A phase I study of bortezomib and temozolomide in patients with advanced solid tumors

PURPOSE

The primary objective was to determine the maximum tolerated doses (MTDs) of the combination of bortezomib and temozolomide in patients with solid tumors. The secondary objective was to evaluate the pharmacokinetics (PK) of bortezomib with and without concurrent hepatic enzyme-inducing anticonvulsants (HEIAs).

METHODS

Bortezomib was administered on days 2, 5, 9, and 12; temozolomide on days 1-5 of a 28-day cycle. Dose escalation proceeded using a standard 3+3 design. Patients with primary or metastatic brain tumors were eligible and were stratified based on whether they were taking HEIAs or not.

RESULTS

Of the 25 patients enrolled, 22 were not taking HEIAs. MTDs were only given to patients not receiving HEIAs. Dose-limiting toxicities (DLTs) consisted of grade-3 constipation, hyponatremia, fatigue, elevated hepatic enzymes, and grade-4 neutropenia, thrombocytopenia, constipation, and abdominal pain. Stable disease (>8 weeks) was observed in 5 patients. Bortezomib systemic clearance (CL(sys)) on day 9 was 51% of the CL(sys) on day 2 (P < 0.01) Similarly, the normalized area under the concentration-time curve (norm AUC) on day 9 was 1.9 times the norm AUC on day 2 (P < 0.01). The median bortezomib CL(sys) on days 2 and 9 was significantly higher (P < 0.04) in patients taking HEIAs, and the median norm AUC was correspondingly lower (P < 0.04).

CONCLUSIONS

The MTDs for the combination of bortezomib and temozolomide in patients not taking HEIAs are 1.3 and 200 mg/m(2), respectively. The rate of bortezomib elimination in patients taking HEIAs was increased twofold. Additional trials are needed to better define the optimal dosing in such patients.

Phase I and pharmacodynamic study of an orally administered novel inhibitor of histone deacetylases, SB939, in patients with refractory solid malignancies

BACKGROUND

The objective of this study was to assess the safety, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, and preliminary efficacy of SB939, a novel histone deacetylase (HDAC) inhibitor, in patients with advanced solid malignancies.

PATIENTS AND METHODS

Dose-escalating cohorts of three to six patients received SB939 orally thrice weekly for 3 weeks in a 4-week cycle. Acetylated histone H3 (acH3) was measured in peripheral blood mononuclear cells (PBMCs).

RESULTS

Thirty patients treated at one of five doses (10-80 mg/day) received 79 cycles of SB939 (range, 1-12 cycles). Dose-limiting toxic effects were fatigue, hypokalemia, troponin T elevation, and QTc prolongation. Peak plasma concentration (C(max)) and area under the concentration-time curve extrapolated to infinity increased dose proportionally. The MTD of SB939 was 80 mg/day. The mean elimination half-life and oral clearance of SB939 were 7.2 ± 0.6 h and 53.0 ± 8.5 l/h, respectively, with no substantial accumulation on day 15. An increase in acH3 was observed at hour 3 and correlated with dose and C(max). Stable disease was seen in several tumor types treated at ≥40 mg. HDAC inhibition was consistently observed at 60 mg, the recommended dose.

CONCLUSIONS

SB939 can be safely administered at the recommended dose and reaches plasma levels that strongly inhibit HDAC in PBMCs. These data support further efficacy studies of SB939.

Completion and toxicity rates of adjuvant chemotherapy in rectal cancer patients previously treated with neoadjuvant therapy and resection

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Background: Adjuvant chemotherapy is recommended after rectal cancer surgery. Yet the success and complication rates of this adjuvant treatment are poorly studied. The purpose of this study is to determine the success rate and define the toxicity profile of adjuvant chemotherapy in rectal cancer patients previously treated with neoadjuvant chemotherapy.

Methods: Study design is a retrospective review of patients from December 2002-December 2007 from the City of Hope database. Data is available with 66 patients diagnosed with locally advanced rectal cancer treated with neoadjuvant chemo radiation and resection. Data points analyzed included demographics, chemotherapy-related toxicity and survival.

Results: Adjuvant chemotherapy was started in 35/66 (53%) of patients. In 31 cases chemotherapy was not given because of patient refusal or physician preference. 9 patients were lost to follow-up. Follow-up ranged from 9-59 months with median follow-up of 27 months. In the 26 patients with adequate follow up there were a total of 165 episodes of toxic events 3a grade 1. Most of the events were mild to moderate grade 1-2. In 10 patients (28%) 22 major toxicities 3a grade 3 episodes were observed. The median Karnofsky performance scale (KPS) showed no significant difference in patients before and after adjuvant chemotherapy (p = 0.071). The rates of 1-year, 3-year and 5-year survival were 100%, 90%, and 60%, respectively; corresponding disease-free survival was 88%, 83%, and 69% respectively.

Conclusions: These preliminary data suggest that only a fraction of rectal cancer patients previously treated with neoadjuvant CRT complete a full course of adjuvant chemotherapy. Future studies will help confirm these preliminary findings and generate an outcome comparison between patients receiving and not receiving adjuvant therapy.

No significant financial relationships to disclose.

A phase I study of neoadjuvant chemoradiotherapy with S-1/oxaliplatin in patients with gastric cancer

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Background: To determine the maximum tolerated dose (MTD) of concurrent radiotherapy with S-1 and oxaliplatin, and antitumor activity of the combination treatment in patients with gastric cancer.

Methods: This was a phase I, escalating multiple-dose tolerability trial. S-1 and oxaliplatin were administered concurrently with radiotherapy for 4 weeks before surgery. The dose escalation scheme is provided in the table below. S-1 was continuously administered during radiotherapy and oxaliplatin was administered weekly for 4 weeks during radiotherapy.

Results: From March 2009 to June 2010, twelve patients were entered at two dose levels. The most common dose-related grade 1 and 2 adverse events were nausea, vomiting, anorexia and abdominal pain. Two of six patients treated at level 1 developed DLT (disabling abdominal pain, stomach perforation). The dose of S-1/oxaliplatin was reduced to 30 mg/m2 bid and 40 mg/m2 (Level -1). There one DLT (vomiting and anorexia, grade 3) observed in the expanded cohort of 6 patients at Level -1. Among 12 patients, 1 patient demonstrated pathological CR after neoadjuvant chemoradiation therapy.

Conclusions: Neoadjuvant CCRT with S-1/oxaliplatin was well tolerated, at a dose 30 mg/m2 bid for S-1 and 40 mg/m2 for oxaliplatin that at which antitumor activity was seen. Phase II study is planned to investigate further the efficacy, tolerability and optimal dose.

[Table: see text]

No significant financial relationships to disclose.

Preoperative chemoradiotherapy for locally advanced rectal adenocarcinoma: A dosimetric comparison of intensity-modulated radiation therapy (IMRT) with three-dimensional conformal radiotherapy (3D-CRT)

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Background: Small bowel and bladder toxicities (bleeding, obstruction, perforation, and stricture) are rare but serious late complications of pelvic radiotherapy (RT) related to dose received by these organs. IMRT has been used effectively in other pelvic malignancies (prostate and gynecologic) to decrease the dose to normal tissues when compared to 3D-CRT. Few studies have examined the use of IMRT in rectal cancer to assess whether a similar dose reduction is feasible.

Methods: Eight consecutively treated patients with T2/T3 and N0/N1 rectal adenocarcinoma underwent 5-FU based neoadjuvant chemo-RT using 7-field sliding-window IMRT between 2008 and 2010. Retrospectively, conventional 4-field 3D-CRT plans were generated for dosimetric comparison with IMRT treatment plans. Planning target volumes included the gross tumor, rectum, peri-rectal tissues, pre-sacral space, and common and internal iliac lymphatics. Organs at risk included small bowel (contoured as all small bowel identified on the planning CT plus a 1 cm symmetrical expansion), bladder, and femoral heads. Small bowel, bladder, and femoral head mean doses and volumes receiving 45 Gy (V45) were compared between conventional and IMRT plans, respectively. Paired Student's t-test was used for statistical analysis.

Results: Mean prescription dose was 52.9 ± 3.3 Gy. Compared to 3D-CRT, IMRT plans had an 11% lower mean dose delivered to the bladder (38.2 ± 4.5 Gy vs 43.1 ± 1.9 Gy, p = 0.028) and 24% lower mean dose to the small bowel (24.0 ± 2.9 Gy vs 31.7 ± 7.7 Gy, p = 0.014). IMRT plans also had a 55% lower bladder V45 (27 ± 19% vs 61 ± 22%, p = 0.0077) and a 96% lower small bowel V45 (1 ± 0% vs 21± 20%, p = 0.021). The femoral heads received a nonsignificant higher mean dose (19.2 ± 3.9 Gy vs 16.6 ± 3.0 Gy, p = 0.069).

Conclusions: Small bowel and bladder volume receiving 45 Gy and mean dose were significantly lower using IMRT compared with 3D-CRT planning. More stringent volumetric planning constraints may be necessary to further reduce the dose to the femoral heads. Further study is warranted to examine the clinical benefit of these dosimetric findings.

No significant financial relationships to disclose.

An automated method for cell-free layer width determination in small arterioles

Histogram-based thresholding techniques utilized for cell-free layer width measurement in arteriolar flow may produce an overestimation of the layer width since they do not consider faint shaded regions near the vessel wall as part of the erythrocyte column. To address this problem, we developed a new method for detecting the boundary of the erythrocyte column based on an edge detection algorithm. This automated method (grayscale method) provides local detections of the inner vessel wall as well as the boundary between the cell-free layer and the erythrocyte column without binarization of grayscale images. The cell-free layer width measurements using the grayscale method and existing techniques (minimum method and Otsu's method) were compared with those determined manually in arteriolar flows of the rat cremaster muscle. In the absence of the shaded regions, values obtained by the grayscale method and minimum method were statistically in good agreement with the manual method but not in the case of Otsu's method. When the faint shaded regions were present, the grayscale method appeared to produce more accurate results than the minimum method and Otsu's method.

102 PROTEOMIC ANALYSIS OF CONDITIONED MEDIUM SUPPLEMENTED WITH PORCINE FOLLICULAR FLUID

Follicular fluid (FF) contains growth factors, electrolytes, hormones, amino acids, and unknown factors. Supplementation of porcine FF (pFF) to in vitro maturation (IVM) medium was reported to improve the oocyte maturation, monospermic fertilization and embryonic development. This study aimed at investigating whether pFF supplementation affects the characteristics of donor cells for somatic cell nuclear transfer and the proteomic composition of the culture medium. Ear fibroblast cells from an NIH major histocompatibility complex (MHC) inbred miniature pig were cultured with different culture methods: 1) DMEM + 10% FBS (FBS); 2) DMEM + 10% FBS + 10% pFF (pFF). The conditioned medium was collected at 72 h. After isoelectric focusing (IEF), the equilibrated strips were submitted to SDS-PAGE. Normalized protein spots were considered significantly different between the two groups if expression levels varied by two standard deviations. To identify the protein spots, an Ettan MALDI-TOF method was used. Upon submission of the amino acid sequences, proteins were identified by a homology search using ProteinInfo or BLAST search using the ExPASy Molecular Biology Server. The proportion of G0/G1 stage cells in the pFF group was significantly higher than the proportions in the other groups (P < 0.05). Among 42 differentially expressed spots, 36 proteins were identified in the pFF group. Some molecular functions of the spots were: catalytic or methytransferase activity, eukaryotic cell surface binding, or ferric iron binding. It can be concluded that pFF supplementation of culture medium positively affects cell-cycle synchronization and cell metabolism. Further studies are needed to analyse the function of these important cellular proteins. This work received grant support from the Agenda Program (No. PJ006688) and (No. PJ007189), Rural Development Administration, Republic of Korea.