Responses to the combination of the glycolytic inhibitor 2-deoxy-glucose (2DG) and docetaxel (DC) in patients with lung and head and neck (H/N) carcinomas

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Background: We demonstrated in mouse xenografts that the combination of docetaxel chemotherapy with 2DG is feasible and increases responses against tumors (CancerRes; 2004 64:31–4). Methods: To determine the maximum tolerated dose (MTD) of daily oral doses of 2DG given alone and in combination with weekly docetaxel (DC) in patients (pts) with advanced malignancies who had relapsed after chemotherapy, and to evaluate the pharmacokinetics (PK) of 2DG alone and in combination with weekly DC. 2DG was initially administered orally once daily for 7 days every other week starting at a dose of 2 mg/kg, and DC was administered at 30mg/m2 for 3 of every 4 weeks. A modified accelerated titration design was used. Following completion of the every other week (EOW) 2DG dosing regimen, 3 weeks on and 1 week off (3–1W) dosing; and then continuous (CW) 2DG dosing were investigated. Results: 21 pts were enrolled in the EOW dosing at 2DG doses up to 88 mg/kg/day; another 10 pts were enrolled in the other dosing regimens. 5 pts had lung cancer (4 NSCLC + 1 SCLC); and another 6 pts had H/N cancers. One pt discontinued for DC-related sensory neuropathy. Single cases of DLT occurred - asymptomatic (64mg/kg) and symptomatic (88 mg/kg) Grade 3 hyperglycemia. The MTD was not reached with the EOW regimen. 2DG is rapidly absorbed (Tmax 0.5–1h) with a half-life of 5–10h. 2DG exhibits linear PK following single and multiple doses with minimal accumulation after multiple doses at 63 and 88 mg/kg. 2DG PK and DC PK do not alter each other. One of 18 evaluable pts in the EOW dosing with breast cancer had a partial response (PR). Another 8 pts achieved disease stabilization (SD) among them: 2 of 4 pts with NSCLC, 2 of 6 pts with H/N cancers, 1 pt with thyroid cancer, and 1 of 3 pts with adenoidcystic carcinoma. The others were unknown primary and a breast lymphoma. Also the MTD was not reached at 63mg/kg (3–1W) dosing where one patient with H/N cancer achieved stabilization of his disease. Enrollment of pts in the CW regimen is ongoing now. Conclusions: The combination of 2DG and DC appears to be feasible and safe with no evidence of PK interactions. Evidence of anti-tumor activity was observed in patients with NSCLC and H/N cancers.

No significant financial relationships to disclose.

Feasibility and functionality of OROS melatonin in healthy subjects

OROS (melatonin), an oral osmotic system for controlled drug delivery, was evaluated in an open-label, two-way crossover study to test the feasibility of continuous overnight melatonin delivery. Twelve healthy subjects with no sleep disorders, ranging from 60 to 73 years of age, were enrolled in the study. Two doses of melatonin (1 x 110 micrograms and 4 x 110 micrograms) were administered on two separate occasions. Endogenous baseline nighttime serum melatonin concentrations were measured the night before each treatment. Following treatment at 2100 hours, the lights were extinguished at 2200 hours and remained so, except during blood sample collection, which was performed under dim light (< 50 lux) at specified times. Serum samples were analyzed for melatonin by an LC/MS/MS method. In addition, safety measurements such as vitals and serum samples for endocrine functions were measured both prior to and after melatonin dosing. The serum melatonin concentration profile following OROS (melatonin) dosing mimicked the normal endogenous serum melatonin concentration-time profile. The mean maximal melatonin concentration occurred at 3 a.m. The mean AUCs of endogenous melatonin before the two treatment days were 248 and 234 pg.h/mL, respectively. Serum concentrations of melatonin corrected for endogenous production increased proportionally with dose, with AUCs of 288 and 1069 pg.h/mL, respectively. Deconvolution of the serum concentration data showed good correlation between the in vitro amount released and the in vivo amount absorbed, suggesting continuous absorption throughout the gastrointestinal tract. Less than 5% residual content was observed in the recovered OROS system. Minimal changes in serum hormone concentrations (luteinizing hormone, follicular stimulating hormone, and prolactin) and no serious adverse events were observed following OROS treatment in these subjects. Delivery of melatonin with OROS formulation may result in a physiologic nocturnal profile in elderly subjects.

An anterior appositional electron field technique with a hanging lens block in orbital radiotherapy: a dosimetric study

A technique for orbital radiotherapy is presented consisting of an anterior, appositional electron beam with a hanging lens block. The beam was modified by introducing two 1.6 mm thick plastic spoilers, at about 3 cm and 15 cm from the lens, to boost in-scattering of electrons under the block. The 9 mm diameter, 2 cm long stainless steel cylindrical block was suspended 0.5-1.0 cm above the eye. We performed film, TLD (Thermo Luminescent Dosimetry), and diode dosimetry to determine the dose fill-in behind the lens. The introduction of the spoilers dramatically changed the dose distribution. The maximum dose under the block increased from 66% to 85% of the open field dose. Moreover, the dose to the posterior surface of the globe directly underneath the block, at a depth of 3 cm, increased from 48% to 76% of maximum dose, while the dose to the lens was still below 20%. This is a simple and easily reproducible treatment and is an improvement on a previously described technique. The dose distribution is adequate for cases where the target volume surrounds and is posterior to the globe.

Differentiation patterns in two- and three-dimensional culture systems of human squamous carcinoma cell lines

Relative quantification of the pattern of differentiation of two squamous carcinoma cell lines of the female genital tract, A431 and CaSki, was studied in various experimental tissue culture states that are frequently used to evaluate drug and radiation effects on human tumors. Two- and three-dimensional in vitro cultures, ie, monolayers and multicellular tumor spheroids (MCTS), and nude mice-xenograft tumors as in vivo tumor models were compared. In addition, epidermal growth factor (EGF) was used comparatively in the in vitro studies. Morphologic signs of epithelial differentiation could be recognized in both cell lines gradually increasing from monolayers to MCTS to xenograft tumors. Cytokeratin (CK) expression is described as stable in A431 cells. Using immunohistochemistry, however, partial masking of CK antigens was found when applying the antibody 8.12 on monolayer cells and could be quantified by flow cytometric measurements. Fundamental cellular changes were found in a CaSki xenograft tumor, which showed newly established features of a keratinizing carcinoma after late onset of tumor growth. Epidermal growth factor caused reduction of both intercellular contacts and later onset of necrosis in MCTS, leading to an increased viability of the spheroids. Significant differences in differentiation of the tumor model systems indicates that the characterization of differentiation with immunohistochemistry and flow cytometry is necessary to assist interpretation of data obtained with these different tumor models.