An Astounding Treatment at an Astounding Price: Who Gets to Benefit?
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.
These doctors have a heart for recycling
This is part 3 of a three part series on a new generation of doctors leading the charge to make the health care industry more sustainable - for the benefit of their patients and the planet. Read part 1 here and part 2 here.
One could say that over 400 people owe their life to the fact that Carsten Israel fell in love. Twenty years ago, as a young doctor in Frankfurt, Germany, he began to court an au pair from Kenya, Elisabeth, his now-wife of 13 years with whom he has three children. When the couple started visiting her parents in Kenya, Israel wanted to check out the local hospitals, “just out of professional curiosity,“ says the cardiologist, who is currently the head doctor at the Clinic for Interior Medicine in Bielefeld. “I was completely shocked.“
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.These technologies may help more animals and plants survive climate change
This article originally appeared in One Health/One Planet, a single-issue magazine that explores how climate change and other environmental shifts are making us more vulnerable to infectious diseases by land and by sea - and how scientists are working on solutions.
Along the west coast of South Florida and the Keys, Florida Bay is a nursery for young Caribbean spiny lobsters, a favorite local delicacy. Growing up in small shallow basins, they are especially vulnerable to warmer, more saline water. Climate change has brought tidal floods, bleached coral reefs and toxic algal blooms to the state, and since the 1990s, the population of the Caribbean spiny lobster has dropped some 20 percent, diminishing an important food for snapper, grouper, and herons, as well as people. In 1999, marine ecologist Donald Behringer discovered the first known virus among lobsters, Panulirus argus virus—about a quarter of juveniles die from it before they mature.
“When the water is warm PaV1 progresses much more quickly,” says Behringer, who is based at the Emerging Pathogens Institute at the University of Florida in Gainesville.
Caribbean spiny lobsters are only one example of many species that are struggling in the era of climate change, both at sea and on land. As the oceans heat up, absorbing greenhouse gases and growing more acidic, marine diseases are emerging at an accelerated rate. Marine creatures are migrating to new places, and carrying pathogens with them. The latest grim report in the journal Science, states that if global warming continues at the current rate, the extinction of marine species will rival the Permian–Triassic extinction, sometimes called the “Great Dying,” when volcanoes poisoned the air and wiped out as much as 90 percent of all marine life 252 million years ago.
Similarly, on land, climate change has exposed wildlife, trees and crops to new or more virulent pathogens. Warming environments allow fungi, bacteria, viruses and infectious worms to proliferate in new species and locations or become more virulent. One paper modeling records of nearly 1,400 wildlife species projects that parasites will double by 2070 in the far north and in high-altitude places. Right now, we are seeing the effects most clearly on the fringes—along the coasts, up north and high in the mountains—but as the climate continues changing, the ripples will reach everywhere.
Few species are spared
On the Hawaiian Islands, mosquitoes are killing more songbirds. The dusky gray akikiki of Kauai and the chartreuse-yellow kiwikiu of Maui could vanish in two years, under assault from mosquitoes bearing avian malaria, according to a University of Hawaiʻi 2022 report. Previously, the birds could escape infection by roosting high in the cold mountains, where the pests couldn’t thrive, but climate change expanded the range of the mosquito and narrowed theirs.
Likewise, as more midge larvae survive over warm winters and breed better during drier summers, they bite more white-tailed deer, spreading often-fatal epizootic hemorrhagic disease. Especially in northern regions of the globe, climate change brings the threat of midges carrying blue tongue disease, a virus, to sheep and other animals. Tick-borne diseases like encephalitis and Lyme disease may become a greater threat to animals and perhaps humans.
"If you put all your eggs in one basket and then a pest comes a long, then you are more vulnerable to those risks," says Mehroad Ehsani, managing director of the food initiative in Africa for the Rockefeller Foundation. "Research is needed on resilient, climate smart, regenerative agriculture."
In the “thermal mismatch” theory of wildlife disease, cold-adapted species are at greater risk when their habitats warm, and warm-adapted species suffer when their habitats cool. Mammals can adjust their body temperature to adapt to some extent. Amphibians, fish and insects that cannot regulate body temperatures may be at greater risk. Many scientists see amphibians, especially, as canaries in the coalmine, signaling toxicity.
Early melting ice can foster disease. Climate models predict that the spring thaw will come ever-earlier in the lakes of the French Pyrenees, for instance, which traditionally stayed frozen for up to half the year. The tadpoles of the midwife toad live under the ice, where they are often infected with amphibian chytrid fungus. When a seven-year study tracked the virus in three species of amphibians in Pyrenees’s Lac Arlet, the research team found that, the earlier the spring thaw arrived, the more infection rates rose in common toads— , while remaining high among the midwife toads. But the team made another sad discovery: with early thaws, the common frog, which was thought to be free of the disease in Europe, also became infected with the fungus and died in large numbers.
Changing habitats affect animal behavior. Normally, spiny lobsters rely on chemical cues to avoid predators and sick lobsters. New conditions may be hampering their ability to “social distance”—which may help PaV1 spread, Behringer’s research suggests. Migration brings other risks. In April 2022, an international team led by scientists at Georgetown University announced the first comprehensive overview, published in the journal Nature, of how wild mammals under pressure from a changing climate may mingle with new populations and species—giving viruses a deadly opportunity to jump between hosts. Droughts, for example, will push animals to congregate at the few places where water remains.
Plants face threats also. At the timberline of the cold, windy, snowy mountains of the U.S. west, whitebark pine forests are facing a double threat, from white pine blister rust, a fungal disease, and multiplying pine beetles. “If we do nothing, we will lose the species,” says Robert Keane, a research ecologist for the U.S. Forest Service, based in Missoula, Montana. That would be a huge shift, he explains: “It’s a keystone species. There are over 110 animals that depend on it, many insects, and hundreds of plants.” In the past, beetle larvae would take two years to complete their lifecycle, and many died in frost. “With climate change, we're seeing more and more beetles survive, and sometimes the beetle can complete its lifecycle in one year,” he says.
Quintessential crops are under threat too
As some pathogens move north and new ones develop, they pose novel threats to the crops humans depend upon. This is already happening to wheat, coffee, bananas and maize.
Breeding against wheat stem rust, a fungus long linked to famine, was a key success in the mid-20th century Green Revolution, which brought higher yields around the world. In 2013, wheat stem rust reemerged in Germany after decades of absence. It ravaged both bread and durum wheat in Sicily in 2016 and has spread as far as England and Ireland. Wheat blast disease, caused by a different fungus, appeared in Bangladesh in 2016, and spread to India, the world’s second largest producer of wheat.
Insects, moths, worms, and coffee leaf rust—a fungus now found in all coffee-growing countries—threaten the livelihoods of millions of people who grow coffee, as well as everybody’s cup of joe. More heat, more intense rain, and higher humidity have allowed coffee leaf rust to cycle more rapidly. It has grown exponentially, overcoming the agricultural chemicals that once kept it under control.
To identify new diseases and fine-tune crops for resistance, scientists are increasingly relying on genomic tools.
Tar spot, a fungus native to Latin America that can cut corn production in half, has emerged in highland areas of Central Mexico and parts of the U.S.. Meanwhile, maize lethal necrosis disease has spread to multiple countries in Africa, notes Mehrdad Ehsani, Managing Director for the Food Initiative in Africa of the Rockefeller Foundation. The Cavendish banana, which most people eat today, was bred to be resistant to the fungus Panama 1. Now a new fungus, Panama 4, has emerged on every continent–including areas of Latin America that rely on the Cavendish for their income, reported a recent story in the Guardian. New threats are poised to emerge. Potato growers in the Andes Mountains have been shielded from disease because of colder weather at high altitude, but temperature fluxes and warming weather are expected to make this crop vulnerable to potato blight, found plant pathologist Erica Goss, at the Emerging Pathogens Institute.
Science seeks solutions
To protect food supplies in the era of climate change, scientists are calling for integrated global surveillance systems for crop disease outbreaks. “You can imagine that a new crop variety that is drought-tolerant could be susceptible to a pathogen that previous varieties had some resistance against,” Goss says. “Or a country suffers from a calamitous weather event, has to import seed from another country, and that seed is contaminated with a new pathogen or more virulent strain of an existing pathogen.” Researchers at the John Innes Center in Norwich and Aarhus University in Denmark have established ways to monitor wheat rust, for example.
Better data is essential, for both plants and animals. Historically, models of climate change predicted effects on plant pathogens based on mean temperatures, and scientists tracked plant responses to constant temperatures, explains Goss. “There is a need for more realistic tests of the effects of changing temperatures, particularly changes in daily high and low temperatures on pathogens,” she says.
To identify new diseases and fine-tune crops for resistance, scientists are increasingly relying on genomic tools. Goss suggests factoring the impact of climate change into those tools. Genomic efforts to select soft red winter wheat that is resistant to Fusarium head blight (FHB), a fungus that plagues farmers in the Southeastern U.S., have had early success. But temperature changes introduce a new factor.
A fundamental solution would be to bring back diversification in farming, says Ehsani. Thousands of plant species are edible, yet we rely on a handful. Wild relatives of domesticated crops are a store of possibly useful genes that may confer resistance to disease. The same is true for livestock. “If you put all your eggs in one basket and then a pest comes along, then you are more vulnerable to those risks. Research is needed on resilient, climate smart, regenerative agriculture,” Ehsani says.
Jonathan Sleeman, director of the U.S. Geological Survey National Wildlife Health Center, has called for data on wildlife health to be systematically collected and integrated with climate and other variables because more comprehensive data will result in better preventive action. “We have focused on detecting diseases,” he says, but a more holistic strategy would apply human public health concepts to assuring animal wellbeing. (For example, one study asked experts to draw a diagram of relationships of all the factors affecting the health of a particular group of caribou.) We must not take the health of plants and animals for granted, because their vulnerability inevitably affects us too, Sleeman says. “We need to improve the resilience of wildlife populations so they can withstand the impact of climate change.”