A phase I study of gemcitabine plus dasatinib (GD) or gemcitabine plus dasatinib plus cetuximab (GDC) in refractory solid tumors

e15506

Background: Dasatinib (D) is a small molecule tyrosine kinase inhibitor with activity against both bcr-abl and src. Cetuximab (C) is a monoclonal antibody that blocks EGFR. Preclinical models suggest D reverses resistance to G. In addition, src and EGFR pathways interact; synergism of dual blockade by D + C is possible. We evaluated two combination regimens, GD and GDC, in a Phase I dose escalation study. Methods: Patients (pts) with advanced solid tumors were enrolled in cohorts of 3–6 to either GD or GDC. G was dosed in mg/m2 weekly for 3 of 4 weeks, D was dosed in mg PO BID, and C was dosed at 250 mg/m2 weekly after loading dose of C=400; cycle length was 28 days. Dose levels were as follows: 1) G 1000 + D 50 ± C; 2) G 1,000 + D 70 ± C; 3) G 1,000 + D 100 ± C. Standard cycle 1 DLT definitions were used. Eligible pts had advanced solid tumors, adequate organ and marrow function, and no co-morbidities that would increase risk of toxicity. Serum, plasma, and skin biopsy biomarkers were obtained pre- and on treatment. Results: 25 pts have been enrolled, including 21 with pancreatic adenocarcinoma, 3 of whom had received prior G. 21 pts were evaluable for toxicity and 18 for efficacy. Four DLT were observed: Gr 3 ANC with infection (GDC1, n=1), Gr 3 ALT (GD2, n=2), and Gr 5 pneumonitis (GDC2, n=1). Possible treatment-related adverse events in later cycles included: Gr3–4 ANC (n=4), Gr4 colitis (n=1), Gr3 bilirubin (n=2), Gr3 Hgb (n=2), Gr3 Plt (n=2), Gr3 edema/fluid retention syndrome (n=1), and Gr3 vomiting (n=2). One previously untreated pt had a partial response. Eight of 18 pts, 3 of whom had received prior G, had stable disease as best response, median duration = 5 months (range 1–7). Biomarker results are pending. Conclusions: The MTD of the GD arm is G1000/D50BID. Stable disease in previous G-refractory pts was noted. Hematologic toxicities were dose-limiting; later toxicities including hematologic, LFT changes, pneumonitis, and fluid retention were seen. To address these toxicities, once daily dosing of D will be explored, followed by an expanded cohort of G + daily D vs G + bid D in pts with treatment-naïve pancreatic cancer.

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Hyperglycemia in vitro up-regulates growth-related cell cycle proteins of adult mouse pancreatic islets

To study effects of glucose on growth-related proteins of adult islets, we cultured mice islets in medium containing either 5.5 mmol/L (LG) or 20 mmol/L (HG) glucose. Total islet proteins were processed for sodium dodecyl sulfate polyacrylamide gel and Western blotting using antibodies against beta-actin (housekeeping), p27kip1 (G1/G0 checkpoint), cyclin D1 (G1/S), cyclin B1 (G2/M), and FoxM1. At day 1, protein levels p27, B1, D1, and FoxM1 of islets on LG and HG were 0.48- and 0.63-fold; 7.09- and 11.58-fold; 1.25- and 1.38-fold; and 1.75- and 1.75-folds, the value of day 0, determinations respectively. At day 3, the proteins of p27, B1, D1, and FoxM1 of islets in LG and HG were 0.84- and 0.84-fold; 3.08- and 17.17-fold; 1.41- and 1.54-fold; and 0.83- and 1.17-fold of those on day 0, respectively. On day 7 the values were 1.19- and 1.09-fold; 3.15- and 14.81-fold; 0.86- and 1.44-fold; and 2.75- and 3.42-fold that of day 0, respectively. At day 1, the ratios of protein in islets after HG verse LG were 1.25, 2.38, 0.94, and 1.00 for p27, B1, D1, and FoxM1, respectively. At days 3 and 7, the protein ratios of HG/LG were 0.81 and 0.82, 5.47 and 2.64, 0.81 and 1.51, and 1.11 and 1.24 for p27, B1, D1, and FoxM1, respectively. In conclusion, adult mouse islets rapidly respond to cultivation by reducing p27 and increasing B1; HG attenuates p27 elevation but enhances B1 and D1 elevations, which favor islet entry into the cell cycle.

Celecoxib reduces microvessel density in patients treated with nasopharyngeal carcinoma and induces changes in gene expression

BACKGROUND

Celecoxib is a selective cyclooxygenase-2 inhibitor with antitumor and antiangiogenic activity. We sought to determine pharmacodynamic change in tumors of patients with nasopharyngeal carcinoma (NPC) treated with celecoxib.

METHODS

Tumor biopsies were obtained before and after treatment with celecoxib 400 mg b.i.d. for 14 days in patients with newly diagnosed, untreated NPC. Tumor angiogenesis and cell proliferation were assessed by immunohistochemistry and gene expression by microarray analysis. Plasma celecoxib concentrations were obtained on days 8 and 14.

RESULTS

Paired samples were analyzed in 15 patients. Microvessel density was reduced in post-treatment samples and mean celecoxib levels reached therapeutic levels. Thirty-five genes (27 down-regulated, eight up-regulated) were differentially expressed on microarray analysis (p < 0.001). Down-regulated genes included cell cycle regulation-related (cyclin-dependent kinase 2, YES1), transcription factor (TRIP-Br2), whereas the antigen processing and presentation-related gene HLA-DM B was up-regulated.

CONCLUSION

Celecoxib reduced angiogenesis and induced tumor transcriptional changes. Further characterization of these transcriptional changes in vivo is needed to provide further insights into the effects of celecoxib in neoplastic tissue. Our findings provide a rationale for clinical studies aimed at assessing the efficacy of celecoxib in the treatment of NPC.

Photonic bus with loop signal routing and multichannel wavelength selection on a single silicon-on-insulator platform

We have demonstrated a silicon-on-insulator-based photonic bus with integrated splitters, a demultiplexer, attenuators, and a multiplexer for loop signal routing and multichannel optical wavelength selection. The integrated photonic bus has demonstrated a 33+ dB optical cross talk, a 32+ dB extinction ratio, and a rise time of 7.6 micros with two-stage Mach-Zehnder attenuators.

Phase II study of the combination of thalidomide and irinotecan in patients with recurrent anaplastic gliomas not on enzyme inducing anticonvulsants

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Background: Patients with recurrent anaplastic glioma (AG) have few treatment options after initial alkylating agent therapy. In this study, the efficacy of thalidomide and irinotecan against recurrent AG was tested to assess if synergistic activity of cytotoxic and antiangiogenic agents could affect clinical outcome. Methods: Patients with recurrent AG with a KPS≥70 not on enzyme inducing anticonvulsants and with fewer than three relapses after radiation therapy and chemotherapies were eligible; the total planned enrollment is 39 patients. Irinotecan is administered at 125 mg/m2 weekly for 4 weeks followed by 2 weeks rest; thalidomide is initiated at 100 mg daily and escalated weekly up to 400 mg daily. Warfarin (1 mg) is given for prevention of venous thromboembolism (VTE). Patients undergo clinical and radiologic evaluations every 6-weeks. The primary endpoint is progression free survival at 6 months (PFS-6). To determine possible radiologic correlates to treatment effects, DCE- MR perfusion-imaging studies are obtained at baseline and subsequent follow up visits. Results: 17 are evaluable for response; the remainder were inevaluable. All evaluable patients had previously failed temozolomide and 9 had also failed nitrosourea therapy. The median age is 44 yrs and median KPS is 90. Four patients are alive and progression free at 6-months whereas 9 have progressed; the median progression free survival is 23 weeks and the PFS-6 is 34%. The best response was a CR in one patient, PR in 2 and stable disease in 9. Two patients have died of unspecified causes probably related to treatment. Median overall survival has not been reached; the 12-month and 18 month survivals by Kaplan Meier analysis are 73% and 26% respectively. Grade 3 and 4 toxicities included fatigue (29%), leukopenia (29%), nausea/vomitting (24%), and diarrhea (18%) requiring dose reductions. Two patients had VTE. Conclusions: The preliminary results of this ongoing study suggest that the combination of irinotecan and thalidomide has activity in patients with recurrent anaplastic gliomas; the ongoing assessment of this combination in patients with AG will more definitively define whether the combination can be an effective second line therapy for this population.

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Toxicity and efficacy profiles of intrathecal injection of I-131 NaI via intraventricular (IVent) or intralumbar (Ilumb) route for leptomeningeal metastases (LM) therapy

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Background: LM is a fatal complication occurring in up to 30% of cancer patients. Intrathecal chemotherapy of LM is limited by diffusion while external beam irradiation is limited by neurotoxicity. Radioiodine I-131 may serve as a ablating agent because of its radiations transverse the meningeal thinkness but spare distant underlying nervous tissues. Two phase I studies are designed to determine MTD and to evaluate potential toxicity and efficacy of intrathecal I-131 sodium iodide (NaI) injected via IVent or the ILumb route. Methods: The IVent or Ilumb protocols each accured 5 groups of patients with cytology-confirmed LM from solid tumors. An injection of 15, 30, 60, 90 or 120 mCi of I-131 NaI was performed after thyroid blockade (Lugol solution and perchlorate), via an Ommaya reservoir (IVent) or lumbar puncture (ILumb). Patients underwent whole-body scintigraphy for biodistribution and radiation dosimetry. Follow-up studies consisted of serial CSF cytology, neuropsychology, ophthalmology, and serum tests (TSH and CBC) to 6 months. Results: The IVent and Ilumb studies accured 16 and 15 patients respectively with LM from melanoma, lung, breast and other tumors (13, 8, 6 and 4 of 31 patients). Because of re-entry into the protocols, one patient received a total of 407 mCi; the maximum radiation absorbed doses were estimated at 3716 cGy in the ventricular CSF and 54 cGy in the red marrow. No treatment-related NCI-Grade II/III/IV neurologic, hematologic or thyroid toxicity is noted. Transient improvements up to 6 weeks are noted in neuropsychologic tests (5/16 and 5/15), ophthalomologic test (3/16 and 1/15) and CSF cytology conversion (to negative) in 5/16 and 4/15 patients, respectively. Electrophysiology tests of 2 patients demonstrated normalization of P37 waves measured by somatosensory evoked potentials along with neuropsychologic test improvements. Conclusions: The MTD has not been reached up to 120 mCi on either the IVent or Ilumb protocol. Intrathecal I-131 NaI is likely to be efficacious to eradicate tumors in the CSF for LM therapy. Because of the low toxicity and likely efficacy, a phase II study with higher dosages is needed to fully explore therapeutic potentials of intrathecal I-131 NaI.

No significant financial relationships to disclose.

A phase I study of temozolomide (TMZ) and the farnesyltransferase inhibitor (FTI), lonafarnib (Sarazar, SCH66336) in recurrent glioblastoma

1556

Background: Farnesylation is essential for the post-translational modification of several proteins that play a role in cell proliferation and growth. FTIs demonstrate antiproliferative effects in a variety of tumor cell lines and xenograft models and enhanced efficacy by combining lonafarnib with TMZ compared with TMZ alone. Clinical studies show that dose-intense TMZ may have better efficacy then conventional dosing (Wick, Neurology 2004). Objective: Determine the maximum tolerated dose of lonafarnib when combined with a dose-intensified schedule of TMZ. Eligibility criteria: Histologically proven GBM; evidence of relaspe or progression; up to 2 prior chemotherapy regimens, prior TMZ permitted; KPS ≥ 60. No enzyme-inducing anticonvulsants. Methods: TMZ was given at 150 mg/m2 days 1–7 and 15–21; lonafarnib escalated by cohort: 100 mg BID, 150 mg BID, 200 mg BID on days 8–14 and 22–28 of a 28-day cycle. Response: Toxicity measured after cycle 1 using NCI CTCAE v3. Patient (pt)accrual used a 3 + 3 design. Response was evaluated q2 cycles. Standard response criteria (MacDonald) were used. Results: 15 patients were accrued. Median age 47 yrs; median KPS 90. M:F ratio was 11:4. No DLTs in any dose cohort, a pt (cohort 1) died day 29 of unrelated cardiac disease. 4 pts demonstrated partial response, all with prior TMZ failure, 3 pts showed prolonged stable disease. 6-month PFS rate estimated at 33%, median PFS 14 weeks. Treatment was well tolerated: 1 episode each of grade 3 diarrhea, esophagitis, fatigue and hypokalemia; 3 episodes of grade 3/4 leukopenia, 2 episodes of grade 3/4 neutropenia, and 2 episodes of grade 4 thrombocytopenia. Seven pts had grade 3/4 lymphopenia, some with persistant lymphopenia from prior TMZ. 1 pt had grade 4 pneumonitis of uncertain etiology. Conclusions: The alternating week schedule of TMZ/lonafarnib was well tolerated. Preliminary results suggest anti-tumor activity even in pts who had failed prior TMZ. It is not certain whether this activity is due to the dose-intensified TMZ or the treatment combination. Studies are planned to evaluate potential predictors of response (i.e MGMT gene promoter methylation) and expand the trial to obtain pharmacokinetic and additional efficacy data.

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Thalidomide: dermatological indications, mechanisms of action and side-effects

Thalidomide was first introduced in the 1950s as a sedative but was quickly removed from the market after it was linked to cases of severe birth defects. However, it has since made a remarkable comeback for the U.S. Food and Drug Administration-approved use in the treatment of erythema nodosum leprosum. Further, it has shown its effectiveness in unresponsive dermatological conditions such as actinic prurigo, adult Langerhans cell histiocytosis, aphthous stomatitis, Behçet's syndrome, graft-versus-host disease, cutaneous sarcoidosis, erythema multiforme, Jessner-Kanof lymphocytic infiltration of the skin, Kaposi sarcoma, lichen planus, lupus erythematosus, melanoma, prurigo nodularis, pyoderma gangrenosum and uraemic pruritus. This article reviews the history, pharmacology, mechanism of action, clinical uses and adverse effects of thalidomide.