Recursion, a drug company that builds its research around artificial intelligence, says its daily pill reduced the amount of polyp tissue in most people with familial adenomatous polyposis, or FAP, an inherited condition that fills the gut with polyps that can turn into cancer1. Based on talks with the US Food and Drug Administration (FDA), the company says it expects to start a larger trial meant to support approval in the second half of 20271. The pill is called REC-4881.
The updated results come from an ongoing trial called TUPELO. They were presented by Lisa Boardman, a gastroenterologist and professor of medicine at Mayo Clinic, at the annual meeting of the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer in Denver1. Recursion announced the data after markets closed on Monday, and its shares barely moved the next day1.
What the company reported
In the trial, people took the pill once a day for 12 weeks and were then checked again after 12 weeks off the drug1. The main measure was “polyp burden,” a way of adding up how much polyp tissue doctors see during a scope, not simply how many polyps there are.
- After 12 weeks on the pill, 13 of 15 people (87%) had less total polyp tissue than when they started1.
- The typical (median) drop was 47%, and about one in three people saw a drop of 65% or more1.
- All four people added since a November 2025 data snapshot had a reduction, including two with drops of 89% and 98%1.
- At week 25, after 12 weeks without the pill, 11 of 13 people (85%) were still below their starting level1.
Most treated patients also had fewer of the larger, higher-risk polyps, according to the company’s update1. Recursion argues that because the effect lasted after people stopped the drug, there may be room for flexible dosing schedules later1.
“REC-4881 is reducing the larger polyps that often drive much of the surgery for these [FAP] patients, across the GI tract from a single oral therapy,” Recursion’s president and CEO Najat Khan said in a statement1.
How the results have changed over the year
This is not the first look at these data. In February, Recursion reported results from 12 evaluable patients: 75% had less polyp tissue after 12 weeks, with a typical drop of 43%2. After 12 weeks off the drug, 9 of 11 had kept a reduction, with a typical drop of 53% from where they started2. In May the company added that 40% of patients had improved on the Spigelman stage, a standard score doctors use to grade polyps in the upper small intestine3.
On safety, the February update said most drug-related side effects were mild or moderate (grade 1 or 2). More serious grade 3 events occurred in 15.8% of patients, and no grade 4 or worse events had been reported2. The most common side effects were an acne-like rash and a rise in CPK, a muscle enzyme measured in the blood2. The company describes this as consistent with other drugs that block the same target2. The new report summarized in coverage did not give updated safety figures.
What these results do not show yet
The trial is small. The registry lists a planned total of 67 participants across two parts, and the study is still recruiting, with its main results expected around June 20274. The registry record includes a placebo (dummy pill) arm4, but the figures released so far describe changes in people taking the drug compared with their own starting point, not a head-to-head comparison with placebo.
The results were shared at a medical meeting and through the company. They have not been published in a peer-reviewed journal. The study also measured polyp tissue over months. It was not designed to show whether the pill lowers cancer rates or lets people put off or avoid surgery, which are the outcomes patients care about most. That is the kind of question a larger, longer trial would need to answer.
Timing is also uncertain. Recursion said its 2027 plan depends on its continuing talks with the FDA, and that it will give more details later this year1.
Who is behind the drug
REC-4881 did not start at Recursion. Takeda first developed it under the name TAK-733 and used Recursion’s AI platform to look for areas of cancer where the drug might help1. The drug blocks two proteins called MEK1 and MEK2, which are part of a signaling chain that tells cells to grow1. Recursion says its platform found that tuning this pathway mattered in cells missing the APC gene, the gene whose loss drives FAP3.
Recursion licensed the drug from Takeda in 2020. It agreed to pay $1.5 million upfront, up to $39.5 million more tied to development and regulatory milestones, and small royalties on future sales1. Recursion has called the FAP results the first clinical validation of its AI-driven approach2, and Khan described REC-4881 as “the clearest proof point yet of what we built Recursion to do”1. That gives the company a strong business interest in how these results are read.
Recursion reported a net loss of $117.5 million in the first quarter of 20263. In February it said it had $754 million in cash and expected that to last into early 2028 without raising more money2.
How it fits the field
For people with FAP, care has long meant scopes for life and, eventually, surgery to remove the colon before cancer develops1. “People have been doing research in the chemoprevention space in FAP for decades, and at least in the United States, we still don’t have an agent that is FDA approved,” said Bryson Katona, a TUPELO investigator who directs the GI Cancer Genetics Program at the University of Pennsylvania1.
How many people have FAP is not settled. Recursion counts more than 50,000 patients in the United States and five large European countries, while other estimates put it at about one in 6,800 to 31,000 people worldwide, including about one in 5,000 to 10,000 Americans1.
Recursion is not alone. Biodexa Pharmaceuticals is running a late-stage trial of eRapa, a tablet form of the drug rapamycin (sirolimus), and said last month it had enrolled 100 patients1. That trial compares eRapa with a placebo, plans to enroll 168 people, and measures whether the disease gets worse over three years5. Its main results are not expected until around July 20305. Tempest Therapeutics is also testing a pill, TPST-1495, in a mid-stage trial of about 38 people, with main results expected by the end of June 20271.
What to watch next
- Details later this year on what the FDA wants to see in a larger trial, and whether the second-half 2027 start holds1.
- Full results from TUPELO, including any comparison with the placebo arm, with main results listed for around June 20274.
- Results from the expansion of the trial to include adults aged 18 and older, which Recursion says supports a broader plan for the drug2.
- Updated safety data as more people take the pill for longer.
Until then, the results show that a small group of people with FAP had less polyp tissue while taking the pill and for some weeks after stopping. Whether that turns into fewer cancers or fewer surgeries is still unknown.
