Clinical pharmacology and tolerability of REC-994, a redox-cycling nitroxide compound, in randomized phase 1 dose-finding studies

Cerebral cavernous malformation (CCM) has variable clinical symptoms, including potentially fatal hemorrhagic stroke. Treatment options are very limited, presenting a large unmet need. REC-994 (also known as tempol), identified as a potential treatment through an unbiased drug discovery platform, is hypothesized to treat CCMs through a reduction in superoxide, a reactive oxygen species. We investigated the safety, tolerability, and pharmacokinetic profile of REC-994 in healthy volunteers. Single- and multiple-ascending dose (SAD and MAD, respectively) studies were conducted in adult volunteers (ages 18-55). SAD study participants received an oral dose of REC-994 or placebo. MAD study participants were randomized 3:1 to oral doses of REC-994 or matching placebo, once daily for 10 days. Thirty-two healthy volunteers participated in the SAD study and 52 in the MAD study. Systemic exposure increased in proportion to REC-994 dose after single doses of 50-800 mg and after 10 days of dosing over the 16-fold dose range of 50-800 mg. Median Tmax and mean t1/2 were independent of dose in both studies, and the solution formulation was more rapidly absorbed. REC-994 was well tolerated. Treatment-emergent adverse effects across both studies were mild and transient and resolved by the end of the study. REC-994 has a favorable safety profile and was well tolerated in single and multiple doses up to 800 mg with no dose-limiting adverse effects identified. Data support conducting a phase 2 clinical trial in patients with symptomatic CCM.

Community Practice Implementation of a Self-administered Version of PREMM1,2,6 to Assess Risk for Lynch Syndrome

BACKGROUND & AIMS

Lynch syndrome is a genetic disorder that greatly increases risk for colorectal and other cancers, although it is underdiagnosed. Prediction of MLH1, MSH2, and MSH6 (PREMM_1,2,6) is a web-based tool that analyzes individuals' personal/family histories of cancer to quantify their likelihood of carrying a germline mutation associated with Lynch syndrome. We investigated the feasibility of systematic risk assessment for Lynch syndrome in a community gastroenterology practice using a patient-completed version of PREMM_1,2,6.

METHODS

PREMM_1,2,6 was adapted into a computer tablet version designed for self-administration by patients. Individuals presenting to a community gastroenterology office and endoscopy facility in California completed the PREMM_1,2,6 assessment before their visit (n = 3134). The total study duration (8 months) comprised a 2-month initiation period (May 1-June 30, 2013) and a 6-month study period (July 1-December 31, 2013). Genetic counseling and germline analysis for mutations in genes associated with Lynch syndrome (MLH1, MSH2, MSH6, PMS2, and EPCAM) were offered to individuals with PREMM_1,2,6 scores of 5% or higher. Patients and providers completed surveys to evaluate the feasibility and satisfaction with the process.

RESULTS

Of the 3134 individuals assessed by PREMM_1,2,6 during the 6-month study period, 177 individuals (5.6%) had scores of 5% or higher. Of these, 146 individuals underwent genetic testing, along with 28 additional participants recruited nonconsecutively during the initiation period. Mutations associated with Lynch syndrome were detected in 3 of the 146 individuals (2.1%) with PREMM_1,2,6 scores of 5% or higher who underwent germline testing, and 3 of the 28 patients (10.7%) recruited during study initiation with PREMM_1,2,6 scores of 5% or higher. Of the participants who underwent genetic analysis, 98.6% stated that they understood the information provided to them. All of the surveyed providers stated that they were satisfied with the incorporation of PREMM_1,2,6 into their clinical practice, and that they would continue using it to assess risk for Lynch syndrome.

CONCLUSIONS

A patient self-administered version of the PREMM_1,2,6 Lynch syndrome risk assessment model can be used systematically in community-based gastroenterology and endoscopy practices.

Clinical validation of a gene expression signature that differentiates benign nevi from malignant melanoma

BACKGROUND

Histopathologic examination is sometimes inadequate for accurate and reproducible diagnosis of certain melanocytic neoplasms. As a result, more sophisticated and objective methods have been sought. The goal of this study was to identify a gene expression signature that reliably differentiated benign and malignant melanocytic lesions and evaluate its potential clinical applicability. Herein, we describe the development of a gene expression signature and its clinical validation using multiple independent cohorts of melanocytic lesions representing a broad spectrum of histopathologic subtypes.

METHODS

Using quantitative reverse-transcription polymerase chain reaction (PCR) on a selected set of 23 differentially expressed genes, and by applying a threshold value and weighting algorithm, we developed a gene expression signature that produced a score that differentiated benign nevi from malignant melanomas.

RESULTS

The gene expression signature classified melanocytic lesions as benign or malignant with a sensitivity of 89% and a specificity of 93% in a training cohort of 464 samples. The signature was validated in an independent clinical cohort of 437 samples, with a sensitivity of 90% and specificity of 91%.

CONCLUSIONS

The performance, objectivity, reliability and minimal tissue requirements of this test suggest that it could have clinical application as an adjunct to histopathology in the diagnosis of melanocytic neoplasms.

Abstract 2635: Antitumor activity of MPC-3100, a synthetic, orally bioavailable Hsp90 inhibitor, in animal models

Background: MPC-3100 is a fully synthetic, orally bioavailable, investigational Hsp90 inhibitor in clinical studies. It is active against many cancer types in xenograft models including colon, gastric, ovary, prostate, breast, lung and myeloid leukemia, when administered on a once a day schedule. We explored alternate dosing schedules, the sensitivity of additional tumor types and compared activity with marketed therapies. We also demonstrated induction of Hsp70 RNA, a biomarker for Hsp90 inhibition, in tumor tissue following a single dose.

Methods: Pharmacokinetic studies were conducted in mice or rats following oral administration. One to ten million cells, depending on cell-type, were implanted subcutaneously into athymic mice (nu/nu) for tumor studies. Dosing was initiated when median tumor volume was >100 mm3. The NCI-N87 (Her2+) gastric cancer xenograft model was used to evaluate dosing schedules. MPC-3100 was dosed at 200 mg/kg daily, once every other day, twice weekly or at 400 mg/kg twice weekly for three weeks. Tumor growth inhibition (TGI) was monitored up to Day 39. For Hsp70 induction studies, RNA was isolated from mouse liver and tumor tissue following a single dose (200 mg/kg). Hsp70 levels were determined by qRT-PCR.

Results: MPC-3100 dosed at 200 mg/kg was effective when dosed either daily (40% regression), once every other day (7% regression), twice weekly (89% TGI) or at 400 mg/kg twice weekly (87% TGI) for three weeks. Although the 200 mg/kg daily schedule was significantly more effective (p<0.03) than all other schedules at the end of dosing on Day 21, there was no significant difference in TGI (79 to 87%) between the various schedules at the end of the study on Day 39. Pharmacokinetic studies in rats comparing once and twice a day (bid) dosing indicated that effective plasma concentrations of compound were maintained with bid dosing.

The anti-tumor activity of MPC-3100 was compared with erlotinib in a lung cancer (A549) xenograft model sensitive to EGFR inhibition. MPC-3100 dosed daily for 21 days at 150 or 200 mg/kg inhibited tumor growth by 88% or resulted in tumor regression by 16%, respectively, and was as effective as erlotinib at its maximum tolerated dose of 100 mg/kg daily (88% TGI). MPC-3100 was also active in a pancreatic cancer (MIA PaCa-2) xenograft, showing 67% and 95% TGI when dosed at 150 mg/kg or 200 mg/kg for 15 days. Tumor growth inhibition observed with MPC-3100 compared favorably to that observed with 5-fluorouracil (5-FU).

Hsp70 mRNA, was induced by ∼70- and ∼110-fold in mouse liver and tumor tissue, respectively, 4 hours after an oral dose of 200 mg/kg. Hsp90 inhibition occurred rapidly in vivo as the Hsp70 induction reverted back to baseline in 12 hours.

Conclusions: MPC-3100 is active against a broad range of cancer cell types and is efficacious in xenograft models with multiple dosing schedules. The anti-tumor activity of MPC-3100 compares favorably to 5-FU and erlotinib.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2635.

Synaesthesia in the normal limb

We explored the degree to which vision may alter kinaesthetic perception by asking participants to view their hand through a prism, introducing different horizontal deviations, while trying to align their fingers above and below a thin table. When the visual image of one hand was displaced this overwhelmed kinaesthetic judgements and participants reliably reported that they felt their limbs were aligned, even when they were laterally mis-aligned by as much as 10 cm. This effect, however, was mediated by 'visual capture' and when the task was attempted in a darkened room with limb position indicated by an LED taped to the finger, kinaesthesis dominated and participants reported that the LED seemed to become detached from their finger tip. In both light and dark conditions the finger was clearly visible and only the background detail was extinguished. Hence, in perceiving limb position, it appears that we believe in what we see, rather than in what we feel, when the visual background is rich, and in what we feel when the visual background is sparse.