Recent advancements in engineering mean that the first preclinical trials for an artificial kidney could happen soon.
Like all those whose kidneys have failed, Scott Burton’s life revolves around dialysis. For nearly two decades, Burton has been hooked up (or, since 2020, has hooked himself up at home) to a dialysis machine that performs the job his kidneys normally would. The process is arduous, time-consuming, and expensive. Except for a brief window before his body rejected a kidney transplant, Burton has depended on machines to take the place of his kidneys since he was 12-years-old. His whole life, the 39-year-old says, revolves around dialysis.
“Whenever I try to plan anything, I also have to plan my dialysis,” says Burton says, who works as a freelance videographer and editor. “It’s a full-time job in itself.”
Many of those on dialysis are in line for a kidney transplant that would allow them to trade thrice-weekly dialysis and strict dietary limits for a lifetime of immunosuppressants. Burton’s previous transplant means that his body will likely reject another donated kidney unless it matches perfectly—something he’s not counting on. It’s why he’s enthusiastic about the development of artificial kidneys, small wearable or implantable devices that would do the job of a healthy kidney while giving users like Burton more flexibility for traveling, working, and more.
Still, the devices aren’t ready for testing in humans—yet. But recent advancements in engineering mean that the first preclinical trials for an artificial kidney could happen soon, according to Jonathan Himmelfarb, a nephrologist at the University of Washington.
“It would liberate people with kidney failure,” Himmelfarb says.
An engineering marvel
Compared to the heart or the brain, the kidney doesn’t get as much respect from the medical profession, but its job is far more complex. “It does hundreds of different things,” says UCLA’s Ira Kurtz.
Kurtz would know. He’s worked as a nephrologist for 37 years, devoting his career to helping those with kidney disease. While his colleagues in cardiology and endocrinology have seen major advances in the development of artificial hearts and insulin pumps, little has changed for patients on hemodialysis. The machines remain bulky and require large volumes of a liquid called dialysate to remove toxins from a patient’s blood, along with gallons of purified water. A kidney transplant is the next best thing to someone’s own, functioning organ, but with over 600,000 Americans on dialysis and only about 100,000 kidney transplants each year, most of those in kidney failure are stuck on dialysis.
Part of the lack of progress in artificial kidney design is the sheer complexity of the kidney’s job. Each of the 45 different cell types in the kidney do something different.
Part of the lack of progress in artificial kidney design is the sheer complexity of the kidney’s job. To build an artificial heart, Kurtz says, you basically need to engineer a pump. An artificial pancreas needs to balance blood sugar levels with insulin secretion. While neither of these tasks is simple, they are fairly straightforward. The kidney, on the other hand, does more than get rid of waste products like urea and other toxins. Each of the 45 different cell types in the kidney do something different, helping to regulate electrolytes like sodium, potassium, and phosphorous; maintaining blood pressure and water balance; guiding the body’s hormonal and inflammatory responses; and aiding in the formation of red blood cells.
There's been little progress for patients during Ira Kurtz's 37 years as a nephrologist. Artificial kidneys would change that.
UCLA
Dialysis primarily filters waste, and does so well enough to keep someone alive, but it isn’t a true artificial kidney because it doesn’t perform the kidney’s other jobs, according to Kurtz, such as sensing levels of toxins, wastes, and electrolytes in the blood. Due to the size and water requirements of existing dialysis machines, the equipment isn’t portable. Physicians write a prescription for a certain duration of dialysis and assess how well it’s working with semi-regular blood tests. The process of dialysis itself, however, is conducted blind. Doctors can’t tell how much dialysis a patient needs based on kidney values at the time of treatment, says Meera Harhay, a nephrologist at Drexel University in Philadelphia.
But it’s the impact of dialysis on their day-to-day lives that creates the most problems for patients. Only one-quarter of those on dialysis are able to remain employed (compared to 85% of similar-aged adults), and many report a low quality of life. Having more flexibility in life would make a major different to her patients, Harhay says.
“Almost half their week is taken up by the burden of their treatment. It really eats away at their freedom and their ability to do things that add value to their life,” she says.
Art imitates life
The challenge for artificial kidney designers was how to compress the kidney’s natural functions into a portable, wearable, or implantable device that wouldn’t need constant access to gallons of purified and sterilized water. The other universal challenge they faced was ensuring that any part of the artificial kidney that would come in contact with blood was kept germ-free to prevent infection.
As part of the 2021 KidneyX Prize, a partnership between the U.S. Department of Health and Human Services and the American Society of Nephrology, inventors were challenged to create prototypes for artificial kidneys. Himmelfarb’s team at the University of Washington’s Center for Dialysis Innovation won the prize by focusing on miniaturizing existing technologies to create a portable dialysis machine. The backpack sized AKTIV device (Ambulatory Kidney to Increase Vitality) will recycle dialysate in a closed loop system that removes urea from blood and uses light-based chemical reactions to convert the urea to nitrogen and carbon dioxide, which allows the dialysate to be recirculated.
Himmelfarb says that the AKTIV can be used when at home, work, or traveling, which will give users more flexibility and freedom. “If you had a 30-pound device that you could put in the overhead bins when traveling, you could go visit your grandkids,” he says.
Kurtz’s team at UCLA partnered with the U.S. Kidney Research Corporation and Arkansas University to develop a dialysate-free desktop device (about the size of a small printer) as the first phase of a progression that will he hopes will lead to something small and implantable. Part of the reason for the artificial kidney’s size, Kurtz says, is the number of functions his team are cramming into it. Not only will it filter urea from blood, but it will also use electricity to help regulate electrolyte levels in a process called electrodeionization. Kurtz emphasizes that these additional functions are what makes his design a true artificial kidney instead of just a small dialysis machine.
One version of an artificial kidney.
UCLA
“It doesn't have just a static function. It has a bank of sensors that measure chemicals in the blood and feeds that information back to the device,” Kurtz says.
Other startups are getting in on the game. Nephria Bio, a spinout from the South Korean-based EOFlow, is working to develop a wearable dialysis device, akin to an insulin pump, that uses miniature cartridges with nanomaterial filters to clean blood (Harhay is a scientific advisor to Nephria). Ian Welsford, Nephria’s co-founder and CTO, says that the device’s design means that it can also be used to treat acute kidney injuries in resource-limited settings. These potentials have garnered interest and investment in artificial kidneys from the U.S. Department of Defense.
For his part, Burton is most interested in an implantable device, as that would give him the most freedom. Even having a regular outpatient procedure to change batteries or filters would be a minor inconvenience to him.
“Being plugged into a machine, that’s not mimicking life,” he says.
This article was first published by Leaps.org on May 5, 2022.
Photo by JPC-PROD on Adobe Stock
These new products have their own pros and cons. Still, doctors are welcoming new contraceptives following a long drought in innovation. "It's been a long time since we've had something new in the world of contraception," says Heather Irobunda, an obstetrician and gynecologist at NYC Health and Hospitals.
On social media, Irobunda often fields questions about one of these new options, a lubricating gel called Phexxi. San Diego-based Evofem, the company behind Phexxi, has been advertising the product on Hulu and Instagram after the gel was approved by the Food and Drug Administration in May 2020. The company's trendy ads target women who feel like condoms diminish the mood, but who also don't want to mess with an IUD or hormones.
Here's how it works: Phexxi is inserted via a tampon-like device up to an hour before sex. The gel regulates vaginal pH — essentially, the acidity levels — in a range that's inhospitable to sperm. It sounds a lot like spermicide, which is also placed in the vagina prior to sex to prevent pregnancy. But spermicide can damage the vagina's cell walls, which can increase the risk of contracting sexually transmitted diseases.
"Not only is innovation needed, but women want a non-hormonal option."
Phexxi isn't without side effects either. The most common one is vaginal burning, according to a late-stage trial. It's also possible to develop a urinary tract infection while using the product. That same study found that during typical use, Phexxi is about 86 percent effective at preventing pregnancy. The efficacy rate is comparable to condoms but lower than birth control pills (91 percent) and significantly lower than an IUD (99 percent).
Phexxi – which comes in a pack of 12 – represents a tiny but growing part of the birth control market. Pharmacies dispensed more than 14,800 packs from April through June this year, a 65 percent increase over the previous quarter, according to data from Evofem.
"We've been able to demonstrate that not only is innovation needed, but women want a non-hormonal option," says Saundra Pelletier, Evofem's CEO.
Beyond contraception, the company is carrying out late-stage tests to gauge Phexxi's effectiveness at preventing the sexually transmitted infections chlamydia and gonorrhea.
Phexxi is inserted via a tampon-like device up to an hour before sex.
Phexxi
A New Pill
The first birth control pill arrived in 1960, combining the hormones estrogen and progestin to stop sperm from joining with an egg, giving women control over their fertility. Subsequent formulations sought to ease side effects, by way of lower amounts of estrogen. But some women still experience headaches and nausea – or more serious complications like blood clots. On social media, women noted that birth control pills are much more likely to cause blood clots than Johnson & Johnson's COVID-19 vaccine that was briefly paused to evaluate the risk of clots in women under age 50. What will it take, they wondered, for safer birth control?
Mithra Pharmaceuticals of Belgium sought to create a gentler pill. In April 2021, the FDA approved Mithra's Nextstellis, which includes a naturally occurring estrogen, the first new estrogen in the U.S. in 50 years. Nextstellis selectively acts on tissues lining the uterus, while other birth control pills have a broader target.
A Phase 3 trial showed a 98 percent efficacy rate. Andrew London, an obstetrician and gynecologist, who practices at several Maryland hospitals, says the results are in line with some other birth control pills. But, he added, early studies indicate that Nextstellis has a lower risk of blood clotting, along with other potential benefits, which additional clinical testing must confirm.
"It's not going to be worse than any other pill. We're hoping it's going to be significantly better," says London.
The estrogen in Nexstellis, called estetrol, was skipped over by the pharmaceutical industry after its discovery in the 1960s. Estetrol circulates between the mother and fetus during pregnancy. Decades later, researchers took a new look, after figuring out how to synthesize estetrol in a lab, as well as produce estetrol from plants.
"That allowed us to really start to investigate the properties and do all this stuff you have to do for any new drug," says Michele Gordon, vice president of marketing in women's health at Mayne Pharma, which licensed Nextstellis.
Bonnie Douglas, who followed the development of Nextstellis as part of a search for better birth control, recently switched to the product. "So far, it's much more tolerable," says Douglas. Previously, the Midwesterner was so desperate to find a contraceptive with fewer side effects that she turned to an online pharmacy to obtain a different birth control pill that had been approved in Canada but not in the U.S.
Contraceptive Access
Even if a contraceptive lands FDA approval, access poses a barrier. Getting insurers to cover new contraceptives can be difficult. For the uninsured, state and federal programs can help, and companies should keep prices in a reasonable range, while offering assistance programs. So says Kelly Blanchard, president of the nonprofit Ibis Reproductive Health. "For innovation to have impact, you want to reach as many folks as possible," she says.
In addition, companies developing new contraceptives have struggled to attract venture capital. That's changing, though.
In 2015, Sabrina Johnson founded DARÉ Bioscience around the idea of women's health. She estimated the company would be fully funded in six months, based on her track record in biotech and the demand for novel products.
But it's been difficult to get male investors interested in backing new contraceptives. It took Johnson two and a half years to raise the needed funds, via a reverse merger that took the company public. "There was so much education that was necessary," Johnson says, adding: "The landscape has changed considerably."
Johnson says she would like to think DARÉ had something to do with the shift, along with companies like Organon, a spinout of pharma company Merck that's focused on reproductive health. In surveying the fertility landscape, DARÉ saw limited non-hormonal options. On-demand options – like condoms – can detract from the moment. Copper IUDs must be inserted by a doctor and removed if a woman wants to return to fertility, and this method can have onerous side effects.
So, DARÉ created Ovaprene, a hormone-free device that's designed to be inserted into the vagina monthly by the user. The mesh product acts as a barrier, while releasing a chemical that immobilizes sperm. In an early study, the company reported that Ovaprene prevented almost all sperm from entering the cervical canal. The results, DARÉ believes, indicate high efficacy. Should Ovaprene eventually win regulatory approval, drug giant Bayer will handle commercializing the device.
Other new forms of birth control in development are further out, and that's assuming they perform well in clinical trials. Among them: a once-a-month birth control pill, along with a male version of the birth control pill. The latter is often brought up among women who say it's high time that men take a more proactive role in birth control.
For Summers, her search for a safe and convenient birth control continues. She tried Phexxi, which caused irritation. Still, she's excited that a non-hormonal option now exists. "I'm sure it will work for others," she says.
This article was first published by Leaps.org on August 31, 2021.