Second carcass-eating fly species cleared by FDA for maggot wound therapy - Ars Technica

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The Food and Drug Administration this week cleared a second carcass-feasting fly species for use in maggot wound therapy, according to an announcement from Cuprina Holdings, a Singapore-based company that has dubbed its new therapeutic larvae MediFly Maggots.

With the clearance, Cuprina appears to be the only company to have FDA clearance to sell two species of fly larvae—and it’s abuzz with the potential to dominate the global maggot market.

The new species is Lucilia cuprina, or Australian sheep blowfly. It’s a close relative of Lucilia sericata, or the common green bottle fly, which is the fly species most often used for wound therapy, often called biosurgery or maggot debridement therapy (MDT). L. sericata is the only other fly with FDA clearance, which the agency first granted in 2004 to Ronald Sherman, who is now Cuprina’s Medical and Scientific Director.

“We now hold FDA clearance for both species used in MDT, a position no other company holds,” Cuprina CEO David Quek said in a statement. “This anchors our wound-care platform in one of the world’s most demanding regulatory markets and gives us a defensible edge as we continue to build our portfolio.”

The company makes no claims of any significant therapeutic difference between the two maggot treatments. Rather, they are seen as fitting into different markets. L. sericata is more familiar in Western wound care, Cuprina says, while L. cuprina may have more recognition in Australia, Africa, Asia, and parts of the Americas.

For his part, Sherman, a long-time champion of wriggling remedies, cheered the clearance as a step forward for MDT generally. “Maggot debridement therapy has earned its place in modern wound care, and adding a second FDA-cleared species strengthens the entire field,” Sherman said. “Lucilia cuprina has a meaningful international track record, and bring[ing] it under US FDA clearance gives clinicians and their patients more flexibility in how this therapy is delivered.”

Niche wigglers

The idea of allowing baby flies to help clean out wounds dates back centuries, but has yet to be embraced by modern medicine—for various reasons. The most obvious is the “ick” factor, which zaps enthusiasm from both patients and healthcare providers. This has led some larvae lovers to push for a rebrand, such as reframing larvae as adorable newborn flies, wee walruses, or maggies.

It likely doesn’t help the effort that the L. curprina clearance lands as the US is facing an invasion of New World screwworm—a parasitic fly whose larvae feast on living flesh, causing horrific wounds on a wide variety of warm-blooded creatures and threatening millions of dollars in damage to the livestock industry.

The two Lucilia species used in MDT are not considered parasitic. They mainly feast on carrion—though L. cuprina can cause a parasitic infestation in sheep called flystrike. In well-controlled MDT use, they feast only on dead and decaying tissue in wounds.

Perhaps the biggest reason MDT hasn’t taken off is that it’s not backed by solid evidence. While small, low-quality studies have indicated that maggot therapy is safe and effective at wound debridement, robust trials and evidence are lacking. As such, the treatment remains niche and is sometimes seen as a last resort for patients who refuse or are poor candidates for surgical or other standard debridement methods.

The hypothesis behind MDT is appealing if the maggots aren’t. To treat chronic, unhealing wounds, such as diabetic ulcers in the feet and legs, sterilized maggots are placed in the wound and secrete enzymes to liquify necrotic tissue. They then wiggle around to consume the slurry from all the nooks and crannies of a wound, which may be less painful and more efficient than surgical methods that try to slice out necrotic tissue. The maggots are thought to secrete various antibacterial compounds to ward off pathogenic bacteria and block biofilms from forming, overall preventing secondary infection. Finally, the activity of the maggots may also stimulate tissue regrowth.

Interesting infestations

While the evidence for all of that remains slim, some researchers have reported benefits from unintentional maggots in wounds, which often go unreported in healthcare settings. In a 2018 report of two cases with accidental maggot infestation in unhealing wounds, researchers in Chicago noted that the maggots appeared helpful. “Accidental myiasis may have been a blessing in...