Publication date: 30 September 2026
Research scope: Eleven international cohorts spanning European, African and Thai ancestry
Source: Nature
Beta thalassemia treatment research is moving toward a new fetal hemoglobin direction after a major Nature study identified the BACH2 NRF2 pathway as a regulator of HbF. This discovery may influence future drug development, gene therapy research and sickle cell disease treatment, although no BACH2 directed therapy is currently approved for patients.
Researchers analyzed fetal hemoglobin levels in 28,279 people and identified 91 conditionally independent genetic associations across 12 genomic regions. The most important new finding involved the BACH2 and NRF2 transcription factors. The results suggest that BACH2 normally restrains NRF2 from activating the gamma globin genes responsible for producing fetal hemoglobin. Reducing BACH2 activity allowed NRF2 to reach these genes and increase fetal hemoglobin production [1].
The finding is scientifically important but remains preclinical. No BACH2 directed treatment has been shown to improve beta thalassemia or sickle cell disease in patients.
One technical detail also requires careful wording. The pharmacological experiment did not use a clinically developed, BACH2 selective medicine. Researchers used a laboratory compound called Compound 8 that inhibits both BACH1 and BACH2 in cultured human blood forming cells. It increased fetal hemoglobin in those cells, but it is not an approved treatment and has not been tested as a therapy in patients [1].
Why Fetal Hemoglobin Matters in Blood Disorders
Hemoglobin is the oxygen carrying protein inside red blood cells. Before birth, the predominant form is fetal hemoglobin, known as HbF. It contains two alpha globin chains and two gamma globin chains.
After birth, the body normally reduces gamma globin production and begins producing beta globin. Adult hemoglobin, or HbA, consequently replaces most HbF during infancy. This developmental change is called the fetal to adult hemoglobin switch.
That switch becomes clinically important because beta thalassemia and sickle cell disease are both caused by abnormalities involving the beta globin gene, HBB.
In beta thalassemia, the body produces insufficient or defective beta globin. Excess unpaired alpha globin accumulates inside developing red blood cells, damaging them and producing ineffective red blood cell formation, chronic anemia and, in severe cases, lifelong transfusion dependence. Gamma globin can partially substitute for missing beta globin by pairing with alpha globin to form HbF.
In sickle cell disease, an abnormal beta globin protein produces sickle hemoglobin, or HbS. Under low oxygen conditions, HbS molecules can polymerize into rigid fibres that deform red blood cells. HbF does not participate in this polymerization in the same manner. Increasing HbF can therefore reduce intracellular HbS concentration, inhibit sickling and lower the risk of vaso occlusive episodes [2,3].
This protective effect explains why fetal hemoglobin induction has become one of the most important therapeutic strategies in modern hemoglobin disorder research.
How the Researchers Conducted the Study
The researchers performed a genome wide association study examining genetic variants associated with differences in HbF levels. The analysis included 28,279 participants from 11 cohorts.
Approximately 22,882 participants were of European ancestry, 4,005 were of African ancestry and 1,392 came from a Thai cohort. The participating datasets included general population cohorts, cohorts of people with sickle cell disease and a Thai population deliberately enriched for individuals with HbF levels above 2 percent [1].
The researchers identified 91 conditionally independent genetic signals across 12 genomic regions. Eight regions met the conventional genome wide significance threshold, while four met a less stringent suggestive threshold.
The analysis rediscovered established fetal hemoglobin regulators, including BCL11A, HBB and the HBS1L MYB region. It also detected signals near KLF1 and ZBTB7A, two transcription factors already known to influence hemoglobin switching, as well as less understood regions involving genes such as CTC1, USP34 and BACH2 [1].
These 91 associations should not be interpreted as 91 treatments or even 91 confirmed causal genes. Genetic association identifies regions linked to a biological trait. Additional experiments are needed to determine which variant is causal, which gene it affects and whether manipulating that gene would be safe and therapeutically useful.
BACH2 received particular attention because its association with HbF was observed across the ancestry specific analyses and because it had not previously been established as an HbF regulator.
The BACH2 NRF2 Pathway Explained
BACH2 and NRF2 are transcription factors. These are proteins that interact with DNA and help determine whether specific genes remain inactive or become transcriptionally active.
The study identified a high HbF associated genetic variant called rs1010474 C. Experimental analysis indicated that this variant reduces the activity of a regulatory enhancer controlling BACH2. Lower enhancer activity produced less BACH2 messenger RNA and protein in erythroid progenitor cells.
When BACH2 levels declined, fetal hemoglobin increased.
The researchers found that BACH2 binds near the promoters of HBG1 and HBG2, the genes encoding gamma globin. NRF2 can bind to an overlapping region. The two factors appear to exert opposing effects: BACH2 restricts gamma globin transcription, whereas NRF2 promotes it [1].
Reducing BACH2 allowed more NRF2 to occupy the gamma globin promoters and other regulatory elements within the beta globin locus. Imaging experiments showed that localized NRF2 concentrations appeared at sites where new HBG1 and HBG2 RNA was being produced.
This led to a working model in which BACH2 functions as a molecular brake. When that brake is reduced, NRF2 gains greater access to gamma globin regulatory regions and activates HbF production.
NRF2 Activation Was More Specific Than a General Stress Response
NRF2 is widely known for regulating cellular responses to oxidative and chemical stress. This could create the impression that any antioxidant, supplement or herb claimed to influence NRF2 might reproduce the study’s results.
The research does not support that conclusion.
The investigators did not observe broad activation of conventional oxidative stress response genes after reducing BACH2. Instead, NRF2 accumulated locally at gamma globin regulatory regions. The authors therefore proposed that the BACH2 NRF2 interaction activates HbF through a mechanism that is at least partly independent of the conventional oxidative stress response [1].
This distinction is clinically important. General NRF2 activation throughout the body is not equivalent to precisely directing NRF2 to the HBG1 and HBG2 promoters inside developing red blood cells.
What the Laboratory Experiments Showed
The researchers used several complementary laboratory approaches to test whether the genetic association represented a genuine biological mechanism.
Deleting the suspected BACH2 enhancer with CRISPR reduced BACH2 expression and increased HbF without producing an obvious disruption of erythroid differentiation under the experimental conditions.
Introducing the rs1010474 C variant through adenine base editing also lowered BACH2 messenger RNA and protein and increased gamma globin expression and the proportion of HbF containing red blood cells.
Short hairpin RNA was then used to reduce BACH2 expression directly. BACH2 messenger RNA declined by as much as approximately 80 percent and protein by as much as approximately 50 percent in the reported experiments. This again increased gamma globin expression and HbF containing cells [1].
The investigators also treated differentiating erythroid cells with Compound 8, an experimental BACH1 and BACH2 inhibitor. HbF increased in a dose dependent manner, while erythroid differentiation showed little or no obvious change at the tested concentrations.
These findings strengthen the biological argument that BACH2 restrains fetal hemoglobin. Nevertheless, the drug experiment involved cultured cells and a nonselective research compound. It did not establish a safe clinical dose, determine long term toxicity or demonstrate benefit in a person with beta thalassemia or sickle cell disease.
Why Independence From BCL11A Is Important
BCL11A is one of the best established repressors of fetal hemoglobin. It helps silence gamma globin after infancy.
The approved gene editing therapy exagamglogene autotemcel modifies an erythroid specific enhancer of BCL11A in a patient’s own blood stem cells. Reduced BCL11A expression allows those cells to produce more HbF. This approach has demonstrated that reactivating fetal hemoglobin can produce major clinical benefits in appropriately selected patients with transfusion dependent beta thalassemia or severe sickle cell disease [2,3].
The new study found that BACH2 regulates HbF independently of BCL11A. BACH2 and NRF2 bind between two established BCL11A binding regions in the gamma globin promoters. Researchers did not detect a direct physical interaction between BCL11A and either BACH2 or NRF2.
When BACH2 and BCL11A were reduced simultaneously in cultured cells, gamma globin expression was higher than when either pathway was altered individually. This additive laboratory effect suggests that the two pathways operate in parallel [1].
In principle, future treatments might target both mechanisms to produce a stronger or more consistent HbF response. However, the combined strategy remains experimental. Increasing the number of genetic modifications could also increase manufacturing complexity and safety concerns.
What the Discovery Could Mean for Beta Thalassemia
In beta thalassemia, insufficient beta globin creates an imbalance between alpha and non alpha globin chains. Unpaired alpha chains damage developing red blood cells, contributing to ineffective erythropoiesis, anemia, marrow expansion, spleen enlargement and transfusion dependence.
Increasing gamma globin allows more alpha chains to form fetal hemoglobin. This may reduce toxic alpha chain accumulation and improve the production and survival of red blood cells.
A future BACH2 targeted therapy could therefore aim to increase endogenous gamma globin without repairing every individual beta thalassemia mutation. That would be attractive because beta thalassemia is caused by many different HBB variants.
However, the Nature study did not treat participants with beta thalassemia. It did not measure reductions in transfusion requirements, improvements in hemoglobin concentration or changes in iron overload. Severe thalassemia was also excluded from the specially selected Thai cohort used in the genetic analysis [1].
The findings establish a biological target, not a demonstrated beta thalassemia treatment.
What the Discovery Could Mean for Sickle Cell Disease
The protective role of HbF in sickle cell disease is well established. Higher and more uniformly distributed HbF can reduce the concentration of HbS inside red blood cells and interfere with the formation of rigid HbS polymers.
In clinical practice, increasing HbF can reduce sickling, hemolysis, pain crises and other complications. Hydroxyurea and BCL11A based gene editing demonstrate the therapeutic value of this principle.
A BACH2 or NRF2 directed approach might eventually provide another method of increasing HbF. A medicine capable of safely producing this effect would be particularly important because current gene therapies require stem cell collection, specialized manufacturing, myeloablative conditioning and treatment at advanced centres.
Nevertheless, the new study does not show that pharmacologically targeting BACH2 will prevent pain crises, stroke, acute chest syndrome, organ damage or hospitalization. Those outcomes would require carefully controlled clinical trials.
Important Limitations of the Study
The work combines strong human genetic evidence with extensive functional laboratory validation, but several limitations prevent immediate clinical translation.
Most participants were of European ancestry. The African and Thai ancestry groups were substantially smaller, even though sickle cell disease and beta thalassemia impose a major burden across Africa, the Middle East, South Asia and Southeast Asia.
The included cohorts also differed considerably. Some represented general populations, some included people with sickle cell disease and the Thai cohort deliberately selected individuals with elevated HbF. The authors cautioned that effect sizes could not be directly compared across ancestry groups [1].
Most cohorts measured HbF through high performance liquid chromatography, while two estimated the phenotype from globin gene expression data. The investigators reported that the expression based approach reproduced expected patterns, but it was not identical to directly measuring circulating HbF.
The naturally occurring BACH2 variant produced a smaller HbF effect than established loci such as BCL11A. Whether a therapeutic intervention can produce a sufficiently large and durable increase without disrupting other BACH2 functions remains unknown.
BACH2 also participates in immune cell development and immune regulation. Broad systemic inhibition might therefore have effects outside the erythroid system. NRF2 similarly regulates numerous protective, metabolic and stress response pathways. Any future medicine would require careful assessment of immune, hematological, metabolic and cancer related risks.
The functional drug experiments involved only small numbers of independent cell culture experiments. They were designed to establish mechanism, not to determine clinical efficacy or long term safety.
The authors also acknowledged that other NFE2 related transcription factors might contribute to gamma globin regulation. NRF2 appears to be the main partner identified in this setting, but it may not be the only relevant factor [1].
What Researchers Need to Establish Next
Before the pathway could become a treatment, researchers would need to develop a selective and controllable method of modifying it.
A drug programme would require compounds that inhibit BACH2 with suitable potency, selectivity and pharmacokinetics. Investigators would then need to show that treatment increases HbF in disease relevant cells without causing unacceptable immune or systemic effects.
An alternative approach could involve editing the BACH2 and NRF2 binding region within the gamma globin promoters. Such editing would ideally be restricted to a patient’s blood forming stem cells, avoiding systemic alteration of BACH2 in immune and other tissues.
Preclinical development would need to evaluate off target editing, stem cell fitness, engraftment, red blood cell development, clonal behaviour and durability of HbF production. Studies would also need to determine whether combining a BACH2 NRF2 modification with BCL11A editing provides enough additional benefit to justify the added complexity.
Only after suitable toxicology and manufacturing studies could a first in human trial evaluate safety, dose, HbF response and early clinical outcomes.
What Patients Should Understand Now
This discovery does not change current treatment recommendations for beta thalassemia or sickle cell disease.
Patients should not stop transfusion programmes, iron chelation, hydroxyurea, disease modifying medicines or specialist follow up because of this research. Eligibility for stem cell transplantation or approved gene therapy must continue to be assessed individually by experienced hematology teams.
There is also no evidence that taking an antioxidant, herbal supplement or product promoted as an NRF2 activator will reproduce the localized gamma globin activation demonstrated in the study. Uncontrolled NRF2 stimulation and targeted manipulation of the BACH2 NRF2 binding mechanism are not biologically interchangeable.
The immediate value of the research is that it expands the scientific map of fetal hemoglobin regulation. It gives researchers a new, genetically supported pathway that may eventually lead to a medicine, gene editing strategy or combination treatment.
Frequently Asked Questions
Is a BACH2 treatment currently available?
No BACH2 directed treatment is currently approved for beta thalassemia or sickle cell disease. The study used gene editing, gene knockdown and experimental compounds in cultured human cells. These experiments identified a target but did not establish a treatment that doctors can prescribe.
Does this study show that beta thalassemia can be cured by blocking BACH2?
No. The researchers demonstrated that reducing BACH2 increased fetal hemoglobin in laboratory models. They did not treat patients or measure transfusion independence, hemoglobin improvement, iron overload or long term survival. Clinical benefit must be demonstrated separately.
Is BACH2 the same target used by current gene therapy?
No. Current fetal hemoglobin focused gene editing primarily targets an erythroid enhancer of BCL11A. The new research indicates that BACH2 and NRF2 regulate gamma globin through a separate pathway that acts in parallel with BCL11A [1,2].
Can NRF2 activating foods or supplements increase fetal hemoglobin?
The study does not demonstrate that foods, supplements or herbal products can raise HbF through this mechanism. The reported effect involved localized NRF2 recruitment to gamma globin regulatory DNA inside developing blood cells, not simply generalized antioxidant pathway activation.
Could BACH2 and BCL11A be targeted together?
The combined laboratory intervention produced an additive increase in gamma globin expression. This makes combination targeting scientifically interesting, but its safety, durability and superiority over single pathway treatment have not been demonstrated in animals or patients.
How soon could a BACH2 therapy become available?
There is no reliable clinical timeline. Researchers must first develop a selective intervention, complete preclinical safety testing and conduct phased human trials. Many biologically promising targets do not ultimately become approved treatments.
References
[1] Guo, C. J., Arora, U. P., Cheng, X., et al. (2026). Human genetics implicates a BACH2–NRF2 axis in fetal haemoglobin activation. Nature. doi:10.1038/s41586-026-11113-2. Nature
[2] European Medicines Agency. (2023). First gene editing therapy to treat beta thalassemia and severe sickle cell disease. European Medicines Agency (EMA)
[3] U.S. Food and Drug Administration. (2026). CASGEVY prescribing and regulatory information for sickle cell disease and transfusion dependent beta thalassemia. U.S. Food and Drug Administration
