The federal 'Right to Try' bill in the United States recently passed the House and requires Senate approval before it becomes law. The bill would provide patients access to experimental drugs and other products that have not received approval from the Food and Drug Administration (FDA), including stem cell treatments.
It's not enough to act on a hunch that it might work.
Most folks think this is a good thing, but several express concern over whether the law would truly help patients. Even if a company allows patients to access an experimental drug, an important question remains: Should a doctor prescribe it?
Before such a drug can be prescribed, the federal bill states that a physician must "certify" that the patient has exhausted all available treatments or does not meet the criteria for standard treatment. Even after determining eligibility, a physician needs to consider a few points first. It's not enough to act on a hunch that it might work. The concept of medical innovation could help doctors figure out if prescribing an experimental treatment is the right thing to do.
Medical innovation falls within the doctor's scope of practice. Based on their experience and sound scientific rationale, physicians can "innovate" and offer treatment tailored to a patient with the goal of improving health. This differs from the goal of clinical research, which is to produce generalizable knowledge, not necessarily to benefit patients. In medical specialties like surgery, many of the standard procedures were developed through medical innovation, not clinical trials. Under the 'Right to Try,' a physician could ethically prescribe an experimental therapy as medical innovation if the following conditions are met.
Medical innovation should follow similar ethical and scientific oversight as clinical research.
First, there must be sound scientific rationale, and evidence of safety and efficacy of the innovative treatment from preclinical (animal and lab) research or clinical (human) research. The 'Right to Try' bill permits access to experimental products only after safety is demonstrated from a phase 1 clinical trial. This initial testing, called "first in human," aims to determine safety and dosing of an experimental product on typically around 20 to 100 people who are healthy volunteers or have a condition. This way, a physician can be assured that there is some evidence indicating the product is safe.
Efficacy must be demonstrated in animal and lab preclinical studies in order to gain permission from the FDA to do a phase 1 trial in the first place. This way, a doctor can also be assured that sound scientific rationale exists indicating a potential benefit to the patient. Only through further phase 2 and 3 clinical trials on hundreds or more people would a doctor know with greater certainty that the therapy works, but this might take many more years.
A doctor should not completely rely on what others in the scientific community think about the experimental treatment and should have appropriate expertise. This includes knowledge about the disease, familiarity with treating such patients, and an understanding of how the experimental treatment works, including administering it.
Second, medical innovation should follow similar ethical and scientific oversight as clinical research. Physicians should write a protocol for administering the experimental therapy and have it reviewed by clinical, scientific, and ethics experts at their institution. A protocol would include all the information on how the doctor would provide the therapy to patients, including dosages, monitoring, what happens if there are side effects, and much more. The experts would examine various components of the plan, look at informed consent, and ensure a favorable benefit-to-risk ratio, among other aspects.
When weighing whether to prescribe an experimental treatment, doctors need to base this decision on sound science and relevant clinical experience, not on hope or desperation.
Third, doctors should properly inform their patients about the risks (including if the risks are unknown), possible benefits, and the details of the procedure to be undertaken, and they must obtain the patient's consent.
Fourth, physicians should thoroughly monitor and diligently document all aspects of the outcomes of the procedure, various clinical indicators, and adverse events. During the course of providing an experimental therapy, if harm to a patient occurs, the physician is obligated to alter the course of the treatment or stop it. Similarly, if evidence from an ongoing clinical trial shows that the experimental treatment might help some but not all patients, the doctor needs to modify the plan accordingly.
Fifth, upon completing the experimental treatment, physicians should publish their findings to share the knowledge. Note that medical innovation is not meant to replace clinical trials. The two can be complementary, and medical innovation can lead to the design of clinical trials to demonstrate safety and efficacy.
Other experts may not agree that it can be ethical for a physician to prescribe an unapproved drug. Such dissenters would claim that physicians should only prescribe medications when there is substantial scientific and clinical certainty that a product is safe and effective for patients. They are also likely to oppose most forms of medical innovation. Yet even after undergoing rigorous clinical trials, some approved products have been shown to be unsafe or ineffective and are removed from the market.
While it seems that more evidence is better, doctors need to be mindful that patients are suffering and some may never receive access to drugs still in the pipeline. Bound by the Hippocratic Oath – the main tenet being "do no harm" – doctors are obligated to prescribe therapies that will help their patients. When weighing whether to prescribe an experimental treatment, doctors need to base this decision on sound science and relevant clinical experience, not on hope or desperation. Given that patients who want to participate in the 'Right to Try' movement have exhausted all other options and their condition may be worsening, it would seem ethically appropriate for a physician to treat them with an experimental drug, as long as the criteria listed above are satisfied.
The views expressed are the author's personal views, and do not necessarily reflect the policy or position of Mayo Clinic.
In November 2020, messenger RNA catapulted into the public consciousness when the first COVID-19 vaccines were authorized for emergency use. Around the same time, an equally groundbreaking yet relatively unheralded application of mRNA technology was taking place at a London hospital.
Over the past two decades, there's been increasing interest in harnessing mRNA — molecules present in all of our cells that act like digital tape recorders, copying instructions from DNA in the cell nucleus and carrying them to the protein-making structures — to create a whole new class of therapeutics.
Scientists realized that artificial mRNA, designed in the lab, could be used to instruct our cells to produce certain antibodies, turning our bodies into vaccine-making factories, or to recognize and attack tumors. More recently, researchers recognized that mRNA could also be used to make another groundbreaking technology far more accessible to more patients: gene editing. The gene-editing tool CRISPR has generated plenty of hype for its potential to cure inherited diseases. But delivering CRISPR to the body is complicated and costly.
"Most gene editing involves taking cells out of the patient, treating them and then giving them back, which is an extremely expensive process," explains Drew Weissman, professor of medicine at the University of Pennsylvania, who was involved in developing the mRNA technology behind the COVID-19 vaccines.
But last November, a Massachusetts-based biotech company called Intellia Therapeutics showed it was possible to use mRNA to make the CRISPR system inside the body, eliminating the need to extract cells out of the body and edit them in a lab. Just as mRNA can instruct our cells to produce antibodies against a viral infection, it can also teach them to produce the two molecular components that make up CRISPR — a guide molecule and a cutting protein — to snip out a problem gene.
"The pandemic has really shown that not only are mRNA approaches viable, they could in certain circumstances be vastly superior to more traditional technologies."
In Intellia's London-based clinical trial, the company applied this for the first time in a patient with a rare inherited liver disease known as hereditary transthyretin amyloidosis with polyneuropathy. The disease causes a toxic protein to build up in a person's organs and is typically fatal. In a company press release, Intellia's president and CEO John Leonard swiftly declared that its mRNA-based CRISPR therapy could usher in a "new era of potential genome editing cures."
Weissman predicts that turning CRISPR into an affordable therapy will become the next major frontier for mRNA over the coming decade. His lab is currently working on an mRNA-based CRISPR treatment for sickle cell disease. More than 300,000 babies are born with sickle cell every year, mainly in lower income nations.
"There is a FDA-approved cure, but it involves taking the bone marrow out of the person, and then giving it back which is prohibitively expensive," he says. It also requires a patient to have a matched bone marrow done. "We give an intravenous injection of mRNA lipid nanoparticles that target CRISPR to the bone marrow stem cells in the patient, which is easy, and much less expensive."
Meanwhile, the overwhelming success of the COVID-19 vaccines has focused attention on other ways of using mRNA to bolster the immune system against threats ranging from other infectious diseases to cancer.
The practicality of mRNA vaccines – relatively small quantities are required to induce an antibody response – coupled with their adaptable design, mean companies like Moderna are now targeting pathogens like Zika, chikungunya and cytomegalovirus, or CMV, which previously considered commercially unviable for vaccine developers. This is because outbreaks have been relatively sporadic, and these viruses mainly affect people in low-income nations who can't afford to pay premium prices for a vaccine. But mRNA technology means that jabs could be produced on a flexible basis, when required, at relatively low cost.
Other scientists suggest that mRNA could even provide a means of developing a universal influenza vaccine, a goal that's long been the Holy Grail for vaccinologists around the world.
"The mRNA technology allows you to pick out bits of the virus that you want to induce immunity to," says Michael Mulqueen, vice president of business development at eTheRNA, a Belgium-based biotech that's developing mRNA-based vaccines for malaria and HIV, as well as various forms of cancer. "This means you can get the immune system primed to the bits of the virus that don't vary so much between strains. So you could actually have a single vaccine that protects against a whole raft of different variants of the same virus, offering more universal coverage."
Before mRNA became synonymous with vaccines, its biggest potential was for cancer treatments. BioNTech, the German biotech company that collaborated with Pfizer to develop the first authorized COVID-19 vaccine, was initially founded to utilize mRNA for personalized cancer treatments, and the company remains interested in cancers ranging from melanoma to breast cancer.
One of the major hurdles in treating cancer has been the fact that tumors can look very different from one person to the next. It's why conventional approaches, such as chemotherapy or radiation, don't work for every patient. But weaponizing mRNA against cancer primes the immune cells with the tumor's specific genetic sequence, training the patient's body to attack their own unique type of cancer.
"It means you're able to think about personalizing cancer treatments down to specific subgroups of patients," says Mulqueen. "For example, eTheRNA are developing a renal cell carcinoma treatment which will be targeted at around 20% of these patients, who have specific tumor types. We're hoping to take that to human trials next year, but the challenge is trying to identify the right patients for the treatment at an early stage."
Repairing Damaged mRNA
While hopes are high that mRNA could usher in new cancer treatments and make CRISPR more accessible, a growing number of companies are also exploring an alternative to gene editing, known as RNA editing.
In genetic disorders, the mRNA in certain cells is impaired due to a rogue gene defect, and so the body ceases to produce a particular vital protein. Instead of permanently deleting the problem gene with CRISPR, the idea behind RNA editing is to inject small pieces of synthetic mRNA to repair the existing mRNA. Scientists think this approach will allow normal protein production to resume.
Over the past few years, this approach has gathered momentum, as some researchers have recognized that it holds certain key advantages over CRISPR. Companies from Belgium to Japan are now looking at RNA editing to treat all kinds of disorders, from Huntingdon's disease, to amyotrophic lateral sclerosis, or ALS, and certain types of cancer.
"With RNA editing, you don't need to make any changes to the DNA," explains Daniel de Boer, CEO of Dutch biotech ProQR, which is looking to treat rare genetic disorders that cause blindness. "Changes to the DNA are permanent, so if something goes wrong, that may not be desirable. With RNA editing, it's a temporary change, so we dose patients with our drugs once or twice a year."
Last month, ProQR reported a landmark case study, in which a patient with a rare form of blindness called Leber congenital amaurosis, which affects the retina at the back of the eye, recovered vision after three months of treatment.
"We have seen that this RNA therapy restores vision in people that were completely blind for a year or so," says de Boer. "They were able to see again, to read again. We think there are a large number of other genetic diseases we could go after with this technology. There are thousands of different mutations that can lead to blindness, and we think this technology can target approximately 25% of them."
Ultimately, there's likely to be a role for both RNA editing and CRISPR, depending on the disease. "I think CRISPR is ideally suited for illnesses where you would like to permanently correct a genetic defect," says Joshua Rosenthal of the Marine Biology Laboratory in Chicago. "Whereas RNA editing could be used to treat things like pain, where you might want to reset a neural circuit temporarily over a shorter period of time."
Much of this research has been accelerated by the COVID-19 pandemic, which has played a major role in bringing mRNA to the forefront of people's minds as a therapeutic.
"The pandemic has really shown that not only are mRNA approaches viable, they could in certain circumstances be vastly superior to more traditional technologies," says Mulqueen. "In the future, I would not be surprised if many of the top pharma products are mRNA derived."
"Making Sense of Science" is a monthly podcast that features interviews with leading medical and scientific experts about the latest developments and the big ethical and societal questions they raise. This episode is hosted by science and biotech journalist Emily Mullin, summer editor of the award-winning science outlet Leaps.org.