Ofirnoflastum (Ofirnoflast) is an orally active first-in-class allosteric NEK7 inhibitor with an IC50 of 46 nM. Ofirnoflastum binds an allosteric site adjacent to NEK7’s ATP-binding pocket, induces conformational shifts, disrupts NEK7- NLRP3 binding, blocks NLRP3 inflammasome assembly, spares NEK7’s physiological functions, and suppresses caspase-1, caspase-8, NF-κB, and TNF activity. Ofirnoflastum reduces pro-inflammatory cytokine production, suppresses ASC specks, IL-1β release, pyroptotic cell death, and leukemic burden, induces apoptosis and erythroid differentiation, restores hematopoiesis, and improves outcomes in colitis models. Ofirnoflastum can be used for the research of myelodysplastic syndromes, chronic myelomonocytic leukemia, and acute myeloid leukemia [1] [2] [3] [4] [5].
In Vivo, Ofirnoflastum (1-5 mg/kg; p.o.; twice daily; day 0 through day 7) reduces disease activity, histopathological damage, and inflammatory cytokine levels in a mouse model of DSS -induced colitis, with maximal efficacy achieved at the lowest tested dose[3]. Ofirnoflastum reduces MDS/AML leukemic burden by ~3-fold in patient-derived xenograft mice via suppression of inflammatory/proliferative pathways and induction of apoptosis and erythroid differentiation[4]. Ofirnoflastum reduces CMML leukemic burden by ~3-fold in patient-derived xenograft mice via suppression of inflammatory/proliferative pathways and induction of apoptosis and erythroid differentiation[4].
In Vitro, Ofirnoflast (range of concentrations; 30 min pre-incubation, 3 h LPS priming, 3 h Nigericin stimulation) inhibits nigericin-induced IL-1β secretion in PMA-differentiated THP-1 macrophages with an IC50 of 198 nM[3]. Ofirnoflast (range of concentrations; 30 min pre-incubation, 3 h LPS priming, 3 h Nigericin stimulation) prevents nigericin-induced pyroptotic cell death in PMA-differentiated THP-1 macrophages with an EC50 of 378 nM[3]. Ofirnoflast (0.01-10 μM; 3 h LPS priming, 2 h pre-incubation, 1 h nigericin stimulation) inhibits nigericin-induced ASC speck formation in THP-1-ASC-GFP cells with an IC50 of 0.194 μM[3]. Ofirnoflast (range of concentrations; 5 h LPS priming, final hour with compound, 30 min nigericin stimulation) inhibits nigericin-induced IL-1β secretion in human iPSC-derived microglia with an IC50 of 44 nM[3]. Ofirnoflast (1 μM; 5 h LPS priming, final hour with compound, 45 min ATP stimulation) potently inhibits ATP-induced IL-1β secretion in human iPSC-derived microglia[3]. Ofirnoflastum potently inhibits proinflammatory cytokine secretion, Caspase-1 and Caspase-8 activity, and reverses erythroid differentiation block in LPS-activated inflammatory monocytes, Tet2-mutant monocytes, CMML patient-derived cells, myeloid leukemia cell lines, and MDS patient-derived cells[4]. Ofirnoflastum's anti-inflammatory effects in myeloid leukemia cells are dependent on NEK7 expression[4]. Ofirnoflastum's anti-leukemic activity in Tet2-mutant cells and primary MDS/CMML patient-derived cells is mediated through suppression of chronic inflammation driven by the IL-1β/IL1R1 axis[4].
References:
[1]. Devan Bursey, et al. The novel allosteric NEK7 inhibitor ofirnoflast (HT-6184) suppresses IL-8 and other pro-inflammatory cytokines in patients with low-risk myelodysplastic syndrome and symptomatic anemia. Blood Volume 146, Supplement 1, 3 November 2025, Page 2092.
[2]. Devan Bursey, et al. The novel allosteric NEK7 inhibit ofirnoflast (HT-6184) reduces oxidized mitochondrial DNA in patients with low-risk myelodysplastic syndrome. Blood Volume 146, Supplement 1, 3 November 2025, Page 2093.
[3]. Mollard A, et al. Ofirnoflast: a first-in-class NEK7-targeted inhibitor of the NLRP3 inflammasome. J Drug Target. 2026;34(1):100-112.
[4]. Divij Verma, et al. Ofirnoflast, a novel inflammasome inhibitor, rewires transcriptional programs and shows clinical and preclinical efficacy in myeloid neoplasms. Blood Volume 146, Supplement 1, 3 November 2025, Page 323.
[5]. Varun Bafna, et al. The novel allosteric NEK7 inhibitor ofirnoflast (HT-6184) demonstrates robust and sustained hematologic response in subjects with IPSS-R very low, low or intermediate risk myelodysplastic syndrome (MDS) and symptomatic anemia. Blood Volume 146, Supplement 1, 3 November 2025, Page 5622.
In Vivo, Ofirnoflastum (1-5 mg/kg; p.o.; twice daily; day 0 through day 7) reduces disease activity, histopathological damage, and inflammatory cytokine levels in a mouse model of DSS -induced colitis, with maximal efficacy achieved at the lowest tested dose[3]. Ofirnoflastum reduces MDS/AML leukemic burden by ~3-fold in patient-derived xenograft mice via suppression of inflammatory/proliferative pathways and induction of apoptosis and erythroid differentiation[4]. Ofirnoflastum reduces CMML leukemic burden by ~3-fold in patient-derived xenograft mice via suppression of inflammatory/proliferative pathways and induction of apoptosis and erythroid differentiation[4].
In Vitro, Ofirnoflast (range of concentrations; 30 min pre-incubation, 3 h LPS priming, 3 h Nigericin stimulation) inhibits nigericin-induced IL-1β secretion in PMA-differentiated THP-1 macrophages with an IC50 of 198 nM[3]. Ofirnoflast (range of concentrations; 30 min pre-incubation, 3 h LPS priming, 3 h Nigericin stimulation) prevents nigericin-induced pyroptotic cell death in PMA-differentiated THP-1 macrophages with an EC50 of 378 nM[3]. Ofirnoflast (0.01-10 μM; 3 h LPS priming, 2 h pre-incubation, 1 h nigericin stimulation) inhibits nigericin-induced ASC speck formation in THP-1-ASC-GFP cells with an IC50 of 0.194 μM[3]. Ofirnoflast (range of concentrations; 5 h LPS priming, final hour with compound, 30 min nigericin stimulation) inhibits nigericin-induced IL-1β secretion in human iPSC-derived microglia with an IC50 of 44 nM[3]. Ofirnoflast (1 μM; 5 h LPS priming, final hour with compound, 45 min ATP stimulation) potently inhibits ATP-induced IL-1β secretion in human iPSC-derived microglia[3]. Ofirnoflastum potently inhibits proinflammatory cytokine secretion, Caspase-1 and Caspase-8 activity, and reverses erythroid differentiation block in LPS-activated inflammatory monocytes, Tet2-mutant monocytes, CMML patient-derived cells, myeloid leukemia cell lines, and MDS patient-derived cells[4]. Ofirnoflastum's anti-inflammatory effects in myeloid leukemia cells are dependent on NEK7 expression[4]. Ofirnoflastum's anti-leukemic activity in Tet2-mutant cells and primary MDS/CMML patient-derived cells is mediated through suppression of chronic inflammation driven by the IL-1β/IL1R1 axis[4].
References:
[1]. Devan Bursey, et al. The novel allosteric NEK7 inhibitor ofirnoflast (HT-6184) suppresses IL-8 and other pro-inflammatory cytokines in patients with low-risk myelodysplastic syndrome and symptomatic anemia. Blood Volume 146, Supplement 1, 3 November 2025, Page 2092.
[2]. Devan Bursey, et al. The novel allosteric NEK7 inhibit ofirnoflast (HT-6184) reduces oxidized mitochondrial DNA in patients with low-risk myelodysplastic syndrome. Blood Volume 146, Supplement 1, 3 November 2025, Page 2093.
[3]. Mollard A, et al. Ofirnoflast: a first-in-class NEK7-targeted inhibitor of the NLRP3 inflammasome. J Drug Target. 2026;34(1):100-112.
[4]. Divij Verma, et al. Ofirnoflast, a novel inflammasome inhibitor, rewires transcriptional programs and shows clinical and preclinical efficacy in myeloid neoplasms. Blood Volume 146, Supplement 1, 3 November 2025, Page 323.
[5]. Varun Bafna, et al. The novel allosteric NEK7 inhibitor ofirnoflast (HT-6184) demonstrates robust and sustained hematologic response in subjects with IPSS-R very low, low or intermediate risk myelodysplastic syndrome (MDS) and symptomatic anemia. Blood Volume 146, Supplement 1, 3 November 2025, Page 5622.