Galanis A.,Johns Hopkins University |
Ma H.,Johns Hopkins University |
Rajkhowa T.,Johns Hopkins University |
Ramachandran A.,AROG Pharmaceuticals LLC |
And 3 more authors.
Blood | Year: 2014
Mutations of the type III receptor tyrosine kinase FLT3 occur in approximately 30% of acute myeloid leukemia patients and lead to constitutive activation. This has made FLT3- activating mutations an attractive drug target because they are probable driver mutations of this disease. As more potent FLT3 inhibitors are developed, a predictable development of resistance-conferring point mutations, commonly at residue D835, has been observed. Crenolanib is a highly selective and potent FLT3 tyrosine kinase inhibitor (TKI) with activity against the internal tandem duplication (FLT3/ITD) mutants and the FLT3/D835 point mutants.Wetested crenolanib against a panel of D835 mutant cell lines and primary patient blasts and observed superior cytotoxic effects when compared with other available FLT3 TKIs such as quizartinib and sorafenib. Another potential advantage of crenolanib is its reduced inhibition of c-Kit compared with quizartinib. In progenitor cell assays, crenolanib was less disruptive of erythroid colony growth, which may result in relatively less myelosuppression than quizartinib. Finally, correlative data from an ongoing clinical trial demonstrate that acute myeloid leukemia patients can achieve sufficient levels of crenolanib to inhibit both FLT3/ITD and resistance-conferring FLT3/D835 mutants in vivo. Crenolanib is thus an important next-generation FLT3 TKI. This study is registered at clinicaltrials.gov (ID: NCT01657682). (Blood. 2014;123(1):94-100). © 2014 by The American Society of Hematology. Source
Zhang W.,University of Texas M. D. Anderson Cancer Center |
Gao C.,University of Texas M. D. Anderson Cancer Center |
Konopleva M.,University of Texas M. D. Anderson Cancer Center |
Chen Y.,University of Texas M. D. Anderson Cancer Center |
And 6 more authors.
Clinical Cancer Research | Year: 2014
Purpose: FMS-like tyrosine kinase-3 (FLT3) internal tandem duplication (FLT3-ITD) mutations are common in patients with acute myeloid leukemia (AML). These patients regularly develop resistance to FLT3 inhibitors suggesting that targeted combination drug strategies are needed to enhance AML therapy efficacy. Experimental Design: Acquired point mutations of FLT3-ITD gene were screened using cDNA-based sequencing approach in vitro sorafenib-resistant cells, which were developed by long-term exposure of Ba/ F3-ITD to increasing doses of sorafenib, and in FLT3-ITD mutated AML patients, who developed relapse following sorafenib therapy. Drug effects (e.g., proliferation inhibition, apoptosis induction, and changes in signal transduction protein expression) were assessed in AML cells harboring the point mutations in vitro and in FLT3-ITD-mutated AML patient samples. Results:Weidentified several acquired point mutations in the tyrosine kinase domains (TKD) of the FLT3 gene in sorafenib-resistant murine leukemia cell line carrying human FLT3-ITD mutations, which were also detected in two of four sorafenib-resistant patient samples. Engineering these point mutations into Ba/F3-ITD cells generated sublines that demonstrated varying degrees of sorafenib [a type II tyrosine kinase inhibitor (TKI)] resistance. Asimilar pattern of resistance could be observed by exposing these sublines to the other type II TKIs AC220 and MLN518. However, these sublines retained sensitivity to the type I TKIs PKC412 or crenolanib. The combination of crenolanib with sorafenib demonstrated marked cytotoxic effects in all of the sorafenib-resistant sublines. Conclusions: These combination strategies could be clinically important in reversing acquired resistance to FLT3 inhibition in AML. © 2014 AACR. Source
Heinrich M.C.,Oregon Health And Science University |
Griffith D.,Oregon Health And Science University |
McKinley A.,Oregon Health And Science University |
Patterson J.,Oregon Health And Science University |
And 3 more authors.
Clinical Cancer Research | Year: 2012
Purpose: To determine the potential of crenolanib, a potent inhibitor of PDGFRA, to treat malignancies driven by mutant PDGFRA. Experimental Design: The biochemical activity of crenolanib was compared with imatinib using a panel of PDGFRA-mutant kinases expressed in several different cell line models, including primary gastrointestinal stromal tumors (GIST) cells. The antiproliferative activity of crenolanib was also studied in several cell lines with PDGFRA-dependent growth. Results: Crenolanib was significantly more potent than imatinib in inhibiting the kinase activity of imatinib-resistant PDGFRA kinases (D842I, D842V, D842Y, DI842-843IM, and deletion I843). For example, crenolanib was 135-fold more potent than imatinib against D842V in our isogenic model system, with an IC50 of approximately 10 nmol/L. The relative potency of crenolanib was further confirmed in BaF3 and primary GIST cells expressing PDGFRA D842V. In contrast, imatinib was at least 10-fold more potent than crenolanib in inhibiting the V561D mutation. For all other tested PDGFRA mutations, crenolanib and imatinib had comparable potency. Conclusions: Crenolanib is a potent inhibitor of imatinib-resistant PDGFRA kinases associated with GIST, including the PDGFRA D842V mutation found in approximately 5% of GISTs. The spectrum of activity of crenolanib suggests that this drug is a type I inhibitor (inhibitor of activated conformation of kinase). Based in part on these results, a phase II clinical study of this agent to treat GIST with the PDGFRA D842V mutation has been initiated. © 2012 AACR. Source
Arog Pharmaceuticals LLC | Date: 2015-05-04
The present invention relates to the use of crenolanib, in a pharmaceutically acceptable salt form for the treatment of FLT3 mutated proliferative disorders driven by constitutively activated mutant FLT3, and to a method of treatment of warm-blooded animals, preferably humans, in which a therapeutically effective dose of crenolanib is administered to an animal suffering from said disease or condition:
AROG Pharmaceuticals LLC | Date: 2014-07-30
The present invention includes a method of inhibiting or reducing deregulated FLT3 tyrosine kinase activity or FLT3 tyrosine kinase expression in a subject with a proliferative disease by administering to the subject having or suspected to have the proliferative disease, a therapeutically or prophylactically effective amount of the compound (CP-673,451) of Formula I: or pharmaceutically acceptable salt thereof.