Search

Author(s): Alexander C. Huang [sup.1] [sup.2] [sup.3] [sup.4] , Robert J. Orlowski [sup.1] [sup.11] , Xiaowei Xu [sup.4] [sup.5] , Rosemarie Mick [sup.3] [sup.4] [sup.6] , Sangeeth M. George [sup.7] [...], Immunologic responses to anti-PD-1 therapy in melanoma patients occur rapidly with pharmacodynamic T cell responses detectable in blood by 3 weeks. It is unclear, however, whether these early blood-based observations translate to the tumor microenvironment. We conducted a study of neoadjuvant/adjuvant anti-PD-1 therapy in stage III/IV melanoma. We hypothesized that immune reinvigoration in the tumor would be detectable at 3 weeks and that this response would correlate with disease-free survival. We identified a rapid and potent anti-tumor response, with 8 of 27 patients experiencing a complete or major pathological response after a single dose of anti-PD-1, all of whom remain disease free. These rapid pathologic and clinical responses were associated with accumulation of exhausted CD8 T cells in the tumor at 3 weeks, with reinvigoration in the blood observed as early as 1 week. Transcriptional analysis demonstrated a pretreatment immune signature (neoadjuvant response signature) that was associated with clinical benefit. In contrast, patients with disease recurrence displayed mechanisms of resistance including immune suppression, mutational escape, and/or tumor evolution. Neoadjuvant anti-PD-1 treatment is effective in high-risk resectable stage III/IV melanoma. Pathological response and immunological analyses after a single neoadjuvant dose can be used to predict clinical outcome and to dissect underlying mechanisms in checkpoint blockade. Neoadjuvant PD-1 blockade in patients with resectable melanoma followed by adjuvant maintenance results in early immunological effects driving clinical benefit and reveals transcriptional and genomic mechanisms of response.

A small-ring phosphacycle is found to catalyze the deoxygenative condensation of α-keto esters and carboxylic acids. The reaction provides a chemoselective catalytic synthesis of α-acyloxy ester products with good functional group compatibility. Based on both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic PIII/PV=O cycling. The importance of ring strain in the phosphacyclic catalyst is substantiated by an observed temperature-dependent product selectivity effect. The results point to an inherent distinction in design criteria for organophosphorus-based catalysts operating via PIII/PV=O redox cycling as opposed to Lewis base (nucleophilic) catalysis. [ABSTRACT FROM AUTHOR]

Reduction of the P-oxide APO with PhSiH3 affords a tricoordinate aminophosphetane which promotes the title reaction to produce α-acyloxy esters with a high functional group compatibility. [ABSTRACT FROM AUTHOR]