Tony and Kelly Mantoan, with their boys Teddy and Fulton, who both suffer from SMA, a genetic disorder that makes walking, swallowing, and breathing progressively difficult.
Kelly Mantoan was nursing her newborn son, Teddy, in the NICU in a Philadelphia hospital when her doctor came in and silently laid a hand on her shoulder. Immediately, Kelly knew what the gesture meant and started to sob: Teddy, like his one-year-old brother, Fulton, had just tested positive for a neuromuscular condition called spinal muscular atrophy (SMA).
The boys were 8 and 10 when Kelly heard about an experimental new treatment, still being tested in clinical trials, called Spinraza.
"We knew that [SMA] was a genetic disorder, and we knew that we had a 1 in 4 chance of Teddy having SMA," Mantoan recalls. But the idea of having two children with the same severe disability seemed too unfair for Kelly and her husband, Tony, to imagine. "We had lots of well-meaning friends tell us, well, God won't do this to you twice," she says. Except that He, or a cruel trick of nature, had.
In part, the boys' diagnoses were so devastating because there was little that could be done at the time, back in 2009 and 2010, when the boys were diagnosed. Affecting an estimated 1 in 11,000 babies, SMA is a degenerative disease in which the body is deficient in survival motor neuron (SMN) protein, thanks to a genetic mutation or absence of the body's SNM1 gene. So muscles that control voluntary movement – such as walking, breathing, and swallowing – weaken and eventually cease to function altogether.
Babies diagnosed with SMA Type 1 rarely live past toddlerhood, while people diagnosed with SMA Types 2, 3, and 4 can live into adulthood, usually with assistance like ventilators and feeding tubes. Shortly after birth, both Teddy Mantoan and his brother, Fulton, were diagnosed with SMA Type 2.
The boys were 8 and 10 when Kelly heard about an experimental new treatment, still being tested in clinical trials, called Spinraza. Up until then, physical therapy was the only sanctioned treatment for SMA, and Kelly enrolled both her boys in weekly sessions to preserve some of their muscle strength as the disease marched forward. But Spinraza – a grueling regimen of lumbar punctures and injections designed to stimulate a backup survival motor neuron gene to produce more SMN protein – offered new hope.
In clinical trials, after just a few doses of Spinraza, babies with SMA Type 1 began meeting normal developmental milestones – holding up their heads, rolling over, and sitting up. In other trials, Spinraza treatment delayed the need for permanent ventilation, while patients on the placebo arm continued to lose function, and several died. Spinraza was such a success, and so well tolerated among patients, that clinical trials ended early and the drug was fast-tracked for FDA approval in 2016. In January 2017, when Kelly got the call that Fulton and Teddy had been approved by the hospital to start Spinraza infusions, Kelly dropped to her knees in the middle of the kitchen and screamed.
Spinraza, manufactured by Biogen, has been hailed as revolutionary, but it's also not without drawbacks: Priced per injection, just one dose of Spinraza costs $125,000, making it one of the most expensive drugs on the global market. What's worse, treatment requires a "loading dose" of four injections over a four-week period, and then periodic injections every four months, indefinitely. For the first year of treatment, Spinraza treatment costs $750,000 – and then $375,000 for every year thereafter.
Last week, a competitive treatment for SMA Type 1 manufactured by Novartis burst onto the market. The new treatment, called Zolgensma, is a one-time gene therapy intended to be given to infants and is currently priced at $2.125 million, or $425,000 annually for five years, making it the most expensive drug in the world. Like Spinraza, Zolgensma is currently raising challenging questions about how insurers and government payers like Medicaid will be able to afford these treatments without bankrupting an already-strained health care system.
To Biogen's credit, the company provides financial aid for Spinraza patients with private insurance who pay co-pays for treatment, as well as for those who have been denied by Medicaid and Medicare. But getting insurance companies to agree to pay for Spinraza can often be an ordeal in itself. Although Fulton and Teddy Mantoan were approved for treatment over two years ago, a lengthy insurance battle delayed treatment for another eight months – time that, for some SMA patients, can mean a significant loss of muscular function.
Kelly didn't notice anything in either boy – positive or negative – for the first few months of Spinraza injections. But one day in November 2017, as Teddy was lowered off his school bus in his wheelchair, he turned to say goodbye to his friends and "dab," – a dance move where one's arms are extended briefly across the chest and in the air. Normally, Teddy would dab by throwing his arms up in the air with momentum, striking a pose quickly before they fell down limp at his sides. But that day, Teddy held his arms rigid in the air. His classmates, along with Kelly, were stunned. "Teddy, look at your arms!" Kelly remembers shrieking. "You're holding them up – you're dabbing!"
Teddy and Fulton Mantoan, who both suffer from spinal muscular atrophy, have seen life-changing results from Spinraza.
(Courtesy of Kelly Mantoan)
Not long after Teddy's dab, the Mantoans started seeing changes in Fulton as well. "With Fulton, we realized suddenly that he was no longer choking on his food during meals," Kelly said. "Almost every meal we'd have to stop and have him take a sip of water and make him slow down and take small bites so he wouldn't choke. But then we realized we hadn't had to do that in a long time. The nurses at school were like, 'it's not an issue anymore.'"
For the Mantoans, this was an enormous relief: Less choking meant less chance of aspiration pneumonia, a leading cause of death for people with SMA Types 1 and 2.
While Spinraza has been life-changing for the Mantoans, it remains painfully out of reach for many others. Thanks to Spinraza's enormous price tag, the threshold for who gets to use it is incredibly high: Adult and pediatric patients, particularly those with state-sponsored insurance, have reported multiple insurance denials, lengthy appeals processes, and endless bureaucracy from insurance and hospitals alike that stand in the way of treatment.
Kate Saldana, a 21-year-old woman with Type 2 SMA, is one of the many adult patients who have been lobbying for the drug. Saldana, who uses a ventilator 20 hours each day, says that Medicaid denied her Spinraza treatments because they mistakenly believed that she used a ventilator full-time. Saldana is currently in the process of appealing their decision, but knows she is fighting an uphill battle.
Kate Saldana, who suffers from Type 2 SMA, has been fighting unsuccessfully for Medicaid to cover Spinraza.
(Courtesy of Saldana)
"Originally, the treatments were studied and created for infants and children," Saldana said in an e-mail. "There is a plethora of data to support the effectiveness of Spinraza in those groups, but in adults it has not been studied as much. That makes it more difficult for insurance to approve it, because they are not sure if it will be as beneficial."
Saldana has been pursuing treatment unsuccessfully since last August – but others, like Kimberly Hill, a 32-year-old with SMA Type 2, have been waiting even longer. Hill, who lives in Oklahoma, has been fighting for treatment since Spinraza went on the U.S. market in December 2016. Because her mobility is limited to the use of her left thumb, Hill is eager to try anything that will enable her to keep working and finish a Master's degree in Fire and Emergency Management.
"Obviously, my family and I were elated with the approval of Spinraza," Hill said in an e-mail. "We thought I would finally have the chance to get a little stronger and healthier." But with Medicare and Medicaid, coverage and eligibility varies wildly by state. Earlier this year, Medicaid approved Spinraza for adult patients only if a clawback clause was attached to the approval, meaning that under certain conditions the Medicaid funds would need to be paid back. Because of the clawback clause, hospitals have been reluctant to take on Spinraza treatments, effectively barring adult Medicaid patients from accessing the drug altogether.
Hill's hospital is currently in negotiations with Medicaid to move forward with Spinraza treatment, but in the meantime, Hill is in limbo. "We keep being told there is nothing we can do, and we are devastated," Hill said.
"I felt extremely sad and honestly a bit forgotten, like adults [with SMA] don't matter."
Between Spinraza and its new competitor, Zolgensma, some are speculating that insurers will start to favor Zolgensma coverage instead, since the treatment is shorter and ultimately cheaper than Spinraza in the long term. But for some adults with SMA who can't access Spinraza and who don't qualify for Zolgensma treatment, the issue of what insurers will cover is moot.
"I was so excited when I heard that Zolgensma was approved by the FDA," said Annie Wilson, an adult SMA patient from Alameda, Calif. who has been fighting for Spinraza since 2017. "When I became aware that it was only being offered to children, I felt extremely sad and honestly a bit forgotten, like adults [with SMA] don't matter."
According to information from a Biogen representative, more than 7500 people worldwide have been treated with Spinraza to date, one third of whom are adults.
While Spinraza has been revolutionary for thousands of patients, it's unclear how many more lives state agencies and insurance companies will allow it to save.
Silkworm silk is fragile, which limits its uses, but a few extra genes can help.
Today, biomimetics is everywhere. Shark-inspired swimming trunks, gecko-inspired adhesives, and lotus-inspired water-repellents are all taken from observing the natural world. After millions of years of evolution, nature has quite a few tricks up its sleeve. They are tricks we can learn from. And now, thanks to some spider DNA and clever genetic engineering, we have another one to add to the list.
The elusive spider silk
We’ve known for a long time that spider silk is remarkable, in ways that synthetic fibers can’t emulate. Nylon is incredibly strong (it can support a lot of force), and Kevlar is incredibly tough (it can absorb a lot of force). But neither is both strong and tough. In all artificial polymeric fibers, strength and toughness are mutually exclusive, and so we pick the material best for the job and make do.
Spider silk, a natural polymeric fiber, breaks this rule. It is somehow both strong and tough. No surprise, then, that spider silk is a source of much study.The problem, though, is that spiders are incredibly hard to cultivate — let alone farm. If you put them together, they will attack and kill each other until only one or a few survive. If you put 100 spiders in an enclosed space, they will go about an aggressive, arachnocidal Hunger Games. You need to give each its own space and boundaries, and a spider hotel is hard and costly. Silkworms, on the other hand, are peaceful and productive. They’ll hang around all day to make the silk that has been used in textiles for centuries. But silkworm silk is fragile. It has very limited use.
The elusive – and lucrative – trick, then, would be to genetically engineer a silkworm to produce spider-quality silk. So far, efforts have been fruitless. That is, until now.
We can have silkworms creating silk six times as tough as Kevlar and ten times as strong as nylon.
Spider-silkworms
Junpeng Mi and his colleagues working at Donghua University, China, used CRISPR gene-editing technology to recode the silk-creating properties of a silkworm. First, they took genes from Araneus ventricosus, an East Asian orb-weaving spider known for its strong silk. Then they placed these complex genes – genes that involve more than 100 amino acids – into silkworm egg cells. (This description fails to capture how time-consuming, technical, and laborious this was; it’s a procedure that requires hundreds of thousands of microinjections.)
This had all been done before, and this had failed before. Where Mi and his team succeeded was using a concept called “localization.” Localization involves narrowing in on a very specific location in a genome. For this experiment, the team from Donghua University developed a “minimal basic structure model” of silkworm silk, which guided the genetic modifications. They wanted to make sure they had the exactly right transgenic spider silk proteins. Mi said that combining localization with this basic structure model “represents a significant departure from previous research.” And, judging only from the results, he might be right. Their “fibers exhibited impressive tensile strength (1,299 MPa) and toughness (319 MJ/m3), surpassing Kevlar’s toughness 6-fold.”
A world of super-materials
Mi’s research represents the bursting of a barrier. It opens up hugely important avenues for future biomimetic materials. As Mi puts it, “This groundbreaking achievement effectively resolves the scientific, technical, and engineering challenges that have hindered the commercialization of spider silk, positioning it as a viable alternative to commercially synthesized fibers like nylon and contributing to the advancement of ecological civilization.”
Around 60 percent of our clothing is made from synthetic fibers like nylon, polyester, and acrylic. These plastics are useful, but often bad for the environment. They shed into our waterways and sometimes damage wildlife. The production of these fibers is a source of greenhouse gas emissions. Now, we have a “sustainable, eco-friendly high-strength and ultra-tough alternative.” We can have silkworms creating silk six times as tough as Kevlar and ten times as strong as nylon.
We shouldn’t get carried away. This isn’t going to transform the textiles industry overnight. Gene-edited silkworms are still only going to produce a comparatively small amount of silk – even if farmed in the millions. But, as Mi himself concedes, this is only the beginning. If Mi’s localization and structure-model techniques are as remarkable as they seem, then this opens up the door to a great many supermaterials.
Nature continues to inspire. We had the bird, the gecko, and the shark. Now we have the spider-silkworm. What new secrets will we unravel in the future? And in what exciting ways will it change the world?
This article originally appeared on Freethink, home of the brightest minds and biggest ideas of all time.
