The oral mTOR inhibitor RAD001 (everolimus) in combination with letrozole in patients with advanced breast cancer: results of a phase I study with pharmacokinetics

PurposeTo investigate the safety and pharmacokinetics (PK) of combined treatment with letrozole and the oral mTOR inhibitor RAD001 in patients with metastatic breast cancer stable or progressing after ⩾4 months on letrozole alone.MethodsEighteen patients received letrozole (2.5 mg/day) and RAD001 at 5 mg/day (cohort 1) or 10 mg/day (cohort 2). In the absence of DLT in cohort 1, cohort 2 was expanded to 12 patients to obtain additional safety and PK data.ResultsMost common adverse events were stomatitis (50.0% of patients), fatigue (44.4%), anorexia and/or decreased appetite (44.4%), diarrhoea (38.9%), headache (33.3%) and rash (33.3%). There was 1 DLT, a grade 3 thrombocytopaenia in cohort 2. No clinically relevant PK interaction was detected. Seven patients received the combination therapy for >6 months. One patient had a complete response, and one had a 28% reduction in liver metastases, both in cohort 2.ConclusionDaily therapy with RAD001 plus letrozole is promising: the results suggest anti-tumour activity with no PK interactions. The overall safety profile of the combination is consistent with that expected for RAD001 monotherapy. A daily dose of RAD001 10 mg is recommended for further trials.     

Phase I pharmacokinetic and pharmacodynamic study of lapatinib in combination with sorafenib in patients with advanced refractory solid tumors

BackgroundThe epidermal growth factor receptor (EGFR) and ERBB2 (HER2) pathways and vascular endothelial growth factor (VEGF)-dependent angiogenesis have a pivotal role in cancer pathogenesis and progression. Robust experimental evidence has shown that these pathways are functionally linked and implicated in acquired resistance to targeted therapies making them attractive candidates for joined targeting. We undertook this phase I trial to assess the safety, the recommended dose for phase II trials (RPTD), pharmacokinetics (PK), pharmacodynamics (PD), and the preliminary antitumour activity of the combination of lapatinib and sorafenib in patients with advanced refractory solid tumours.MethodsFour cohorts of at least three patients each received lapatinib once daily and sorafenib twice daily together on a continuous schedule. Doses of lapatinib and sorafenib were escalated based on dose-limiting toxicities (DLTs) in the first treatment cycle following a traditional 3 + 3 design until the RPTD was reached. Additional patients were treated at the RPTD to characterise PK profiles of this combination and to investigate the potential interaction between lapatinib and sorafenib. Serum samples were collected at baseline and then prospectively every two cycles to assess changes in PD parameters. This trial is registered with ClinicalTrials.gov, number NCT00984425.FindingsThirty patients with advanced refractory solid tumours were enroled. DLTs were grade three fatigue and grade 3 atypical skin rash observed at dose levels 3 and 4, respectively. The higher dose level explored (lapatinib 1250 mg/day and sorafenib 400 mg twice daily) represented the RPTD of the combination. The most common drug-related adverse events were fatigue (68%), hypocalcemia (61%), diarrhoea (57%), lymphopaenia (54%), anorexia (50%), rash (50%), and hypophosphatemia (46%). PK analysis revealed no significant effect of sorafenib on the PK profile of lapatinib. Of the 27 assessable patients for clinical activity, one achieved a confirmed complete response, four (15%) had a partial response, and 12 (44%) achieved disease stabilisation. The disease control rate overall was 63%.InterpretationCombination treatment with lapatinib and sorafenib was feasible with promising clinical activity and without significant PK interactions. Long term tolerability seems to be challenging.     

Phase I targeted combination trial of sorafenib and erlotinib in patients with advanced solid tumors.

PURPOSE: Sorafenib and erlotinib are potent, orally administered receptor tyrosine kinase inhibitors with antiproliferative and antiangiogenic activities. Given their inhibitory target profile and efficacy as single agents, the combination of these drugs is of considerable interest in solid malignancies. This study aimed to determine the recommended phase II dose of this targeted combination, their toxicity profile, pharmacokinetic interaction, and preliminary clinical activities. EXPERIMENTAL DESIGN: Sorafenib was administered alone for a 1-week run-in period, and then both drugs were given together continuously, with every 28 days considered as a cycle. Three dose levels were assessed. RESULTS: Seventeen patients with advanced solid tumors received 75 cycles of treatment. The most frequent adverse events of all grades were constitutional and gastrointestinal in nature followed by electrolytes and dermatologic toxicities. Fatigue was the most common adverse event (17 patients; 100%) followed by diarrhea (15 patients; 88%), hypophosphatemia (13 patients; 76%), and acneiform rash (12 patients; 71%). These adverse events were predominantly mild to moderate. The recommended phase II dose of this combination was determined as 400 mg twice daily sorafenib and 150 mg daily erlotinib. Pharmacokinetic analysis revealed no significant effect of erlotinib on the pharmacokinetic profile of sorafenib. Among 15 evaluable patients, 3 (20%) achieved a confirmed partial response and 9 (60%) had stable disease as best response. CONCLUSIONS: Sorafenib and erlotinib are well tolerated and seem to have no pharmacokinetic interactions when administered in combination at their full single-agent recommended doses. This well tolerated combination resulted in promising activity that needs further validation in phase II studies.     

A phase 1 study of weekly everolimus (RAD001) in combination with docetaxel in patients with metastatic breast cancer

BACKGROUND:

Inhibition of mammalian target of rapamycin with everolimus may improve the efficacy of taxanes. Everolimus and docetaxel are both metabolized by CYP3A4, which could result in a pharmacokinetic (PK) interaction.

METHODS:

Fifteen patients with metastatic breast cancer were treated with docetaxel (doses of 40‐75 mg/m² intravenously on day 1 of a 21‐day cycle) in combination with everolimus (doses ranging from 20 to 50 mg orally on days 1 and 8 of a 21‐day cycle) in a phase 1 trial using the continuous reassessment method to determine maximum tolerated dose. The first 2 patients developed a dose‐limiting toxicity (neutropenic infection), prompting a mandatory dose reduction and PK evaluation of both everolimus and docetaxel for patients enrolled in subsequent dosing cohorts.

RESULTS:

Fifteen patients were treated. Dose‐limiting toxicity included grade 3 mucositis (n = 1), prolonged grade 4 neutropenia (n = 1), and grade 3 infection/febrile neutropenia (n = 3). Day 8 of everolimus was commonly held for neutropenia despite a dose reduction in docetaxel to 40 mg/m². Eleven patients underwent complete PK evaluation for everolimus, and 9 patients underwent complete PK evaluation for both everolimus and docetaxel. Widely variable changes in clearance were seen for both drugs, and the study was terminated because of lack of efficacy and concerns regarding toxicity seen with the combination.

CONCLUSIONS:

Weekly everolimus in combination with docetaxel every 3 weeks was associated with excessive neutropenia and variable clearance of both drugs, making combination therapy unpredictable, even at low doses of both drugs. Cancer 2012. © 2011 American Cancer Society.     

Phase I trial of everolimus plus sorafenib for patients with advanced renal cell cancer

Background

Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, and sorafenib, a RAF kinase inhibitor, has shown efficacy in renal cell cancer (RCC) as single agents. We conducted a phase I study to evaluate the maximum tolerated dose (MTD) of combining these agents for potential additive or synergistic effects when treating progressive metastatic RCC (mRCC).

Patients and Methods

The 15 patients enrolled in the study had predominantly clear cell RCC (cRCC) and progressive measurable disease with previous treatment that included immunotherapy, tyrosine kinase inhibitors, and/or everolimus. Patients received daily everolimus and twice-daily sorafenib at escalating dose levels of 2.5 mg/400 mg (cohort 1), 5 mg/400 mg (cohort 2), and 10 mg/400 mg (cohort 3), and they were evaluated weekly for toxicity and every 8 weeks for response, using computed tomography/positron emission tomography (CT/PET) and CT at baseline and at first staging.

Results

In cohort 1, 2 of 6 patients experienced dose-limited toxicity (DLT) of thrombocytopenia/leukopenia and pneumonitis. In cohort 2, 1 of 6 patients experienced a DLT of pulmonary embolism, and the 3 patients in cohort 3 experienced no DLTs. The MTD was 10 mg/400 mg. Common adverse events included grade 1/2 hand-foot syndrome. Using Response Evaluation Criteria in Solid Tumors (RECIST), 1 patient achieved a pathologic complete response (CR), 1 patient achieved a radiographic CR, and 1 patient achieved a surgical CR. Seven patients achieved stable disease; 10 patients had decreased fluorine-18 fluorodeoxyglucose uptake. Median progressive-free survival was 5.6 months; overall survival was 7.9 months.

Conclusion

The MTD of daily everolimus 10 mg and twice-daily sorafenib 400 mg is safe and effective for progressive mRCC.     

Phase I/II study of the mammalian target of rapamycin inhibitor everolimus (RAD001) in patients with relapsed or refractory hematologic malignancies.

PURPOSE: Everolimus (RAD001, Novartis), an oral derivative of rapamycin, inhibits the mammalian target of rapamycin (mTOR), which regulates many aspects of cell growth and division. A phase I/II study was done to determine safety and efficacy of everolimus in patients with relapsed or refractory hematologic malignancies. EXPERIMENTAL DESIGN: Two dose levels (5 and 10 mg orally once daily continuously) were evaluated in the phase I portion of this study to determine the maximum tolerated dose of everolimus to be used in the phase II study. RESULTS: Twenty-seven patients (9 acute myelogenous leukemia, 5 myelodysplastic syndrome, 6 B-chronic lymphocytic leukemia, 4 mantle cell lymphoma, 1 myelofibrosis, 1 natural killer cell/T-cell leukemia, and 1 T-cell prolymphocytic leukemia) received everolimus. No dose-limiting toxicities were observed. Grade 3 potentially drug-related toxicities included hyperglycemia (22%), hypophosphatemia (7%), fatigue (7%), anorexia (4%), and diarrhea (4%). One patient developed a cutaneous leukocytoclastic vasculitis requiring a skin graft. One patient with refractory anemia with excess blasts achieved a major platelet response of over 3-month duration. A second patient with refractory anemia with excess blasts showed a minor platelet response of 25-day duration. Phosphorylation of downstream targets of mTOR, eukaryotic initiation factor 4E-binding protein 1, and/or, p70 S6 kinase, was inhibited in six of nine patient samples, including those from the patient with a major platelet response. CONCLUSIONS: Everolimus is well tolerated at a daily dose of 10 mg daily and may have activity in patients with myelodysplastic syndrome. Studies of everolimus in combination with therapeutic agents directed against other components of the phosphatidylinositol 3-kinase/Akt/mTOR pathway are warranted.     

Phase II study of pemetrexed in patients with advanced neuroendocrine tumors

Purpose

In some reports, 5-fluorouracil has been associated with modest activity in patients with neuroendocrine tumors. Pemetrexed is a multitargeted antifolate with activity in tumor types not significantly responsive to other antifolates. We evaluated the efficacy of pemetrexed in a phase II study of patients with advanced neuroendocrine tumors.

Methods

Patients with metastatic neuroendocrine tumors (excluding small-cell carcinoma) were treated with pemetrexed administered intravenously at a dose of 500 mg/m² every 21 days. To reduce potential toxicity, patients also received folic acid, vitamin B12 supplementation, and peri-infusional treatment with dexamethasone. Patients were followed for response, toxicity, and survival.

Results

The study was designed with a total accrual goal of 32 patients. Due to lack of radiographic responses in patients during the study period, accrual was terminated at 17. However, one patient achieved a delayed partial response following discontinuation of pemetrexed. Ten patients were evaluable for biochemical response; five (50%) experienced >50% decrease in plasma chromogranin A. Among the 17 patients, 5 (29%) discontinued therapy due to treatment-related toxicity. The median overall survival was 12.1 months.

Conclusion

Pemetrexed does not appear to have significant antitumor activity in patients with advanced neuroendocrine tumors. The limited antitumor activity and potential toxicity associated with pemetrexed mirrors experience with the majority of other cytotoxic agents in patients with neuroendocrine tumors. Investigation of novel, molecularly targeted agents may offer more promise in this disease.     

Phase I study of pegylated liposomal doxorubicin (Caelyx) in combination with carboplatin in patients with advanced solid tumors

PURPOSE: To determine the maximum tolerated dose of the combination of Carboplatin and Caelyx, a pegylated liposomal doxorubicin, with promising activities in various solid tumors. PATIENTS AND METHODS: Twenty-two patients with various advanced solid tumors were included. Three dose levels of Caelyx were explored: 30, 35 and 40 mg/m2 in association with a fixed dose of Carboplatin (AUC 5) every 3 weeks. Dose escalation followed a modified continuous reassessment method. RESULTS: Dose-limiting toxicities were almost exclusively hematological: 3 febrile neutropenia, 1 grade 4 neutropenia lasting more than 7 days and 2 grade 4 thrombopenia were observed. Grade 4 neutropenia and febrile neutropenia were observed in 20 and 10% of courses, respectively. The median interval between courses was 25 days after cycle 1 and 27-28 days after subsequent cycles. Palmar-plantar erythrodysesthesia, mucositis and other non hematological toxicities were mild and uncommon. One patient experienced a severe anaphylactic reaction immediately after Caelyx infusion. No clinical heart dysfunction was observed. Three patients responded to therapy including 2 clinical complete responses in relapsing ovarian cancer. CONCLUSION: The recommended dose for future studies is Caelyx 35 mg/m2 + Carboplatin AUC 5 every 3 or 4 weeks. Antitumor activity, especially in ovarian cancer, warrants further investigation in phase II studies.     

Phase I study of bevacizumab, everolimus, and panobinostat (LBH-589) in advanced solid tumors

Purpose

To define the maximum tolerated dose, clinical toxicities, and pharmacodynamics of bevacizumab, everolimus, and panobinostat (LBH-589) when administered in combination to patients with advanced solid tumor malignancies.

Experiment design

Subjects received 10?mg of panobinostat three times weekly, 5 or 10?mg everolimus daily, and bevacizumab at 10?mg/kg every 2?weeks. Dose-limiting toxicities (DLTs) were assessed in cycle 1; toxicity evaluation was closely monitored throughout treatment. Treatment continued until disease progression or undesirable toxicity. Protein acetylation was assessed in peripheral blood mononuclear cells (PBMC) both at baseline and on treatment.

Results

Twelve subjects were evaluable for toxicity and nine subjects for response. DLTs in cohort 1 included grade 2 esophagitis and grade 3 oral mucositis; DLTs in cohort -1 were grade 2 ventricular arrhythmia and grade 2 intolerable skin rash. Common adverse events were diarrhea (50?%), headache (33?%), mucositis/stomatitis (25?%), hyperlipidemia (25?%), and thrombocytopenia (25?%). There was 1 partial response; an additional 2 subjects had stable disease as best response. No consistent changes in protein acetylation in PBMC were observed in samples available from eight patients on treatment compared with baseline.

Conclusions

Bevacizumab, everolimus, and panobinostat in combination at the lowest proposed doses did not have an acceptable safety and tolerability profile and did not consistently inhibit HDAC activity; therefore, we do not recommend further evaluation.     

A Phase I study of pazopanib in combination with gemcitabine in patients with advanced solid tumors

Purpose

Pazopanib plus gemcitabine combination therapy was explored in patients with advanced solid tumors.

Methods

In a modified 3 + 3 enrollment scheme, oral once-daily pazopanib was administered with intravenous gemcitabine (Days 1 and 8, 21-day cycles). Three protocol-specified dose levels were tested: pazopanib 400 mg plus gemcitabine 1,000 mg/m², pazopanib 800 mg plus gemcitabine 1,000 mg/m², and pazopanib 800 mg plus gemcitabine 1,250 mg/m². Maximum-tolerated dose was based on dose-limiting toxicities during treatment Cycle 1. In the expansion phase, six additional patients were enrolled at the highest tolerable dose level.

Results

Twenty-two patients were enrolled. At the highest dose level tested (pazopanib 800 plus gemcitabine 1,250), patients received >80 % of their planned dose and the regimen was deemed safe and tolerable. The most common treatment-related adverse events included fatigue, neutropenia, nausea, and decreased appetite. Neutropenia and thrombocytopenia were the most common events leading to dose modifications. Pharmacokinetic interaction between pazopanib and gemcitabine was not observed. One objective partial response at the highest dose was observed in a patient with metastatic melanoma. Prolonged disease stabilization (>12 cycles) was reported in three patients (metastatic melanoma, cholangiocarcinoma, and colorectal carcinoma).

Conclusion

Combination pazopanib plus gemcitabine therapy is tolerable, with an adverse event profile reflective of that associated with the individual agents. There was no apparent pharmacokinetic interaction with pazopanib plus gemcitabine co-administration, although patient numbers were limited. Further investigation of combined pazopanib plus gemcitabine is warranted.     

Phase I study of pazopanib in combination with weekly paclitaxel in patients with advanced solid tumors

Purpose.

To evaluate the maximum tolerated regimen (MTR), dose-limiting toxicities, and pharmacokinetics of pazopanib, an oral small-molecule tyrosine kinase inhibitor of vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit, in combination with paclitaxel.

Patients and Methods.

Pazopanib was given daily with weekly paclitaxel on days 1, 8, and 15 every 28 days. Dose levels of pazopanib (mg/day)/paclitaxel (mg/m²) were 400/15, 800/15, 800/50, and 800/80. An expanded cohort was enrolled at the MTR. Plasma samples were collected to evaluate the effect of pazopanib, an inhibitor of cytochrome P450 (CYP)3A4, on the pharmacokinetics of paclitaxel, a CYP3A4 and CYP2C8 substrate.

Results.

Of 26 enrolled patients, 17 were treated at the MTR of 800 mg pazopanib and 80 mg/m² paclitaxel. Dose-limiting toxicities included a grade 3 abscess and grade 2 hyperbilirubinemia. Other toxicities included elevated liver transaminases and diarrhea. Six patients (23%) had partial responses and 15 patients (58%) had stable disease. Administration of 800 mg pazopanib resulted in a 14% lower paclitaxel clearance and a 31% higher paclitaxel maximal concentration than with administration of paclitaxel alone at 15, 50, and 80 mg/m². At the MTR, coadministration of 800 mg pazopanib and 80 mg/m² paclitaxel resulted in a 26% higher geometric mean paclitaxel area under the curve.

Conclusion.

Pazopanib, at a dose of 800 mg daily, can be safely combined with a therapeutic dose of paclitaxel at 80 mg/m² when administered on days 1, 8, and 15, every 28 days. The observed greater plasma concentrations of paclitaxel given concurrently with pazopanib suggest that pazopanib is a weak inhibitor of CYP3A4 and CYP2C8.     

Phase 2 study of everolimus monotherapy in patients with nonfunctioning neuroendocrine tumors or pheochromocytomas/paragangliomas

BACKGROUND:

The current study was conducted to evaluate the efficacy and safety of everolimus in the treatment of patients with nonfunctioning neuroendocrine tumors (NETs) or pheochromocytomas/paragangliomas.

METHODS:

Patients with histologically confirmed nonfunctioning NETs or pheochromocytomas/paragangliomas and with documented disease progression before study enrollment were eligible for the current study. Everolimus was administered daily at a dose of 10 mg for 4 weeks. Response was assessed by Response Evaluation Criteria In Solid Tumors (RECIST; version 1.0) every 8 weeks. The primary endpoint was the 4‐month progression‐free survival rate (PFSR). The hypothesis of the current study was that the 4‐month PFSR would increase from 50% to 65%. Safety was evaluated using the National Cancer Institute's Common Terminology Criteria for Adverse Events (version 3.0).

RESULTS:

A total of 34 patients were enrolled. Of these, 27 patients had nonfunctioning NETs, 5 had pheochromocytomas, and 2 had paragangliomas. The 4‐month PFSR was 78%. Partial response (PR) was observed in 3 patients. Twenty‐eight patients had stable disease (SD) and 2 patients developed progressive disease (PD). The response rate (RR) and overall disease control rate (DCR) were 9.0% (95% confidence interval [95% CI], 0%‐18.6%) and 93.9% (95% CI, 85.8%‐100%), respectively. The PFS was 15.3 months (95% CI, 4.6 months‐26.0 months). Of the patients with nonfunctioning NETs, 3 achieved a PR and 23 had SD (RR, 11.1%; DCR, 100%); the PFS was 17.1 months (95% CI, 11.1 months‐23.0 months) and the 4‐month PFSR was 90.0%. Twenty‐one patients (80.8%) demonstrated tumor shrinkage. In 7 patients with pheochromocytomas/paragangliomas, 5 achieved SD, and 2 developed PD. The PFS was 3.8 months (95% CI, 0.5 months‐7.0 months) and the 4‐month PFSR was 42.9%. Four patients demonstrated tumor shrinkage. The major grade 3/4 adverse events were thrombocytopenia (14.7%), hyperglycemia (5.9%), stomatitis (5.9%), and anemia (5.9%).

CONCLUSIONS:

Everolimus was associated with high therapeutic efficacy and tolerability in patients with nonfunctioning NETs, and demonstrated modest efficacy in patients with pheochromocytomas/paragangliomas. Cancer 2012. © 2012 American Cancer Society.     

Efficacy of everolimus (RAD001) in patients with advanced NSCLC previously treated with chemotherapy alone or with chemotherapy and EGFR inhibitors

BackgroundTreatment options are scarce in pretreated advanced non-small-cell lung cancer (NSCLC) patients. RAD001, an oral inhibitor of the mammalian target of rapamycin (mTOR), has shown phase I efficacy in NSCLC.MethodsStage IIIb or IV NSCLC patients, with two or fewer prior chemotherapy regimens, one platinum based (stratum 1) or both chemotherapy and epidermal growth factor receptor tyrosine kinase inhibitors (stratum 2), received RAD001 10 mg/day until progression or unacceptable toxicity. Primary objective was overall response rate (ORR). Analyses of markers associated with the mTOR pathway were carried out on archival tumor from a subgroup using immunohistochemistry (IHC) and direct mutation sequencing.ResultsEighty-five patients were enrolled, 42 in stratum 1 and 43 in stratum. ORR was 4.7% (7.1% stratum 1; 2.3% stratum 2). Overall disease control rate was 47.1%. Median progression-free survivals (PFSs) were 2.6 (stratum 1) and 2.7 months (stratum 2). Common ≥grade 3 events were fatigue, dyspnea, stomatitis, anemia, and thrombocytopenia. Pneumonitis, probably or possibly related, mainly grade 1/2, occurred in 25%. Cox regression analysis of IHC scores found that only phospho AKT (pAKT) was a significant independent predictor of worse PFS.ConclusionsRAD001 10 mg/day was well tolerated, showing modest clinical activity in pretreated NSCLC. Evaluation of RAD001 plus standard therapy for metastatic NSCLC continues.     

A Phase II study of high-dose paclitaxel in patients with advanced neuroendocrine tumors

BACKGROUND: New agents with antitumor activity in patients with neuroendocrine tumors are sorely needed. A Phase II study of high-dose paclitaxel in patients with metastatic carcinoid and islet cell tumors was performed at the Mayo Clinic. Granulocyte-colony-stimulating factor (GCSF) also was administered to ameliorate neutropenia. METHODS: Twenty-four patients (14 with carcinoid tumors, 9 with islet cell tumors, and 1 with an anaplastic tumor) were enrolled on this Phase II study of paclitaxel given as a 24-hour continuous infusion at a dose of 250 mg/m(2) every 3 weeks plus GCSF at a dose of 5 microg/kg/day subcutaneously, beginning 24 hours after the completion of the paclitaxel dose and continuing until the absolute neutrophil count was > 10,000/microL. RESULTS: All 24 patients were evaluable for analysis. The overall response rate was 8% (95% confidence interval [95% CI], 0-0.11). At last follow-up all patients except 1 had developed disease progression, with an estimated median time to disease progression of 3.2 months (95% CI, 1.6-6.0 months). The estimated median survival was 1.5 years (95% CI, 1.0-1.8 years). Hematologic toxicity was significant with 12 of 24 patients developing Grade 4 (according to the National Cancer Institute Common Toxicity Criteria scale) neutropenia; however, there were no septic deaths reported. There were 17 episodes of Grade 4 neutropenia in these 12 patients and the duration of these events ranged from 2-5 days. More common nonhematologic toxicities included arthralgia (21 patients), anorexia (15 patients), nausea (15 patients), diarrhea (12 patients), and allergic reactions (2 patients). CONCLUSIONS: Given the lack of antitumor activity of paclitaxel and the significant hematologic toxicity observed despite the use of GCSF support in the current study cohort of patients with neuroendocrine tumors, further studies of this combination in this particular patient population are not recommended.     

Phase I dose-escalation study of tezacitabine in combination with 5-fluorouracil in patients with advanced solid tumors

BACKGROUND: Tezacitabine [(E)-2'-deoxy-2'-(fluoromethylene) cytidine; FMdC] is a novel nucleoside analog with potent antiproliferative and antitumor activity in preclinical studies. A tolerable safety profile and clinical activity have been shown in Phase I and Phase II clinical studies. The purpose of the current open-label, Phase I dose-escalation trial was to evaluate the combination of tezacitabine and 5-fluorouracil (5-FU) in the treatment of patients with advanced solid tumors. METHODS: Twenty-four patients with a variety of advanced solid tumors for which there was no curative therapy were enrolled. Bolus infusion tezacitabine was administered on Day 1 of a 14-day cycle at escalating doses of 150-350 mg/m(2), with continuous infusion 5-FU (CI 5-FU) given on Days 1-7 at a fixed dose of 200 mg/m(2) per day. Patients underwent objective tumor evaluation by radiologic methods or clinical examination at baseline and after every fourth treatment cycle. RESULTS: The maximum tolerated dose of the combination therapy was determined to be tezacitabine, 200 mg/m(2), with CI 5-FU, 200 mg/m(2) per day. The toxicities were manageable, the most notable being transient severe (National Cancer Institute Common Toxicity Criteria Grade 3 or 4) neutropenia in 23 patients (96%). Eleven (55%) of the 20 assessable patients had partial responses or stabilization of disease. The highest response rate was in patients with primary tumors of esophageal origin. CONCLUSIONS: Tezacitabine at a dose of 200 mg/m(2) in combination with CI 5-FU at a dose of 200 mg/m(2) per day was relatively well tolerated and had clinical activity in patients with advanced solid tumors, particularly in patients with esophageal and other gastrointestinal carcinomas.     

Comparative pharmacokinetics of RAD001 (everolimus) in normal and tumor-bearing rodents

Purpose

Comparative pharmacokinetic (PK) analysis of the mTOR inhibitor RAD001 (everolimus) in rats and mice.

Methods

Blood cell partitioning, plasma protein binding and PK parameters of RAD001 in blood and tissues (including brain) of both mice and rats were determined. PK modeling predicted plasma/blood and tumor levels from a variety of regimens and these were compared with the known human PK profile. DCE-MRI was used to compare tumor vascularity between mice and rats. Estimation of IC50 values in vitro and ED50 values in vivo were used to provide an indication of anti-tumor activity.

Results

The PK properties of RAD001 differed between mice and rats, including erythrocyte partitioning, plasma protein binding, plasma/blood t _1/2, oral bioavailability, volume of distribution, tissue/tumor penetration and elimination. Modeling of tumor and blood/plasma PK suggested that in mice, multiple daily administrations result in a ~2-fold increase in tumor levels of RAD001 at steady state, whereas in rats, a ~7.9-fold increase would occur. Weekly high-dose regimens were predicted not to facilitate tumor accumulation in either species. Total tumor levels of RAD001 were four- to eight-fold greater in rats than in mice. Rat tumors had a >2-fold greater plasma content and permeability compared to mouse tumors, which could contribute to differences in tumor drug uptake. Maximal antitumor effects (T/C of 0.04–0.35) were observed in both species after daily administration with similar C _max and AUC values of unbound (free) RAD001. These free levels of RAD001 are exceeded in serum from cancer patients receiving clinically beneficial daily regimens. In rodents, brain penetration of RAD001 was poor, but was dose-dependent and showed over-proportional uptake in rats with a longer t _1/2 compared to the systemic circulation.

Conclusions

The PK of RAD001 differed between mice and rats, with rats having a PK profile closer to that of humans. High intermittent doses of RAD001 may be more appropriate for treatment of brain tumors.     

Phase IB study of sorafenib in combination with gemcitabine and cisplatin in patients with refractory solid tumors

Purpose  

Sorafenib (BAY 43-9006), a multikinase inhibitor, has been shown to inhibit tumor growth and tumor angiogenesis by targeting Raf kinase, vascular endothelial growth factor receptor, and platelet-derived growth factor receptor. This study investigated the safety, pharmacokinetics, and preliminary efficacy of sorafenib in combination with gemcitabine and cisplatin.