Executives from Q32 Bio (NASDAQ:QTTB) detailed progress on the company’s lead program, bempikibart, during a discussion at Oppenheimer’s 36th Annual Life Science Conference, emphasizing upcoming data in alopecia areata (AA) and a sharpened corporate focus following the divestiture of a non-core asset.
Lead program: bempikibart and its mechanism
Chief Executive Officer Jodie Morrison described bempikibart as a fully human antibody that binds the IL-7 alpha receptor and blocks signaling of two cytokines associated with Th2 and Th1 pathways. Management said the drug’s breadth could translate across multiple diseases, but the company is currently “laser-focused” on advancing bempikibart in alopecia areata.
SIGNAL-AA Phase IIa: Part A results and durability observations
Management pointed to proof-of-concept data from Part A of the SIGNAL-AA Phase IIa study, which read out at the end of 2024. Morrison said Part A showed a meaningful and statistically significant drop in SALT (Severity of Alopecia Tool) percentage, with responses observed in both per-protocol and intent-to-treat analyses.
She also highlighted what the company characterized as durability following dosing cessation in Part A, with some patients showing stable outcomes—and in some cases additional hair growth—after the last dose at week 24. Morrison contrasted this with what she described as rapid hair loss after discontinuation of JAK inhibitors. The company also conducted additional follow-up beyond week 36 in certain patients and said it observed continued durability and, in some cases, significant hair growth, including through approximately week 55 for some patients.
From a patient-characteristics standpoint, Morrison said responses were seen in “hard-to-treat” populations, including patients with longer disease duration and both severe and very severe populations. She also noted the mean current episode duration in Part A was more than five years, which she described as higher than in JAK studies.
On safety, Morrison said the Part A profile was consistent with expectations for a biologic and supportive of competitive positioning versus JAK inhibitors.
Part B design changes and expected timing
The company has initiated Part B of SIGNAL-AA and enrolled 33 patients, exceeding an original goal of 20 evaluable patients, according to management. Morrison attributed strong enrollment interest to the drug’s safety profile and the potential for durability and a cycling paradigm.
Part B includes a 36-week dosing period followed by a 16-week follow-up, with a 200 mg dose (the same dose used in Part A). Patients receive a four-week loading regimen followed by 32 weeks of every-other-week dosing. Morrison said the company expects top-line data at week 36 by midyear 2026 and expects remission-related follow-up data out to week 52 later in the year.
Key Part B modifications versus Part A, as described during the event, included:
- Central eligibility review to confirm diagnosis and eligibility at the front end of the study.
- Reduced duration of episode to less than four years, aligning more closely with JAK study populations; Morrison said Part B’s duration was lowered to approximately two years.
- Operational changes using a functional service model and more direct oversight and site relationships rather than relying entirely on CRO execution, which the company said should support trial control and retention.
Morrison also said preliminary pharmacokinetic data indicate the Part B loading regimen is achieving steady state about nine weeks earlier than in Part A, with patients held at steady state longer due to extended dosing.
What management said investors should watch
In discussing upcoming data, Morrison said investors are likely to focus on mean percent change in SALT and SALT 20 responses, adding that SALT 20 is expected to be a key endpoint in Phase III based on precedent from JAK programs. She also referenced injection-site reaction (ISR) rates as an important consideration for injectable biologics and said the company has seen low and mild ISRs to date.
Asked what efficacy would support a move to Phase III, Morrison referenced a “9%–14% SALT 20” observation from Part A and said the company is aiming to be above that, describing “mid-20s” as a goal and characterizing the 20%–25% range as a gating point for SALT 20.
Commercial positioning and additional indications
Chief Financial Officer Lee Kalowski described the alopecia areata opportunity as substantial, arguing that limited JAK penetration—alongside use of non-approved options such as minoxidil—underscores demand for alternatives. He said the company believes a safer biologic with more durable responses could both penetrate and expand the market, drawing a comparison to biologic-driven market growth seen in atopic dermatitis.
On sequencing, Morrison said the company expects bempikibart would be used before JAK inhibitors, consistent with other markets where biologics are positioned ahead of JAKs, and said there could be an opportunity over time to move earlier in disease severity.
While reiterating that AA remains the priority, Chief Scientific Officer Shelia Violette said the drug’s biology could have broader application, particularly in diseases driven by pathogenic T cells. She cited ulcerative colitis and celiac disease as areas of interest and said she remains encouraged by prior Phase II atopic dermatitis biomarker changes. She also listed other possible areas where dual pathway impact could matter, including rheumatoid arthritis, asthma, COPD, multiple sclerosis, and type 1 diabetes.
Separately, Kalowski discussed the company’s completed sale of ADX-097 to Akebia in the fourth quarter, saying the transaction aligned with a previously announced effort to seek strategic alternatives for its tissue-targeted complement platform to focus on bempikibart. He said the deal included $12 million in upfront and near-term milestones, with eligibility for up to about $592 million in total milestones plus royalties.
Management closed by reiterating that the midyear top-line readout for Part B remains on track and said the target product profile—combining safety, ISR profile, durability potential, and efficacy—will be central to how clinicians and patients evaluate the therapy if development continues successfully.
About Q32 Bio (NASDAQ:QTTB)
Q32 Bio Inc, a clinical-stage biotechnology company, develops biologic therapeutics to restore healthy immune balance in patients with autoimmune and inflammatory diseases driven by pathological immune dysfunction in the United States. Its lead product candidate is ADX-097, a humanized anti-C3d monoclonal antibody fusion protein to restore complement regulation, which has completed Phase I clinical trial for the treatment of renal and other complement-mediated diseases of high unmet need, including lupus nephritis, immunoglobulin A nephropathy, complement component 3 glomerulopathy, and anti-neutrophil cytoplasmic antibody-associated vasculitis.
