All three patients are transfusion-independent with no vaso-occlusive events; predominant adult hemoglobin profile restored, with sickle hemoglobin below 20% beyond six months
Data to be featured in an oral presentation at the 68th ASH Annual Meeting on December 14, 2026
SAN FRANCISCO, Nov. 4, 2026 — Kamau Therapeutics, a clinical-stage company creating medicines that endure by precisely engineering patients’ own blood stem cells, today announced that new clinical data, including the first results from its optimized manufacturing process, from the ongoing Phase 1/2 RESTORE trial of nula-cel in severe sickle cell disease have been accepted for an oral presentation at the 68th American Society of Hematology (ASH) Annual Meeting, taking place December 12–15, 2026, in New Orleans.
“Sickle cell disease has a single root cause, one letter in the β-globin gene, and nula-cel is designed to correct it rather than work around it,” said Vali Barsan, MD, Co-Founder and Chief Executive Officer of Kamau Therapeutics. “Correction has been the promise of gene editing from the beginning, and these are the first patients in whom it has been shown. Results and a process built to repeat them are not the same thing. We built the process; patient after patient is how a corrected gene becomes ordinary medicine, and how the lasting power of hematopoietic stem cells becomes a durable way to treat disease.”
The presentation, titled “First Clinical Results of Precise HBB Gene Correction by Homology-Directed Repair in Patients with Severe Sickle Cell Disease: Safety and Efficacy from Phase 1A of the RESTORE Study,” will deliver the first results from the ongoing study using a revised manufacturing process (V2.0) for nula-cel. Data include three patients treated with the V2.0 product, two with more than six months of follow-up, along with continued follow-up of the first patient ever treated with nula-cel (V1.0 process), now four years post-infusion.
Key results reported in the abstract include:
- Transfusion independence and no vaso-occlusive events: All three V2.0-treated patients achieved transfusion independence prior to hospital discharge. No vaso-occlusive events have occurred in any patient following nula-cel infusion.
- Hemoglobin correction and stable engraftment: All three V2.0-treated patients achieved neutrophil engraftment at a median of 21 days (range: 19–32 days). In the two patients with more than six months of follow-up, total hemoglobin exceeded 10 g/dL (10.2 and 11.1 g/dL), with low sickle hemoglobin (HbS: 17.6% at 12 months and 19.1% at 8 months) and high adult hemoglobin (HbA: 76.8% at 12 months and 66.8% at 8 months). Bone marrow HDR allele frequencies stabilized at approximately 20%, consistent with durable engraftment of gene-corrected stem cells, and single-cell analyses showed more than 90% of circulating red blood cells contained protective levels of anti-sickling hemoglobin.
- Safety and tolerability: No serious adverse events related to nula-cel or the gene-editing procedure were observed in V2.0-treated patients. Adverse events were consistent with myeloablative busulfan conditioning and autologous stem cell transplantation, and off-target editing remained low and unchanged.
- Manufacturing performance: Drug product HDR allele frequencies exceeded the 20% target in all three patients (range: 32%–38%), and mobilization required a median of one apheresis cycle (range: 1–3) to reach target cell dose.
- Data will be presented by John F. DiPersio, MD, Washington University School of Medicine, at 2:45–3:00 p.m. CT on December 14, 2026.
John F. DiPersio, MD, Director of the Center for Gene and Cellular Immunotherapy, Washington University School of Medicine, said, “Achieving hemoglobin levels above 10 g/dL, with sickle hemoglobin below 20% and adult hemoglobin predominant, in patients who also remain free of vaso-occlusive events is an encouraging early signal. Seeing that profile alongside stable engraftment of corrected cells is what we would hope to see from a durable correction of the underlying mutation. These are early data in a small number of patients, and longer follow-up will be essential, but they support continued evaluation of this approach.”
Matthew Porteus, MD, PhD, Co-Founder and Head of R&D of Kamau Therapeutics, said, “Our approach is designed to do two things in one step: deeply reduce pathogenic sickle hemoglobin and restore the body’s own production of normal adult hemoglobin by converting the sickle mutation directly to the normal adult hemoglobin sequence. We developed nula-cel to work in a patient’s own stem cells, enabling those cells to produce adult hemoglobin under the body’s normal regulation. The findings reported to date provide early clinical evidence that precise HDR-mediated correction of the native HBB gene is feasible. We look forward to learning more as the RESTORE trial progresses, both for people living with sickle cell disease and for the broader potential of this approach.”
Nula-cel, Kamau’s investigational stem cell medicine for sickle cell disease, has received Fast Track and Orphan Drug designations from the U.S. Food and Drug Administration (FDA). Rather than inducing fetal hemoglobin to compensate for the disease, nula-cel is designed to correct the sickle mutation itself, converting it to the normal adult β-globin sequence. Using ex vivo homology-directed repair (HDR), Kamau precisely engineers a patient’s own long-lived stem cells outside the body, rigorously verifying each cell product’s quality, identity, potency, and safety before it is returned to the patient, a level of control not possible when editing occurs inside the body. As these cells self-renew, a one-time treatment is designed to deliver durable, potentially lifelong benefit.
Kamau is supported by a syndicate of leading technology and life science investors including Khosla Ventures, Cormorant Asset Management, NEVA SGR, Draper VC, Modi Ventures, and Regeneron Ventures. The company is led by Co-Founder and Chief Executive Officer Vali Barsan, MD, a pediatric hematologist-oncologist and genome sequencing engineer who previously led growth-stage investments in cell and gene therapy, and Co-Founder Matthew Porteus, MD, PhD, Sutardja Chuk Professor of Definitive and Curative Medicine at Stanford University, whose pioneering research showed that engineered nucleases can correct disease-causing mutations in human cells, the basis of nula-cel. Annalisa Lattanzi, PhD, Vice President of Research and Development and nula-cel Program Lead, directed nula-cel’s IND-enabling development in the Porteus laboratory at Stanford, authoring key publications on the platform, and now leads the program in the clinic. The leadership team also includes Chief Technology Officer Ramji Krishnan, PhD, who brings 17 years of CMC leadership at BMS/Celgene, including as MSAT lead for REBLOZYL, and autologous hematopoietic stem cell gene therapy experience at Rocket; Chief Medical Officer Jacob Garcia, MD, most recently SVP of Clinical Development and Operations at Umoja Biopharma and previously Clinical Efficacy Lead on the BREYANZI BLA at Juno/BMS; and Chief Business Officer Reza Afkhami, formerly SVP of Corporate Development at Global Blood Therapeutics, where he was central to its 2022 acquisition by Pfizer.
About the RESTORE Trial
RESTORE (NCT04819841) is an ongoing Phase 1/2, single-arm, open-label clinical trial evaluating the safety, preliminary efficacy, and pharmacodynamics of nula-cel in adults with severe sickle cell disease. The trial enrolls approximately 15 participants who receive a single infusion of nula-cel following myeloablative busulfan conditioning.
About Sickle Cell Disease
Sickle cell disease (SCD) is an inherited blood disorder affecting approximately 100,000 people in the United States and millions globally. A single mutation in the beta-globin gene produces sickle hemoglobin (HgbS), which polymerizes, stiffening red cells and driving chronic hemolysis. Pain crises are the visible burden; chronic organ damage such as stroke, kidney, retinal and bone damage accumulate silently between them, shortening US life expectancy by about 30 years. While approved pharmacologic and gene therapies reduce pain crises, none restores native adult hemoglobin (HgbA) or consistently achieves the sustained HgbS levels below 30% that ASH guidelines associate with stroke prevention in chronic exchange transfusion protocols.
About Kamau Therapeutics
Kamau Therapeutics is a clinical-stage company developing a new generation of stem cell medicines designed to create lasting benefit through a single intervention. Kamau’s platform precisely engineers long-lived stem cells outside the body, providing control to select, modify, characterize, and verify cells before they return to the patient. As these cells self-renew and continually produce new cells, a change made once has the potential to endure. Kamau’s approach is built on homology-directed repair (HDR), the high-fidelity pathway cells naturally use to repair their own DNA, which Kamau has engineered to be efficient and reproducible in hematopoietic stem cells. Kamau’s lead program, nula-cel, is an investigational therapy for sickle cell disease designed to directly correct the sickle-causing mutation at its native location in the β-globin gene, restoring production of adult hemoglobin under the body’s own regulation rather than relying on fetal hemoglobin. The ability to engineer stem cells at specific genomic sites unlocks new possibilities across immunology, oncology, and neurology. Kamau is applying this capability to a growing range of diseases and applications beyond sickle cell disease, with the goal of replacing repeated treatment with medicines designed to last. Learn more at kamautx.com.
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