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Identification and Preclinical Pharmacology of the γ-Secretase Modulator BMS-869780.

Toyn JH, Thompson LA, Lentz KA, Meredith JE, Burton CR, Sankaranararyanan S, Guss V, Hall T, Iben LG, Krause CM, Krause R, Lin XA, Pierdomenico M, Polson C, Robertson AS, Denton RR, Grace JE, Morrison J, Raybon J, Zhuo X, Snow K, Padmanabha R, Agler M, Esposito K, Harden D, Prack M, Varma S, Wong V, Zhu Y, Zvyaga T, Gerritz S, Marcin LR, Higgins MA, Shi J, Wei C, Cantone JL, Drexler DM, Macor JE, Olson RE, Ahlijanian MK, Albright CF - Int J Alzheimers Dis (2014)

Bottom Line: Off-target and safety margins were then based on comparisons to the predicted exposure required for robust Aβ1-42 lowering.Because of insufficient safety predictions and the relatively high predicted human daily dose of 700 mg, further evaluation of BMS-869780 as a potential clinical candidate was discontinued.Nevertheless, BMS-869780 demonstrates the potential of the GSM approach for robust lowering of brain Aβ1-42 without Notch-related side effects.

View Article: PubMed Central - PubMed

Affiliation: Exploratory Biology and Genomics, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA.

ABSTRACT
Alzheimer's disease is the most prevalent cause of dementia and is associated with accumulation of amyloid-β peptide (Aβ), particularly the 42-amino acid Aβ1-42, in the brain. Aβ1-42 levels can be decreased by γ-secretase modulators (GSM), which are small molecules that modulate γ-secretase, an enzyme essential for Aβ production. BMS-869780 is a potent GSM that decreased Aβ1-42 and Aβ1-40 and increased Aβ1-37 and Aβ1-38, without inhibiting overall levels of Aβ peptides or other APP processing intermediates. BMS-869780 also did not inhibit Notch processing by γ-secretase and lowered brain Aβ1-42 without evidence of Notch-related side effects in rats. Human pharmacokinetic (PK) parameters were predicted through allometric scaling of PK in rat, dog, and monkey and were combined with the rat pharmacodynamic (PD) parameters to predict the relationship between BMS-869780 dose, exposure and Aβ1-42 levels in human. Off-target and safety margins were then based on comparisons to the predicted exposure required for robust Aβ1-42 lowering. Because of insufficient safety predictions and the relatively high predicted human daily dose of 700 mg, further evaluation of BMS-869780 as a potential clinical candidate was discontinued. Nevertheless, BMS-869780 demonstrates the potential of the GSM approach for robust lowering of brain Aβ1-42 without Notch-related side effects.

No MeSH data available.


Related in: MedlinePlus

BMS-869780 had minimal effect on APP-CTF accumulation in vitro. H4-APPsw cell cultures were treated overnight with the indicated concentrations of BMS-869780, BMS-299897 or vehicle (0.1% DMSO). (a) Cells were harvested and analyzed by western blotting for APP-CTFα, APP-CTFβ, and GAPDH. Lane 1; culture treated with vehicle 0.1% DMSO. Lanes 2–5; cultures treated with BMS-869780 at 100 nM, 300 nM, 1000 nM, or 3000 nM, respectively. Lanes 6–8; cultures treated with BMS-299897 at 30 nM, 100 nM, or 300 nM, respectively. (b) Levels of Aβ1-42 (red; left Y-axis), Aβ1-40 (green; right Y-axis), and Aβ1-x (grey; right Y-axis) were quantified.
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fig4: BMS-869780 had minimal effect on APP-CTF accumulation in vitro. H4-APPsw cell cultures were treated overnight with the indicated concentrations of BMS-869780, BMS-299897 or vehicle (0.1% DMSO). (a) Cells were harvested and analyzed by western blotting for APP-CTFα, APP-CTFβ, and GAPDH. Lane 1; culture treated with vehicle 0.1% DMSO. Lanes 2–5; cultures treated with BMS-869780 at 100 nM, 300 nM, 1000 nM, or 3000 nM, respectively. Lanes 6–8; cultures treated with BMS-299897 at 30 nM, 100 nM, or 300 nM, respectively. (b) Levels of Aβ1-42 (red; left Y-axis), Aβ1-40 (green; right Y-axis), and Aβ1-x (grey; right Y-axis) were quantified.

Mentions: BMS-869780 showed only a 4-fold shift in IC50 values between Aβ1-42 and Aβ1-40. The effect of BMS-869780 on Aβ1-37 and Aβ1-38 was therefore evaluated, as a more diagnostic test of the GSM mechanism [25]. H4-APPsw cultures were treated overnight with BMS-869780, and Aβ peptides were evaluated by mass spectrometry and western blotting. Using MALDI mass spectrometry, Aβ1-37, Aβ1-38, and Aβ1-40 were readily detected in vehicle-treated cultures, although Aβ1-42 levels were near the limit of quantitation. After treatment with BMS-869780 (100 nM), Aβ1-37 and Aβ1-38 were dramatically increased, whereas Aβ1-40 and Aβ1-42 were essentially undetectable (Figure 3(a)). The same conclusion was reached in experiments using a western blot method that separates different forms of Aβ. Increased levels of the shorter Aβ1-37 and Aβ1-38 peptides, which migrate more slowly than Aβ1-40 or Aβ1-42 by this method, were observed in cultures treated with BMS-869780 at 100 nM and 10 nM (Figure 3(b), lanes 3 and 4, resp.). Thus, taking the experimental data illustrated in Figures 2 and 3 together, BMS-869780 increased Aβ1-37 and Aβ1-38, while decreasing Aβ1-40 and Aβ1-42. This suggested that BMS-869780 would have a minimal effect, if any, on APP-CTFα and APP-CTFβ turnover. H4-APPsw cell cultures were therefore treated at high concentrations, relative to the IC50s, of BMS-869780 and the GSI BMS-299897. For APP-CTFα, BMS-299897 caused an 8-fold increase in APP-CTFα, whereas BMS-869780 showed a 1.4-fold increase, averaged across doses (Figure 4(a)). The two compounds also showed a dramatic contrast in their effects on Aβ under these conditions. Whereas the GSI BMS-299897 dramatically reduced all Aβ1-x peptides, including Aβ1-42 and Aβ1-40, BMS-869780 selectively lowered Aβ1-42 and Aβ1-40, without any decrease in the overall levels of Aβ1-x (Figure 4(b)). In contrast to the result for APP-CTFα, APP-CTFβ levels were not affected in this experiment by either compound (Figure 4(a)), suggesting that γ-secretase was not a major pathway for APP-CTFβ turnover under these conditions. Indeed, it was recently reported that APP-CTFβ turnover in H4 cells occurs largely through proteasomal and lysosomal pathways, in contrast to APP-CTFα turnover which is more dependent on γ-secretase [74]. Thus, the effect of BMS-869780 on APP-CTFβ could not be directly evaluated in the H4-APPsw cell line under these conditions. To address the effect of BMS-869780 on APP-CTFβ, experiments were carried out in the context of the intended target organ, that is, in the brain of rats given oral doses of BMS-869780. The GSI BMS-698861 was dosed for comparison. BMS-869780 decreased Aβ1-40 and Aβ1-42 and increased Aβ1-37 and Aβ1-38 in rat brain. The sum total of Aβ1-40, Aβ1-42, Aβ1-38, and Aβ1-37 suggested no significant change in overall Aβ levels (Figure 5(a)). This was consistent with results obtained in the Aβ1-x assay, which showed no significant decrease despite the robust decrease in Aβ1-42 (Figure 5(b)). In contrast, BMS-698861 decreased levels of all the peptides, Aβ1-40, Aβ1-42, Aβ1-38, Aβ1-37, and Aβ1-x (Figures 5(a) and 5(b)). APP-CTFβ and APP-CTFα in samples of the same rat brains were evaluated by immunoprecipitation and western blotting. Neither APP-CTFβ nor APP-CTFα levels were affected in rats given BMS-869780, whereas levels of both peptides increased several-fold in rats given the GSI BMS-698861 (Figures 5(c)–5(f)). Thus, in brain, inhibition of γ-secretase by BMS-698861 resulted in APP-CTFβ and APP-CTFα accumulation, whereas modulation of Aβ by BMS-869780 had no effect on APP-CTFβ or APP-CTFα levels.


Identification and Preclinical Pharmacology of the γ-Secretase Modulator BMS-869780.

Toyn JH, Thompson LA, Lentz KA, Meredith JE, Burton CR, Sankaranararyanan S, Guss V, Hall T, Iben LG, Krause CM, Krause R, Lin XA, Pierdomenico M, Polson C, Robertson AS, Denton RR, Grace JE, Morrison J, Raybon J, Zhuo X, Snow K, Padmanabha R, Agler M, Esposito K, Harden D, Prack M, Varma S, Wong V, Zhu Y, Zvyaga T, Gerritz S, Marcin LR, Higgins MA, Shi J, Wei C, Cantone JL, Drexler DM, Macor JE, Olson RE, Ahlijanian MK, Albright CF - Int J Alzheimers Dis (2014)

BMS-869780 had minimal effect on APP-CTF accumulation in vitro. H4-APPsw cell cultures were treated overnight with the indicated concentrations of BMS-869780, BMS-299897 or vehicle (0.1% DMSO). (a) Cells were harvested and analyzed by western blotting for APP-CTFα, APP-CTFβ, and GAPDH. Lane 1; culture treated with vehicle 0.1% DMSO. Lanes 2–5; cultures treated with BMS-869780 at 100 nM, 300 nM, 1000 nM, or 3000 nM, respectively. Lanes 6–8; cultures treated with BMS-299897 at 30 nM, 100 nM, or 300 nM, respectively. (b) Levels of Aβ1-42 (red; left Y-axis), Aβ1-40 (green; right Y-axis), and Aβ1-x (grey; right Y-axis) were quantified.
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fig4: BMS-869780 had minimal effect on APP-CTF accumulation in vitro. H4-APPsw cell cultures were treated overnight with the indicated concentrations of BMS-869780, BMS-299897 or vehicle (0.1% DMSO). (a) Cells were harvested and analyzed by western blotting for APP-CTFα, APP-CTFβ, and GAPDH. Lane 1; culture treated with vehicle 0.1% DMSO. Lanes 2–5; cultures treated with BMS-869780 at 100 nM, 300 nM, 1000 nM, or 3000 nM, respectively. Lanes 6–8; cultures treated with BMS-299897 at 30 nM, 100 nM, or 300 nM, respectively. (b) Levels of Aβ1-42 (red; left Y-axis), Aβ1-40 (green; right Y-axis), and Aβ1-x (grey; right Y-axis) were quantified.
Mentions: BMS-869780 showed only a 4-fold shift in IC50 values between Aβ1-42 and Aβ1-40. The effect of BMS-869780 on Aβ1-37 and Aβ1-38 was therefore evaluated, as a more diagnostic test of the GSM mechanism [25]. H4-APPsw cultures were treated overnight with BMS-869780, and Aβ peptides were evaluated by mass spectrometry and western blotting. Using MALDI mass spectrometry, Aβ1-37, Aβ1-38, and Aβ1-40 were readily detected in vehicle-treated cultures, although Aβ1-42 levels were near the limit of quantitation. After treatment with BMS-869780 (100 nM), Aβ1-37 and Aβ1-38 were dramatically increased, whereas Aβ1-40 and Aβ1-42 were essentially undetectable (Figure 3(a)). The same conclusion was reached in experiments using a western blot method that separates different forms of Aβ. Increased levels of the shorter Aβ1-37 and Aβ1-38 peptides, which migrate more slowly than Aβ1-40 or Aβ1-42 by this method, were observed in cultures treated with BMS-869780 at 100 nM and 10 nM (Figure 3(b), lanes 3 and 4, resp.). Thus, taking the experimental data illustrated in Figures 2 and 3 together, BMS-869780 increased Aβ1-37 and Aβ1-38, while decreasing Aβ1-40 and Aβ1-42. This suggested that BMS-869780 would have a minimal effect, if any, on APP-CTFα and APP-CTFβ turnover. H4-APPsw cell cultures were therefore treated at high concentrations, relative to the IC50s, of BMS-869780 and the GSI BMS-299897. For APP-CTFα, BMS-299897 caused an 8-fold increase in APP-CTFα, whereas BMS-869780 showed a 1.4-fold increase, averaged across doses (Figure 4(a)). The two compounds also showed a dramatic contrast in their effects on Aβ under these conditions. Whereas the GSI BMS-299897 dramatically reduced all Aβ1-x peptides, including Aβ1-42 and Aβ1-40, BMS-869780 selectively lowered Aβ1-42 and Aβ1-40, without any decrease in the overall levels of Aβ1-x (Figure 4(b)). In contrast to the result for APP-CTFα, APP-CTFβ levels were not affected in this experiment by either compound (Figure 4(a)), suggesting that γ-secretase was not a major pathway for APP-CTFβ turnover under these conditions. Indeed, it was recently reported that APP-CTFβ turnover in H4 cells occurs largely through proteasomal and lysosomal pathways, in contrast to APP-CTFα turnover which is more dependent on γ-secretase [74]. Thus, the effect of BMS-869780 on APP-CTFβ could not be directly evaluated in the H4-APPsw cell line under these conditions. To address the effect of BMS-869780 on APP-CTFβ, experiments were carried out in the context of the intended target organ, that is, in the brain of rats given oral doses of BMS-869780. The GSI BMS-698861 was dosed for comparison. BMS-869780 decreased Aβ1-40 and Aβ1-42 and increased Aβ1-37 and Aβ1-38 in rat brain. The sum total of Aβ1-40, Aβ1-42, Aβ1-38, and Aβ1-37 suggested no significant change in overall Aβ levels (Figure 5(a)). This was consistent with results obtained in the Aβ1-x assay, which showed no significant decrease despite the robust decrease in Aβ1-42 (Figure 5(b)). In contrast, BMS-698861 decreased levels of all the peptides, Aβ1-40, Aβ1-42, Aβ1-38, Aβ1-37, and Aβ1-x (Figures 5(a) and 5(b)). APP-CTFβ and APP-CTFα in samples of the same rat brains were evaluated by immunoprecipitation and western blotting. Neither APP-CTFβ nor APP-CTFα levels were affected in rats given BMS-869780, whereas levels of both peptides increased several-fold in rats given the GSI BMS-698861 (Figures 5(c)–5(f)). Thus, in brain, inhibition of γ-secretase by BMS-698861 resulted in APP-CTFβ and APP-CTFα accumulation, whereas modulation of Aβ by BMS-869780 had no effect on APP-CTFβ or APP-CTFα levels.

Bottom Line: Off-target and safety margins were then based on comparisons to the predicted exposure required for robust Aβ1-42 lowering.Because of insufficient safety predictions and the relatively high predicted human daily dose of 700 mg, further evaluation of BMS-869780 as a potential clinical candidate was discontinued.Nevertheless, BMS-869780 demonstrates the potential of the GSM approach for robust lowering of brain Aβ1-42 without Notch-related side effects.

View Article: PubMed Central - PubMed

Affiliation: Exploratory Biology and Genomics, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA.

ABSTRACT
Alzheimer's disease is the most prevalent cause of dementia and is associated with accumulation of amyloid-β peptide (Aβ), particularly the 42-amino acid Aβ1-42, in the brain. Aβ1-42 levels can be decreased by γ-secretase modulators (GSM), which are small molecules that modulate γ-secretase, an enzyme essential for Aβ production. BMS-869780 is a potent GSM that decreased Aβ1-42 and Aβ1-40 and increased Aβ1-37 and Aβ1-38, without inhibiting overall levels of Aβ peptides or other APP processing intermediates. BMS-869780 also did not inhibit Notch processing by γ-secretase and lowered brain Aβ1-42 without evidence of Notch-related side effects in rats. Human pharmacokinetic (PK) parameters were predicted through allometric scaling of PK in rat, dog, and monkey and were combined with the rat pharmacodynamic (PD) parameters to predict the relationship between BMS-869780 dose, exposure and Aβ1-42 levels in human. Off-target and safety margins were then based on comparisons to the predicted exposure required for robust Aβ1-42 lowering. Because of insufficient safety predictions and the relatively high predicted human daily dose of 700 mg, further evaluation of BMS-869780 as a potential clinical candidate was discontinued. Nevertheless, BMS-869780 demonstrates the potential of the GSM approach for robust lowering of brain Aβ1-42 without Notch-related side effects.

No MeSH data available.


Related in: MedlinePlus