TPX-0046 is a novel and potent RET/SRC inhibitor …...TPX-0046 is a novel and potent RET/SRC...
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TPX-0046 is a novel and potent RET/SRC inhibitor for RET-driven cancers 1. Drilon A, et al. Nat Rev Clin Oncol. 2018, 15(3):150. 2. Gainor JF, et al. J Clin Oncol 37, 2019 (suppl; abstr 9008) 3. Drilon A, et al. WCLC 2019 (abstr PL02.08) Figure 1. Modeling of BLU-667, LOXO-292 and TPX-0046 in complex with RET kinase • Oncogenic activation of the receptor tyrosine kinase (RTK) rearranged during transfection (RET) via point mutation or genomic rearrangement has been identified in multiple cancers, including medullary and papillary thyroid cancers, and non-small cell lung cancer (NSCLC). • Two multi-kinase inhibitors with demonstrated RET activity, vandetanib and cabozantinib, have been approved for thyroid cancer. • Current investigational selective RET inhibitors BLU-667 and LOXO-292 have demonstrated efficacy in RET aberrant NSCLC and thyroid cancers. 1,2,3 • Multiple resistance mutations have been reported from preclinical studies, including the gatekeeper mutation V804L to cabozantinib and solvent front mutations (SFMs) G810A/S to vandetanib. 4,5 • Given that current TKIs often lead to resistance, TPX-0046, a next generation RET inhibitor that is structurally differentiated and potent against a broad range of mutations, especially SFMs, was designed. Alexander Drilon 1 , Evan Rogers 2 , Dayong Zhai 2 , Wei Deng 2 , Xin Zhang 2 , Dong Lee 2 , Jane Ung 2 , Jeffrey Whitten 2 , Han Zhang 2 , Jing Liu 2 , Tao Hu 2 , Hong Zhuang 2 , Yuelie Lu 2 , Zhongdong Huang 2 , Armin Graber 2 , Zach Zimmerman 2 , Robert Xin 2 , J. Jean Cui 2 , Vivek Subbiah 3 1 Memorial Sloan Kettering Cancer Center, New York, USA ; 2 Turning Point Therapeutics, Inc., San Diego; 3 The University of Texas MD Anderson Cancer Center, Houston Abstract # 4307 Poster # 506P • RET kinase adopts a unique autoinhibitory conformation with a “closed” glycine rich loop (GLP) tethered by E734 from GLP, R912 from activation loop (AL) and D771 from αC helix (Figure 1A). • Our internal modeling indicates that both BLU-667 (pralsetinib/WHO INN record) and LOXO-292 (selpercatinib/WHO INN record) have a long arm reaching to the tethered pocket (Figure 1B & 1C). • TPX-0046 was designed with a macrocyclic structure targeting the RET active conformation (Figure 1D). • TPX-0046, with a molecular weight (MW) < 430, is much more compact than BLU-667 (MW 533.6) and LOXO-292 (MW 525.6). • Based on our modeling, TPX-0046 is structurally distinguished from BLU-667 and LOXO-292 and was designed to overcome potential RET TKI-resistant mutations that we predict may develop after either BLU-667 or LOXO-292 treatment. • TPX-0046 is potent against wildtype (WT) and mutant RET (Table 2) Table 1: TPX-0046 kinase selectivity at 10 µM ATP a TPX-0046 RET PEAK1 SRC ARG TXK TRKC FYN FGFR2 LYN MUSK YES HCK IC 50 (nM) 1 0.4 1 1.4 1.7 1.8 1.9 2 2 2.4 2.6 2.7 FGR FLT3 BMX TRKB DDR1 LCK BTK TIE2 JAK2 TRKA FGFR1 IC 50 (nM) 3.1 3.2 3.3 3.4 4.3 4.4 4.7 5.6 7.7 7.8 9.8 a Kinase activity was determined at Reaction Biology, Inc. • TPX-0046 has potent activity against a broad array of disease-relevant RET mutations including the solvent front mutation G810R, which is predicted to cause resistance to current RET TKIs including BLU-667 and LOXO-292. • TPX-0046 has promising drug-like properties and a unique pharmacology profile that warrant clinical studies in advanced solid tumors with RET gene alterations. • IND has been submitted. • TPX-0046 is potent against wildtype (WT) and mutant RET in comparison with BLU-667 and LOXO-292 in the enzymatic assay (Table 2). • The results of the Ba/F3 cell proliferation assays and western blots are presented in Table 3 and Figure 2, respectively. • In comparison with BLU-667 and LOXO-292, ‐ TPX-0046 has comparable activity against KIF5B-RET WT and Y806N; ‐ TPX-0046 is more potent against SFMs KIF5B-RET G810S and G810R; ‐ TPX-0046 is less potent against gatekeeper mutation KIF5B-RET V804M. Figure 2. Inhibition of RET Phosphorylation b Data based on evaluation of comparable proxy chemical reagents purchased from commercial sources • TPX-0046 demonstrates marked antitumor effects in xenograft tumor models, including Ba/F3 KIF5B-RET WT and G810R, TT (C634W) cell-derived models and the lung cancer PDX model harboring KIF5B-RET fusion and the colorectal cancer PDX model harboring NCOA4-RET fusion (Figure 3). • Dose-dependent inhibition of RET phosphorylation was observed in the Ba/F3 KIF5B-RET cell-derived tumor model. Figure 3. Antitumor efficacy of TPX-0046 in xenograft mouse tumor models Antitumor Effect of TPX-0046 in Ba/F3 Cell-Derived Xenograft Tumors with a KIF5B-RET WT Fusion The Pharmacokinetic/Pharmacodynamic Relationship of TPX-0046 in Ba/F3 Cell-Derived Xenograft Tumors with a KIF5B-RET WT Fusion Antitumor Effect of TPX-0046 in TT Cell-Derived Xenograft Tumors with a RET C634W Mutation Antitumor Effect of TPX-0046 in Ba/F3 Cell-Derived Xenograft Tumors with a KIF5B-RET G810R Fusion Antitumor Effect of TPX-0046 in the CTG-0838 Patient-Derived Xenograft Tumor Model of NSCLC Harboring a KIF5B-RET Fusion Antitumor Effect of TPX-0046 in the CR1520 Patient-Derived Xenograft Tumor Model of Colorectal Cancer Harboring a NCOA4-RET Fusion This study was sponsored by Turning Point Therapeutics, Inc. AG, DL, DZ, ER, HZ, HZ, JL, JJC, JU, JW, RX, TH, WD, XZ, YL, ZH, & ZZ: Turning Point Therapeutics – employment/ shareholder. Presented at: European Society for Medical Oncology (ESMO) 2019; 27 Sep–1 Oct 2019; Barcelona, Spain. Corresponding Contact — Jim Mazzola: [email protected] TPX-0046 BLU-667 b LOXO-292 b Ba/F3 KIF5B-RET 0.4 0.7 0.2 Ba/F3 KIF5B-RET Y806N 13.2 22.1 13.5 Ba/F3 KIF5B-RET G810S 0.4 4.9 62.8 Ba/F3 KIF5B-RE G810R 16.9 749 568 Ba/F3 KIF5B-RET V804M 533 1.1 23.4 TT RET C634W 0.9 NA NA LC2/ad CCDC6-RET 1 NA NA NA: not available b Data based on evaluation of comparable proxy chemical reagents purchased from commercial sources Kinase IC 50 (nM) at 10 µM ATP TPX-0046 BLU-667 b LOXO-292 b RET 1 1.7 1.9 RET (A883F) 1.2 1.1 1.2 RET (E762Q) 1 1.6 1.8 RET (G691S) 1.8 2.5 3.1 RET (L790F) 0.4 0.5 0.4 RET (M918T) 0.3 0.5 0.4 RET (R749T) 0.8 1 1.1 RET (R813Q) 1.7 2.5 2.6 RET (S891A) 0.2 0.6 0.8 RET (S904A) 0.9 1.2 1.6 RET (S904F) 0.5 0.6 0.7 RET (V778I) 0.1 0.3 0.4 RET (V804E) >1000 8.4 15.1 RET (V804L) 6.2 0.8 0.9 RET (V804M) 8.1 2.8 4.6 RET (Y791F) 0.4 0.8 0.8 RET (Y806H) 2.6 3.7 3.5 RET-CCDC6 (PTC1) 0.5 0.8 0.9 RET-NCOA4 (PTC3) 0.7 1.5 1.6 RET-PRKAR1A (PTC2) 0.4 0.8 0.9 a Kinase activity was determined at Reaction Biology, Inc. b Data based on evaluation of comparable proxy chemical reagents purchased from commercial sources Table 2. Inhibitory activities against WT and mutant RET at 10 µM ATP a Table 3. Cell proliferation assay IC 50 (nM) BLU-667 LOXO-292 TPX-0046 F735 D771 R912 E734 A B C D Tethered Pocket • The kinase selectivity profile of TPX-0046 was evaluated against 374 kinases at 100 nM concentration. • IC 50 s are listed in Table 1 for the hits that have less than 10-fold selectivity over RET. • TPX-0046 had potent inhibition against RET and SRC family kinases (highlighted in red). 4. Liu X, et al. Br J Pharmacol. 2018, 175, 3504. 5. Nakaoku T, et al. Nat Commun. 2018, 9, 625.
Transcript of TPX-0046 is a novel and potent RET/SRC inhibitor …...TPX-0046 is a novel and potent RET/SRC...
TPX-0046 is a novel and potent RET/SRC inhibitor for RET-driven cancers
1. Drilon A, et al. Nat Rev Clin Oncol. 2018, 15(3):150. 2. Gainor JF, et al. J Clin Oncol 37, 2019 (suppl; abstr 9008)3. Drilon A, et al. WCLC 2019 (abstr PL02.08)
Figure 1. Modeling of BLU-667, LOXO-292 and TPX-0046 in complex with RET kinase
• Oncogenic activation of the receptor tyrosine kinase (RTK) rearranged during transfection (RET) via point mutation or genomic rearrangement has been identified in multiple cancers, including medullary and papillary thyroid cancers, and non-small cell lung cancer (NSCLC).
• Two multi-kinase inhibitors with demonstrated RET activity, vandetanib and cabozantinib, have been approved for thyroid cancer.
• Current investigational selective RET inhibitors BLU-667 and LOXO-292 have demonstrated efficacy in RET aberrant NSCLC and thyroid cancers.1,2,3
• Multiple resistance mutations have been reported from preclinical studies, including the gatekeeper mutation V804L to cabozantinib and solvent front mutations (SFMs) G810A/S to vandetanib.4,5
• Given that current TKIs often lead to resistance, TPX-0046, a next generation RET inhibitor that is structurally differentiated and potent against a broad range of mutations, especially SFMs, was designed.
Alexander Drilon1, Evan Rogers2, Dayong Zhai2, Wei Deng2, Xin Zhang2, Dong Lee2, Jane Ung2, Jeffrey Whitten2, Han Zhang2, Jing Liu2, Tao Hu2, Hong Zhuang2, Yuelie Lu2, Zhongdong Huang2, Armin Graber2, Zach Zimmerman2, Robert Xin2, J. Jean Cui2, Vivek Subbiah3
1Memorial Sloan Kettering Cancer Center, New York, USA ; 2Turning Point Therapeutics, Inc., San Diego; 3The University of Texas MD Anderson Cancer Center, Houston
INTRODUCTION
CONCLUSIONS
REFERENCES & DISCLOSURES
DESIGN OF TPX-0046 EVALUATION OF TPX-0046 IN IN VITRO ASSAYS
EVALUATION OF TPX-0046 IN IN VIVO TUMOR MODELS
Abstract # 4307Poster # 506P
• RET kinase adopts a unique autoinhibitory conformation with a “closed” glycine rich loop (GLP) tethered by E734 from GLP, R912 from activation loop (AL) and D771 from αC helix (Figure 1A).
• Our internal modeling indicates that both BLU-667 (pralsetinib/WHO INN record) and LOXO-292 (selpercatinib/WHO INN record) have a long arm reaching to the tethered pocket (Figure 1B & 1C).
• TPX-0046 was designed with a macrocyclic structure targeting the RET active conformation (Figure 1D).
• TPX-0046, with a molecular weight (MW) < 430, is much more compact than BLU-667 (MW 533.6) and LOXO-292 (MW 525.6).
• Based on our modeling, TPX-0046 is structurally distinguished from BLU-667 and LOXO-292 and was designed to overcome potential RET TKI-resistant mutations that we predict may develop after either BLU-667 or LOXO-292 treatment.
• TPX-0046 is potent against wildtype (WT) and mutant RET (Table 2)
Table 1: TPX-0046 kinase selectivity at 10 µM ATPa
TPX-0046 RET PEAK1 SRC ARG TXK TRKC FYN FGFR2 LYN MUSK YES HCK
IC50 (nM) 1 0.4 1 1.4 1.7 1.8 1.9 2 2 2.4 2.6 2.7
FGR FLT3 BMX TRKB DDR1 LCK BTK TIE2 JAK2 TRKA FGFR1
IC50 (nM) 3.1 3.2 3.3 3.4 4.3 4.4 4.7 5.6 7.7 7.8 9.8
a Kinase activity was determined at Reaction Biology, Inc.
• TPX-0046 has potent activity against a broad array of disease-relevant RET mutations including the solvent front mutation G810R, which is predicted to cause resistance to current RET TKIs including BLU-667 and LOXO-292.
• TPX-0046 has promising drug-like properties and a unique pharmacology profile that warrant clinical studies in advanced solid tumors with RET gene alterations.
• IND has been submitted.
• TPX-0046 is potent against wildtype (WT) and mutant RET in comparison with BLU-667 and LOXO-292 in the enzymatic assay (Table 2).
• The results of the Ba/F3 cell proliferation assays and western blots are presented in Table 3 and Figure 2, respectively.
• In comparison with BLU-667 and LOXO-292,
‐ TPX-0046 has comparable activity against KIF5B-RET WT and Y806N;
‐ TPX-0046 is more potent against SFMs KIF5B-RET G810S and G810R;
‐ TPX-0046 is less potent against gatekeeper mutation KIF5B-RET V804M.
Figure 2. Inhibition of RET Phosphorylation
b Data based on evaluation of comparable proxy chemical reagents purchased from commercial sources
• TPX-0046 demonstrates marked antitumor effects in xenograft tumor models, including Ba/F3 KIF5B-RET WT and G810R, TT (C634W) cell-derived models and the lung cancer PDX model harboring KIF5B-RET fusion and the colorectal cancer PDX model harboring NCOA4-RET fusion (Figure 3).
• Dose-dependent inhibition of RET phosphorylation was observed in the Ba/F3 KIF5B-RET cell-derived tumor model.
Figure 3. Antitumor efficacy of TPX-0046 in xenograft mouse tumor models
Antitumor Effect of TPX-0046 in Ba/F3 Cell-Derived Xenograft Tumors with a KIF5B-RET WT Fusion
The Pharmacokinetic/Pharmacodynamic Relationship of TPX-0046 in Ba/F3 Cell-Derived Xenograft Tumors with a KIF5B-RET WT Fusion
Antitumor Effect of TPX-0046 in TT Cell-Derived Xenograft Tumors with a RET C634W Mutation
Antitumor Effect of TPX-0046 in Ba/F3 Cell-Derived Xenograft Tumors with a KIF5B-RET G810R Fusion
Antitumor Effect of TPX-0046 in the CTG-0838 Patient-Derived Xenograft Tumor Model of NSCLC Harboring a KIF5B-RET Fusion
Antitumor Effect of TPX-0046 in the CR1520 Patient-Derived Xenograft Tumor Model of Colorectal Cancer Harboring a NCOA4-RET Fusion
This study was sponsored by Turning Point Therapeutics, Inc.
AG, DL, DZ, ER, HZ, HZ, JL, JJC, JU, JW, RX, TH, WD, XZ, YL, ZH, & ZZ: Turning Point Therapeutics – employment/shareholder. Presented at: European Society for Medical Oncology (ESMO) 2019; 27 Sep–1 Oct 2019; Barcelona, Spain. Corresponding Contact — Jim Mazzola: [email protected]
TPX-0046 BLU-667b LOXO-292b
Ba/F3 KIF5B-RET 0.4 0.7 0.2Ba/F3 KIF5B-RET Y806N 13.2 22.1 13.5Ba/F3 KIF5B-RET G810S 0.4 4.9 62.8Ba/F3 KIF5B-RE G810R 16.9 749 568Ba/F3 KIF5B-RET V804M 533 1.1 23.4TT RET C634W 0.9 NA NALC2/ad CCDC6-RET 1 NA NANA: not availableb Data based on evaluation of comparable proxy chemical reagents purchased from commercial sources
Kinase IC50 (nM) at 10 µM ATPTPX-0046 BLU-667b LOXO-292b
RET 1 1.7 1.9RET (A883F) 1.2 1.1 1.2RET (E762Q) 1 1.6 1.8RET (G691S) 1.8 2.5 3.1RET (L790F) 0.4 0.5 0.4RET (M918T) 0.3 0.5 0.4RET (R749T) 0.8 1 1.1RET (R813Q) 1.7 2.5 2.6RET (S891A) 0.2 0.6 0.8RET (S904A) 0.9 1.2 1.6RET (S904F) 0.5 0.6 0.7RET (V778I) 0.1 0.3 0.4RET (V804E) >1000 8.4 15.1RET (V804L) 6.2 0.8 0.9RET (V804M) 8.1 2.8 4.6RET (Y791F) 0.4 0.8 0.8RET (Y806H) 2.6 3.7 3.5
RET-CCDC6 (PTC1) 0.5 0.8 0.9RET-NCOA4 (PTC3) 0.7 1.5 1.6
RET-PRKAR1A (PTC2) 0.4 0.8 0.9a Kinase activity was determined at Reaction Biology, Inc.b Data based on evaluation of comparable proxy chemical reagents purchased from commercial sources
Table 2. Inhibitory activities against WT and mutant RET at 10 µM ATPa
Table 3. Cell proliferation assay IC50 (nM)
KINASE SELECTIVITY OF TPX-0046 (CONTINUED)
BLU-667 LOXO-292 TPX-0046F735D771
R912E734
A B C D
TetheredPocket
• The kinase selectivity profile of TPX-0046 was evaluated against 374 kinases at 100 nM concentration.
• IC50 s are listed in Table 1 for the hits that have less than 10-fold selectivity over RET.
• TPX-0046 had potent inhibition against RET and SRC family kinases (highlighted in red).
KINASE SELECTIVITY OF TPX-0046
4. Liu X, et al. Br J Pharmacol. 2018, 175, 3504. 5. Nakaoku T, et al. Nat Commun. 2018, 9, 625.
