Site-Specific Antibody Prodrugs via -Arylation: a Bioconjugation Approach Toward Masked Tyrosine Analogues.

The utility of antibody therapeutics is hampered by potential cross-reactivity with healthy tissue. Over the past decade, significant advances have been made in the design of activatable antibodies, which increase, or create altogether, the therapeutic window of a parent antibody. Of these, antibody prodrugs (pro-antibodies) are masked antibodies that have advanced the most for therapeutic use.

A repository of grade 1 and 2 meningioma MRIs in a public dataset for radiomics reproducibility tests.

Purpose: Meningiomas are the most common primary brain tumors in adults with management varying widely based on World Health Organization (WHO) grade. However, there are limited datasets available for researchers to develop and validate radiomic models. The purpose of our manuscript is to report on the first dataset of meningiomas in The Cancer Imaging Archive (TCIA).

Automatic differentiation of Grade I and II meningiomas on magnetic resonance image using an asymmetric convolutional neural network.

The Grade of meningioma has significant implications for selecting treatment regimens ranging from observation to surgical resection with adjuvant radiation. For most patients, meningiomas are diagnosed radiologically, and Grade is not determined unless a surgical procedure is performed. The goal of this study is to train a novel auto-classification network to determine Grade I and II meningiomas using T1-contrast enhancing (T1-CE) and T2-Fluid attenuated inversion recovery (FLAIR) magnetic resonance (MR) images.

Automatic segmentation of high-risk clinical target volume for tandem-and-ovoids brachytherapy patients using an asymmetric dual-path convolutional neural network.

Purposes: Preimplant diagnostic magnetic resonance imaging is the gold standard for image-guided tandem-and-ovoids (T&O) brachytherapy for cervical cancer. However, high dose rate brachytherapy planning is typically done on postimplant CT-based high-risk clinical target volume (HR-CTV ) because the transfer of preimplant Magnetic resonance (MR)-based HR-CTV (HR-CTV ) to the postimplant planning CT is difficult due to anatomical changes caused by applicator insertion, vaginal packing, and the filling status of the bladder and rectum. This study aims to train a dual-path convolutional neural network (CNN) for automatic segmentation of HR-CTV on postimplant planning CT with guidance from preimplant diagnostic MR.

Evidence for Simultaneous Dearomatization of Two Aromatic Rings under Mild Conditions in Cu(I)-Catalyzed Direct Asymmetric Dearomatization of Pyridine.

Bis(phosphine) copper hydride complexes are uniquely able to catalyze direct dearomatization of unactivated pyridines with carbon nucleophiles, but the mechanistic basis for this result has been unclear. Here we show that, contrary to our initial hypotheses, the catalytic mechanism is monometallic and proceeds via dearomative rearrangement of the phenethylcopper nucleophile to a C-metalated form prior to reaction at heterocycle C4. Our studies support an unexpected heterocycle-promoted pathway for this net 1,5-Cu-migration beginning with a doubly dearomative imidoyl-Cu-ene reaction.

Asymmetric Cu-Catalyzed 1,4-Dearomatization of Pyridines and Pyridazines without Preactivation of the Heterocycle or Nucleophile.

We show that a chiral copper hydride (CuH) complex catalyzes C-C bond-forming dearomatization of pyridines and pyridazines at room temperature. The catalytic reaction operates directly on free heterocycles and generates the nucleophiles in situ, eliminating the need for stoichiometric preactivation of either reaction partner; further, it is one of very few methods available for the enantioselective 1,4-dearomatization of heteroarenes. Combining the dearomatization with facile derivatization steps enables one-pot syntheses of enantioenriched pyridines and piperidines.

Asymmetric Copper Hydride-Catalyzed Markovnikov Hydrosilylation of Vinylarenes and Vinyl Heterocycles.

We report a highly enantioselective CuH-catalyzed Markovnikov hydrosilylation of vinylarenes and vinyl heterocycles. This method has a broad scope and enables both the synthesis of isolable silanes and the conversion of crude products to chiral alcohols. Density functional theory calculations support a mechanism proceeding by hydrocupration followed by σ-bond metathesis with a hydrosilane.

Convenient route to secondary sulfinates: application to the stereospecific synthesis of α-C-chiral sulfonamides.

A convenient synthesis of α-chiral sulfinates from readily available precursors has been accomplished via the corresponding heterocyclic thioethers and sulfones. Treatment of the sulfinates with hydroxylamine sulfonate in aqueous solution provides α-C-chiral primary sulfonamides in good yield (14 examples) with retention of stereochemical purity.

Discovery of Potent and Simplified Piperidinone-Based Inhibitors of the MDM2-p53 Interaction.

Continued optimization of the N-substituent in the piperidinone series provided potent piperidinone-pyridine inhibitors 6, 7, 14, and 15 with improved pharmacokinetic properties in rats. Reducing structure complexity of the N-alkyl substituent led to the discovery of 23, a potent and simplified inhibitor of MDM2. Compound 23 exhibits excellent pharmacokinetic properties and substantial in vivo antitumor activity in the SJSA-1 osteosarcoma xenograft mouse model.

Discovery of AMG 925, a FLT3 and CDK4 dual kinase inhibitor with preferential affinity for the activated state of FLT3.

We describe the structural optimization of a lead compound 1 that exhibits dual inhibitory activities against FLT3 and CDK4. A series of pyrido[4',3':4,5]pyrrolo[2,3-d]pyrimidine derivatives was synthesized, and SAR analysis, using cell-based assays, led to the discovery of 28 (AMG 925), a potent and orally bioavailable dual inhibitor of CDK4 and FLT3, including many FLT3 mutants reported to date. Compound 28 inhibits the proliferation of a panel of human tumor cell lines including Colo205 (Rb(+)) and U937 (FLT3(WT)) and induced cell death in MOLM13 (FLT3(ITD)) and even in MOLM13 (FLT3(ITD, D835Y)), which exhibits resistance to a number of FLT3 inhibitors currently under clinical development.

Discovery of AMG 232, a potent, selective, and orally bioavailable MDM2-p53 inhibitor in clinical development.

We recently reported the discovery of AM-8553 (1), a potent and selective piperidinone inhibitor of the MDM2-p53 interaction. Continued research investigation of the N-alkyl substituent of this series, focused in particular on a previously underutilized interaction in a shallow cleft on the MDM2 surface, led to the discovery of a one-carbon tethered sulfone which gave rise to substantial improvements in biochemical and cellular potency. Further investigation produced AMG 232 (2), which is currently being evaluated in human clinical trials for the treatment of cancer.

Synthesis of a Benzodiazepine-derived Rhodium NHC Complex by C-H Bond Activation.

The synthesis and characterization of a Rh(I)-NHC complex generated by C-H activation of 1,4-benzodiazepine heterocycle are reported. This complex constitutes a rare example of a carbene tautomer of a 1,4-benzodiazepine aldimine stabilized by transition metal coordination and demonstrates the ability of the catalytically relevant RhCl(PCy(3))(2) fragment to induce NHC-forming tautomerization of heterocycles possessing a single carbene-stabilizing heteroatom. Implications for the synthesis of benzodiazepines and related pharmacophores via C-H functionalization are discussed.

Long-term outcome by risk factors using conformal high-dose-rate brachytherapy (HDR-BT) boost with or without neoadjuvant androgen suppression for localized prostate cancer.

Purpose: The aim of this study is to analyze, during the prostate-specific antigen (PSA) era, the long-term outcome of patients treated with conformal high-dose-rate (HDR) brachytherapy boost to the prostate with or without androgen deprivation therapy (ADT) when patients are stratified by risk factors for failure.

Methods And Materials: Between 1986 and 2000, 611 patients were treated for clinically localized prostate cancer in three prospective trials of external beam radiation therapy (EBRT) and dose-escalating HDR brachytherapy (BT) boost. There were 104 patients treated at Seattle, 198 at Kiel University, and 309 at William Beaumont Hospital.

An Internet-ready database for prospective randomized clinical trials of high-dose-rate brachytherapy for adenocarcinoma of the prostate.

Purpose: To demonstrate a new interactive Internet-ready database for prospective clinical trials in high-dose-rate (HDR) brachytherapy for prostate cancer.

Methods And Materials: An Internet-ready database was created that allows common data acquisition and statistical analysis. Patient anonymity and confidentiality are preserved.