark in personalized NSCLC care. It is no longer possible for oncologists to decry the use of surgical biopsies for the identification of active treatments.

As none of the patients in this study signed informed consents for biopsy, we can only conclude that the most august institutions in the US now view such procedures as appropriate for the greater good of their patients. Thus, we are witness to the establishment of a new paradigm in cancer medicine. Surgical biopsies in the service of better treatment are warranted, supported and recommended. Whatever platform, functional or genomic, patient-directed therapy is the new normal and the landscape of lung cancer management has changed for the better.

With Cancer, Don’t Ask the Experts

I was recently provided a video link to a December 2013 TEDx conference presentation entitled, “Big Data Meets Cancer” by Neil Hunt, product manager for Netflix. Mr. Hunt’s background has nothing to do with cancer or cancer research. His expertise is in technology, product development, leadership and strategy and has personally shepherded Netflix to its current market dominance. With his background and lack of expertise in cancer, he is an ideal person to examine cancer research from a fresh perspective.

The Long Tail of CancerMr. Hunt begins with a (admittedly) simplistic look at cancer research today. Because he is a data guy, naïve to all of the reasons why cancer cannot be cured, he can look anew at how it might be cured. Using a graphic, he defines cancer as “a long-tail disease” made up of outliers. He points out that most 20th century medical successes have been in the common diseases that fall close to the thick end of the curve. As one moves to the less common illnesses data becomes more scant. Echoing a new conceptual thinking, he points out that cancer is not a single disease but many, possibly thousands.  His concept is to accumulate all of the individual patient data to allow investigators to explore patterns and trends: a bottom up model of cancer biology. Many of his points bear consideration.

For those of you who have read these blogs, you know that I am an adherent to the concept of personalized cancer care. I have articulated repeatedly that cancer patients must be treated as individuals. Each tumor must be profiled using available platforms so that time and resources will not be wasted. We have used the same term “N-of-1” (a clinical trial for one patient) that Mr. Hunt uses in his discussion. He provides two anecdotes regarding patients who benefitted dramatically from unexpected treatment choices. His rallying cry is that contemporary clinical trials are failing. Again, this is an issue that I have addressed many times. He then describes broad-brush clinical protocols as the “tyranny of the average.”

The remainder of the discussion focuses upon possible solutions. Among the obvious hurdles:
1.    Cancer centers are hesitant to share data.
2.    The publication process is slow.
3.    Few are willing to publish negative trials.

To counter these challenges, he points out that small organizations are more incentivized to share and that successes in long-tail diseases can resurrect failed drugs, thereby repaying the costs. Several points were particularly resonant as he pointed out that early adopters face outsized resistance but their perseverance against adversity ultimately evolves the field. He sees this as a win-win-win scenario with patients receiving better care, physicians witnessing better outcomes, and pharmaceutical companies gaining more rapid approval of drugs.

As I watched, it occurred to me that Mr. Hunt was articulating many points that we have raised for over the last decade. As an outsider, he can see, only too clearly, the shortcomings of current methods. His clear perceptions reflect the luxury of distance from the field he is describing. Mr. Hunt’s grasp of cancer research is direct and open-minded. Many problems need fresh eyes. Indeed as we confront problems as complex as cancer it may be best not to ask the experts.

Truly Personalized Cancer Care

In the mid 1980s, it became apparent to me that cancer did not result from uncontrolled cell proliferation, but instead from the lack of cell death. Yet, cancer research labored for almost a century under the erroneous belief that cancer represented dysregulation of cell proliferation. Today, we confront another falsehood: the complexities and redundancies of human tumor biology can be easily characterized based on genomic analyses.

The process of carcinogenesis reflects the accumulation of cellular changes that provide a selective survival advantage to transformed cells.  However, the intricate circuitry that provide these survival advantages, reflect harmonic osolations between DNA, RNA and protein. Put simply, Genotype does not equal Phenotype. It is the phenotype that determines biological behavior and clinical response in cancer. Thus, it is overly simplistic to imagine that a DNA profile by itself can provide more than a fraction of the information required to make individual patient treatment decisions.

Colon cancer

Colon cancer

When therapies are based on genomic analysis, only a portion of the patient’s profile is taken into consideration. These analyses disregard the environmental, epigenetic and proteomic factors that make each of us individuals. Though useful prognostically and applicable in select circumstances where a unique genetic perturbation leads to a clinical response (c-ABL and Imatinib response in CML), genomic analyses provide only a veneer of information.

The Rational Therapeutics Ex Vivo Analysis – Programmed Cell Death™ (EVA-PCD) assay focuses upon the complexity of human tumors by measuring cell death, the end result of all cellular mechanisms of response and resistance acting in concert. By incorporating cell-cell, vascular, stromal and inflammatory elements into the tumor response assessment, the EVA-PCD platform provides a robust surrogate for human tumor response. While much of modern cancer research pursues the question of “Why” cancer arises, the clinical oncologist must confront the more practical question of “How” the best outcome can be achieved.

Assay-directed therapy is truly personalized cancer care providing treatments unique to the individual.

 

Reblogged from February 2010.

The Frustrating Reality – When a Tumor Sample isn’t Sufficient for Testing

A dying leukemia cell

A dying leukemia cell

The principles underlying the Rational Therapeutics EVA-PCD platform reflect many years of development. Recognizing the importance of cell death measures — apoptotic and non-apoptotic — our laboratory dismissed growth-based assays. The closure of Oncotech, the principal purveyor of proliferation-based assays, illustrates the demise of a failed paradigm in the study and testing of human tumor biology. A second principal of our work is the need to examine all of the operative mechanisms of cell death (autophagic, necrotic, etc.). Laboratories that measure only one mechanism of cell death (e.g. caspase activation as a measure of apoptosis) miss important cell responses that are critical to the accurate prediction of clinical response. The third principle of our work is the maintenance of cells in their native state.

These fundamentals provide the basis of our many successes, but also a constraint. Because we do not propagate, subculture or expand tissues, we can only work with the amounts of tissue provided to us by our surgeons. While some labs propagate small biopsy samples into larger populations by growth to confluence, this introduces irreconcilable artifacts, which diminish the quality of sensitivity profiles. Avoiding this pitfall, however, demands that a tissue sample be large enough (typically 1cm3) to provide an adequate number of cells for study without growth or propagation.

This is the reason our laboratory must request biopsies of adequate size. The old computer dictum of “garbage in, garbage out” is doubly true for small tissue samples. Those that contain too few tumor cells, are contaminated, fibrotic or inadequately processed will not serve the patients who are so desperately in need of therapy selection guidance. As a medical oncologist, I am deeply disappointed by every failed assay and I am more familiar than most with the implications of a patient requiring treatment predicated on little more than intuition or randomization.

We do everything within our power to provide results to our patients. This sometimes requires low yield samples be repeatedly processed. It may also set limitations on the size of the study or, in some circumstances, forces us to report a “no go” (characterized as an assay with insufficient cells or insufficient viability). Of course, it goes without saying that we would never charge a patient for a “no-go” assay beyond a minimal set up fee (if applicable). But, more to the point, we suffer the loss of an opportunity to aid a patient in need.

Cancer patients never undergo therapy without a tissue biopsy. Many have large-volume disease at presentation, so it is virtually always possible to obtain tissue for study if a dedicated team of physicians makes the effort to get it processed and submitted to our laboratory. The time and energy required to conduct an excisional biopsy pales in comparison to the time, energy and lost opportunities associated with months of ineffective, toxic therapy.

What is Cancer Research?

According to Wikipedia, cancer research is “basic research into cancer in order to identify causes and develop strategies for prevention, diagnosis, treatments and cure.” At face value this seems self-evident, yet “cancer research” means different things to different people.

Most cancer patients think of cancer research as the effort to achieve the best possible outcome for individual patients. Taxpayers and donors to charitable organizations also tend to view the process through the lens of therapeutics. But patient treatment is but a small part of cancer research. One of the largest cancer research organizations, the American Cancer Society, was the subject of an investigative report by Channel 2 in Atlanta, Georgia. They found that this billion dollar organization spent 32% of the money it raised on raising money. What of the other 68%? How much of that money actually goes to patient care? When one factors in education, transportation, administration, PR, salaries and basic research, actual patient care support is close to the bottom of the list.

More instructive is an examination of how people engaged in cancer research define their work. On one side are clinical investigators (trialists) who administer the treatments developed in the laboratories of scientists after pre-clinical analyses. On the other side are the basic researchers whose job it is to answer questions and resolve scientific dilemmas. They are granted enormous amounts of money to delve into the deepest intricacies of cancer biology, genomics, transcriptomic and proteomics in an effort to better understand the etiology (causation) of this dreaded disease.

Well Tray Closeup2 small In examining this disjointed field, I considered my own area of work. I am a clinical investigator who also conducts research in a laboratory. As such, I straddle the fence between basic research and clinical science. This is increasingly dangerous ground, as the gap between scientists and clinicians grows wider by the day. Most clinical investigators have, at best, a passing understanding of molecular biology, and most molecular biologist have absolutely no idea what clinical medicine is. This is unfortunate, for it is the greater blending of science with clinical therapy that will lead to better outcomes. Pondering this dichotomy I recognized that my job is first and foremost to save lives and to alleviate suffering. For me, the laboratory is a means to an end. It is a tool that I use to resolve clinical questions. What drug, what combination, what sequence? These questions are best answered in the laboratory, not in patients, wherever possible.

For the basic scientist the task is to answer a question. For them the laboratory is an end unto itself. They use multiple parameters to examine the same question from different angles, seeking to control every variable. A good scientific paper will use genomic (DNA), transcriptomic (RNA), and proteomic (protein expression) analyses until the issues have all been resolved to their satisfaction. In the literature this is known as “elegant” science. The operative term here is control. The scientist controls the experiment, controls the environment, controls the outcome, and controls the publication process. They are in charge.

What of the poor clinical investigator, who must, per force of necessity, be humble. They are not in control of the clinical environment and rarely understand the intricacies of the metabolic, genomic and proteomic events taking place before their eyes. They must approximate, sometimes guess and then act. For the clinician, the laboratory is an opportunity to answer practical real-world questions, not nuanced theoretical principles.

The greatest criticism that a scientist can level at an opponent is a lack of focus, defined as the inability to drill down onto the essence of the question. These scientists sit on study sections, review manuscripts and fund grants. Over decades they have been allowed to define the best research as the most narrowly focused. Incrementalists have out-stripped, out-funded and out-maneuvered big thinkers. While basic researchers examine which residue on the EGFr domain becomes phosphorylated, clinical physicians must do hand-to-hand combat with the end result of these mutations: non-small cell lung cancer.

Medical history instructs that big questions are best answered when prepared minds (William Withering, Ignaz Semmelweis, etc.) pursue scientific answers to real clinical questions. Unfortunately, today’s clinicians have been relegated to the role of “hypothesis testers.” This has led to a profusion of blind alleys, failed clinical trials and the expenditure of billions of dollars on extremely “interesting questions.”

George Bernard Shaw said, “England and America are two countries separated by a common language.” Increasingly, cancer research has become two distinctly different disciplines divided by a common name.

The Rising Cost of Cancer Research: Is It Necessary?

JCO coverFor anyone engaged in developmental therapeutics and for those patients who need new approaches to their cancers, an editorial in the Journal of Clinical Oncology casts a disturbing light on the field The authors examine the impact of the growing research bureaucracy upon the conduct of clinical trials. They use Thomas Edison, who filed 1,093 U.S. patents, to exemplify successful trial and error research. By inference, they suggest that if Mr. Edison were working today in the modern regulatory environment we would all be reading this blog by candlelight. While much of Edison’s work focused upon household conveniences like light bulbs and phonographs, the principals that underlie discovery work are every bit the same.

Although regulations have been put in place to protect human subjects, the redundancies and rigorous re-reviews have outstripped their utility for the patients in need. The process has become so complex  that it is now necessary for many institutions to use professional organizations to conduct trials that could easily have done in the past by an investigator with a small staff. These clinical research organizations (CRO’s) are under the gun to adhere to an ever growing collection of standards. Thus, every detail of every consent form is pored over sometimes for years. This has had the effect of driving up the cost of research such that the average Phase III clinical trial conducted in the 1990s that cost $3,000 to $5,000 per accrued patient, today costs between $75,000 and $125,000 per patient. Despite this, the safety of individuals is no better protected today than it was 30 years ago when all of this was done easily and cheaply.

While funding for cancer research has increased slowly, the cancer research bureaucracy has exploded. One need only visit any medium to large size hospital or university medical center to witness the expansion of these departments. Are we safer? Do our patients do better? The answer is a resounding “No.” In 2013, according to the authors,  the average patient spent a mere 53 seconds reviewing their consent forms before signing them, while the average parent, signing on behalf of their child, spent only 13 seconds.

The take home messages are several. First, the regulatory process has become too cumbersome. Were this the cost of scientific advance we would accept it as a fact of life, but patients are not safer, trials are not faster and outcomes are not being enhanced. Second, the cancer research process has overwhelmed and undermined cancer researchers. In keeping with Pournelle’s Iron Law of Bureaucracy, “. . . in any bureaucratic organization there will be two kinds of people: those who work to further the actual goals of the organization, and those who work for the organization itself.”Is there anyone who donates to the American Cancer Society who wants their money to go toward more regulation?

The problem is not with the academic physician. Medical scientists want to do studies. Marching alongside are the patients who are desperate to get new treatments. While many criticize the pharmaceutical industry, it is highly unlikely that these companies wouldn’t relish the opportunity to see their drugs enter the market expeditiously. Standing between patients and better clinical outcomes is the research bureaucracy. Should we fail to arrest the explosive growth in regulatory oversight we will approach a time in the near future when no clinical trials will be conducted whatsoever.

The Meaning of Meaningful Improvement in Lung Cancer

When asked to define what constituted pornography in his 1964 Supreme Court decision (Jacobellis versus Ohio 1964) Justice Potter Stewart stated, “I know it when I see it.” When I reviewed an article on the changing landscape of clinical trials in non-small cell lung cancer (NSCLC) (Shifting patterns in the interpretation of phase 3 clinical trial outcomes in advanced non-small cell lung cancer: The bar is dropping, Sacher A. G. et al, J Clin Oncol May 10, 2014), Justice Stewart came to mind.

The authors selected 203 NSCLC trials from a total of 245 studies conducted between 1980 and 2010. They compared how often the studies met their endpoints with how often the study authors’ called the results “positive.” Among the findings, it seems that earlier studies (before the year 2000) were geared for overall survival, while later studies (after 2000) overwhelmingly favored progression free survival. Although patient survivals changed little, the number of trials reported as successful increased dramatically.

Non-small cell lung cancer

Non-small cell lung cancer

Progression-free survival measures how long it takes for a patient to fail treatment. That is, for the disease to worsen on therapy. Its use increased after 2000 when Docetaxel, for the first time, provided a survival advantage in recurrent disease.

The FDA’s willingness to accept progression-free survival for drug approval was originally based on their expectation that the benefit would be “substantial and robust” but they did not define the term. One group has suggested that improvements should be of the magnitude of 50 percent. Another went even further suggesting a doubling of the survival advantage.

Unfortunately, the trend has been just the opposite. Trials from the 1980s on average gave a 3.9 month improvement, which fell to a meager 0.9 months after 2000.

What are patients and their physicians to make of these trends? First, the large clinical trials, that are so common today, are much more likely to achieve significance. The troubling corollary is that statistical significance is not the same as clinical relevance. The “publish or perish” climate, combined with the skyrocketing cost of drug development has placed inordinate demands upon investigators and their sponsors to achieve “positive results.” Fearing failure, many pharmaceutical companies sponsor “safe” trials that provide incremental advances but few breakthroughs.

Meaningful advances in oncology are generally quite evident. The first use of Interferon alpha for the treatment of hairy cell leukemia provided a response rate of 100 percent and earned a lead article in the New England Journal of Medicine (NEJM) with only seven patients!

Similarly the 57 percent response rate for Crizotinib in ALK positive lung cancer required only 82 patients for a place in the NEJM. Unfortunately, the failure of contemporary investigators to identify more “paradigm changing therapies” has forced many to lower the bar.

The clear solution to the problem is the better selection of candidates for therapy. Despite advances in molecular biopsy a paucity of truly effective companion diagnostics exist. Outside of EGFR, ALK, and ROS-1, it is anybody’s guess how to manage the vast majority of non-small cell lung cancer patients.

While we expand our armamentarium and develop better companion diagnostics, today we can apply measures of cellular response (as found in an EVA-PCD assay)
that capture all of operative mechanisms of sensitivity for all classes of drugs. While it is not always possible to know why a patient will respond, it is possible to know that they will respond. In the words of Judge Stewart, when it comes to a responsive lung cancer patient “I know it when I see it.”

Every Cancer Patient’s Outcome is Important

Clinical oncologists can be divided into different camps. There are those who see patient outcomes as a means-to-an-end. Each clinical response provides a data point and when those data points reach critical mass they become reportable. These are the trialists. They see the world through a utilitarian lens. They use aggregate data, through sufficient patient accrual, to achieve significance. This, they hope, will lead practice-changing observations. Trialists populate academic centers and an ever-expanding number of “mega medical groups” that are now gobbling up private oncology practices. They apply metrics to gauge success, as their focus has moved away from individual patient needs toward the achievement of a “greater good” for the population as a whole. Statistical significance is the currency of their realm and clinical protocols their preferred tool.

In the other camp reside physicians, that dwindling cadre of doctors whose principal focus is the good response of each individual patient. They are the practitioners who eke out a living in an environment of diminishing returns. Having relinquished both autonomy and income over recent years, their one remaining reward is the benefit they can bring to each patient. With neither the desire nor ability to publish their results, individual patient survival becomes their paramount goal. Their job is to alleviate suffering, provide comfort and sponsor the health of their clients. Patients preparing to meet with a cancer specialist should consider carefully who is treating them – and why.

I was reminded of this when a 48-year-old gentleman recently requested an opinion. He had presented to an emergency room with a month-long history of sharp abdominal pain. The CT scan revealed extensive intra-abdominal disease, which upon endoscopic biopsy, proved to be of gastric (stomach) origin. He was immediately referred to an accomplished university-based clinical investigator for consultation.

Metastatic gastric cancer is a very difficult disease to treat. One bright spot has been the discovery that 20 percent of patients carry an epidermal growth factor receptor (HER-2) mutation that enables them to receive Herceptin-based therapy. As luck would have it, this patient did not carry the HER-2 mutation. The university investigator explained that there were limited treatment options. In light of his metastatic presentation, the doctor felt that aggressive, multi-agent chemotherapy might only engender toxicity. The patient was offered either single agent 5-FU for palliation or the opportunity to participate in a clinical trial. The patient considered his options and chose to seek an opinion with me.

20 percent response rateI reviewed the patient’s status and explained that while the opinion of the university investigator was valid it might underestimate the patient’s individual chance of response. I explained that gastric cancer statistics, like all medical statistics, are population based. That is, a 20 percent response rate does not mean that every patient gets 20 percent better, but instead, that 20 out of every 100 respond while 80 do not. Our job was to find out which group he belonged to.

The patient decided to undergo a biopsy and submitted tissue to Rational Therapeutics for EVA-PCD® analysis. The results were strikingly favorable with several drug combinations revealing both activity and synergy. After careful comparison, I recommended the combination of a Cisplatin, Taxotere and 5-FU (DCF), a regimen originally developed at the MD Anderson almost 10 years earlier.

On March 12th, the patient began treatment on an every-other-week schedule. As he did not circulate tumor markers like CEA or CA 19-9, there was no easy measure of his response so I elected to repeat the PET/CT after just two cycles. Much to my delight, the patient had achieved a complete remission with resolution of all measurable disease, including the bulky abdominal masses, numerous lymph nodes and the stomach. As I described the remarkable PET/CT results, the patient’s wife began to weep. Her husband, the father of their two young children, wasn’t dying after all. He was no longer a grim cancer statistic. With mother’s day approaching, this was the first good news that they had received in six months. At once, the patient began to discuss business trips, travel plans and family outings. He breathed a slow sigh of relief as he realized that, once again, he had a life.

Good outcomes, even in the worst diseases, occur in all oncology practices. Every doctor can regale you with the story of a patient who responded beautifully and went on to survive years beyond everyone’s expectations. The reason we remember these stories is because they occur so infrequently. Complete remissions in metastatic gastric cancer are vanishingly rare. That is the reason that the university investigator offered single agent 5-FU. It’s easy, nontoxic, well tolerated, but it also cures no one. The rationale is well established: Why poison patient’s you cannot cure? Playing the averages, this strategy is a winner. Yet, on an individual patient basis it may, in fact, be a very big loser.

What are we to do with the “non-average” patient? What about the outliers? Should we not, at least, try to find them? We do it with stocks, racehorses, Indy-drivers, real-estate investments and every underdog sports team in every league. It’s the outliers after all that we call winners.

Cancer patients are not clinical trial subjects. They are unique individuals with their own very unique biology. Every patient is an experiment in real time, an “N of 1.” We must respect the dignity of each individual and we are duty-bound to apply every tool at our disposal to assist him or her in the pursuit of his or her own very personal best outcome – providing truly personalized cancer treatment. This patient did not have a 20 percent response. Instead, he was one of the fortunate few who responded very well. And for him that response was 100 percent.

Cancer Patient’s Need to Know – Whose Avatar is it?

The 1984 celebrated case of Baby Fae described the efforts of intrepid investigators at Loma Linda University in California to save the life of an infant born with a hypoplastic heart (the left side of the heart was severely underdeveloped). To salvage this unfortunate child, the heart of a baboon was transplanted into her chest, which successfully maintained her cardiac function. Unfortunately, the child died 21 days later after rejecting the heart.

The experience nonetheless spawned a lively discussion of ethics in human experimentation and the lengths to which we will go to save a life. A friend residing in New York contacted me shortly thereafter. Knowing that I was in medical training in California, he was intrigued by this report and posed the question. “What is the fastest animal in the world?” When I suggested a cheetah or African gazelle, he answered “No, a baboon running past Loma Linda Medical Center.”

I am reminded of this quip following a news report about Champions Oncology. This biotech company located in Hackensack, NJ, founded by investigators from Johns Hopkins University has developed a technique to transplant human tumors into immunocompromised (known as nude for their loss of hair) mice to test drugs and combinations. They use the term “avatar” to describe these human-tumor-bearing mice and like their video-game counterparts these mice serve as surrogates for their patient “users.” It takes 20 to 30 mice to complete the analyses for each patient. Although the work is based on sound science, the practicality, predictive validity and ultimate utility of this approach has yet to be established. This has not dampened the enthusiasm of desperate cancer patients who have proven willing to spend tens of thousands of dollars to undergo a Champion analysis.

Nude-mouseSo what are the upsides of the avatar model? For one, this is a living organism with a functioning blood supply, liver, kidneys and the capability of metabolizing pro-drugs (precursor) into active species. The process utilizes cell clusters, not individual single cells in their analysis. Responses are ultimately “phenotypic” in as much as they reflect cellular responses to injury and not genotypic profiles. Finally, toxicities can also be assessed by measuring the animal’s tolerance of the drug or combination administered.

But let’s drill down for a moment and take a closer look. The avatar approach requires months of preparation, the operation of a vivarium (animal zoo) and several mice for every single drug or combination tested. It requires prolonged (many months) maintenance of the animals with highly unpredictable engraftment of the transplanted tumors. Furthermore, significant time, energy and skill are needed to maintain these in-vivo systems.

Ultimately, only a handful of drugs can be examined, lest the number of mice required becomes unmanageable. At the end of the day these investigators are making a valiant effort to approximate work that we, and our colleagues, have successfully conducted for more than two decades – the accurate selection of chemotherapies and drug combinations for individual patients.

If we allow for the obvious downsides of expense, difficulty, time, limited sample size, low efficiency and resource intensity required to conduct even a single patient’s study there are more daunting concerns.

First, these cells are not actually in their “native state.” Over a period of time the tumors will no longer be host to human immune cells, nor will they be exposed to human cytokines and VEGF. The observed growth of the implanted tumors in the mice-avatars may, in part, reflect an ingrowth of mouse-derived fibroblasts and blood vessels, which have distinctly different biology from those of a human host.

Even if we accept the expense and difficultly of avatars, there is no clear evidence on an individual patient basis, that this approach holds any advantage over the much simpler and direct evaluation of human primary culture microspheroids. That is, the avatar approach appears to be a difficult, cumbersome, inefficient and a very expensive way to do something that we can already do inexpensively, rapidly and efficiently. Further, the purported advantages of in vivo-avatar system are actually less than meets the eye.

After all, most clinical drugs have “active” derivatives that can be utilized for testing in short-term culture without the need for a mouse liver. Our careful calibration of in vitro drug exposures against actual patient responses (P < 0.001) has established the predictive validity of these culture conditions. Finally, the toxicities of virtually all clinically relevant drugs that patients would request for testing (and likely receive) are already well-known to clinicians from existing Phase I and Phase II clinical data sets.

Human tumor sensitivity to chemotherapy (or targeted agents) is driven by what might be described as “response elements.” These unique features of each patient’s tumor can be accurately probed at the phenotypic level through the use of simple assays conducted in short-term culture. Our microspheroid model has proven highly predictive of clinical outcome in virtually every tumor type ever tested.

Our analyses are conducted in seven days, with samples that are the same size or smaller than those required for avatar generation. Furthermore, short-term platforms can analyze dozens of drugs and combinations at a price that is far less expensive. While it might be argued that avatars, once established, can be used as repositories for future research, that is small comfort to patients in need of immediate answers who find themselves paying handsomely for a service that will not be available in a timely manner, e.g. that which can help them in their need for immediate drug selection.

It seems that the medical science community is less interested in results than process. The fact that short-term cultures are predictive of clinical outcome seems less important than the provocative scientific results that these avatar models can provide Avatars enable scientists to interrogate cancer cells for genomic and proteomic signals, offering the opportunity to conduct interesting science. But has that science become more important than the clinical utility of the tests that were purportedly developed (and sold) to improve patient outcomes?

Patients who are considering spending tens of thousands of dollars for these glorified chemosensitivity tests would do themselves a service to first carefully examine the predictive validity, breadth of data, cost and turn-around-time of short-term culture methods, like the EVA-PCD® assay before they commit their precious time and resources to so “interesting” an endeavor as an avatar analysis. After all, it is the patient and their good outcome that should be at the top of the list when the advantages of any system or method are being weighed. Truly personalized cancer care should be just that – personalized.

With the rise of avatars it may be timely to re-examine the original question and wonder whetherNude-mouse the fastest animal in the world will soon be a nude mouse running past Johns Hopkins University.

The False Economy of Genomic Analyses

Dr. Robert A. Nagourney:

While Dr. Nagourney is enjoying Spring Break with his family, here is a very topical subject in light of the constant press given to genetic testing.

Originally posted on Dr. Robert A. Nagourney - Rational Therapeutics - Blog:

We are witness to a revolution in cancer therapeutics. Targeted therapies, named for their capacity to target specific tumor related features, are being developed and marketed at a rapid pace. Yet with an objective response rate of 10 percent (Von Hoff et al JCO, Nov 2011) reported for a gene array/IHC platform that attempted to select drugs for individual patients we have a long way to go before these tests will have meaningful clinical applications.

So, let’s examine the more established, accurate and validated methodologies currently in use for patients with advanced non-small cell lung cancer. I speak of patients with EGFR mutations for which erlotinib (Tarceva®) is an approved therapy and those with ALK gene rearrangements for which the drug crizotinib (Xalkori®) has recently been approved.

The incidence of ALK gene rearrangement within patients with non-small cell lung cancer is in the range of 2–4 percent, while EGFR mutations…

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