The Precision Medicine Revolution Will Be Driven By Diagnostic Technologies
In the fight against cancer, the spending, praise, and focus have largely been on cancer therapies, rather than diagnostics. In 2018, Jim Allison won the Nobel prize for his work establishing that a novel pathway within a patient’s immune system could be harnessed to fight cancer. This transformative discovery reinvigorated the field of cancer immunotherapy and resulted in the launch of a revolutionary class of blockbuster therapies dubbed “checkpoint inhibitors.”
These expensive therapies are certainly invaluable, novel tools in the therapeutic armamentarium. However, they are often administered in later stages of disease progression and are far from a cure, typically prolonging a patient’s life a few months or a couple of years when used in combination with other therapies. So, how do we win the war on cancer? And how do we improve healthcare at large?
I’d argue that the answer lies within diagnostics technologies. Unacceptably, despite its major and increasing impact on medical decisions, diagnostic tests are now largely priced based on how much they cost, in sharp contrast to therapies that are priced based on their value. This discrepancy has significantly stifled innovation, and it needs to change, given what diagnostic technologies have to offer. This article highlights three examples of how diagnostics may radically transform patient outcomes within the lens of the patient journey: cancer early detection, improved cancer therapy selection and longitudinal monitoring.
Generally, cancer prognosis is more based on the stage of diagnosis than the therapy a patient receives. In the case of lung cancer, one of the most aggressive cancers, five-year survival is, dismally, around 5% if detected at stage 4, after metastasis. Standing in sharp contrast is the five-year survival rate when detected at stage 1, which is over 60%. When detected early, tumors may often be removed surgically.
How well do therapies fare? In its FDA filing for the drug Keytruda, Merck demonstrated improvement in survival of four and a half to eight months compared to chemotherapy for late-stage patients in its KEYNOTE-042 trial. A dramatic improvement in outcomes would be seen if we were able to detect all cancers at the earliest stages. As a result, this is an area of intense interest, with multiple technology companies working on being able to detect cancer at the earliest stages from a simple blood test. These companies have raised more than a combined $5 billion in VC funding in the last six years. In the next few years, we will most likely begin to see the approval of these tests for select populations at risk for certain cancers — for example, heavy smokers over a certain age for lung cancer. In the long run, the holy grail is the development of a “pan-cancer test” — a single test that detects a broad set of cancer types — that can be incorporated into annual physicals for all patients. The impact could transform cancer into a chronic disease, closely monitored, not unlike HIV. By the end of this decade, I predict that these early detection tests will impact cancer survival to a greater extent than therapies.
Some patients, however, will inevitably progress to later-stage disease. Again, diagnostic testing will help. Today, diagnostic tests can assess the uniqueness of a patient’s cancer to select the best therapy by assessing hundreds of genes, whereas 15 years ago, tumors were assessed for a handful of biomarkers. This shift, driven by a disruptive diagnostic tool called next-generation sequencing (NGS), enables clinicians to select the best drug combinations and to grasp a more complete understanding of the patient’s cancer and their immune response. While the increase in complexity of these tests has been staggering, this trend shows no sign of slowing down, as the complexity of biomarker signatures continues to increase (e.g., tumor mutational burden).
Lastly, once a patient has been treated and, hopefully, healed, precision diagnostics will enable that patient to be followed in a process of longitudinal monitoring (on a serial basis for a single patient) for what’s known as minimal residual disease, or MRD. Today, patients are primarily monitored for recurrence using conventional imaging technology with relatively limited sensitivity. MRD monitoring has started for patients with hematological cancers for potential recurrence. These blood tests have been shown to detect potential recurrence months before they appear on a CT scan. In many cases, starting a therapeutic course of treatment early may be the difference between life and death.
Diagnostics will act as an ally for patients through their cancer journey. These tests, now largely offered in silos by different companies, will become increasingly interconnected and analyzed to uncover new insights. Looking decades into the future, these repeat blood tests may seamlessly inform patient management.
Of note, while this article focuses on oncology, the same themes will percolate across diseases, and with additional diagnostic modalities, such as wearables. Sensors such as a simple watch now enable us to capture longitudinal information about our physiology at an unprecedented scale. Within neurology, for example, remote patient monitoring and wearables are helping to monitor for early onset and progression of neurodegenerative diseases such as Alzheimer’s or Parkinson’s, as well as mental health. There are products for cardiac disease, with the Apple watch being the highest-profile example, having received FDA clearance for determining the presence of atrial fibrillation. And regarding current events and infectious diseases, sensors as simple as smart thermometers may be used for real-time, community-level outbreak monitoring.
There is no doubt that therapeutics will continue to play a pivotal role in precision medicine, which will soon be known simply as “medicine.” But in the future, diagnostic technologies will matter just as much, and significantly improve the deployment of healthcare spending. As a result, precision medicine diagnostics need to be financially rewarded as the ally they are to patients and to our healthcare systems and receive appropriate payment to continue to fuel innovation.