Michael E. Cunningham

Long-term outcome with dasatinib after imatinib failure in chronic-phase chronic myeloid leukemia: follow-up of a phase 3 study.

We present long-term follow-up of a dasatinib phase 3 study of patients with imatinib-resistant/-intolerant chronic myeloid leukemia (CML). In the CA180-034 study, 670 patients with imatinib-resistant/-intolerant CML in chronic phase (CML-CP) received dasatinib 100 mg once daily, 50 mg twice daily, 140 mg once daily, or 70 mg twice daily. At 6 years, 188 (28%) of 670 patients remained on study treatment. Estimated 6-year protocol-defined progression-free survival (PFS) rates were 49%, 51%, 40%, and 47%, respectively, and estimated 6-year overall survival (OS) rates were 71%, 74%, 77%, and 70%, respectively (intent-to-treat population, including protocol-defined progression or death after discontinuation). Estimated 6-year rates of survival without transformation on study treatment were 76%, 80%, 83%, and 74%, respectively. Major molecular response was achieved in 43% (100 mg once daily) and 40% (all other arms) of patients by 6 years. Molecular and cytogenetic responses at 3 and 6 months were highly predictive of PFS and OS. Notably, estimated 6-year PFS rates based on ≤1%, >1% to 10%, and >10% BCR-ABL transcripts at 3 months were 68%, 58%, and 26%, respectively. Most adverse events occurred by 2 years. Imatinib-resistant/-intolerant patients with CML-CP can experience long-term benefit with dasatinib therapy, particularly if achieving BCR-ABL ≤10% at 3 months. This study was registered at ClinicalTrials.gov: NCT00123474.

Discovery of 3-Substituted Aminocyclopentanes as Potent and Orally Bioavailable NR2B Subtype-Selective NMDA Antagonists

A series of 3-substituted aminocyclopentanes has been identified as highly potent and selective NR2B receptor antagonists. Incorporation of a 1,2,4-oxadiazole linker and substitution of the pendant phenyl ring led to the discovery of orally bioavailable analogues that showed efficient NR2B receptor occupancy in rats. Unlike nonselective NMDA antagonists, the NR2B-selective antagonist 22 showed no adverse affects on motor coordination in the rotarod assay at high dose. Compound 22 was efficacious following oral administration in a spinal nerve ligation model of neuropathic pain and in an acute model of Parkinsons disease in a dose dependent manner.