Development and validation of circulating tumour cell enumeration (Epic Sciences) as a prognostic biomarker in men with metastatic castration-resistant prostate cancer

PURPOSE

To evaluate the prognostic significance of circulating tumour cell (CTC) number determined on the Epic Sciences platform in men with metastatic castration-resistant prostate cancer (mCRPC) treated with an androgen receptor signalling inhibitor (ARSI).

PATIENTS AND METHODS

A pre-treatment blood sample was collected from men with progressing mCRPC starting either abiraterone or enzalutamide as a first-, second- or third-line systemic therapy at Memorial Sloan Kettering Cancer Center (Discovery cohort, N = 171) or as a first- or second-line therapy as part of the multicenter PROPHECY trial (NCT02269982) (Validation cohort, N = 107). The measured CTC number was then associated with overall survival (OS) in the Discovery cohort, and progression-free survival (PFS) and OS in the Validation cohort. CTC enumeration was also performed on a concurrently obtained blood sample using the CellSearch® Circulating Tumor Cell Kit.

RESULTS

In the MSKCC Discovery cohort, CTC count was a statistically significant prognostic factor of OS as a dichotomous (<3 CTCs/mL versus ≥ 3 CTCs/mL; hazard ratio [HR] = 1.8 [95% confidence interval {CI} 1.3-3.0]) and a continuous variable when adjusting for line of therapy, presence of visceral metastases, prostate-specific antigen, lactate dehydrogenase and alkaline phosphatase. The findings were validated in an independent datas et from PROPHECY (HR [95% CI] = 1.8 [1.1-3.0] for OS and 1.7 [1.1-2.9] for PFS). A strong correlation was also observed between CTC counts determined in matched samples on the CellSearch® and Epic platforms (r = 0.84).

CONCLUSION

The findings validate the prognostic significance of pretreatment CTC number determined on the Epic Sciences platform for predicting OS in men with progressing mCRPC starting an ARSI.

Classification of C2C12 cells at differentiation by convolutional neural network of deep learning using phase contrast images

In the field of regenerative medicine, tremendous numbers of cells are necessary for tissue/organ regeneration. Today automatic cell-culturing system has been developed. The next step is constructing a non-invasive method to monitor the conditions of cells automatically. As an image analysis method, convolutional neural network (CNN), one of the deep learning method, is approaching human recognition level. We constructed and applied the CNN algorithm for automatic cellular differentiation recognition of myogenic C2C12 cell line. Phase-contrast images of cultured C2C12 are prepared as input dataset. In differentiation process from myoblasts to myotubes, cellular morphology changes from round shape to elongated tubular shape due to fusion of the cells. CNN abstract the features of the shape of the cells and classify the cells depending on the culturing days from when differentiation is induced. Changes in cellular shape depending on the number of days of culture (Day 0, Day 3, Day 6) are classified with 91.3% accuracy. Image analysis with CNN has a potential to realize regenerative medicine industry.

Fabrication of nanobeads from nanocups by controlling scission/crosslinking in organic polymer materials

The development of several kinds of micro/nanofabrication techniques has resulted in many innovations in the micro/nanodevices that support today's science and technology. With feature miniaturization, the fabrication tools have shifted from light to ionizing radiation. Here, we propose a simple micro/nanofabrication technique for organic materials using a scanning beam (SB) of ionizing radiation. By controlling the scission/crosslinking of the material via three-dimensional energy-deposition distribution of the SB, appropriate solvents can easily peel off only the crosslinked region from the bulk material. The technique was demonstrated using a focused ion beam and a chlorinated organic polymer. The polymer underwent main-chain scission upon irradiation, but it crosslinked after high-dose irradiation. Appropriate solvents could easily peel off only the crosslinked region from the bulk material. The technique, 'nanobead from nanocup', enabled the production of desired structures such as nanowires and nanomembranes. It can be also applied to the micro/nanofabrication of functional materials.

A phase I study of CNTO328, an anti-interleukin (IL)-6 monoclonal antibody combined with docetaxel in subjects with metastatic castration-resistant prostate cancer (CRPC)

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Background: IL-6 is a potential mediator of prostate cancer morbidity and mortality and may protect prostate cancer cells from chemotherapy-induced apoptosis. CNTO328, a chimeric anti-IL-6 antibody, has been shown to inhibit prostate tumor growth in xenograft mouse models. Methods: Chemotherapy-naïve patients with metastatic CRPC were administered CNTO328 in combination with T (75 mg/m2 q3w) in 3 dose-escalation cohorts (6 mg/kg q2w, and 9 and 12 mg/kg q3w) following an initial run-in cycle of T alone to examine the effect of CNTO328 on T pharmacokinetics (PK). Safety was evaluated prior to each dose escalation. Prostate specific antigen (PSA), radiological response, and C-reactive protein (CRP), the best-known surrogate of serum IL-6 bioactivity, were also assessed. Results: This study is fully enrolled December 2008 with 38 patients. 36 patients with KPS ≥70, median age 66 (range 43–82) received 6 (median) cycles of T (range 1–37). 32 patients received at least one dose of CNTO328 in combination with T and are evaluable. Baseline patient characteristics included: median PSA of 59 ng/mL (range 12–1430) and median CRP was 3.85 mg/L (range <1 to 91.3). One DLT was observed in each cohort (grade 4 neutropenic infection, grade 3 syncope and dehydration, grade 3 GI bleeding), though MTD for the combination was not reached. Most frequent ≥grade 3 adverse events (AE) were neutropenia (69%); leukopenia (63%); lymphopenia (31%); dyspnea (19%); fatigue (16%). One patient died due to AE (sepsis) reported as possible related to T and unlikely related to CNTO328 by investigator. Preliminary data show CNTO328 does not appear to have a major effect on T PK. Preliminary efficacy data is shown in the table . Ongoing evaluation indicates 3/12 partial responses in patients with measurable disease reported thus far. Conclusions: CNTO328 with T is well tolerated and demonstrates biological and clinical activity in CRPC that warrants further study.

[Table: see text]

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Maintenance sunitinib postchemotherapy (CT) in patients (pts) with advanced urothelial carcinoma (UC): A randomized placebo controlled phase II trial

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Background: Although response to CT is common in pts with advanced UC it is rarely durable. Sunitinib is an oral small molecule inhibitor of receptor tyrosine kinases regulating angiogenesis including VEGFR-1, -2, -3, and PDGFR-α, -β with demonstrated antitumor activity in a variety of solid tumors. Inhibition of angiogenesis following CT may delay disease progression. Therefore, we are evaluating maintenance sunitinib in a phase II study. Methods: Pts with advanced UC, > stable disease (SD) after 4–6 cycles of CT, a performance status (PS) 0–2, adequate organ function and < 42 days from last CT dose were randomized to sunitinib 50 mg or placebo; 4 weeks (wks) on 2 off in 6 wk cycles. Pts were stratified by response to CT. Disease was assessed every 12 wks. Pts were unblinded for progression or unacceptable adverse events (AEs), with placebo pts offered open label sunitinib. The primary end point is 6 month progression rate using a modified version of the randomized selection design (Simon 1985). 42 pts/arm are to be accrued to allow selection of the superior arm with 90% probability. Other endpoints include safety, response rate (RR), time to progression, median survival, RR to open label sunitinib and correlation of changes in serum VEGF and sVEGFR-2 levels with outcome. Results: To date, 28 pts have been registered and 26 have completed > 12 wks of therapy. Median age is 69 years (48–81) and PS is 1 (37% PS 0, 52% PS 1). 12% had a complete response (CR) to prior CT, 46% a partial response (PR) and 42% SD. 14 pts have progressed after a median of 2 cycles (range 1–12). 7 pts received open label sunitinib at progression, 1/7 remains on treatment. Median duration on open label therapy is 2.2 months (11 days-15 months). Best response to open label therapy to date is progressive disease (2 pts), SD (2 pts) for 24 wks, PR in 1 pt through 60 weeks and 2 pts have not reached first assessment. Grade 3 AEs on open label sunitinib included: bladder hemorrhage, increased creatinine, fatigue, thrombocytopenia and hand-and-foot syndrome. No grade 4 or 5 AEs were observed. Conclusions: Preliminary results indicate that maintenance sunitinib post CT is feasible in advanced UC pts and is associated with clinical activity. Supported by Pfizer.

[Table: see text]

Intramolecular electron transfer processes in Cu(B)-deficient cytochrome bo studied by pulse radiolysis

The Escherichia coli cytochrome bo is a heme-copper terminal ubiquinol oxidase, and functions as a redox-driven proton pump. We applied pulse radiolysis technique for studying the one-electron reduction processes in the Cu(B)-deficient mutant, His333Ala. We found that the Cu(B) deficiency suppressed the heme b-to-heme o electron transfer two order of the magnitude (4.0 x 10(2) s(-1)), as found for the wild-type enzyme in the presence of 1 mM KCN (3.0 x 10(2) s(-1)). Potentiometric analysis of the His333Ala mutant revealed the 40 mV decrease in the E(m) value for low-spin heme b and the 160 mV increase in the E(m) value of high-spin heme o. Our results indicate that Cu(B) not only serves as one-electron donor to the bound dioxygen upon the O-O bond cleavage, but also facilitates dioxygen reduction at the heme-copper binuclear centre by modulating the E(m) value of heme o through magnetic interactions. And the absence of a putative OH(-) bound to Cu(B) seems not to affect the uptake of the first chemical proton via K-channel in the His333Ala mutant.