Looking Beyond Translation

An article in the May 3, 2012, New England Journal of Medicine, (NEJM) from the Mount Sinai School of Medicine and Mayo Clinic, examined the concept of translational research and its largely unfulfilled mission.  (Gelijns AC, Gabriel SC. Looking Beyond Translation – Integrating Clinical Research with Medical Practice. NEJM 2012; 366:1659–1661).  These investigators reviewed many of the precepts of clinical research and described mechanisms by which outcomes could be improved. Among the points they raised is the need to integrate clinical research with clinical practice to create “patient-centered, science-driven healthcare.”

Despite their academic credentials, Drs. Gelijns and Gabriel recognized that academic medical settings are not always conducive to conducting clinical research. They also describe the lack of incentives for clinical physicians to undertake research studies.  They go on to examine the need to refocus medical education onto a science of healthcare delivery. Finally, they decry the performance metrics by which clinical physicians are gauged (tests performed and numbers of patients seen) and contrast that with the equally unsatisfactory metrics for academicians (grants received and papers published). We couldn’t agree more.

While many of the points raised are worthwhile, these authors fail to grasp the fundamental problem at hand. Falling back on the age-old adage that pediatric malignancies have been cured through the clinical trial process, they criticize the adult oncology physicians for their lack of accrual. Their focus on participation in clinical trials as the highest accomplishment to which a medical oncologist might aspire is misguided and misleading. Grinding patients through ill-conceived clinical trials is no way to cure cancer. What are needed are intelligent solutions to complex problems. Complexity by its nature precludes the use of linear reasoning in the solution of problems. So complex is the cancer problem that investigators long since abdicated insights for statistical significance hoping that by throwing enough patients onto protocols, discernible patterns will emerge.

Childhood cancers have not been cured by protocols. They have been cured because they are curable. The average pediatric malignancy manifests a small number of mutational changes. Founder clones identified within these tumors can be eradicated even with the blunt instrument of contemporary chemotherapy. It is not an accident that childhood leukemia is curable, but instead a manifestation of the cells of origin.  Childhood ALL, the most common pediatric malignancy is a prime example. Hematopoietic elements by nature are good at dying. Chemotherapy just helps them along.

As we move from pediatric oncology to adult oncology however, we encounter a horse of a different color. There are the common adult tumors like colon and lung that have accumulated a myriad of perturbations over a lifetime of exposures and genetic errors. The pathway back to normality is fraught with hazards and the founder clones are often numerous and diverse.

To meaningfully advance cancer therapeutics we need wholly new conceptual frameworks that connect complex systems to available solutions. Analytic platforms that can reproduce human tumor biology in the laboratory will provide clinicians the targets for treatment, the results they seek and the incentive to participate in clinical trials.

No One is More Interested in Curing Your Cancer Than You

A diagnosis of cancer thrusts a, heretofore, healthy individual into the strange and unfamiliar territory of medical oncology. Many of my patients describe this transition as “entering the cancer bubble.” Suddenly, you are on the inside and everyone on the outside is talking at you about what to do, where to go, whom to see, and what treatments to receive.

From the inside of the bubble however, all of this has a hollow ring as you ponder many options, few good and some, positively frightening. Unfortunately, few patients have the time to complete a MD, or PhD, between diagnosis and the initiation of treatment. Lacking the requisite expertise, they turn to the “authorities” for advice.

Depending on which “authority” one consults, the recommendations may be colored by prejudices and biases. Some physicians adhere strictly to the National Comprehensive Cancer Network guidelines. Others insist upon accrual to Cooperative Group and Phase II trials. University-based investigators will often recommend developmental studies. And some physicians will follow the path of least resistance, examining such issues as cost, chair time and reimbursement, before considering what treatment to deliver.

It is in this milieu, that patients find themselves adrift. Who exactly should you trust? What is their motivation? To put it crassly, when they recommend a specific treatment, what’s in it for them: Cooperative Group points (provided to the most active accruers), academic accolades (the currency of junior faculty), cost containment (the purview of the managed care physicians), or finally, profit margins? Yes, there are a small number of physicians whose choices reflect their own pecuniary interests.

The antidote to all this uncertainty lies within each patient; answers to vexing questions crying out to be heard. These answers reflect the biologic features of each individual’s tumor. What pathway, what repair mechanism, what survival signal drives your tumor? No one has a perfect answer, not the genomic investigators (despite their protestations to the contrary), nor the immunohistochemists, despite the significant appeal of the platform. And not the immunologist (despite brilliant progress in this field over recent years). The closest approximation to human tumor biology is, well, human tumor biology. Using cellular constructs, in the form of native state microspheroids, we can today approximate the response profiles of patients undergoing systemic therapies. Using systems approaches to complex questions, the multitude of factors that contribute to objective response can be examined and elucidated.

No test is perfect. No patient is guaranteed a good outcome. Yet, doubling the objective response rate, and as we and others have documented, improving the time to progression and overall survival can be achieved with available methodologies that apply functional profiling to individual tumors.

No one would walk away from an investment formula that doubled the value of their portfolio. Few would turn down the opportunity to enhance their real estate positions predicated on reliable information from a realtor. Yet everyday, physicians convince patients to walk away from available, published, established methods that can improve response rates, diminish toxicities and avoid futile care. In this environment it is critical for patients to take charge of their own cancer management. Patients must not be dissuaded from seeking the best possible outcomes. Physicians, no matter how well intentioned, are human. Their opinions can be colored by misconceptions and an incomplete understanding of the questions at hand. Laboratory analysis empowers patients to make smart decisions.

In the game of cancer we need all the help we can get. After all, no one is more interested in saving your life than you.

Gee (G719X) Whiz: Novel Mutations and Response to Targeted Therapies

In a recent online forum a patient described her experience using Tarceva as a therapy for an EGFR mutation negative lung cancer. For those of you familiar with the literature you will know that Lynch and Paez both described the sensitizing mutations that allow patients with certain adenocarcinoma to respond beautifully to the small molecule inhibitors.  The majority of these mutations are found in Exon 19 and Exon 21, within the EGFR domain. Response rates for the EGFR-TKI (gefitinib and erlotinib) clearly favor mutation positive patients. Depending upon the study, mutation positive patients have response rates from 53 – 100 percent, generally around 70 percent, while mutation negative response patients have a response rate of 0 – 25 percent, generally about 10 percent.So why don’t all the mutation positive patients respond and conversely why do some mutation negative patients respond?

The story outlined in this online forum gives some insight. The individual in question carried a rare, and only recently recognized, Exon 18 mutation known as a G719X. This uncommon form of mutation had previously been unknown and few laboratories knew to test for it. Nonetheless, G719X positive patients respond to erlotinib and related agents. Indeed, there may be reason to believe that the more potent irreversible EGFR/HER2 dual inhibitor HKI-272, may be even more selective for this point mutation.

The excellent and durable response described by this individual, would not have been possible had the patient’s first physician followed the rules. That is, had her physician refused to give erlotinib to an (putatively) EGFR mutation negative patient she might well not be here to tell her story. More to the point, her good response (a clinical observation) led to the next level of investigation, namely the identification of this specific EGFR variant

The lessons from this experience are numerous. The first is that cancer biology is complex and, to paraphrase E.O. Wilson, was not put on earth for us to necessarily figure it out. The second, is that molecular biologists can only seek and identify that which they know about apriori.  To wit, if you don’t know about it (G719X) and you don’t have a test for it, and you don’t know to look for it, then it’s a virtual certainty that you aren’t going to find it.

The premise of our work at Rational Therapeutics is that the observation of a biological signal identifies a candidate for therapy whether we understand or recognize the target. Crizotinib was originally developed as a clinical therapy for patients who carried the CMET mutation. Serendipity led to the recognition that the responding subpopulation was actually carrying a heretofore-unrecognized ALK gene rearrangement. Sorafenib was originally evaluated for the treatment of BRAF mutation positive diseases. Yet it was the drug’s cross-reactivity with the VGEF tyrosine kinases that lead to its broad clinical applications. Each of these phenomena represents accidental successes. Were it not for the clinical observation of response in patients, the investigators conducting these trials would have been unlikely to make the discoveries that today provide such good clinical responses in others.

To put it quite simply, these patients and their disease entities educated the molecular biologists.

When we first identified lung cancer as a target for gefitinib, and began to administer the closely related erlotinib to lung cancer patients, neither Lynch nor Paez had identified the sensitizing EGFR mutations. That had absolutely no impact upon the excellent responses that we observed. It didn’t matter why it worked, but that it worked.  While the EGFR story has now been well-described, might we not use functional analytical platforms (functional profiling) to gain insights into the next, and the next generation of drugs and therapies that target pathways like MEK, ERK, SHH, FGFR, PI3K, etc., etc., etc. . . .

What is Personalized Cancer Therapy?

Personalized therapy is the right treatment, at the right dose for the right patient. Like the weather, however, it seems that everyone’s talking about it, but no one is doing anything about it.

In its simplest form personalized care is treatment that is designed to meet an individual’s unique biological features. Like a key in a lock, the right drug or combination opens the door to a good outcome.

When over the years I lectured on the development of the cisplatin/gemcitabine doublet, my two boys were quite young. I would show a slide depicting a doorknob with a key in the keyhole. I likened our lab’s capacity to identify sensitivity to the cisplatin/gemcitabine combination as “unlocking” an individual’s response.

At the time my wife and I would leave the key in the inside of the front door enabling us to unlock it when going out. We reasoned at the time that our 2-year-old would not be strong enough, nor tall enough to turn the key and let himself outside.  We reasoned wrong, for one day our son Alex reached up, turned the key and opened the door right in front of us. Lesson learned: Given the right key, anyone can open a door.

I continued my analogy by saying that even Arnold Schwarzenegger would be unable to open a door given the wrong key, but might, if he continued trying, snap it off in the lock.

The right key is the right treatment, effortlessly unlocking a good response, while the wrong key is the wrong treatment more often than not too much, too late, akin to a solid tumor bone marrow transplant.

In recent years, personalized care has come to be considered synonymous with genomic profiling. While we applaud breakthroughs in human genomics today, there is no molecular platform that can match patients to treatments.  The objective response rate of just 10 percent, almost all in breast and ovarian cancer patients in one study (Von Hoff J Clin Oncol 2010 Nov 20:28(33): 4877-83), suggests that cancer biology is demonstrably more complex than an enumeration of its constituent DNA base pairs. The unilateral focus on this area of investigation over others might be described as “the triumph of hope over experience” (James Boswell, Life of Samuel Johnson, 1791).

But hope springs eternal and with it the very real possibility of improving our patients outcomes. By accepting, even embracing, the complexity of human tumor biology we are at the crossroads of a new future in cancer medicine.

William Withering (1741-1799) the English physician and botanist credited with discovering digitalis as the therapy for dropsy, e.g. congestive heart failure (An Account of the Foxglove and some of its Medical Uses, Withering W. 1785), had absolutely no idea what a membrane ATPase was, when he made his remarkable discovery. It didn’t matter. Cardiac glycosides provided lifesaving relief to those who suffered from this malady for fully two centuries before Danish scientist, Jens Christian Skou, identified these membrane bound enzymes, for which he was awarded a Nobel Prize in 1997.

Similarly, penicillin, aspirin, and morphine were in all use for decades, centuries, even millenia before their actual modes of action were unraveled. Medical doctors must use any and all resources at their disposal to meet the needs of their patients. They do not need to know “how” something works so much as they (and their patients) need to know “that” it works.

The guiding principle of personalized medicine is to match patients to therapies. Nowhere in this directive is there a prescription of the specific platform to be used. Where genomic signatures provide useful insights for drug selection, as they do in APL (ATRA, Arsenic trioxide); NSCLC (EGFr, ROS1, ALK); CML (Imatinib, Dasatanib) then they should be used.

However, in those disease where we haven’t the luxury of known targets or established pathways, i.e. most human malignancies, then more global assessments of human tumor biology should, indeed must, be used if we are to meet the needs of our patients.  Primary culture analyses like the EVA/PCD® provide a window onto human tumor biology. They are vehicles for therapy improvement and conduits for drug discovery.  Scientists and clinicians alike need to apply any and all available methodologies to advance their art. The dawn of personalized medicine will indeed be bright if we use all the arrows in our quiver to advance clinical therapeutics and basic research.