ABSTRACT
Pim kinases are promising targets for the development of cancer therapeutics. Among the three Pim isoforms, Pim-2 is particularly important in multiple myeloma, yet is the most difficult to inhibit due to its high affinity for ATP. We identified compound 1 via high throughput screening. Using property-based drug design and co-crystal structures with Pim-1 kinase to guide analog design, we were able to improve potency against all three Pim isoforms including a significant 10,000-fold gain against Pim-2. Compound 17 is a novel lead with low picomolar potency on all three Pim kinase isoforms.
Subject(s)
Drug Design , Protein Kinase Inhibitors/chemistry , Proto-Oncogene Proteins c-pim-1/antagonists & inhibitors , Pyrazoles/chemistry , Pyrimidines/chemistry , Animals , Binding Sites , Cell Line , Cell Survival/drug effects , Crystallography, X-Ray , Drug Evaluation, Preclinical , Humans , Kinetics , Mice , Protein Isoforms/antagonists & inhibitors , Protein Isoforms/metabolism , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacology , Protein Structure, Tertiary , Proto-Oncogene Proteins c-pim-1/metabolism , Pyrazoles/chemical synthesis , Pyrazoles/pharmacology , Pyrimidines/chemical synthesis , Pyrimidines/pharmacology , Structure-Activity RelationshipABSTRACT
Pim kinases have been targets of interest for a number of therapeutic areas. Evidence of durable single-agent efficacy in human clinical trials validated Pim kinase inhibition as a promising therapeutic approach for multiple myeloma patients. Here, we report the compound optimization leading to GDC-0339 (16), a potent, orally bioavailable, and well tolerated pan-Pim kinase inhibitor that proved efficacious in RPMI8226 and MM.1S human multiple myeloma xenograft mouse models and has been evaluated as an early development candidate.
Subject(s)
Antineoplastic Agents/therapeutic use , Multiple Myeloma/drug therapy , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins c-pim-1/antagonists & inhibitors , Pyrazoles/therapeutic use , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/metabolism , Cell Line, Tumor , Dogs , Female , Humans , Macaca fascicularis , Madin Darby Canine Kidney Cells , Male , Mice, SCID , Molecular Structure , Protein Binding , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/metabolism , Proto-Oncogene Proteins c-pim-1/metabolism , Pyrazoles/chemical synthesis , Pyrazoles/metabolism , Rats, Sprague-Dawley , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
Pim kinases have been identified as promising therapeutic targets for hematologic-oncology indications, including multiple myeloma and certain leukemia. Here, we describe our continued efforts in optimizing a lead series by improving bioavailability while maintaining high inhibitory potency against all three Pim kinase isoforms. The discovery of extensive intestinal metabolism and major metabolites helped refine our design strategy, and we observed that optimizing the pharmacokinetic properties first and potency second was a more successful approach than the reverse. In the resulting work, novel analogs such as 20 (GNE-955) were discovered bearing 5-azaindazole core with noncanonical hydrogen bonding to the hinge.
Subject(s)
Indazoles/chemistry , Indazoles/pharmacology , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-pim-1/antagonists & inhibitors , Animals , Biological Availability , Crystallography, X-Ray , Humans , Indazoles/metabolism , Indazoles/pharmacokinetics , Intestinal Mucosa/metabolism , Molecular Docking Simulation , Protein Isoforms/antagonists & inhibitors , Protein Isoforms/metabolism , Protein Kinase Inhibitors/metabolism , Protein Kinase Inhibitors/pharmacokinetics , Proto-Oncogene Proteins c-pim-1/metabolism , RatsABSTRACT
Bispecific antibodies and antibody fragments in various formats have been explored as a means to recruit cytolytic T cells to kill tumor cells. Encouraging clinical data have been reported with molecules such as the anti-CD19/CD3 bispecific T cell engager (BiTE) blinatumomab. However, the clinical use of many reported T cell-recruiting bispecific modalities is limited by liabilities including unfavorable pharmacokinetics, potential immunogenicity, and manufacturing challenges. We describe a B cell-targeting anti-CD20/CD3 T cell-dependent bispecific antibody (CD20-TDB), which is a full-length, humanized immunoglobulin G1 molecule with near-native antibody architecture constructed using "knobs-into-holes" technology. CD20-TDB is highly active in killing CD20-expressing B cells, including primary patient leukemia and lymphoma cells both in vitro and in vivo. In cynomolgus monkeys, CD20-TDB potently depletes B cells in peripheral blood and lymphoid tissues at a single dose of 1 mg/kg while demonstrating pharmacokinetic properties similar to those of conventional monoclonal antibodies. CD20-TDB also exhibits activity in vitro and in vivo in the presence of competing CD20-targeting antibodies. These data provide rationale for the clinical testing of CD20-TDB for the treatment of CD20-expressing B cell malignancies.