It was the best of times, it was the worst of times for research in 2025. Medical breakthroughs and stunning discoveries were paired with the undermining of the very foundation of American science as the Trump administration began dismantling the federal funding apparatus that has supported biomedical research in this country since World War II.
But all of that is a bit too intense for the holiday season.
Let’s instead wrap up this wild year by highlighting the positives: Here are some of Fierce’s favorite research stories from 2025.
That’s history, baby
The prize for top science story of the year easily goes to KJ Muldoon, who stole our hearts by becoming the first person to receive a custom CRISPR gene therapy. After displaying symptoms of a rare metabolic disease just after birth, scientists at the Children’s Hospital of Philadelphia (CHOP) and Penn Medicine raced to prepare a custom gene editing therapy to correct the genetic mutations causing KJ's illness.
His condition was initially so severe that if a doctor hadn’t noticed something was wrong right away, “he wouldn’t have made it to day five,” KJ’s mother Nicole Muldoon said during a May 12 press briefing.
KJ was born with genetic mutations that cause a urea cycle disorder called carbamoyl phosphate synthetase 1 deficiency, which is when patients lack an enzyme important for processing ammonia during protein digestion. Without enough of this enzyme, ammonia builds up to toxic levels, threatening serious brain injury and death.
Since his treatment, KJ has been hitting milestone after milestone and was able to go home with his parents. He is now walking, as adorable new photos from CHOP demonstrate.
Scientists are determined to make sure KJ’s story isn’t a one-off. His doctors hope to pioneer an approach they call “interventional genetics,” where therapeutic gene edits are given to patients with the precision and personalization of surgery. Other members of the team that crafted KJ’s treatment followed up with a different personalized CRISPR therapy that corrected the mutation behind a rare blood vessel disease in mice.
In July, the Center for Pediatric CRISPR Cures launched with $20 million from the Chan Zuckerberg Initiative and the Innovative Genomics Institute to treat more babies born with genetic diseases.
And, in September, the Advanced Research Projects Agency for Health unveiled two new funding opportunities meant to support those working on custom gene editing therapies.
FDA officials Vinay Prasad, M.D., and Martin Makary, M.D., seem to be on board, too, outlining a novel regulatory pathway for bespoke gene editing therapies in a November article.
Here’s hoping the world welcomes many more like KJ in 2026 and beyond!
Building new antibiotics from scratch
The biotech industry has been feverish with excitement over generative AI all year, though the technology has thus far not resulted in new medicines being developed and approved faster than before. But, in August, we finally got a taste of what this much-hyped technology can do: cook up never-before-seen antibiotics from scratch.
The work was done in the lab of James Collins, Ph.D., a synthetic biologist at the Broad Institute of MIT and Harvard who is a leading expert on antibiotic development.
Collins’ team has been trying to understand how antibiotics work and how to make new ones for more than two decades. He launched a collaboration in 2018 with two AI experts at MIT to develop deep learning models that can screen chemicals for antibiotic activity. This led to the 2020 discovery of a new antibiotic called halicin and, in late 2023, an improved model revealed an entirely new class of bacteria-killing compounds hidden within a vast chemical library.
After these successes, the team decided to aim higher: using models not to discover antibiotics but to design entirely new ones.
The first of these models was trained on compounds known to be effective against gonorrhea. The model analyzed fragments of the chemicals and rated their antibacterial activity, finding that one structure, called F1, seemed particularly potent. Using F1 as a starting point, the model iteratively added elements and judged the resulting compounds’ potential to subdue bacteria as it went, a kind of antibiotic improv.
The second model did something similar, but, instead of starting from a molecule fragment, it built new compounds starting from a single atom. These two models ultimately "yes, and"-ed their way to two novel antibiotic candidates.
Collins is now working with Phare Bio, a nonprofit antibiotic developer he co-founded in 2020, to move the two new antibiotics into the clinic. With antibiotic resistance one of the most pernicious threats facing humanity, we're hoping these and other new compounds survive their clinical auditions and make their debuts in hospitals around the world.
Tyrannosaurus reg
Before the October announcement that their discoverers had won the Nobel Prize, you’d be in good company if you hadn't heard of regulatory T cells. Tregs, as they’re known, are rare but potent immune cells that patrol our bodies for self-reactive T cells to tame, fighting off autoimmune disease in the process.
The prize went to Mary Brunkow, Ph.D., Fred Ramsdell, Ph.D., and Shimon Sakaguchi, M.D., Ph.D. Sakaguchi discovered that a population of T cells expressing the interleukin-2 receptor alpha chain (known as CD25) were responsible for protecting mice from autoreactive immune cells. Brunkow and Ramsdell collaborated at Celltech (acquired by UCB) to piece together how a gene called Foxp3 controls the creation of these cells, now known as Tregs.
Just a few weeks after winning the Nobel Prize, Sakaguchi and colleagues published two papers showing how rogue T cells can be converted into Tregs to treat a suite of autoimmune diseases.
There are currently no approved therapies that use Tregs, but that’s likely to change next year. Bay Area-based Orca Bio is expecting an approval decision from the FDA for its Orca-T cell therapy, which contains a cocktail of Tregs, stem cells and other T cells, by April 6, 2026.
And a host of other companies, including Ramsdell’s own Sonoma Biotherapeutics, is endeavoring to turn the prize-winning discovery into tangible treatments for patients with autoimmune and inflammatory diseases.
“I think the best answer is that these things become a universal drug,” Ramsdell told Fierce in October. An off-the-shelf Treg therapy could, in theory, be tuned to target any disease-ridden tissue and even engineered to directly support tissue repair. “If you could do this in a universal manner, then I think you could address an enormous number of inflammatory diseases.”
Honorable mentions
A few of the other stellar science stories that stood out this year include: rigorous experiments revealing new targets for tuberculosis vaccines; a common diabetes drug that could be repurposed for multiple sclerosis; an antibody from Denali Therapeutics that cleared amyloid plaques without dangerous brain bleeds; how disappearing Y chromosomes worsen cancer outcomes; and the discovery of the expanding gene behind Huntington’s disease.