Kraig M. Yager

Discovery of (2S)-1-[4-(2-{6-amino-8-[(6-bromo-1,3-benzodioxol-5-yl)sulfanyl]-9H-purin-9-yl}ethyl)piperidin-1-yl]-2-hydroxypropan-1-one (MPC-3100), a purine-based Hsp90 inhibitor.

Modulation of Hsp90 (heat shock protein 90) function has been recognized as an attractive approach for cancer treatment, since many cancer cells depend on Hsp90 to maintain cellular homeostasis. This has spurred the search for small-molecule Hsp90 inhibitors. Here we describe our lead optimization studies centered on the purine-based Hsp90 inhibitor 28a containing a piperidine moiety at the purine N9 position. In this study, key SAR was established for the piperidine N-substituent and for the congeners of the 1,3-benzodioxole at C8. These efforts led to the identification of orally bioavailable 28g that exhibits good in vitro profiles and a characteristic molecular biomarker signature of Hsp90 inhibition both in vitro and in vivo. Favorable pharmacokinetic properties along with significant antitumor effects in multiple human cancer xenograft models led to the selection of 28g (MPC-3100) as a clinical candidate.

Lead optimization of purine based orally bioavailable Mps1 (TTK) inhibitors.

Efforts to optimize biological activity, novelty, selectivity and oral bioavailability of Mps1 inhibitors, from a purine based lead MPI-0479605, are described in this Letter. Mps1 biochemical activity and cytotoxicity in HCT-116 cell line were improved. On-target activity confirmation via mechanism based G2/M escape assay was demonstrated. Physico-chemical and ADME properties were optimized to improve oral bioavailability in mouse.

Triterpene based compounds with potent anti-maturation activity against HIV-1.

Efforts towards developing orally bioavailable HIV-1 maturation inhibitors starting from betulinic acid 1 are described. SAR resulted in improved potency, physicochemical properties, and enhanced oral absorption in rats.

Novel Mps1 kinase inhibitors: From purine to pyrrolopyrimidine and quinazoline leads

Mps1, also known as TTK, is a mitotic checkpoint protein kinase that has become a promising new target of cancer research. In an effort to improve the lead-likeness of our recent Mps1 purine lead compounds, a scaffold hopping exercise has been undertaken. Structure-based design, principles of conformational restriction, and subsequent scaffold hopping has led to novel pyrrolopyrimidine and quinazoline Mps1 inhibitors. These new single-digit nanomolar leads provide the basis for developing potent, novel Mps1 inhibitors with improved drug-like properties.

Cell cycle progression score is a marker for five-year lung cancer-specific mortality risk in patients with resected stage I lung adenocarcinoma

Purpose The goals of our study were (a) to validate a molecular expression signature (cell cycle progression [CCP] score and molecular prognostic score [mPS; combination of CCP and pathological stage {IA or IB}]) that identifies stage I lung adenocarcinoma (ADC) patients with a higher risk of cancer-specific death following curative-intent surgical resection, and (b) to determine whether mPS stratifies prognosis within stage I lung ADC histological subtypes. Methods Formalin-fixed, paraffin-embedded stage I lung ADC tumor samples from 1200 patients were analyzed for 31 proliferation genes by quantitative RT-PCR. Prognostic discrimination of CCP score and mPS was assessed by Cox proportional hazards regression, using 5-year lung cancer–specific mortality as the primary outcome. Results In multivariable analysis, CCP score was a prognostic marker for 5-year lung cancer–specific mortality (HR=1.6 per interquartile range; 95% CI, 1.14–2.24; P=0.006). In a multivariable model that included mPS instead of CCP, mPS was a significant prognostic marker for 5-year lung cancer–specific mortality (HR=1.77; 95% CI, 1.18–2.66; P=0.006). Five-year lung cancer–specific survival differed between low-risk and high-risk mPS groups (96% vs 81%; P<0.001). In patients with intermediate-grade lung ADC of acinar and papillary subtypes, high mPS was associated with worse 5-year lung cancer–specific survival (P<0.001 and 0.015, respectively), compared with low mPS. Conclusion This study validates CCP score and mPS as independent prognostic markers for lung cancer–specific mortality and provides quantitative risk assessment, independent of known high-risk features, for stage I lung ADC patients treated with surgery alone.

Cost-Utility of a Prognostic Test Guiding Adjuvant Chemotherapy Decisions in Early-Stage Non-Small Cell Lung Cancer

BACKGROUND A prognostic test was developed to guide adjuvant chemotherapy (ACT) decisions in early-stage non-small cell lung cancer (NSCLC) adenocarcinomas. The objective of this study was to compare the cost-utility of the prognostic test to the current standard of care (SoC) in patients with early-stage NSCLC. MATERIALS AND METHODS Lifetime costs (2014 U.S. dollars) and effectiveness (quality-adjusted life-years [QALYs]) of ACT treatment decisions were examined using a Markov microsimulation model from a U.S. third-party payer perspective. Cancer stage distribution and probability of receiving ACT with the SoC were based on data from an academic cancer center. The probability of receiving ACT with the prognostic test was estimated from a physician survey. Risk classification was based on the 5-year predicted NSCLC-related mortality. Treatment benefit with ACT was based on the prognostic score. Discounting at a 3% annual rate was applied to costs and QALYs. Deterministic one-way and probabilistic sensitivity analyses examined parameter uncertainty. RESULTS Lifetime costs and effectiveness were

Discovery of an l-alanine ester prodrug of the Hsp90 inhibitor, MPC-3100

137,403 and 5.45 QALYs with the prognostic test and

Abstract B137: Pharmacokinetics, antitumor activity, and therapeutic index of Nampt inhibitor MPC-8640 in mice.

127,359 and 5.17 QALYs with the SoC. The resulting incremental cost-effectiveness ratio for the prognostic test versus the SoC was

Compounds and therapeutic uses thereof

35,867/QALY gained. One-way sensitivity analyses indicated the model was most sensitive to the utility of patients without recurrence after ACT and the ACT treatment benefit. Probabilistic sensitivity analysis indicated the prognostic test was cost-effective in 65.5% of simulations at a willingness to pay of

Amino-pyrimidine compounds as inhibitors of TBKL and/or IKK epsilon

50,000/QALY. CONCLUSION The study suggests using a prognostic test to guide ACT decisions in early-stage NSCLC is potentially cost-effective compared with using the SoC based on globally accepted willingness-to-pay thresholds. IMPLICATIONS FOR PRACTICE Providing prognostic information to decision makers may help some patients with high-risk early stage non-small cell lung cancer receive appropriate adjuvant chemotherapy while avoiding the associated toxicities and costs in patients with low-risk disease. This study used an economic model to assess the effectiveness and costs associated with using a prognostic test to guide adjuvant chemotherapy decisions compared with the current standard of care in patients with non-small cell lung cancer. When compared with current standard care, the prognostic test was potentially cost effective at commonly accepted thresholds in the U.S. This study can be used to help inform decision makers who are considering using prognostic tests.