The Algorithm Will See You Now
There's a quiet revolution going on in medicine. It's driven by artificial intelligence, but paradoxically, new technology may put a more human face on healthcare.
AI's usefulness in healthcare ranges far and wide.
Artificial intelligence is software that can process massive amounts of information and learn over time, arriving at decisions with striking accuracy and efficiency. It offers greater accuracy in diagnosis, exponentially faster genome sequencing, the mining of medical literature and patient records at breathtaking speed, a dramatic reduction in administrative bureaucracy, personalized medicine, and even the democratization of healthcare.
The algorithms that bring these advantages won't replace doctors; rather, by offloading some of the most time-consuming tasks in healthcare, providers will be able to focus on personal interactions with patients—listening, empathizing, educating and generally putting the care back in healthcare. The relationship can focus on the alleviation of suffering, both the physical and emotional kind.
Challenges of Getting AI Up and Running
The AI revolution, still in its early phase in medicine, is already spurring some amazing advances, despite the fact that some experts say it has been overhyped. IBM's Watson Health program is a case in point. IBM capitalized on Watson's ability to process natural language by designing algorithms that devour data like medical articles and analyze images like MRIs and medical slides. The algorithms help diagnose diseases and recommend treatment strategies.
But Technology Review reported that a heavily hyped partnership with the MD Anderson Cancer Center in Houston fell apart in 2017 because of a lack of data in the proper format. The data existed, just not in a way that the voraciously data-hungry AI could use to train itself.
The hiccup certainly hasn't dampened the enthusiasm for medical AI among other tech giants, including Google and Apple, both of which have invested billions in their own healthcare projects. At this point, the main challenge is the need for algorithms to interpret a huge diversity of data mined from medical records. This can include everything from CT scans, MRIs, electrocardiograms, x-rays, and medical slides, to millions of pages of medical literature, physician's notes, and patient histories. It can even include data from implantables and wearables such as the Apple Watch and blood sugar monitors.
None of this information is in anything resembling a standard format across and even within hospitals, clinics, and diagnostic centers. Once the algorithms are trained, however, they can crunch massive amounts of data at blinding speed, with an accuracy that matches and sometimes even exceeds that of highly experienced doctors.
Genome sequencing, for example, took years to accomplish as recently as the early 2000s. The Human Genome Project, the first sequencing of the human genome, was an international effort that took 13 years to complete. In April of this year, Rady Children's Institute for Genomic Medicine in San Diego used an AI-powered genome sequencing algorithm to diagnose rare genetic diseases in infants in about 20 hours, according to ScienceDaily.
"Patient care will always begin and end with the doctor."
Dr. Stephen Kingsmore, the lead author of an article published in Science Translational Medicine, emphasized that even though the algorithm helped guide the treatment strategies of neonatal intensive care physicians, the doctor was still an indispensable link in the chain. "Some people call this artificial intelligence, we call it augmented intelligence," he says. "Patient care will always begin and end with the doctor."
One existing trend is helping to supply a great amount of valuable data to algorithms—the electronic health record. Initially blamed for exacerbating the already crushing workload of many physicians, the EHR is emerging as a boon for algorithms because it consolidates all of a patient's data in one record.
Examples of AI in Action Around the Globe
If you're a parent who has ever taken a child to the doctor with flulike symptoms, you know the anxiety of wondering if the symptoms signal something serious. Kang Zhang, M.D., Ph.D., the founding director of the Institute for Genomic Medicine at the University of California at San Diego, and colleagues developed an AI natural language processing model that used deep learning to analyze the EHRs of 1.3 million pediatric visits to a clinic in Guanzhou, China.
The AI identified common childhood diseases with about the same accuracy as human doctors, and it was even able to split the diagnoses into two categories—common conditions such as flu, and serious, life-threatening conditions like meningitis. Zhang has emphasized that the algorithm didn't replace the human doctor, but it did streamline the diagnostic process and could be used in a triage capacity when emergency room personnel need to prioritize the seriously ill over those suffering from common, less dangerous ailments.
AI's usefulness in healthcare ranges far and wide. In Uganda and several other African nations, AI is bringing modern diagnostics to remote villages that have no access to traditional technologies such as x-rays. The New York Times recently reported that there, doctors are using a pocket-sized, hand-held ultrasound machine that works in concert with a cell phone to image and diagnose everything from pneumonia (a common killer of children) to cancerous tumors.
The beauty of the highly portable, battery-powered device is that ultrasound images can be uploaded on computers so that physicians anywhere in the world can review them and weigh in with their advice. And the images are instantly incorporated into the patient's EHR.
Jonathan Rothberg, the founder of Butterfly Network, the Connecticut company that makes the device, told The New York Times that "Two thirds of the world's population gets no imaging at all. When you put something on a chip, the price goes down and you democratize it." The Butterfly ultrasound machine, which sells for $2,000, promises to be a game-changer in remote areas of Africa, South America, and Asia, as well as at the bedsides of patients in developed countries.
AI algorithms are rapidly emerging in healthcare across the U.S. and the world. China has become a major international player, set to surpass the U.S. this year in AI capital investment, the translation of AI research into marketable products, and even the number of often-cited research papers on AI. So far the U.S. is still the leader, but some experts describe the relationship between the U.S. and China as an AI cold war.
"The future of machine learning isn't sentient killer robots. It's longer human lives."
The U.S. Food and Drug Administration expanded its approval of medical algorithms from two in all of 2017 to about two per month throughout 2018. One of the first fields to be impacted is ophthalmology.
One algorithm, developed by the British AI company DeepMind (owned by Alphabet, the parent company of Google), instantly scans patients' retinas and is able to diagnose diabetic retinopathy without needing an ophthalmologist to interpret the scans. This means diabetics can get the test every year from their family physician without having to see a specialist. The Financial Times reported in March that the technology is now being used in clinics throughout Europe.
In Copenhagen, emergency service dispatchers are using a new voice-processing AI called Corti to analyze the conversations in emergency phone calls. The algorithm analyzes the verbal cues of callers, searches its huge database of medical information, and provides dispatchers with onscreen diagnostic information. Freddy Lippert, the CEO of EMS Copenhagen, notes that the algorithm has already saved lives by expediting accurate diagnoses in high-pressure situations where time is of the essence.
Researchers at the University of Nottingham in the UK have even developed a deep learning algorithm that predicts death more accurately than human clinicians. The algorithm incorporates data from a huge range of factors in a chronically ill population, including how many fruits and vegetables a patient eats on a daily basis. Dr. Stephen Weng, lead author of the study, published in PLOS ONE, said in a press release, "We found machine learning algorithms were significantly more accurate in predicting death than the standard prediction models developed by a human expert."
New digital technologies are allowing patients to participate in their healthcare as never before. A feature of the new Apple Watch is an app that detects cardiac arrhythmias and even produces an electrocardiogram if an abnormality is detected. The technology, approved by the FDA, is helping cardiologists monitor heart patients and design interventions for those who may be at higher risk of a cardiac event like a stroke.
If having an algorithm predict your death sends a shiver down your spine, consider that algorithms may keep you alive longer. In 2018, technology reporter Tristan Greene wrote for Medium that "…despite the unending deluge of panic-ridden articles declaring AI the path to apocalypse, we're now living in a world where algorithms save lives every day. The future of machine learning isn't sentient killer robots. It's longer human lives."
The Risks of AI Compiling Your Data
To be sure, the advent of AI-infused medical technology is not without its risks. One risk is that the use of AI wearables constantly monitoring our vital signs could turn us into a nation of hypochondriacs, racing to our doctors every time there's a blip in some vital sign. Such a development could stress an already overburdened system that suffers from, among other things, a shortage of doctors and nurses. Another risk has to do with the privacy protections on the massive repository of intimately personal information that AI will have on us.
In an article recently published in the Journal of the American Medical Association, Australian researcher Kit Huckvale and colleagues examined the handling of data by 36 smartphone apps that assisted people with either depression or smoking cessation, two areas that could lend themselves to stigmatization if they fell into the wrong hands.
Out of the 36 apps, 33 shared their data with third parties, despite the fact that just 25 of those apps had a privacy policy at all and out of those, only 23 stated that data would be shared with third parties. The recipients of all that data? It went almost exclusively to Facebook and Google, to be used for advertising and marketing purposes. But there's nothing to stop it from ending up in the hands of insurers, background databases, or any other entity.
Even when data isn't voluntarily shared, any digital information can be hacked. EHRs and even wearable devices share the same vulnerability as any other digital record or device. Still, the promise of AI to radically improve efficiency and accuracy in healthcare is hard to ignore.
AI Can Help Restore Humanity to Medicine
Eric Topol, director of the Scripps Research Translational Institute and author of the new book Deep Medicine, says that AI gives doctors and nurses the most precious gift of all: time.
Topol welcomes his patients' use of the Apple Watch cardiac feature and is optimistic about the ways that AI is revolutionizing medicine. He says that the watch helps doctors monitor how well medications are working and has already helped to prevent strokes. But in addition to that, AI will help bring the humanity back to a profession that has become as cold and hard as a stainless steel dissection table.
"When I graduated from medical school in the 1970s," he says, "you had a really intimate relationship with your doctor." Over the decades, he has seen that relationship steadily erode as medical organizations demanded that doctors see more and more patients within ever-shrinking time windows.
"Doctors have no time to think, to communicate. We need to restore the mission in medicine."
In addition to that, EHRs have meant that doctors and nurses are getting buried in paperwork and administrative tasks. This is no doubt one reason why a recent study by the World Health Organization showed that worldwide, about 50 percent of doctors suffer from burnout. People who are utterly exhausted make more mistakes, and medical clinicians are no different from the rest of us. Only medical mistakes have unacceptably high stakes. According to its website, Johns Hopkins University recently announced that in the U.S. alone, 250,000 people die from medical mistakes each year.
"Doctors have no time to think, to communicate," says Topol. "We need to restore the mission in medicine." AI is giving doctors more time to devote to the thing that attracted them to medicine in the first place—connecting deeply with patients.
There is a real danger at this juncture, though, that administrators aware of the time-saving aspects of AI will simply push doctors to see more patients, read more tests, and embrace an even more crushing workload.
"We can't leave it to the administrators to just make things worse," says Topol. "Now is the time for doctors to advocate for a restoration of the human touch. We need to stand up for patients and for the patient-doctor relationship."
AI could indeed be a game changer, he says, but rather than squander the huge benefits of more time, "We need a new equation going forward."
Scientists Are Growing an Edible Cholera Vaccine in Rice
The world's attention has been focused on the coronavirus crisis but Yemen, Bangladesh and many others countries in Asia and Africa are also in the grips of another pandemic: cholera. The current cholera pandemic first emerged in the 1970s and has devastated many communities in low-income countries. Each year, cholera is responsible for an estimated 1.3 million to 4 million cases and 21,000 to 143,000 deaths worldwide.
Immunologist Hiroshi Kiyono and his team at the University of Tokyo hope they can be part of the solution: They're making a cholera vaccine out of rice.
"It is much less expensive than a traditional vaccine, by a long shot."
Cholera is caused by eating food or drinking water that's contaminated by the feces of a person infected with the cholera bacteria, Vibrio cholerae. The bacteria produces the cholera toxin in the intestines, leading to vomiting, diarrhea and severe dehydration. Cholera can kill within hours of infection if it if's not treated quickly.
Current cholera vaccines are mainly oral. The most common oral are given in two doses and are made out of animal or insect cells that are infected with killed or weakened cholera bacteria. Dukoral also includes cells infected with CTB, a non-harmful part of the cholera toxin. Scientists grow cells containing the cholera bacteria and the CTB in bioreactors, large tanks in which conditions can be carefully controlled.
These cholera vaccines offer moderate protection but it wears off relatively quickly. Cold storage can also be an issue. The most common oral vaccines can be stored at room temperature but only for 14 days.
"Current vaccines confer around 60% efficacy over five years post-vaccination," says Lucy Breakwell, who leads the U.S. Centers for Disease Control and Prevention's cholera work within Global Immunization Division. Given the limited protection, refrigeration issue, and the fact that current oral vaccines require two disease, delivery of cholera vaccines in a campaign or emergency setting can be challenging. "There is a need to develop and test new vaccines to improve public health response to cholera outbreaks."
A New Kind of Vaccine
Kiyono and scientists at Tokyo University are creating a new, plant-based cholera vaccine dubbed MucoRice-CTB. The researchers genetically modify rice so that it contains CTB, a non-harmful part of the cholera toxin. The rice is crushed into a powder, mixed with saline solution and then drunk. The digestive tract is lined with mucosal membranes which contain the mucosal immune system. The mucosal immune system gets trained to recognize the cholera toxin as the rice passes through the intestines.
The cholera toxin has two main parts: the A subunit, which is harmful, and the B subunit, also known as CTB, which is nontoxic but allows the cholera bacteria to attach to gut cells. By inducing CTB-specific antibodies, "we might be able to block the binding of the vaccine toxin to gut cells, leading to the prevention of the toxin causing diarrhea," Kiyono says.
Kiyono studies the immune responses that occur at mucosal membranes across the body. He chose to focus on cholera because he wanted to replicate the way traditional vaccines work to get mucosal membranes in the digestive tract to produce an immune response. The difference is that his team is creating a food-based vaccine to induce this immune response. They are also solely focusing on getting the vaccine to induce antibodies for the cholera toxin. Since the cholera toxin is responsible for bacteria sticking to gut cells, the hope is that they can stop this process by producing antibodies for the cholera toxin. Current cholera vaccines target the cholera bacteria or both the bacteria and the toxin.
David Pascual, an expert in infectious diseases and immunology at the University of Florida, thinks that the MucoRice vaccine has huge promise. "I truly believe that the development of a food-based vaccine can be effective. CTB has a natural affinity for sampling cells in the gut to adhere, be processed, and then stimulate our immune system, he says. "In addition to vaccinating the gut, MucoRice has the potential to touch other mucosal surfaces in the mouth, which can help generate an immune response locally in the mouth and distally in the gut."
Cost Effectiveness
Kiyono says the MucoRice vaccine is much cheaper to produce than a traditional vaccine. Current vaccines need expensive bioreactors to grow cell cultures under very controlled, sterile conditions. This makes them expensive to manufacture, as different types of cell cultures need to be grown in separate buildings to avoid any chance of contamination. MucoRice doesn't require such an expensive manufacturing process because the rice plants themselves act as bioreactors.
The MucoRice vaccine also doesn't require the high cost of cold storage. It can be stored at room temperature for up to three years unlike traditional vaccines. "Plant-based vaccine development platforms present an exciting tool to reduce vaccine manufacturing costs, expand vaccine shelf life, and remove refrigeration requirements, all of which are factors that can limit vaccine supply and accessibility," Breakwell says.
Kathleen Hefferon, a microbiologist at Cornell University agrees. "It is much less expensive than a traditional vaccine, by a long shot," she says. "The fact that it is made in rice means the vaccine can be stored for long periods on the shelf, without losing its activity."
A plant-based vaccine may even be able to address vaccine hesitancy, which has become a growing problem in recent years. Hefferon suggests that "using well-known food plants may serve to reduce the anxiety of some vaccine hesitant people."
Challenges of Plant Vaccines
Despite their advantages, no plant-based vaccines have been commercialized for human use. There are a number of reasons for this, ranging from the potential for too much variation in plants to the lack of facilities large enough to grow crops that comply with good manufacturing practices. Several plant vaccines for diseases like HIV and COVID-19 are in development, but they're still in early stages.
In developing the MucoRice vaccine, scientists at the University of Tokyo have tried to overcome some of the problems with plant vaccines. They've created a closed facility where they can grow rice plants directly in nutrient-rich water rather than soil. This ensures they can grow crops all year round in a space that satisfies regulations. There's also less chance for variation since the environment is tightly controlled.
Clinical Trials and Beyond
After successfully growing rice plants containing the vaccine, the team carried out their first clinical trial. It was completed early this year. Thirty participants received a placebo and 30 received the vaccine. They were all Japanese men between the ages of 20 and 40 years old. 60 percent produced antibodies against the cholera toxin with no side effects. It was a promising result. However, there are still some issues Kiyono's team need to address.
The vaccine may not provide enough protection on its own. The antigen in any vaccine is the substance it contains to induce an immune response. For the MucoRice vaccine, the antigen is not the cholera bacteria itself but the cholera toxin the bacteria produces.
"The development of the antigen in rice is innovative," says David Sack, a professor at John Hopkins University and expert in cholera vaccine development. "But antibodies against only the toxin have not been very protective. The major protective antigen is thought to be the LPS." LPS, or lipopolysaccharide, is a component of the outer wall of the cholera bacteria that plays an important role in eliciting an immune response.
The Japanese team is considering getting the rice to also express the O antigen, a core part of the LPS. Further investigation and clinical trials will look into improving the vaccine's efficacy.
Beyond cholera, Kiyono hopes that the vaccine platform could one day be used to make cost-effective vaccines for other pathogens, such as norovirus or coronavirus.
"We believe the MucoRice system may become a new generation of vaccine production, storage, and delivery system."
An Investigational Drug Offers Hope to Patients with a Disabling Neuromuscular Disease
Robert Thomas was a devoted runner, gym goer, and crew member on a sailing team in San Diego when, in his 40s, he noticed that his range of movement was becoming more limited.
He thought he was just getting older, but when he was hiking an uphill trail in Lake Tahoe, he kept tripping over rocks. "I'd never had this happen before," Robert says. "I knew something was wrong but didn't know what it was."
It wasn't until age 50 when he was diagnosed with Charcot-Marie-Tooth disease. The genetic disorder damages the peripheral nerves, which connect the brain and spinal cord to the rest of the body. This network of nerves is responsible for relaying information and signals about sensation, movement, and motor coordination. Over time, the disease causes debilitating muscle weakness and the loss of limb control.
Charcot-Marie-Tooth usually presents itself in childhood or in a person's teens, but in some patients, like Robert, onset can be later in life. Symptoms may include muscle cramping, tingling, or burning. Many patients also have high foot arches or hammer toes — toes that curl from the middle joint instead of pointing forward. Those affected often have difficulty walking and may lose sensation in their lower legs, feet, hands, or forearms. One of the most common rare diseases, it affects around 130,000 people in the United States and 2.8 million worldwide.
Like many people with Charcot-Marie-Tooth, or CMT, Robert wears corrective braces on his legs to help with walking. Now 61, he can't run or sail anymore because of the disease, but he still works out regularly and can hike occasionally. CMT also affects his grip, so he has to use special straps while doing some exercises.
For the past few years, Robert has been participating in a clinical trial for an investigational CMT drug. He takes the liquid formulation every morning and evening using an oral syringe. Scientists are following patients like Robert to learn if their symptoms stabilize or improve while on the drug. Dubbed PXT300, the drug was designed by French biopharmaceutical company Pharnext and is the farthest along in development for CMT. If approved, it would be the first drug for the disease.
Currently, there's no cure for CMT, only supportive treatments like pain medication. Some individuals receive physical and occupational therapy. A drug for CMT could be a game-changer for patients whose quality of life is severely affected by the disease.
Genetic Underpinnings
CMT arises from mutations in genes that are responsible for creating and maintaining the myelin sheath — the insulating layer around nerves. Pharnext's drug is meant to treat patients with CMT1A, the most common form of the disease, which represents about half of CMT cases. Around 5% of those with CMT1A become severely disabled and end up in wheelchairs. People with CMT1A have an extra copy of the gene PMP22, which makes a protein that's needed to maintain the myelin sheath around peripheral nerves.
Typically, an individual inherits one copy of PMP22 from each parent. But a person with CMT1A receives a copy of PMP22 from one parent and two copies from a parent with the disease. This extra copy of the gene results in excess protein production, which damages the cells responsible for preserving and regenerating the myelin sheath, called Schwann cells.
The myelin sheath helps ensure that a signal from the brain gets carried to nerves in the muscles so that a part of the body can carry out a particular action or movement. This sheath is like the insulation on an electrical cord and the action is like a light bulb. If the insulation is fine, the light bulb turns on. But if the insulation is frayed, the light will flicker.
"The same happens to these patients," says David Horn Solomon, CEO of Pharnext. "The signal to their muscle is weak and flickers." Over time, their muscles become weaker and thinner.
The PMP22 gene has proven difficult to target with a drug because it's located in a protected space — the Schwann cells that make up the insulation around nerves. "There's not an easy way to tamp it down," Solomon says.
Another company, Acceleron Pharma of Cambridge, Massachusetts, was developing an injectable CMT drug meant to increase the strength of leg muscles. But the company halted development last year after the experimental drug failed in a mid-stage trial. While the drug led to a statistically significant increase in muscle volume, it didn't translate to improvements in muscle function or quality of life for trial participants.
Made by Design
Pharnext's drug, PXT3003, is a combination of three existing drugs — baclofen, a muscle relaxant; naltrexone, a drug that decreases the desire for alcohol and opioids; and sorbitol, a type of sugar alcohol.
The company designed the drug using its artificial intelligence platform, which screened 20,000 existing drugs to predict combinations that could inhibit the PMP22 gene and thereby lower protein production. The AI system narrowed the search to several hundreds of combinations and Pharnext tested around 75 of them in the lab before landing on baclofen, naltrexone, and sorbitol. Individually, the drugs don't have much effect on the PMP22 gene. But combined, they work to lower how much protein the gene makes.
"How the drug inside the cell reduces expression isn't quite clear yet," says Florian Thomas, director of the Hereditary Neuropathy Center, and founding chair and professor in the department of neurology at Hackensack University Medical Center and Hackensack Meridian School of Medicine in New Jersey (no relation to Robert Thomas, the CMT patient). "By reducing the amount of protein being produced, we hopefully can stabilize the nerves."
In rodents genetically engineered to have the PMP22 gene, the drug reduced protein levels and delayed onset of muscle weakness when given to rats. In another animal study, the drug increased the size of the myelin sheath around nerves in rats.
"Like humans with CMT, one of the problems the animals have is they can't grip things, their grip strength is poor," Solomon says. But when treated with Pharnext's drug, "the grip strength of these animals improves dramatically even over 12 weeks."
Human trials look encouraging, too. But the company ran into a manufacturing issue during a late-stage trial. The drug requires refrigeration, and as a result of temperature changes, crystals formed inside vials containing the high dose of the drug. The study was a double-blind trial, meaning neither the trial participants nor investigators were supposed to know who received the high dose of the drug, who received the low dose, and who received a placebo. In these types of studies, the placebo and experimental drug should look the same so that investigators can't tell them apart. But because only the high dose contained crystals, not the low dose or placebo, regulators said the trial data could be biased.
Pharnext is now conducting a new randomized, double-blind trial to prove that its drug works. The study is recruiting individuals aged 16 through 65 years old with mild to moderate CMT. The company hopes to show that the drug can stop patients' symptoms from worsening, or in the best case scenario, possibly even improve them. The company doesn't think the drug will be able to help people with severe forms of the disease.
"In neurologic disease, you're looking for plasticity, where there's still the possibility of stabilization or reversal," Solomon says. Plasticity refers to the ability of the nervous system to change and adapt in response to stimuli.
Preventing Disability
Allison Moore, a CMT patient and founder and CEO of the Hereditary Neuropathy Foundation, has been following drug development for CMT since she founded the organization in 2001. She says many investigational drugs haven't moved forward because they've shown little success in animals. The fact that Pharnext's drug has made it to a late-stage human trial is promising, she says.
"It's really exciting," Moore says. "There's a chance that if you take the drug early before you're very severe, you'll end up not developing the disease to a level that's super disabling."
CMT has damaged Moore's peroneal nerve, a main nerve in the foot. As a result, she has foot drop, the inability to lift the front part of her foot, and needs to wear leg braces to help her walk. "The idea that you could take this early on and that it could stop progression, that's the hope that we have."
Thomas, the neurologist, says a drug doesn't have to be a cure to have a significant impact on patients. "If I have a CMT patient who's 50 years old, that patient will be more disabled by age 60," he says. "If I can treat that person with a drug, and that person is just as disabled at age 60 as they were at age 50, that's transformative in my mind."
While Robert Thomas says he hasn't noticed a dramatic improvement since he's been on the drug, he does think it's helping. Robert is now in an open-label study, which means he and his health provider are aware that he's receiving the drug.
When the COVID-19 pandemic hit, manufacturing and supply chain disruptions meant that Robert was without the trial drug for two months. When his medication ran out, his legs felt unstable again and walking was harder. "There was a clear distinction between being on and off that medication," he says.
Pharnext's current trial will take about a year and a half to complete. After that, the FDA will decide on whether to approve the drug for CMT patients.
As scientists learn more about the PMP22 gene and the more than 100 other genes that when mutated cause CMT, more precise treatments could be possible. For instance, scientists have used the gene-editing tool CRISPR to correct a CMT-causing mutation in human cells in the lab. The results were published August 16 in the journal Frontiers in Cell and Developmental Biology.
Pharnext is also interested in pursuing genetic treatments for CMT, but in the meantime, repurposed drugs may be the best shot at helping patients until more advanced treatments are available.