Q32 Bio, a Massachusetts biotech company, says that hair regrowth seen in its trial of an experimental antibody shot for alopecia areata did not fade once people stopped taking it. In a filing with US regulators on November 4, the company said responses were “maintained or deepened” during a 16-week period off the drug, with no new safety concerns1.
The same filing says the company had $289.6 million in cash at the end of September, which it believes is enough to keep running until the first results from the larger trials it plans next1. The findings are the company’s own report from a small trial in which every participant got the drug.
What happened
Alopecia areata is an autoimmune disease: the immune system attacks hair follicles, and hair falls out in patches or across the whole scalp. About 700,000 people in the United States live with it, according to figures from the National Alopecia Areata Foundation cited by the company2.
Q32 Bio’s drug, called bempikibart, is an antibody, a lab-made protein that latches onto a specific target. It is designed to block two immune signals, known as IL-7 and TSLP, and in doing so to “re-regulate” part of the immune system2. The company says these signaling pathways have been linked by genetic and biological research to immune attacks in several autoimmune diseases2.
The new report covers the second part, called Part B, of a mid-stage trial named SIGNAL-AA. It enrolled 33 people with severe or very severe alopecia areata1. People were treated for 36 weeks and followed up to week 523, which leaves the 16 weeks off the drug that the new update describes. The shots were given weekly for the first four doses, then every other week3.
The evidence so far
Hair loss in this disease is measured with a scale called the Severity of Alopecia Tool, or SALT, which scores how much of the scalp has lost its hair. A “SALT-20 response” means a score of 20 or lower, or roughly 80% of the scalp covered with hair14.
The company reported these results at week 36, the end of treatment1:
- Average improvement: SALT scores fell by 35.3% on average from the start of the trial, in the company’s pre-planned main analysis1.
- Reaching about 80% coverage, main analysis: 40.0% of people1.
- Reaching about 80% coverage, everyone enrolled: 30.3% of all 33 people1.
The two percentages differ because they count different groups. The main analysis, called “modified intent-to-treat,” leaves out some participants, while the second counts every person who enrolled1. The filing does not say how many people were left out of the main analysis or why. The more cautious figure, counting everyone, is 30.3%.
These headline numbers were first shared in July. Global Genes, a rare-disease news outlet, reported then that about 40% of treated patients reached at least 80% scalp coverage, that results were lower when all enrolled patients were counted, and that researchers had seen “early signs” the benefit might persist after treatment stopped4. The November filing is the company’s first statement that responses held through the full 16 weeks off the drug1.
On safety, Global Genes reported that the drug was generally well tolerated, with no serious safety issues, and that the most common side effect was mild reactions where the shot was given4. The new filing reports no new safety signals during the off-drug period1.
What it does not show yet
This part of the trial was “open-label,” meaning everyone knew they were getting the real drug and there was no group given a placebo (a dummy shot) for comparison2. Hair in alopecia areata can sometimes grow back on its own, so without a comparison group it is not possible to tell how much of the regrowth came from the drug.
The trial is also small. With 33 people, a few patients more or fewer reaching the 80% mark changes the percentages noticeably. And the results come from a company filing and press materials, not a paper checked by outside scientists. Global Genes reported that more data from the study are expected to be presented at a future medical meeting4.
The off-drug finding is described only in general terms. The filing says responses were “maintained or deepened” but, in the summary available, does not give the share of people still at 80% coverage at week 521. Sixteen weeks is also a limited window; whether regrowth lasts longer is still open. The company says longer-term data from an extension study, where earlier patients kept getting the drug, are expected in the second half of 20271.
Who is behind it
All of the trial results come from Q32 Bio, which develops and would profit from the drug. The company’s chief executive is Jodie Morrison, and its co-founder and chief scientific officer is Shelia Violette34.
The company’s finances have changed sharply in a year. In September 2025 it had $49.0 million in cash, which it said would last into 20273. In July 2026, after the trial results, it raised about $200.0 million in a public stock sale, before fees1. It now reports $289.6 million in cash1. Its loss for the July-to-September quarter was $8.9 million, up from $7.4 million a year earlier, with research spending rising to $5.1 million1.
Q32 Bio has narrowed its focus to this drug. It stopped a mid-stage trial of another drug, ADX-0973, and in November 2025 sold that program to Akebia Therapeutics for $7.0 million up front, a further $3.0 million six months later, and possible future payments5.
Violette described the July results this way:
“These results provide further evidence that our differentiated approach to targeting the biology underlying alopecia areata has the potential to translate into meaningful and durable clinical benefit for patients.”
That is the company’s interpretation4.
How it fits the field
People with alopecia areata already have some approved options. Global Genes noted that newer drugs called JAK inhibitors are available but may not work for everyone and can carry safety concerns4. Q32 Bio has said patients need “new, safer and more durable” alternatives to currently approved drugs3.
The off-drug result matters because of that word “durable.” If regrowth lasted after stopping, people might not need to stay on treatment indefinitely. Q32 Bio had already pointed to signs of a lasting effect in long-term follow-up of patients from the first part of the trial, Part A, and opened an extension study in April 2025 so those patients could keep being followed3. Both parts were small and uncontrolled, so this idea still needs testing in larger studies.
Part B was changed along the way. It was first planned for about 20 people and grew to 33 because of demand from patients and doctors, the company said2. It also added a starting “loading” schedule of weekly shots, which the company said brought drug levels to a steady state at least nine weeks sooner than in Part A2.
What to watch next
- Talks with regulators: Q32 Bio plans discussions with regulators in the last quarter of 20261.
- Larger trials: the company expects to start a program of larger trials aimed at approval in the first half of 2027, depending on those discussions1. It has not yet disclosed how those trials will be designed, including how many people they will enroll or whether they will compare the drug with a placebo.
- Full data: more detail from this trial is expected at a medical meeting4, which may show how many people kept their regrowth at week 52.
- Longer follow-up: extension study data are expected in the second half of 20271.
Biohack will follow this thread as those results arrive. For another recent hair-loss story, see our report on a broccoli compound tested in lab cells, which concerns a different, hormone-driven type of hair loss.
