Lenalidomide-based response-adapted therapy for older adults without high risk myeloma.

Combined lenalidomide and dexamethasone is a standard-of-care therapy for the treatment of older adults with multiple myeloma. Lenalidomide monotherapy has not been evaluated in newly diagnosed myeloma patients. We conducted a phase II study, evaluating a response-adapted therapy for older adults newly diagnosed with multiple myeloma without high-risk features who were ineligible for high-dose therapy and stem cell transplant. Patients were started on single-agent lenalidomide, and low-dose dexamethasone was added in the event of progressive disease, in a response-adapted approach. The primary endpoint was progression-free survival (PFS), and the International Myeloma Working Group's uniform response criteria were used to assess response and progression. Twenty-seven patients were enrolled, and 20 (74%) experienced a partial response or better to this response-adapted therapy. After a median follow-up of 69 months, the median PFS was 36 months [95% confidence interval (CI), 29·8 to not reached], and the median overall survival was 65 months (95% CI, 35·3 to not reached). Grade 3/4 adverse events were mainly haematological in nature. This response-adapted therapy in this patient population is feasible and results in durable responses that compare favourably with concurrent lenalidomide and dexamethasone. These results should be validated in prospective studies.

Randomized multicenter phase 2 study of pomalidomide, cyclophosphamide, and dexamethasone in relapsed refractory myeloma.

Pomalidomide and low-dose dexamethasone (PomDex) is standard treatment of lenalidomide refractory myeloma patients who have received >2 prior therapies. We aimed to assess the safety and efficacy of the addition of oral weekly cyclophosphamide to standard PomDex. We first performed a dose escalation phase 1 study to determine the recommended phase 2 dose of cyclophosphamide in combination with PomDex (arm A). A randomized, multicenter phase 2 study followed, enrolling patients with lenalidomide refractory myeloma. Patients were randomized (1:1) to receive pomalidomide 4 mg on days 1 to 21 of a 28-day cycle in combination with weekly dexamethasone (arm B) or pomalidomide, dexamethasone, and cyclophosphamide (PomCyDex) 400 mg orally on days 1, 8, and 15 (arm C). The primary end point was overall response rate (ORR). Eighty patients were enrolled (10 in phase 1 and 70 randomized in phase 2: 36 to arm B and 34 to arm C). The ORR was 38.9% (95% confidence interval [CI], 23-54.8%) and 64.7% (95% CI, 48.6-80.8%) for arms B and C, respectively (P = .035). As of June 2015, 62 of the 70 randomized patients had progressed. The median progression-free survival (PFS) was 4.4 (95% CI, 2.3-5.7) and 9.5 months (95% CI, 4.6-14) for arms B and C, respectively (P = .106). Toxicity was predominantly hematologic in nature but was not statistically higher in arm C. The combination of PomCyDex results in a superior ORR and PFS compared with PomDex in patients with lenalidomide refractory multiple myeloma. The trial was registered at www.clinicaltrials.gov as #NCT01432600.

A Randomized Phase II Study of Linsitinib (OSI-906) Versus Topotecan in Patients With Relapsed Small-Cell Lung Cancer.

LESSONS LEARNED: Targeted therapy options for SCLC patients are limited; no agent, thus far, has resulted in a strategy promising enough to progress to phase III trials.Linsitinib, a potent insulin growth factor-1-receptor tyrosine kinase inhibitor, may be one agent with activity against SCLC.Despite lack of a reliable predictive biomarker in this disease, which may have partly contributed to the negative outcome reported here, linsitinib, although safe, showed no clinical activity in unselected, relapsed SCLC patients. BACKGROUND: Treatment of relapsed small-cell lung cancer (SCLC) remains suboptimal. Insulin growth factor-1 receptor (IGF-1R) signaling plays a role in growth, survival, and chemoresistance in SCLC. Linsitinib is a potent IGF-1R tyrosine kinase inhibitor that potentially may be active against SCLC. METHODS: In this phase II study, 8 eligible patients were randomly assigned in a 1:2 ratio to topotecan (1.5 mg/m2 intravenously or 2.3 mg/m2 orally, daily for 5 days for 4 cycles) or linsitinib (150 mg orally twice daily until progression). The primary endpoint was progression-free survival. Patients with relapsed SCLC, platinum sensitive or resistant, performance status (PS) 0-2, and adequate hematologic, renal, and hepatic function were enrolled. Patients with diabetes, cirrhosis, and those taking insulinotropic agents were excluded. Crossover to linsitinib was allowed at progression. RESULTS: Fifteen patients received topotecan (8 resistant, 3 with PS 2) and 29 received linsitinib (16 resistant, 5 with PS 2). Two partial responses were observed with topotecan. Only 4 of 15 patients with topotecan and 1 of 29 with linsitinib achieved stable disease. Median progression-free survival was 3.0 (95% confidence interval [CI], 1.5-3.6) and 1.2 (95% CI, 1.1-1.4) months for topotecan and linsitinib, respectively (p = .0001). Median survival was 5.3 (95% CI, 2.2-7.6) and 3.4 (95% CI, 1.8-5.6) months for topotecan and linsitinib, respectively (p = .71). Grade 3/4 adverse events (>5% incidence) included anemia, thrombocytopenia, neutropenia/leukopenia, diarrhea, fatigue, dehydration, and hypokalemia for topotecan; and thrombocytopenia, fatigue, and alanine aminotransferase/aspartate aminotransferase elevations for linsitinib. CONCLUSION: Linsitinib was safe but showed no clinical activity in unselected, relapsed SCLC patients.

Inhibition of CRM1-dependent nuclear export sensitizes malignant cells to cytotoxic and targeted agents.

Nuclear-cytoplasmic trafficking of proteins is a significant factor in the development of cancer and drug resistance. Subcellular localization of exported proteins linked to cancer development include those involved in cell growth and proliferation, apoptosis, cell cycle regulation, transformation, angiogenesis, cell adhesion, invasion, and metastasis. Here, we examined the basic mechanisms involved in the export of proteins from the nucleus to the cytoplasm. All proteins over 40kDa use the nuclear pore complex to gain entry or exit from the nucleus, with the primary nuclear export molecule involved in these processes being chromosome region maintenance 1 (CRM1, exportin 1 or XPO1). Proteins exported from the nucleus must possess a hydrophobic nuclear export signal (NES) peptide that binds to a hydrophobic groove containing an active-site Cys528 in the CRM1 protein. CRM1 inhibitors function largely by covalent modification of the active site Cys528 and prevent binding to the cargo protein NES. In the absence of a CRM1 inhibitor, CRM1 binds cooperatively to the NES of the cargo protein and RanGTP, forming a trimer that is actively transported out of the nucleus by facilitated diffusion. Nuclear export can be blocked by CRM1 inhibitors, NES peptide inhibitors or by preventing post-translational modification of cargo proteins. Clinical trials using the classic CRM1 inhibitor leptomycin B proved too toxic for patients; however, a new generation of less toxic small molecule inhibitors is being used in clinical trials in patients with both hematological malignancies and solid tumors. Additional trials are being initiated using small-molecule CRM1 inhibitors in combination with chemotherapeutics such as pegylated liposomal doxorubicin. In this review, we present evidence that combining the new CRM1 inhibitors with other classes of therapeutics may prove effective in the treatment of cancer. Potential combinatorial therapies discussed include the use of CRM1 inhibitors and the addition of alkylating agents (melphalan), anthracyclines (doxorubicin and daunomycin), BRAF inhibitors, platinum drugs (cisplatin and oxaliplatin), proteosome inhibitors (bortezomib and carfilzomib), or tyrosine-kinase inhibitors (imatinib). Also, the sequence of treatment may be important for combination therapy. We found that the most effective treatment regimen involved first priming the cancer cells with the CRM1 inhibitor followed by doxorubicin, bortezomib, carfilzomib, or melphalan. This order sensitized both de novo and acquired drug-resistant cancer cell lines.

Effect of Age on Clinical Outcomes in Phase 1 Trial Participants.

BACKGROUND: Most persons with cancer living in the United States are older than 65 years of age; however, in general, elderly persons are under-represented in clinical trials and outcomes data are lacking. METHODS: Outcomes data were analyzed of elderly participants (≥65 years of age) enrolled in phase 1 clinical trials and the results compared with those of younger patients. All consecutive, single-center, phase 1 oncology trials initiated and completed at the H. Lee Moffitt Cancer Center & Research Institute between 1997 and 2007 were included. Patient data (including survival, response, and toxicity rates) were extracted from a cancer registry database and electronic medical records at Moffitt Cancer Center. RESULTS: After excluding multi-institution trials, we analyzed 39 trials for a total of 1,162 enrolled study participants, 32.7% of whom were elderly. Among patients who underwent transplantation, median survival rates were worse in those who were elderly compared with those who were younger (44.9 vs 32.9 months; P = .0037). However, in the no-transplantation setting, participants who were elderly had a median survival rate of 10.9 months (95% confidence interval [CI]: 8.9-13.1) compared with 8.8 months (95% CI: 7.9-10.3) in those who were younger (P = .15). Both groups had similar overall response rates (15.2% vs 13.1%) and similar treatment-related mortality rates (1% vs 0.9%, respectively). Adverse events occurring among the elderly and younger participants were not statistically significant. CONCLUSIONS: Survival, response, toxicity, and treatment-related mortality rates were not significantly different between the elderly and younger phase 1 trial participants in the no-transplantation setting. Regardless of the complex pharmacological profiles and logistical issues involved in treating the elderly population, our data imply that elderly study participants do at least as well as their younger counterparts, contributing to the justification of increasing the phase 1 trial enrollment of elderly patients.

Phase II study of pegylated liposomal doxorubicin, low-dose dexamethasone, and lenalidomide in patients with newly diagnosed multiple myeloma.

Our previous phase I/II trial of pegylated liposomal doxorubicin (PLD), low-dose dexamethasone, and lenalidomide in patients with relapsed and refractory myeloma showed an overall response rate of 75%, with 29% achieving ≥ VGPR. Here, we investigated this combination (PLD 30 or 40 mg/m(2) intravenously, day 1; dexamethasone 40 mg orally, days 1-4; lenalidomide 25 mg orally, days 1-21; administered every 28 days) in a phase II study in patients with newly diagnosed symptomatic multiple myeloma to determine its efficacy and tolerability (ClinicalTrials.gov NCT00617591). At best response, patients could proceed with high-dose melphalan or with maintenance lenalidomide and dexamethasone. In 57 patients, we found that the overall response rate and rate of very good partial response and better on intent-to-treat, our primary endpoints, were 77.2% and 42.1%, respectively, with responses per the International Myeloma Working Group. Median progression-free survival was 28 months (95% CI 18.1-34.8), with 1- and 2-year overall survival rates of 98.1 and 79.6%. During induction, grade 3/4 toxicities were neutropenia (49.1%), anemia (15.8%), thrombocytopenia (7%), fatigue (14%), febrile neutropenia (8.8%), and venous thromboembolic events (8.8%). During maintenance, grade 3/4 toxicities were mainly hematologic. We found this combination to be active in patients with newly diagnosed myeloma, with results comparable to other lenalidomide-based induction strategies without proteasome inhibition. In addition, maintenance therapy with lenalidomide was well tolerated.

A phase 1 study evaluating the combination of an allosteric AKT inhibitor (MK-2206) and trastuzumab in patients with HER2-positive solid tumors.

INTRODUCTION: Trastuzumab is effective in human epidermal growth factor receptor 2 (HER2)-over-expressing breast and gastric cancers. However, patients may develop resistance through downstream signaling via the phosphatidylinositol 3-kinase (PI3K)/AKT pathway. This phase 1 trial was conducted to determine the safety and tolerability of the investigational AKT inhibitor MK-2206, to prepare for future studies to determine whether the combination with trastuzumab could inhibit compensatory signaling. METHODS: Patients with HER2+ treatment-refractory breast and gastroesophageal cancer were enrolled. Treatment consisted of standard doses of intravenous trastuzumab and escalating dose levels of oral MK-2206 using either an every-other-day (45 mg and 60 mg QOD) or once-weekly (135 mg and 200 mg QW) schedule. RESULTS: A total of 34 patients with HER2+ disease were enrolled; 31 received study-drug. The maximum tolerated dose (MTD) for MK-2206 in combination with trastuzumab was 60 mg for the QOD schedule and 135 mg for the QW schedule, although a true MTD was not established due to early termination of the trial. The most common treatment-emergent toxicities included fatigue, hyperglycemia, and dermatologic rash, consistent with prior experience; one death unrelated to treatment was reported. There was one complete response in a patient with metastatic breast cancer, one patient achieved a partial response, and 5 patients had stable disease for at least 4 months, despite progression on multiple prior trastuzumab- and lapatinib-based therapies. Results also indicate that trastuzumab does not affect the pharmacokinetics of MK-2206. CONCLUSIONS: Results suggest the AKT inhibitor MK-2206 can be safely combined with trastuzumab, and is associated with clinical activity, supporting further investigation. TRIAL REGISTRATION: ClinicalTrials.gov; identifier: NCT00963547.

Maximally tolerated busulfan systemic exposure in combination with fludarabine as conditioning before allogeneic hematopoietic cell transplantation.

Systemic exposure to high-dose busulfan has been correlated with efficacy and toxicity after hematopoietic cell transplantation for malignancy. We used the area under the concentration-time curve (AUC) to prospectively determine the maximally tolerated systemic exposure to i.v. busulfan when given once daily after fludarabine administered at 40 mg/m(2) for 4 days. Three target AUC levels were planned: 6,000, 7,500, and 9,000 µM-min. Included were patients 16 to 65 years old, with a hematologic malignancy, an HLA A, B, or C, DRB1 8/8 or 7/8 matched donor, Karnofsky performance status ≥70%, and adequate organ function. For level 1 patients, i.v. busulfan doses 1 and 2 were 170 mg/m(2)/day, then doses 3 and 4 were adjusted based on first-dose pharmacokinetic modeling to achieve an average daily AUC of 6,000 µM-min. Doses 1 and 2 for the subsequent cohorts were based on the level 1 data: 180 mg/m(2)/day for AUC 7,500 µM-min (level 2) and 220 mg/m(2)/day for AUC 9,000 µM-min (level 3), with pharmacokinetic targeting for doses 3 and 4. Pharmacokinetic analysis after the last dose showed that 88% of the patients had been exposed to a mean AUC within 10% of the target. Forty patients were treated at level 1, 29 patients at level 2, and three patients at level 3. DLT was veno-occlusive disease of the liver, which occurred in none of 40 patients (0%) at level 1, two of 29 patients (7%) at level 2, and three of three patients (100%) at level 3. Dermatitis (P < .01) and pulmonary toxicity (P = .01) were also increased at higher AUC levels. Level 2 (7,500 µM-min × 4 days) was the maximally tolerated AUC. Within the confines of the trial's small sample size, there was no suggestion that escalating busulfan AUC from 6,000 to 7,500 µM-min × 4 days increased nonrelapse mortality. Assessment of the higher busulfan AUC on relapse prevention requires trials in patients with a homogeneous risk of relapse.

Bortezomib salvage followed by a Phase I/II study of bortezomib plus high-dose melphalan and tandem autologous transplantation for patients with primary resistant myeloma.

We conducted a Phase 1/2 study of bortezomib administered in combination with high-dose melphalan followed by tandem autologous transplants in patients with primary resistant multiple myeloma. Thirty patients received two cycles of salvage bortezomib followed by stem cell mobilization with granulocyte colony-stimulating factor and harvest. Melphalan 100 mg/m(2) per day on two consecutive days was administered, immediately followed by one dose of bortezomib (dose escalation) and stem cell infusion. The median beta 2-microglobulin was 4·35 mg/l (range: 1·8-11·4); albumin was 37 g/l (range: 3·1-4·9); high-risk karyotypes were noted in 45% of patients. The maximum planned dose of bortezomib at 1·3 mg/m(2) was well tolerated and a formal maximum tolerated dose was not determined. The peak of best overall response (≥partial response) and complete response rates after tandem transplants were 84% and 36%, respectively. With a median follow-up of 48 months, the median progression-free survival was 15 [95% confidence interval (CI): 11-21] months and the median overall survival was 35 (95% CI: 22-43) months. Correlative studies demonstrated decreased expression of BRCA2 (P = 0·0072) and FANCF (P = 0·0458) mRNA following bortezomib treatment. Bortezomib combined with high-dose melphalan is a well-tolerated conditioning with some activity in patients with resistant myeloma.

Phase I pharmacokinetic and pharmacodynamic study of triciribine phosphate monohydrate, a small-molecule inhibitor of AKT phosphorylation, in adult subjects with solid tumors containing activated AKT.

PURPOSE: Triciribine phosphate is a potent, small-molecule inhibitor of activation of all three isoforms of AKT in vitro. AKT is an intracellular protein that, when activated, leads to cellular division; it is dysregulated in a large number of malignancies, and constitutively activating AKT mutations are present in a minority of cancers. PATIENTS AND METHODS: In this phase I study triciribine phosphate monohydrate (TCN-PM) was administered to subjects whose tumors displayed evidence of increased AKT phosphorylation (p-AKT) as measured by immunohistochemical analysis (IHC). TCN-PM was administered over 30 min on days 1, 8 and 15 of a 28-day cycle. Tumor biopsy specimens, collected before treatment and on day +15, were assessed for p-AKT by IHC and western blot analyses. RESULTS: Nineteen subjects were enrolled; 13 received at least one cycle of therapy, and a total of 34 complete cycles were delivered. One subject was treated at the 45 mg/m(2) dose before the study was closed due to its primary objective having been met. No dose-limiting toxic effects were observed. Modest decreases in tumor p-AKT following therapy with TCN-PM were observed at the 35 mg/m(2) and 45 mg/m(2) dose levels, although definitive conclusions were limited by the small sample size. CONCLUSIONS: These preliminary data suggest that treatment with TCN-PM inhibits tumor p-AKT at doses that were tolerable. Although single agent activity was not observed in this enriched population, further combination studies of TCN-PM with other signal transduction pathway inhibitors in solid tumors is warranted.

Potentiation of a topoisomerase I inhibitor, karenitecin, by the histone deacetylase inhibitor valproic acid in melanoma: translational and phase I/II clinical trial.

PURPOSE: The novel topoisomerase I inhibitor karenitecin (KTN) shows activity against melanoma. We examined whether histone deacetylase inhibition could potentiate the DNA strand cleavage, cytotoxicity as well as the clinical toxicity, and efficacy of KTN in melanoma. EXPERIMENTAL DESIGN: Apoptosis, COMET, and xenograft experiments were carried out as described previously. A phase I/II trial of valproic acid (VPA) and KTN was conducted in patients with stage IV melanoma, with any number of prior therapies, Eastern Cooperative Oncology Group performance status 0-2, and adequate organ function. RESULTS: VPA pretreatment potentiated KTN-induced apoptosis in multiple melanoma cell lines and in mouse A375 xenografts. VPA increased KTN-induced DNA strand breaks. In the phase I/II trial, 39 patients were entered, with 37 evaluable for toxicity and 33 evaluable for response. Somnolence was the dose-limiting toxicity. The maximum tolerated dose for VPA was 75 mg/kg/d; at maximum tolerated dose, serum VPA was approximately 200 microg/mL (1.28 mmol/L). At the dose expansion cohort, 47% (7 of 15) of patients had stable disease; median overall survival and time to progression were 32.8 and 10.2 weeks, respectively. Histone hyperacetylation was observed in peripheral blood mononuclear cells at maximum tolerated dose. CONCLUSION: VPA potentiates KTN-induced DNA strand breaks and cytotoxicity. VPA can be combined at 75 mg/kg/d for 5 days with full-dose KTN without overlapping toxicities. In metastatic poor prognosis melanoma, this combination is associated with disease stabilization in 47% of patients. Further testing of this combination appears warranted.

Insights into the nature of DNA binding of AbrB-like transcription factors.

Understanding the DNA recognition and binding by the AbrB-like family of transcriptional regulators is of significant interest since these proteins enable bacteria to elicit the appropriate response to diverse environmental stimuli. Although these "transition-state regulator" proteins have been well characterized at the genetic level, the general and specific mechanisms of DNA binding remain elusive. We present RDC-refined NMR solution structures and dynamic properties of the DNA-binding domains of three Bacillus subtilis transition-state regulators: AbrB, Abh, and SpoVT. We combined previously investigated DNase I footprinting, DNA methylation, gel-shift assays, and mutagenic and NMR studies to generate a structural model of the complex between AbrBN(55) and its cognate promoter, abrB8. These investigations have enabled us to generate a model for the specific nature of the transition-state regulator-DNA interaction, a structure that has remained elusive thus far.

Melphalan and Exportin 1 Inhibitors Exert Synergistic Antitumor Effects in Preclinical Models of Human Multiple Myeloma.

High-dose chemotherapy with melphalan followed by autologous transplantation is a first-line treatment for multiple myeloma. Here, we present preclinical evidence that this treatment may be significantly improved by the addition of exportin 1 inhibitors (XPO1i). The XPO1i selinexor, eltanexor, and KOS-2464 sensitized human multiple myeloma cells to melphalan. Human 8226 and U266 multiple myeloma cell lines and melphalan-resistant cell lines (8226-LR5 and U266-LR6) were highly sensitized to melphalan by XPO1i. Multiple myeloma cells from newly diagnosed and relapsed/refractory multiple myeloma patients were also sensitized by XPO1i to melphalan. In NOD/SCIDγ mice challenged with either parental 8226 or U266 multiple myeloma and melphalan-resistant multiple myeloma tumors, XPO1i/melphalan combination treatments demonstrated stronger synergistic antitumor effects than single-agent melphalan with minimal toxicity. Synergistic cell death resulted from increased XPO1i/melphalan-induced DNA damage in a dose-dependent manner and decreased DNA repair. In addition, repair of melphalan-induced DNA damage was inhibited by selinexor, which decreased melphalan-induced monoubiquitination of FANCD2 in multiple myeloma cells. Knockdown of FANCD2 was found to replicate the effect of selinexor when used with melphalan, increasing DNA damage (γH2AX) by inhibiting DNA repair. Thus, combination therapies that include selinexor or eltanexor with melphalan may have the potential to improve treatment outcomes of multiple myeloma in melphalan-resistant and newly diagnosed patients. The combination of selinexor and melphalan is currently being investigated in the context of high-dose chemotherapy and autologous transplant (NCT02780609). SIGNIFICANCE: Inhibition of exportin 1 with selinexor synergistically sensitizes human multiple myeloma to melphalan by inhibiting Fanconi anemia pathway-mediated DNA repair.

Phase I Clinical Trial of Selinexor in Combination with Daunorubicin and Cytarabine in Previously Untreated Poor-Risk Acute Myeloid Leukemia.

PURPOSE: Induction chemotherapy results in complete remission (CR) rates of 20% to 50% among patients with poor-risk AML. Selinexor is an oral selective inhibitor of nuclear export with promising single-agent activity. By inhibiting the primary export protein, XPO1, selinexor localizes and activates tumor suppressor proteins in the nucleus and inhibits DNA damage repair, rationalizing combination with DNA-damaging agents. PATIENTS AND METHODS: This was a single-arm phase I clinical trial of selinexor combined with cytarabine and daunorubicin (7+3). Dose escalation was selinexor alone (3+3) with an expansion at the MTD. Cohorts 1 and 2 received 60 and 80 mg orally, respectively, twice weekly during induction. Consolidation cycles (≤ 2) with selinexor at induction dose plus 5+2 were allowed for patients who achieved CR. MTD and recommended phase II dose of selinexor were the primary endpoints. RESULTS: Twenty-one patients with poor-risk AML were enrolled. All 21 patients were included in the safety evaluations and survival analyses (4 in each of 2 cohorts; 13 in the expansion); 8 (53%) of the 19 patients evaluable for response achieved CR/CRi. MTD was not reached. Selinexor 80 mg (orally, twice weekly) was used in the expansion phase. The most common grade 3/4 nonhematologic treatment-emergent adverse events were febrile neutropenia (67%), diarrhea (29%), hyponatremia (29%), and sepsis (14%). At median follow-up (28.9 months), 38% of patients were alive. Median overall survival was 10.3 months. CONCLUSIONS: Selinexor plus 7+3 is a safe regimen for patients with newly diagnosed poor-risk AML and warrants further investigation in a larger clinical trial.

Phase I/II study of atrasentan, an endothelin A receptor antagonist, in combination with paclitaxel and carboplatin as first-line therapy in advanced non-small cell lung cancer.

PURPOSE: Endothelins and their cell membrane receptors (ET(A)R and ET(B)R) are implicated in neoplastic pathogenesis. atrasentan, a potent, selective ET(A)R antagonist, has a direct effect on tumor proliferation, apoptosis, and angiogenesis. This study was designed to assess the influence of atrasentan on paclitaxel pharmacokinetics and to determine the safety and efficacy of atrasentan in combination with paclitaxel-carboplatin. EXPERIMENTAL DESIGN: Chemonaive patients with stage IIIB (malignant pleural effusion) and IV non-small cell lung cancer were enrolled. Toxicity and response were determined using the National Cancer Institute Common Toxicity Criteria version 2.0 and Response Evaluation Criteria in Solid Tumors criteria, respectively. Treatment consisted of paclitaxel (225 mg/m(2)) and carboplatin (area under the curve, 6) administered on day 1 every 3 weeks. A fixed 10 mg daily oral dose ofAtrasentan was administered continuously, starting on day 4 of cycle 1. Paclitaxel clearance was calculated during the first two cycles (pre- and post-atrasentan) in the first 10 patients. RESULTS: All 44 patients were evaluable for survival, toxicity, and response. No significant change in mean paclitaxel clearance was detected (mean +/- SD, 21.2 +/- 4.5 L/h versus 21.3 +/- 4.9 L/h) for pre- and post-atrasentan values, respectively (P = 0.434). Grade 3/4 toxicities > or = 10% were lymphopenia (22.7%), neutropenia (20.5%), dyspnea (11.4%), and hyperglycemia (11.4%). Response rate was 18.2%, with progression-free survival of 4.2 months, median survival of 10.6 months, and 1-year survival of 43%. CONCLUSION: Atrasentan plus paclitaxel-carboplatin was safe and well tolerated, with no apparent paclitaxel-atrasentan pharmacokinetic interaction. Efficacy and survival in advanced non-small cell lung cancer were comparable with studies of chemotherapy alone.

Co-evolving motions at protein-protein interfaces of two-component signaling systems identified by covariance analysis.

Short-lived protein interactions determine signal transduction specificity among genetically amplified, structurally identical two-component signaling systems. Interacting protein pairs evolve recognition precision by varying residues at specific positions in the interaction surface consistent with constraints of charge, size, and chemical properties. Such positions can be detected by covariance analyses of two-component protein databases. Here, covariance is shown to identify a cluster of co-evolving dynamic residues in two-component proteins. NMR dynamics and structural studies of both wild-type and mutant proteins in this cluster suggest that motions serve to precisely arrange the site of phosphoryl transfer within the complex.

CRM1-mediated nuclear export of proteins and drug resistance in cancer.

Expression levels of intact tumor suppressor proteins and molecular targets of anti-neoplastic agents are critical in defining cancer cell drug sensitivity; however, the intracellular location of a specific protein may be as important. Many tumor suppressor proteins must be present in the cell nucleus to perform their policing activities or for the cell to respond to chemotherapeutic agents. Nuclear proteins needed to prevent cancer initiation or progression or to optimize chemotherapeutic response include the tumor suppressor proteins p53, APC/beta-catenin, and FOXO family genes; negative regulators of cell cycle progression and survival such as p21(CIP1) and p27(KIP1;) and chemotherapeutic targets such as DNA topoisomerases I and IIalpha. Mislocalization of a nuclear protein into the cytoplasm can render it ineffective as a tumor suppressor or as a target for chemotherapy. Blocking nuclear export of any or all of these proteins may restore tumor suppression or apoptosis or, for topoisomerases I and IIalpha, reverse drug resistance to inhibitors of these enzymes. During disease progression or in response to the tumor environment, cancer cells appear to acquire intracellular mechanisms to export anti-cancer nuclear proteins. These mechanisms generally involve modification of nuclear proteins, causing the proteins to reveal leucine-rich nuclear export signal protein sequences. Subsequent export is mediated by CRM1. This review defines the general processes involved in nuclear export mediated by CRM1/RanGTP (exportin/XPO1), examines the functions of individual tumor suppressor nuclear proteins and nuclear targets of chemotherapy, and explores potential mechanisms of cancer cells to induce export of these proteins. Novel drugs that could potentially counteract nuclear export of specific proteins are also discussed.

A phase I pharmacokinetic and pharmacodynamic study of s-3304, a novel matrix metalloproteinase inhibitor, in patients with advanced and refractory solid tumors.

PURPOSE: Matrix metalloproteinases (MMP) play a fundamental role in cancer development and progression. S-3304 is a potent, orally active, noncytotoxic inhibitor of MMPs, primarily MMP-2 and MMP-9, that prolongs survival in mice xenografts and is well tolerated in healthy volunteers. EXPERIMENTAL DESIGN: The aims of this phase I clinical trial were to determine the maximum tolerated dose, dose-limiting toxicities, pharmacokinetic profile, and intratumoral MMP inhibitory activity of single-agent S-3304 in advanced and refractory solid tumors. MMP activity was determined by film in situ zymography (FIZ). Patients had tumor biopsies before and after S-3304 administration and were also evaluated for response and survival. RESULTS: Four dose levels were explored [DL1-DL4 or 800, 1,600, 2,400, and 3200 mg twice daily (BID), respectively], and 32 patients were enrolled. Toxicities were mostly gastrointestinal. The maximum tolerated dose was not reached, but dose escalations beyond DL4 were impractical (number of capsules needed). S-3304 steady-state concentrations were reached by day 8, and day 1 mean C(max) and AUC(0-8) increases were less than dose proportional. After S-3304 administration, 17 of 18 patients experienced inhibition of MMP activity by FIZ. Strong mean inhibition of MMP activity was observed in DL1 to DL3. The negative mean inhibitory activity calculated for DL4 was due to one patient with a 397% MMP activity increase. CONCLUSION: S-3304 is safe, well tolerated, and achieves plasma concentrations above those required to inhibit MMP-2 and MMP-9. Its intratumoral MMP inhibitory activity has been shown using FIZ, which is useful as a biomarker with this and other MMP inhibitors.

Phase I trial of poly-L-glutamate camptothecin (CT-2106) administered weekly in patients with advanced solid malignancies.

PURPOSE: CT-2106 is a 20(S)-camptothecin poly-L-glutamate conjugate. This linkage stabilizes the active lactone form of camptothecin and enhances aqueous solubility. In addition, poly-L-glutamate is postulated to increase tumor delivery of the active compound through enhanced permeability and retention effect in tumor. We studied a weekly schedule of CT-2106 in patients with refractory solid tumor malignancies. EXPERIMENTAL DESIGN: CT-2106 was infused (10 min i.v. infusion) on days 1, 8, and 15 of each 28-day cycle. Plasma and urine were analyzed for total and unconjugated camptothecin by high-performance liquid chromatography equipped with a fluorescence detector. Toxicity and response assessments were done with Common Toxicity Criteria for Adverse Events version 3 and Response Evaluation Criteria in Solid Tumors, respectively. RESULTS: Twenty-six patients were enrolled. Median age was 58 years (range, 36-83) and median number of doses was 6 (range, 1-9). The most frequent tumor type (50%) was melanoma. Dose limiting toxicities were thrombocytopenia and fatigue. A weekly dose of 25 mg/m2 given every 3 of 4 weeks was the maximum tolerated dose. The majority of grade 3 and 4 toxicities were hematologic. The pharmacokinetic profile of conjugated and unconjugated camptothecin showed a polyexponential decline with similar terminal half life (t1/2 range was 44-63 and 31-48 h for conjugated and unconjugated, respectively). Pharmacokinetics of conjugated and unconjugated camptothecin were dose and time independent in the tested dose range. Urinary excretion of conjugated and unconjugated camptothecin accounted for about 30% and 4% of the administered dose, respectively. CONCLUSIONS: CT-2106 has a more manageable toxicity profile compared with unconjugated camptothecin. The maximum tolerated dose is 25 mg/m2 weekly given 3 of 4 weeks. This compound results in prolonged release of unconjugated camptothecin.

A phase 1 escalating single-dose and weekly fixed-dose study of cetuximab: pharmacokinetic and pharmacodynamic rationale for dosing.

PURPOSE: This phase 1 study evaluated the pharmacokinetic and pharmacodynamic effects of cetuximab on patients with epithelial malignancies. EXPERIMENTAL DESIGN: Following a skin and tumor biopsy, patients with advanced epithelial malignancies were randomized to receive a single dose of cetuximab at 50, 100, 250, 400, or 500 mg/m2 i.v. Repeat skin (days 2, 8, 15, and 22) and tumor (day 8) biopsies were obtained. Immunohistochemical expression of epidermal growth factor receptor (EGFR) and its pathway members was done on biopsies. Blood samples were obtained over 22 days for pharmacokinetic analyses. After day 22, all patients received weekly 250 mg/m2 cetuximab until disease progression or unacceptable toxicity. RESULTS: Thirty-nine patients enrolled. Rash was noted in 26 (67%) patients. Three patients (two with colon cancer and one with laryngeal cancer) achieved a partial response and 13 patients had stable disease. Pharmacokinetic data revealed mean maximum observed cetuximab concentrations and mean area under the concentration-time curve from time zero to infinity increased in a dose-dependent manner up to 400 mg/m2 cetuximab. Mean clearance was similar at cetuximab doses>or=100 mg/m2, supporting saturation of EGFR binding at 250 mg/m2. Pharmacodynamic evaluation revealed that patients with partial response/stable disease had a higher-grade rash and higher cetuximab trough levels than those with progressive disease (P=0.032 and 0.002, respectively). Administration of single doses (250-500 mg/m2) of cetuximab resulted in a dose-dependent decrease in EGFR protein expression levels in skin over time, supporting a minimal dose of cetuximab at 250 mg/m2 for a pharmacodynamic effect. CONCLUSION: This study provides a pharmacokinetic and pharmacodynamic rationale for the dosing of cetuximab.