Jamie Rettinger with his now fiance Amie Purnel-Davis, who helped him through the clinical trial.
Melanoma is the deadliest form of skin cancer. About 85,000 people are diagnosed with it each year in the U.S. and more than 8,000 die of the cancer when it spreads to other parts of the body, according to the Centers for Disease Control and Prevention (CDC).
There are two peaks in diagnosis of melanoma; one is in younger women ages 30-40 and often is tied to past use of tanning beds; the second is older men 60+ and is related to outdoor activity from farming to sports. Light-skinned people have a twenty-times greater risk of melanoma than do people with dark skin.
"When I graduated from medical school, in 2005, melanoma was a death sentence" --Diwakar Davar.
Jamie had a follow up PET scan about six months after his surgery. A suspicious spot on his lung led to a biopsy that came back positive for melanoma. The cancer had spread. Treatment with a monoclonal antibody (nivolumab/Opdivo®) didn't prove effective and he was referred to the UPMC Hillman Cancer Center in Pittsburgh, a four-hour drive from his home in western Ohio.
An alternative monoclonal antibody treatment brought on such bad side effects, diarrhea as often as 15 times a day, that it took more than a week of hospitalization to stabilize his condition. The only options left were experimental approaches in clinical trials.
Early research
"When I graduated from medical school, in 2005, melanoma was a death sentence" with a cure rate in the single digits, says Diwakar Davar, 39, an oncologist at UPMC Hillman Cancer Center who specializes in skin cancer. That began to change in 2010 with introduction of the first immunotherapies, monoclonal antibodies, to treat cancer. The antibodies attach to PD-1, a receptor on the surface of T cells of the immune system and on cancer cells. Antibody treatment boosted the melanoma cure rate to about 30 percent. The search was on to understand why some people responded to these drugs and others did not.
At the same time, there was a growing understanding of the role that bacteria in the gut, the gut microbiome, plays in helping to train and maintain the function of the body's various immune cells. Perhaps the bacteria also plays a role in shaping the immune response to cancer therapy.
One clue came from genetically identical mice. Animals ordered from different suppliers sometimes responded differently to the experiments being performed. That difference was traced to different compositions of their gut microbiome; transferring the microbiome from one animal to another in a process known as fecal transplant (FMT) could change their responses to disease or treatment.
When researchers looked at humans, they found that the patients who responded well to immunotherapies had a gut microbiome that looked like healthy normal folks, but patients who didn't respond had missing or reduced strains of bacteria.
Davar and his team knew that FMT had a very successful cure rate in treating the gut dysbiosis of Clostridioides difficile, a persistant intestinal infection, and they wondered if a fecal transplant from a patient who had responded well to cancer immunotherapy treatment might improve the cure rate of patients who did not originally respond to immunotherapies for melanoma.
The ABCDE of melanoma detection
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Clinical trial
"It was pretty weird, I was totally blasted away. Who had thought of this?" Jamie first thought when the hypothesis was explained to him. But Davar's explanation that the procedure might restore some of the beneficial bacterial his gut was lacking, convinced him to try. He quickly signed on in October 2018 to be the first person in the clinical trial.
Fecal donations go through the same safety procedures of screening for and inactivating diseases that are used in processing blood donations to make them safe for transfusion. The procedure itself uses a standard hollow colonoscope designed to screen for colon cancer and remove polyps. The transplant is inserted through the center of the flexible tube.
Most patients are sedated for procedures that use a colonoscope but Jamie doesn't respond to those drugs: "You can't knock me out. I was watching them on the TV going up my own butt. It was kind of unreal at that point," he says. "There were about twelve people in there watching because no one had seen this done before."
A test two weeks after the procedure showed that the FMT had engrafted and the once-missing bacteria were thriving in his gut. More importantly, his body was responding to another monoclonal antibody (pembrolizumab/Keytruda®) and signs of melanoma began to shrink. Every three months he made the four-hour drive from home to Pittsburgh for six rounds of treatment with the antibody drug.
"We were very, very lucky that the first patient had a great response," says Davar. "It allowed us to believe that even though we failed with the next six, we were on the right track. We just needed to tweak the [fecal] cocktail a little better" and enroll patients in the study who had less aggressive tumor growth and were likely to live long enough to complete the extensive rounds of therapy. Six of 15 patients responded positively in the pilot clinical trial that was published in the journal Science.
Davar believes they are beginning to understand the biological mechanisms of why some patients initially do not respond to immunotherapy but later can with a FMT. It is tied to the background level of inflammation produced by the interaction between the microbiome and the immune system. That paper is not yet published.
Surviving cancer
It has been almost a year since the last in his series of cancer treatments and Jamie has no measurable disease. He is cautiously optimistic that his cancer is not simply in remission but is gone for good. "I'm still scared every time I get my scans, because you don't know whether it is going to come back or not. And to realize that it is something that is totally out of my control."
"It was hard for me to regain trust" after being misdiagnosed and mistreated by several doctors he says. But his experience at Hillman helped to restore that trust "because they were interested in me, not just fixing the problem."
He is grateful for the support provided by family and friends over the last eight years. After a pause and a sigh, the ruggedly built 47-year-old says, "If everyone else was dead in my family, I probably wouldn't have been able to do it."
"I never hesitated to ask a question and I never hesitated to get a second opinion." But Jamie acknowledges the experience has made him more aware of the need for regular preventive medical care and a primary care physician. That person might have caught his melanoma at an earlier stage when it was easier to treat.
Davar continues to work on clinical studies to optimize this treatment approach. Perhaps down the road, screening the microbiome will be standard for melanoma and other cancers prior to using immunotherapies, and the FMT will be as simple as swallowing a handful of freeze-dried capsules off the shelf rather than through a colonoscopy. Earlier this year, the Food and Drug Administration approved the first oral fecal microbiota product for C. difficile, hopefully paving the way for more.
An older version of this hit article was first published on May 18, 2021
New research focuses on methods that could change medicine-making worldwide. The scientists propose bursting cells open, removing their DNA and using the cellular gears inside to make therapies.
Rao and his team of collaborators, which spans multiple research institutions, believe they have a better approach that may change medicine-making worldwide. They suggest forgoing the concept of using living cells as medicine-producers. Instead, they propose breaking the cells and using the remaining cellular gears for assembling the therapeutic compounds. Instead of inserting the DNA into living cells, the team burst them open, and removed their DNA altogether. Yet, the residual molecular machinery of ribosomes, polymerases and other cogwheels still functioned the way it would in a cell. “Now if you drop your DNA drug-making instructions into that soup, this machinery starts making what you need,” Rao explains. “And because you're no longer worrying about living cells, it becomes much simpler and more efficient.” The collaborators detail their cell-free protein synthesis or CFPS method in their recent paper published in preprint BioAxiv.
While CFPS does not use living cells, it still needs the basic building blocks to assemble proteins from—such as amino acids, nucleotides and certain types of enzymes. These are regularly added into this “soup” to keep the molecular factory chugging. “We just mix everything in as a batch and we let it integrate,” says James Robert Swartz, professor of chemical engineering and bioengineering at Stanford University and co-author of the paper. “And we make sure that we provide enough oxygen.” Rao likens the process to making milk from milk powder.
For a variety of reasons—from the field’s general inertia to regulatory approval hurdles—the method hasn’t become mainstream. The pandemic rekindled interest in medicines that can be made quickly and easily, so it drew more attention to the technology.
The idea of a cell-free protein synthesis is older than one might think. Swartz first experimented with it around 1997, when he was a chemical engineer at Genentech. While working on engineering bacteria to make pharmaceuticals, he discovered that there was a limit to what E. coli cells, the workhorse darling of pharma, could do. For example, it couldn’t grow and properly fold some complex proteins. “We tried many genetic engineering approaches, many fermentation, development, and environmental control approaches,” Swartz recalls—to no avail.
“The organism had its own agenda,” he quips. “And because everything was happening within the organism, we just couldn't really change those conditions very easily. Some of them we couldn’t change at all—we didn’t have control.”
It was out of frustration with the defiant bacteria that a new idea took hold. Could the cells be opened instead, so that the protein-forming reactions could be influenced more easily? “Obviously, we’d lose the ability for them to reproduce,” Swartz says. But that also meant that they no longer needed to keep the cells alive and could focus on making the specific reactions happen. “We could take the catalysts, the enzymes, and the more complex catalysts and activate them, make them work together, much as they would in a living cell, but the way we wanted.”
In 1998, Swartz joined Stanford, and began perfecting the biochemistry of the cell-free method, identifying the reactions he wanted to foster and stopping those he didn’t want. He managed to make the idea work, but for a variety of reasons—from the field’s general inertia to regulatory approval hurdles—the method hasn’t become mainstream. The pandemic rekindled interest in medicines that can be made quickly and easily, so it drew more attention to the technology. For their BioArxiv paper, the team tested the method by growing a specific antiviral protein called griffithsin.
First identified by Barry O’Keefe at National Cancer Institute over a decade ago, griffithsin is an antiviral known to interfere with many viruses’ ability to enter cells—including HIV, SARS, SARS-CoV-2, MERS and others. Originally isolated from the red algae Griffithsia, it works differently from antibodies and antibody cocktails.
Most antiviral medicines tend to target the specific receptors that viruses use to gain entry to the cells they infect. For example, SARS-CoV-2 uses the infamous spike protein to latch onto the ACE2 receptor of mammalian cells. The antibodies or other antiviral molecules stick to the spike protein, shutting off its ability to cling onto the ACE2 receptors. Unfortunately, the spike proteins mutate very often, so the medicines lose their potency. On the contrary, griffithsin has the ability to cling to the different parts of viral shells called capsids—namely to the molecules of mannose, a type of sugar. That extra stuff, glued all around the capsid like dead weight, makes it impossible for the virus to squeeze into the cell.
“Every time we have a vaccine or an antibody against a specific SARS-CoV-2 strain, that strain then mutates and so you lose efficacy,” Rao explains. “But griffithsin molecules glom onto the viral capsid, so the capsid essentially becomes a sticky mess and can’t enter the cell.” Mannose molecules also don’t mutate as easily as viruses’ receptors, so griffithsin-based antivirals do not have to be constantly updated. And because mannose molecules are found on many viruses’ capsids, it makes griffithsin “a universal neutralizer,” Rao explains.
“When griffithsin was discovered, we recognized that it held a lot of promise as a potential antiviral agent,” O’Keefe says. In 2010, he published a paper about griffithsin efficacy in neutralizing viruses of the corona family—after the first SARS outbreak in the early 2000s, the scientific community was interested in such antivirals. Yet, griffithsin is still not available as an off-the-shelf product. So during the Covid pandemic, the team experimented with synthesizing griffithsin using the cell-free production method. They were able to generate potent griffithsin in less than 24 hours without having to grow living cells.
The antiviral protein isn't the only type of medicine that can be made cell-free. The proteins needed for vaccine production could also be made the same way. “Such portable, on-demand drug manufacturing platforms can produce antiviral proteins within hours, making them ideal for combating future pandemics,” Rao says. “We would be able to stop the pandemic before it spreads.”
Top: Describes the process used in the study. Bottom: Describes how the new medicines and vaccines could be made at the site of a future viral outbreak.
Image courtesy of Rao and team, sourced from An approach to rapid distributed manufacturing of broad spectrumanti-viral griffithsin using cell-free systems to mitigate pandemics.
Rao’s idea is to perfect the technology to the point that any hospital or pharmacy can load up the media containing molecular factories, mix up the required amino acids, nucleotides and enzymes, and harvest the meds within hours. That will allow making medicines onsite and on demand. “That would be a self-contained production unit, so that you could just ship the production wherever the pandemic is breaking out,” says Swartz.
These units and the meds they produce, will, of course, have to undergo rigorous testing. “The biggest hurdles will be validating these against conventional technology,” Rao says. The biotech industry is risk-averse and prefers the familiar methods. But if this approach works, it may go beyond emergency situations and revolutionize the medicine-making paradigm even outside hospitals and pharmacies. Rao hopes that someday the method might become so mainstream that people may be able to buy and operate such reactors at home. “You can imagine a diabetic patient making insulin that way, or some other drugs,” Rao says. It would work not unlike making baby formula from the mere white powder. Just add water—and some oxygen, too.
In the U.S. and Europe, it is illegal to reuse pacemakers and other implants. Therefore, cardiologists export them to the global South where they save the lives of people of all ages.
Often he observed there were no doctors in the E.R.s, and hte nurses could render only basic first aid. “When somebody fell into a coma, they fell into a coma,“ Israel remembers. “There weren’t even any defibrillators to restart a patient’s heart,” while defibrillators are standard equipment in most clinics in the U.S. and Europe as lifesaving devices. When Israel finally visited the largest and most modern hospital in Nairobi, he found it better equipped but he learned that its services were only available to patients who could afford them. The cardiologist there had a drawer full of petitions from patients with heart ailments who couldn’t afford lifesaving surgery. Even two decades ago, a pacemaker cost $5,000 in Kenya, which made it unaffordable for most Kenyans who earn an average of $600 per month.
Since 2003, Israel and a team of two doctors and two nurses visit Kenya and Zambia once or twice a year to implant German pacemakers for free. Notably, the pacemakers and defibrillators Israel exports to Africa would end up in the landfill in Germany. Clinics have to pay for specialized services to dispose of this medical equipment. “In Germany, I could go to jail if I used a defibrillator that is one day past its expiration date,“ Israel says, “but in Kenya, people don’t have the money for the cheapest model. What nonsense to throw this precious medical equipment away while people in poorer countries die because they desperately need it.“
Israel works at the breakpoint between the laws in a wealthy country like Germany and the reality in the global South. The U.S. and most European countries have strict laws that ban the reuse of medical implants and enforce strict expiration dates for medical equipment. “But if a pacemaker is a few days past its expiration date, it still works perfectly fine,“ Israel says. “And it also happens that we implant a pacemaker and five months later it turns out that the patient needs a different kind. Then we replace it and we’d have to trash the first one in Germany, though it could easily run another 12 years.“
“If we get this right, we have lots of devices we can implant, hips and knees, etcetera. Where this will lead is limitless," says Eva Kline Rogers, the program coordinator for My Heart, Your Heart.
Israel has been collecting donations of pacemakers and defibrillators from manufacturers but also from other doctors and from funeral homes for his nonprofit Pacemakers for East Africa since 2003. Most funeral homes in the U.S. and Europe are legally obliged to remove pacemakers from the dead before cremation. “Most pacemakers survive their owners,“ says Israel. He sterilizes the pacemakers and finds them a new life in East Africa. Studies show that reused pacemakers carry no greater risk for the patients than new ones.
In the U.S., University of Michigan professor Thomas Crawford heads up a similar initiative, My Heart, Your Heart. “Each year 1 to 2 million individuals worldwide die due to a lack of access to pacemakers and defibrillators,” the organization notes on its website. The nonprofit was founded in 2009, but it took four years for the doctors to get permission from the FDA to export pacemakers. Since receiving permission, the organization has sent dozens of devices to the Philippines, Haiti, Venezuela, Kenya, Sierra Leone and Ukraine. “We were the first doctors ever to implant a pacemaker in Sierra Leone in 2018,” says Crawford, who has traveled extensively to most of the recipient countries.
Even individuals can donate their pacemakers; the organization offers a prepaid envelope. “My mother recently passed and she donated her device,” says Tina Alexandris-Souphis, one of the doctors at University of Michigan who collaborates on My Heart, Your Heart. The organization works with World Medical Relief and the U.K. based charity Pace4Life to maintain a registry of the most urgent patients and send devices to where they are needed the most.
My Heart, Your Heart is also conducting a randomized controlled trial to provide further evidence that reused pacemakers pose no additional risk. “Our vision is that we establish this is safe and create a blueprint for organizations around the world to safely reuse these devices instead of them being thrown in the trash,” says Eva Kline Rogers, the program’s coordinator. “If we get this right, we have lots of devices we can implant, hips and knees, etc. Where this will lead is limitless.” She points out that in addition to receiving the donated devices, the doctors in the global South also benefit from the expertise of renowned cardiologists, such as Crawford, who sometimes advise them in complex cases.
And Adrian Baranchuk, a Canadian doctor at the Kingston General Hospital at the Queen’s University, regularly travels through South America with his “cardiology van” to help villagers in remote areas with heart problems.
Israel says that he’s been accused of racism, in thinking that these pacemakers are suitable for those in the global South - many of whom are people of color - even though officials in wealthier countries consider them to be trash. The cardiologist counters such criticism with stories about desperate need of his patients. At his first medical visit to Nairobi that he organized with a local cardiologist, six patients were waiting for him. “In Germany, they would all be considered emergencies,” Israel says. One eighty-year old grandmother had a heartrate of 18. “I’ve never before seen anything like this,” Israel exclaims. “At first I thought I couldn’t find her pulse before I realized that her heart was only beating once every three seconds.” After the surgery, she got up, dressed herself and hurriedly packed her bag, explaining she had a ton of work to accomplish. Her family was in disbelief, Israel says. “They told me she had been bedridden for five years because as soon as she tried to get up she would faint.”
Israel has been accused of racism, in thinking that these pacemakers are suitable for those in the global South even though they're considered to be trash by officials in wealthier countries. The cardiologist counters such criticism with stories about desperate need of his patients.
Carsten Israel
The hospital in Nairobi where Israel conducts the surgeries, charges patients $200 for the use of its facilities. If patients can’t afford that sum, Israel will pay it from the funds of his nonprofit. For some people, $200 far exceeds their resources. Once, a family from the extremely poor Northern region of Kenya told him they couldn’t afford the $3 for the bus ride to Nairobi. Israel suspected this was a pretense because they were afraid of the surgery and agreed to reimburse the $3, “but when they came, they were wearing rags and were so rail-thin, I understood that they really needed every cent they had for food.”
Israel is a renowned cardiologists in Germany. And yet, he considers his work in East Africa to be particularly meaningful. “Generally, most patients in Germany will get the treatment they need,” he says, “and I never before experienced that people have an illness that is easily curable but simply won’t be treated.” He also feels a heavy responsibility. Many patients have his personal cell phone and call him when they have problems or good news about how they’re doing.
Some of those progress reports come much faster than in Israel’s home country. Before he implanted a pacemaker in a tall Massai in Kenya, the man had been picked on by his family because he wouldn’t help much with the hard work on the family peanut farm. “When I examined him, he had a pulse of 40,” Israel says. “It’s a miracle he was even standing upright, let alone hauling heavy bags.” After the surgery, Israel advised his patient to stay the night for observation, but the patient couldn’t wait to leave. Two hours later, he returned, covered in sweat. He’d been running sprints with his brothers to test the new device. Israel shakes his head. In Germany, it would be unthinkable for a patient to engage in athletics immediately after surgery. But the patient was exuberant: “I was the fastest!”
The success stories are notable partly because the challenges remain so steep. In Zambia, for instance, there is a single cardiologist; she determined to become one after losing her younger sister to an easily curable heart disease. Often, the hospitals not only lack pacemakers but also sterile surgery equipment, antibiotics and other essential material. Therefore, Israel and his team import everything they need for the surgeries, including medication. If necessary, they improvise. “I’ve done surgery with a desk lamp hanging from the ceiling by threads,” Israel says. He already knows that he will need to return to Kenya in six months to replace the pacemaker of one of his patients and replace the batteries in others. If he doesn’t travel, lives are at risk.