M3541 is an orally effective DNA-dependent protein kinase ( DNA-PK ) inhibitor. M3541 inhibits ionizing radiation-induced ATM autophosphorylation and phosphorylation of downstream substrates ( KAP1, CHK2, p53 ), blocks DSB end resection and homologous recombination repair, and simultaneously induces non-homologous end joining, G2-M phase arrest, polyploidization, and cell death. M3541 can be used for research on solid tumors, acute myeloid leukemia, non-small cell lung cancer, triple-negative breast cancer, etc. [1] [2] [3] [4] [5] [7] [8] [9] [10].
In Vivo, M3541 (100 mg/kg; p.o.; single dose 10 min before 2 Gy IR) suppresses ATM pathway activity in vivo and demonstrates dose-dependent tumor growth inhibition in the FaDu xenograft model, with 200 mg/kg plus fractionated radiotherapy achieving complete tumor regression by day 30[1]. M3541 (100 mg/kg; p.o.; in combination with fractionated radiotherapy (30 × 2 Gy over 6 weeks)) achieves complete and durable tumor regressions in 3 out of 4 xenograft models for 140-160 days[1]. The triple combination of M3541 (100 mg/kg; p.o.; 10 minutes before each IR fraction (2 Gy, 5 days on/2 days off for 2 weeks)), cisplatin (3 mg/kg), and fractionated radiotherapy (20 Gy total) demonstrates enhanced antitumor activity and progression-free survival in the FaDu xenograft model with reversible body weight effects[1]. The combination of M4076 (50-100 mg/kg; p.o.; once daily) and M4344 results in complete tumor growth inhibition in the MiaPaCa2 model and almost complete tumor regression in the MV4.11 model[5]. M4076 (50 mg/kg; p.o.; twice daily) potentiates the efficacy of ATRis in multiple TNBC PDX cancer models, achieving a tumor control rate of approximately 42% and an objective response rate of approximately 20% in combination with M4344[5]. M3541 (p.o.) strongly enhances the antitumor activity of fractionated radiation in human tumor xenograft-bearing nude mice, leading to complete tumor regression[7].
In Vitro, M3541 is a potent and selective ATP-competitive ATM kinase inhibitor with an IC50 of 0.25 nM[1]. The inhibitory activity of M3541 requires wild-type ATM kinase and functional signaling, with an average IC50 of 71 nM in wild-type ATM cell lines and 670 nM in mutant ATM cell lines[1]. M3541 (1 μM) alone causes growth inhibition in IMR90 and WI38 fibroblast cell lines, but induces only slight cell death[5]. M3541 (0.125-3 μM; 1 h) effectively inhibits IR-induced ATM catalytic activity and downstream signaling in A549 cells[1]. M3541 (1 μM; 1 h) significantly impairs DSB repair in A549 cells, leading to the accumulation of unrepaired DSBs[1]. M3541 (1 μM; 1 h) combined with IR (5 Gy) inhibits the growth of A549 cells[1]. M3541 (1 μM; 1 h) exhibits radiosensitizing effects in A549 and 13 other cancer cell lines, significantly reducing clonogenic survival[1]. M3541 (1 µM; 6-96 h) inhibits early p53 activation induced by the combination of Calicheamicin /M3814 (Nedisertib) in MV4-11 cells, supporting that enhanced p53 activity is a downstream effect of M3814-induced ATM hyperactivation[2]. M3541 alone (up to 1.0 μM) shows minimal toxicity in A549 and NCI-H460 cells but sensitizes these cells to ionizing radiation[3]. M3541 (1 μM; 24 h) inhibition of ATM impairs RAD51 and RPA foci formation and increases DNA damage in FA-deficient HeLa and U2OS cells[3]. M3541 further impairs DNA end resection in FANCD2-deficient U2OS cells[3]. M3541 (1 μM; 24 h) further reduces DNA end resection in FANCD2-knockout U2OS cells[3]. M3541 (1 μM; 72 h) further increases NHEJ activity in U2OS cells with knockdown of FA/BRCA pathway components[3]. M3541 (1 μM; 72 h) reduces HR activity in FA/BRCA pathway-knockdown U2OS cells[3]. M3541 selectively inhibits the growth of PL11, HS766T, and TOV21G cancer cell lines with FA pathway defects[3]. M3541 (1 μM; 24 h) slightly decreases phospho-ATM levels below baseline and significantly reverses M6620 (Berzosertib) -induced phospho-ATM levels in A549 cancer cells[5]. M3541 (1 μM; 24 h) alone has minimal effect on ATM/p53 signaling proteins, but in A549 cells it inhibits M6620-induced activation of these proteins[5]. M3541 (5 days) alone has minimal effect on the cell viability of A549 parental cells and ATM-deficient cells, but exhibits a synergistic effect with M6620 in A549 parental cells[5]. M3541 (1 μM; 1 h) abolishes the elevation of p53 induced by DNA-PK inhibitors in irradiated HCT116 and RKO cells, indicating that this event occurs downstream of the ATM pathway[6]. M3541 sensitizes multiple tumor cell lines to ionizing radiation and a topoisomerase inhibitor in vitro[7]. M3541 (1 μM; 1 h) effectively inhibits the catalytic activity of ATM and its downstream signaling in irradiated A549, A375, and RKO cancer cells, with 1 μM causing over 90% inhibition[9]. M3541 (1 μM; 1 h) initially suppresses IR-induced γH2AX foci but leads to the accumulation of numerous unrepaired DSBs at 24 h in A549 cells[9]. M3541 (1 h) significantly enhances radiation-induced cell death and inhibits the growth of HeLa cells[9]. M3541 (7 days) significantly enhances radiation-induced chromosome misalignment, missegregation, and prolonged metaphase in HeLa cells[9]. M3541 (1 μM; 1 h) promotes total chromosomal aberrations in irradiated A549 cells[9]. M3541 strongly enhances structural damage and micronucleus formation in irradiated A549 cells[9]. M3541 strongly enhances inflammatory signaling in irradiated A549 cells[9]. M3541 is a highly potent ATP-competitive ATM kinase inhibitor with an IC50 < 1 nM[10]. M3541 (1 μM; 1 h) combined with IR (5 Gy) induces aberrant mitotic transition in A549 cells, leading to cell death[1]. M3541 (1 μM; 24 h) alone does not affect cell cycle distribution, but partially reverses the G1 phase arrest induced by M6620 in A549, A375, and H460 cancer cells[5]. M3541 (1 μM) prevents complete cell cycle arrest induced by DNA-PK inhibition in irradiated A375 cells, confirming the role of ATM in this process[6]. M3541 (1 μM; 1 h) inhibits the function of ATM in cell cycle checkpoint control in irradiated A549 cells, causing cell cycle arrest to shift primarily toward G2/M[9]. M3541 (1 μM; 6 days) alone has no effect on A549 parental cells and enhances M6620-induced cell death in A549 p53-deficient cells[5]. M3541 activates the STING/TBK1 pathway and upregulates PD-L1 in irradiated A549 cells[9]. M3541 (7 days) treatment increases the sensitivity of irradiated A549 cells to NK cell-mediated killing[9]. M3541 (7 days) enhances the expression of specific NK cell ligands in irradiated A549 cells[9]. M3541 (7 days) enhances the secretion of multiple inflammatory cytokines/chemokines in irradiated A549 cells[9].
References:
[1]. Zimmermann A, et al. A New Class of Selective ATM Inhibitors as Combination Partners of DNA Double-Strand Break Inducing Cancer Therapies. Molecular cancer therapeutics. 2022 Jun 01;21(6):859-870.
[2]. Carr MI, et al. DNA-PK Inhibitor, M3814, as a New Combination Partner of Mylotarg in the Treatment of Acute Myeloid Leukemia. Frontiers in oncology. 2020;10:127.
[3]. Cai MY, et al. Cooperation of the ATM and Fanconi Anemia/BRCA Pathways in Double-Strand Break End Resection. Cell reports. 2020 Feb 18;30(7):2402-2415.e5.
[4]. Zhang H, et al. Mapping combinatorial drug effects to DNA damage response kinase inhibitors. Nature communications. 2023 Dec 14;14(1):8310.
[5]. Turchick A, et al. Selective Inhibition of ATM-dependent Double-strand Break Repair and Checkpoint Control Synergistically Enhances the Efficacy of ATR Inhibitors. Molecular cancer therapeutics. 2023 Jul 05;22(7):859-872.
[6]. Sun Q, et al. Therapeutic Implications of p53 Status on Cancer Cell Fate Following Exposure to Ionizing Radiation and the DNA-PK Inhibitor M3814. Molecular cancer research: MCR. 2019 Dec;17(12):2457-2468.
[7]. Zimmermann A, et al. Abstract 338: A new investigational ATM Inhibitor, M3541, synergistically potentiates fractionated radiotherapy and chemotherapy in cancer cells and animal models. Cancer Res. 2018;78(13_Suppl):338.
[8]. Fuchss T, et al. Imidazolylchinoline [Patent]. DE 102010035744 A1. Germany; 2012‑03‑01.
[9]. Chiu LY, et al. Selective ATM inhibition augments radiation-induced inflammatory signaling and cancer cell death. Aging. 2023 Jan 17;15(2):492-512.
[10]. Fuchss T, et al. Abstract 329: Highly potent and selective ATM kinase inhibitor M3541: A clinical candidate drug with strong antitumor activity in combination with radiotherapy. Cancer Res. 2018;78(13_Suppl):329.
In Vivo, M3541 (100 mg/kg; p.o.; single dose 10 min before 2 Gy IR) suppresses ATM pathway activity in vivo and demonstrates dose-dependent tumor growth inhibition in the FaDu xenograft model, with 200 mg/kg plus fractionated radiotherapy achieving complete tumor regression by day 30[1]. M3541 (100 mg/kg; p.o.; in combination with fractionated radiotherapy (30 × 2 Gy over 6 weeks)) achieves complete and durable tumor regressions in 3 out of 4 xenograft models for 140-160 days[1]. The triple combination of M3541 (100 mg/kg; p.o.; 10 minutes before each IR fraction (2 Gy, 5 days on/2 days off for 2 weeks)), cisplatin (3 mg/kg), and fractionated radiotherapy (20 Gy total) demonstrates enhanced antitumor activity and progression-free survival in the FaDu xenograft model with reversible body weight effects[1]. The combination of M4076 (50-100 mg/kg; p.o.; once daily) and M4344 results in complete tumor growth inhibition in the MiaPaCa2 model and almost complete tumor regression in the MV4.11 model[5]. M4076 (50 mg/kg; p.o.; twice daily) potentiates the efficacy of ATRis in multiple TNBC PDX cancer models, achieving a tumor control rate of approximately 42% and an objective response rate of approximately 20% in combination with M4344[5]. M3541 (p.o.) strongly enhances the antitumor activity of fractionated radiation in human tumor xenograft-bearing nude mice, leading to complete tumor regression[7].
In Vitro, M3541 is a potent and selective ATP-competitive ATM kinase inhibitor with an IC50 of 0.25 nM[1]. The inhibitory activity of M3541 requires wild-type ATM kinase and functional signaling, with an average IC50 of 71 nM in wild-type ATM cell lines and 670 nM in mutant ATM cell lines[1]. M3541 (1 μM) alone causes growth inhibition in IMR90 and WI38 fibroblast cell lines, but induces only slight cell death[5]. M3541 (0.125-3 μM; 1 h) effectively inhibits IR-induced ATM catalytic activity and downstream signaling in A549 cells[1]. M3541 (1 μM; 1 h) significantly impairs DSB repair in A549 cells, leading to the accumulation of unrepaired DSBs[1]. M3541 (1 μM; 1 h) combined with IR (5 Gy) inhibits the growth of A549 cells[1]. M3541 (1 μM; 1 h) exhibits radiosensitizing effects in A549 and 13 other cancer cell lines, significantly reducing clonogenic survival[1]. M3541 (1 µM; 6-96 h) inhibits early p53 activation induced by the combination of Calicheamicin /M3814 (Nedisertib) in MV4-11 cells, supporting that enhanced p53 activity is a downstream effect of M3814-induced ATM hyperactivation[2]. M3541 alone (up to 1.0 μM) shows minimal toxicity in A549 and NCI-H460 cells but sensitizes these cells to ionizing radiation[3]. M3541 (1 μM; 24 h) inhibition of ATM impairs RAD51 and RPA foci formation and increases DNA damage in FA-deficient HeLa and U2OS cells[3]. M3541 further impairs DNA end resection in FANCD2-deficient U2OS cells[3]. M3541 (1 μM; 24 h) further reduces DNA end resection in FANCD2-knockout U2OS cells[3]. M3541 (1 μM; 72 h) further increases NHEJ activity in U2OS cells with knockdown of FA/BRCA pathway components[3]. M3541 (1 μM; 72 h) reduces HR activity in FA/BRCA pathway-knockdown U2OS cells[3]. M3541 selectively inhibits the growth of PL11, HS766T, and TOV21G cancer cell lines with FA pathway defects[3]. M3541 (1 μM; 24 h) slightly decreases phospho-ATM levels below baseline and significantly reverses M6620 (Berzosertib) -induced phospho-ATM levels in A549 cancer cells[5]. M3541 (1 μM; 24 h) alone has minimal effect on ATM/p53 signaling proteins, but in A549 cells it inhibits M6620-induced activation of these proteins[5]. M3541 (5 days) alone has minimal effect on the cell viability of A549 parental cells and ATM-deficient cells, but exhibits a synergistic effect with M6620 in A549 parental cells[5]. M3541 (1 μM; 1 h) abolishes the elevation of p53 induced by DNA-PK inhibitors in irradiated HCT116 and RKO cells, indicating that this event occurs downstream of the ATM pathway[6]. M3541 sensitizes multiple tumor cell lines to ionizing radiation and a topoisomerase inhibitor in vitro[7]. M3541 (1 μM; 1 h) effectively inhibits the catalytic activity of ATM and its downstream signaling in irradiated A549, A375, and RKO cancer cells, with 1 μM causing over 90% inhibition[9]. M3541 (1 μM; 1 h) initially suppresses IR-induced γH2AX foci but leads to the accumulation of numerous unrepaired DSBs at 24 h in A549 cells[9]. M3541 (1 h) significantly enhances radiation-induced cell death and inhibits the growth of HeLa cells[9]. M3541 (7 days) significantly enhances radiation-induced chromosome misalignment, missegregation, and prolonged metaphase in HeLa cells[9]. M3541 (1 μM; 1 h) promotes total chromosomal aberrations in irradiated A549 cells[9]. M3541 strongly enhances structural damage and micronucleus formation in irradiated A549 cells[9]. M3541 strongly enhances inflammatory signaling in irradiated A549 cells[9]. M3541 is a highly potent ATP-competitive ATM kinase inhibitor with an IC50 < 1 nM[10]. M3541 (1 μM; 1 h) combined with IR (5 Gy) induces aberrant mitotic transition in A549 cells, leading to cell death[1]. M3541 (1 μM; 24 h) alone does not affect cell cycle distribution, but partially reverses the G1 phase arrest induced by M6620 in A549, A375, and H460 cancer cells[5]. M3541 (1 μM) prevents complete cell cycle arrest induced by DNA-PK inhibition in irradiated A375 cells, confirming the role of ATM in this process[6]. M3541 (1 μM; 1 h) inhibits the function of ATM in cell cycle checkpoint control in irradiated A549 cells, causing cell cycle arrest to shift primarily toward G2/M[9]. M3541 (1 μM; 6 days) alone has no effect on A549 parental cells and enhances M6620-induced cell death in A549 p53-deficient cells[5]. M3541 activates the STING/TBK1 pathway and upregulates PD-L1 in irradiated A549 cells[9]. M3541 (7 days) treatment increases the sensitivity of irradiated A549 cells to NK cell-mediated killing[9]. M3541 (7 days) enhances the expression of specific NK cell ligands in irradiated A549 cells[9]. M3541 (7 days) enhances the secretion of multiple inflammatory cytokines/chemokines in irradiated A549 cells[9].
References:
[1]. Zimmermann A, et al. A New Class of Selective ATM Inhibitors as Combination Partners of DNA Double-Strand Break Inducing Cancer Therapies. Molecular cancer therapeutics. 2022 Jun 01;21(6):859-870.
[2]. Carr MI, et al. DNA-PK Inhibitor, M3814, as a New Combination Partner of Mylotarg in the Treatment of Acute Myeloid Leukemia. Frontiers in oncology. 2020;10:127.
[3]. Cai MY, et al. Cooperation of the ATM and Fanconi Anemia/BRCA Pathways in Double-Strand Break End Resection. Cell reports. 2020 Feb 18;30(7):2402-2415.e5.
[4]. Zhang H, et al. Mapping combinatorial drug effects to DNA damage response kinase inhibitors. Nature communications. 2023 Dec 14;14(1):8310.
[5]. Turchick A, et al. Selective Inhibition of ATM-dependent Double-strand Break Repair and Checkpoint Control Synergistically Enhances the Efficacy of ATR Inhibitors. Molecular cancer therapeutics. 2023 Jul 05;22(7):859-872.
[6]. Sun Q, et al. Therapeutic Implications of p53 Status on Cancer Cell Fate Following Exposure to Ionizing Radiation and the DNA-PK Inhibitor M3814. Molecular cancer research: MCR. 2019 Dec;17(12):2457-2468.
[7]. Zimmermann A, et al. Abstract 338: A new investigational ATM Inhibitor, M3541, synergistically potentiates fractionated radiotherapy and chemotherapy in cancer cells and animal models. Cancer Res. 2018;78(13_Suppl):338.
[8]. Fuchss T, et al. Imidazolylchinoline [Patent]. DE 102010035744 A1. Germany; 2012‑03‑01.
[9]. Chiu LY, et al. Selective ATM inhibition augments radiation-induced inflammatory signaling and cancer cell death. Aging. 2023 Jan 17;15(2):492-512.
[10]. Fuchss T, et al. Abstract 329: Highly potent and selective ATM kinase inhibitor M3541: A clinical candidate drug with strong antitumor activity in combination with radiotherapy. Cancer Res. 2018;78(13_Suppl):329.