Snippet of Science
A blog about medical innovations and news.
Snippet #8 | The state of biomarker testing in Europe
The promise of precision medicine - a targeted treatment approach based on an individual's genetic profile - is that it could lead to better health outcomes for patients and substantial healthcare savings through more effective therapies with reduced toxicities. The number of precision medicine drugs has grown over the past two decades, from 5 in 2008 to 132 in 2016, for a wide range of cancers (e.g. chronic myeloid leukemia, melanoma, non-small cell lung cancer, colorectal cancer, etc.)
The development of such targeted treatments goes hand in hand with the development of related companion diagnostics known as cancer biomarkers - molecules produced by cancer cells that are detected in fluids or tissue. Such biomarkers are essential to predict which particular patients may benefit from specific targeted drugs, and to monitor the course of a disease. Biomarker testing is now possible for numerous cancer types, but its adoption in clinical practice varies by region. In Europe, adoption has been slow, uneven, and underfunded. Although companion diagnostics (e.g. biomarker testing) influence 60% of clinical decision-making, they account for less than 2% of total healthcare spending. The unavailability of companion biomarker testing has at times even prevented patient access to certain approved targeted drugs.
Several challenges have hindered widespread equitable clinical adoption in the EU. These include unequal access to biomarker testing across countries; uneven availability of infrastructure for diagnostic testing, such as laboratories with advanced next generation sequencing capabilities; delays in getting test results (results can take from 6 days in Germany to up to 30 days in Romania); inconsistent reimbursement and limited healthcare budgets allocated for testing; slow updating of guidelines for clinical decisions; a lack of stringent, uniform regulatory requirements regarding approval of both drugs and their companion diagnostics; and uneven physician knowledge about biomarker testing. In fact, a survey conducted in 2016 by The European Cancer Patient Coalition (ECPC) found that biomarkers are largely unknown by patients and underutilized by physicians: 30% of patients were not familiar with biomarkers, and 60% were not proposed biomarker testing by their physicians.
What can be done to address these challenges? Several efforts are currently underway. New medical legislation set to go into effect in 2022 is expected to harmonize regulations across EU states, improving the timing and uniformity of approvals for targeted drugs and their companion diagnostic testing. Other solutions proposed by stakeholders include adapting regulatory frameworks to account for the importance of biomarkers; reallocating healthcare expenditures to biomarker testing, education and infrastructure; adapting reimbursement frameworks to include biomarkers; updating testing guidelines in a timely manner; and improving physician knowledge about biomarkers.
Such measures are critical for realizing the full potential of precision medicine, by translating research advances into actionable measures that could benefit both patients and healthcare systems.
Snippet #7 | Feeling the pressure?
February is American Heart Month, a federal event dating back to 1964 to raise awareness about cardiovascular health. This year, the Center for Disease Control (CDC) is putting the spotlight on hypertension (high blood pressure) and its role in heart health. The World Health Organization estimates that 1.13 billion people around the world have high blood pressure, and that fewer than 1 in 5 of them have it under control. This is an alarming figure, since hypertension is a risk factor for heart disease and stroke. And this number could be even higher, as proper blood pressure monitoring is often a challenge. To obtain more accurate and valuable data, novel technologies have recently been developed that enable people to easily and continuously monitor blood pressure (e.g. Aktiia’s novel medical-grade blood pressure monitoring bracelet), which can provide better estimates and improve treatment decisions.
Blood pressure is caused by a complex interplay of common lifestyle factors (e.g. diet, exercise, alcohol, smoking), but also, importantly, genetic ones. In fact, genetics account for 40% of the variation in blood pressure among people - and the genetics are complex, with a multitude of genes playing a role in blood pressure. Scientists have been working on discovering those underlying genes for years and using them in the development of novel treatments. In 2000, The Millennium Genome Project for Hypertension was launched to understand the root causes of hypertension and identify responsible genes, and in 2017, more than 100 new genes associated with hypertension were discovered.
But what does this all mean for people with hypertension? For one thing, identifying underlying genes can form the basis for new treatments. For another, it can play a crucial, and more immediate role, in predicting people's responses and side effects to existing treatments. With five major classes and more than 60 medications to choose from to treat hypertension (e.g. diuretics, angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), beta-blockers, and calcium channel blockers (CCB)), identifying the most effective and best tolerated treatments is currently a challenging process characterized by trial and error. As responses to different medications vary among patients, for reasons that include genetic variation, exploiting genetics has the potential to improve treatment effectiveness, leading to better health outcomes for patients and cost savings for healthcare systems.
In recent years, pharmacogenomics – the study of how genetics affects drug response – has grown rapidly in the field of hypertension, and a 2019 study of a large genetic database in the United Kingdom showed that genetic variants can be used to investigate the effectiveness and side effects of hypertension medications.
How quickly will these research innovations make it into clinical practice where they can help patients? Some of them already have, with genetic testing for hypertension having increased in the last couple of years. Geneticure, a personalized medicine company, is a pioneer in using genetic testing to guide hypertension treatment decisions. Blood pressure in patients prescribed medication recommended by Geneticure's genetic testing strategy was substantially lower than in patients whose medication did not match this recommendation. Meanwhile, more applications of genetics in hypertension are currently in the works in this rapidly growing field, with many new developments on the horizon in the upcoming years.
Snippet #6 | Toward a molecular taxonomy of cancer
In the 2008 book "The Innovator's Prescription," authors Clay Christensen, Jerome Grossman and Jason Hwang argued that a key factor for medical advances is the identification of root causes of complex diseases, such as cancer. To date, cancer has routinely been classified according to the organ in which it originates (e.g. breast, lung, prostate), and this classification serves to guide treatment decisions. More recently, scientists have been working on understanding the root causes of cancer, exploring it from a molecular, rather than organ of origin, angle. This is pushing the field of oncology toward a more molecular taxonomy of cancer.
The Pan-Cancer Atlas, a collaboration launched in 2012 with the support of the National Cancer Institute (NCI) and the National Human Genome Research Institute (NHGRI), has conducted over the past few years one of the largest analyses of the molecular origins of cancer. Researchers involved in the initiative analyzed more than 11,000 tumors from 33 types of cancer, comparing tumors based on cellular and genetic makeup to understand how different cancers relate to each other. Findings to date have revealed that cancers originating in different organs can share molecular commonalities. This is especially important given research and therapeutic advances in precision medicine, a model of medicine in which a patient's underlying genetic makeup informs diagnostics and treatment decisions.
Precision medicine drugs are developed to target specific molecular-level mutations that may be common across cancer types, meaning that treatment options developed for one type of cancer could be applicable to other types if shared mutations are discovered. An example is the precision medicine drug Lynparza (olaparib), originally approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) in 2014 to treat advanced ovarian cancer for patients with mutations in the BRCA1 and BRCA2 genes. It was later approved for metastatic BRCA-mutated breast cancer, and most recently, in 2019, for BRCA-mutated metastatic pancreatic cancer. The discovery that different types of cancer may have an underlying BRCA genetic mutation widened the applicability of Lynparza.
As the field of precision medicine continues to develop rapidly, it is becoming increasingly important for patients diagnosed with cancer to undergo tumor profiling (the testing of a tumor's genetic and biomarker makeup) in order to understand the most appropriate treatment options.
Snippet #5 | The emergence of liquid biopsies
When doctors suspect that a patient has cancer, they generally perform a tumor biopsy, which involves removing a tissue sample from the tumor. Tissue biopsy is currently the gold standard in cancer diagnosis and treatment, providing important information about tumor composition. However, this tool also has some drawbacks. The procedure is typically invasive, costly, and, depending on tumor location and patient condition, difficult to collect. It can also be challenging to maintain the genetic integrity of the sample for testing, as preservation agents may alter the sample's DNA. Moreover, since tissue biopsy samples are taken from certain areas of a tumor, they may not capture the heterogeneous genetic makeup of a tumor, preventing potentially effective precision medicine treatments.
In recent years, liquid biopsies, which are collected through a simple blood test, have emerged as potentially valuable complementary testing tools, since cancer sheds some of its cells and DNA into the blood. Liquid biopsies are less invasive, cheaper, and more representative of overall tumor heterogeneity. They can therefore be performed more frequently and may be used for early detection, treatment decisions, and patient monitoring. However, more research is needed before liquid biopsies can be widely adopted in clinical practice. In particular, more studies are required to evaluate the sensitivity of liquid biopsies (i.e. their ability to correctly identify individuals with a disease), since tumor cells and tumor DNA circulating in the blood are relatively rare compared to other blood molecules.
In 2020, the US Food and Drug Administration (FDA) approved the first two liquid biopsy diagnostic tests that use next-generation sequencing technology (NGS), for use alongside tissue biopsies in clinical practice. The first is Guardant 360 CDx, a test developed by Guardant Health, and the second is FoundationOne Liquid CDx, developed by Foundation Medicine. They are primarily used to detect non-small cell lung cancer and solid tumors, by identifying mutated cancer cell DNA circulating in the blood.
While tissue biopsies still provide important information directly from the tumor, liquid biopsies are emerging as increasingly valuable complementary tools in the detection and treatment of cancer.
Snippet #4 | DNA could hold the key for data storage
Genomic data, which contains information on individuals' sequenced genetic codes (DNA), plays a key role in advancing precision medicine - the approach of developing therapies that take into account one's underlying genetic makeup. But finding storage space for the vast amounts of genomic data produced is increasingly challenging. It takes roughly 100 GB of space to store one individual's DNA, and scientists are estimating that 1 billion people will sequence their genomes by 2025. Genomic data could soon generate up to 40 exabytes of data annually (one exabyte equals 1 billion GB). Genomic data are currently stored in physical storage facilities, or through cloud services, which are housed on physical servers throughout the world.
Amidst these growing data storage demands, the concept of DNA storage stands out as a potentially promising solution. Scientists at the Swiss Federal Institute of Technology have recently discovered a way to encode digital data directly onto DNA itself. Though DNA storage technology is still in the early stages of development, it holds a lot of potential: DNA can store enormous amounts of data in a very small space (1 gram of DNA holds up to 455 exabytes of data), it is highly durable (lasting tens of thousands of years compared to the 50 years of current digital storage systems), and it does not need electricity. As with any new technology, there are obstacles to overcome to achieve the full potential of DNA storage. Presently, storage costs are still very high ($12,400/MB stored), and the process of encoding data onto DNA is slow. But scientists believe that both cost and encoding time will decrease significantly over the next decade.
How exactly does DNA storage work? Computers use binary code (1s and 0s) to store data digitally. In order to store it onto DNA, such digital data is converted into the language of DNA (a four letter alphabet - A, C, G, T - representing the four nucleotides that make up DNA). A machine then reads this sequence to produce a DNA molecule. To turn it back into readable digital data, a sequencing machine reads back the DNA language, and a computer program converts that language into binary code that computers can interpret. See more here.
DNA storage has vast applications (an excerpt from Dr. Martin Luther King Jr.'s "I have a dream" speech and William Shakespeare's sonnets were recently stored onto DNA), and its potential for the field of genomics, when realized, could be huge.
Snippet #3 | Pfizer and BioNTech's vaccine brings hope
Earlier this week, as COVID-19 cases continue to soar around the world, Pfizer and BioNTech, a German cancer precision medicine biotech company, announced that their vaccine is 90% effective at preventing the disease. Scientists have expressed cautious optimism that this news could signal the light at the end of the tunnel for the ongoing pandemic, which has ravaged economies around the globe and has so far led to 1.31M deaths worldwide.
The Pfizer - BioNTech vaccine is an mRNA vaccine. It operates by injecting parts of the virus' genetic material (mRNA) into our cells, which leads to the creation of proteins that mimic the SARS-CoV-2 virus and train our immune systems to build a defense to it. It accomplishes this through two doses, which are spaced three weeks apart.
Despite the positive news, many open questions still remain, regarding the vaccine's strength and length of protection, its production, storage, and distribution, vaccine uptake, who should be vaccinated first, and whether the vaccine can effectively block transmission, i.e. stop vaccinated people from being contagious to others if infected. More time, analysis and vaccine trials are necessary to answer these questions, which are crucial to ending the pandemic.
The Pfizer - BioNTech vaccine is only one of a number of vaccines in late-stage trials around the world in the race to end the deadly pandemic, aiming to receive emergency authorization from the FDA by the end of November. Other vaccine candidates currently under development come from Johnson & Johnson; Moderna Therapeutics and NIH; AstraZeneca and University of Oxford; and Medicago and GSK. Among other things, such as contact tracing and therapeutics, the success of these vaccines, developed at unheard-of-before speeds, will play a vital role in ending the pandemic.
Snippet #2 | PanCAN to accelerate pancreatic cancer research
Pancreatic cancer is one of the most lethal forms of cancer. With few discernible symptoms in its early stages, it is often caught late, when curative surgery is no longer an option. Standard chemotherapies that are effective against other cancers often do not work well against pancreatic tumors, and newer targeted therapies that fight specific genetic mutations also have limited success. This is because unlike some other cancers that are predominantly caused by one genetic mutation, pancreatic cancer tumors tend to have many cancer-causing mutations. This makes it difficult to enroll enough patients in traditional clinical trials, and it also means that pharmaceutical companies have few incentives to develop therapies for small subsets of patients. (For more information, see https://www.mskcc.org/news/why-pancreatic-cancer-so-hard-treat)
The Pancreatic Cancer Action Network (PanCAN), founded in 1999, is a patient advocacy organization whose mission is to fight pancreatic cancer. It does so by supporting research and clinical initiatives, and by providing free, personalized patient support. One of its services, called Know Your Tumor, offers patients biomarker testing of tumor tissue to help determine their best therapeutic options.
To address the challenges associated with developing therapies for pancreatic cancer, PanCAN, in collaboration with Novartis, has launched a new, innovative adaptive clinical trial approach, called Precision Promise. Its goal is to disrupt the current clinical trial system and accelerate progress through a quicker, more efficient and patient-centric approach to drug development. The trial is open and enrolling patients at multiple top cancer institutions in the United States.
To find out more, see: https://www.pancan.org/
Snippet #1 | How citizen science helps advance Alzheimer's research
Citizen science has emerged as a practice through which the public can make real contributions to scientific knowledge. Stall Catchers is an exciting citizen science initiative to help accelerate research on Alzheimer’s disease. Scientists at Cornell University found initial evidence of links between clogged blood vessels that reduce blood flow in the brain (or stalls), and Alzheimer’s disease.
But to further understand this connection and explore whether it could ultimately lead to new treatments, they needed to analyze enormous amounts of brain scan data, more than they could feasibly do on their own. The scientists enlisted the help of crowdsourcing experts from the Human Computation Institute, and together they launched the online game Stall Catchers to harness the power of citizen scientists worldwide to identify stalls in brain images.
To date, the project has been hugely successful in attracting millions of contributors, leading the effort to analyze in one hour what scientists in the lab could analyze in one week, and providing training data to teach machines to contribute as well and speed up research even more.
For a recent research update from scientists using the efforts of Stall Catchers volunteers, see: https://www.youtube.com/watch?v=L7WGg6-cZF8.
Play Stall Catchers and contribute to Alzheimer’s research: https://stallcatchers.com/main