Panobinostat, a pan-deacetylase inhibitor, increases acetylation of proteins associated with growth and survival of malignant cells. This phase 2 study evaluated the efficacy of intravenous (IV) panobinostat in patients with castration-resistant prostate cancer (CRPC) who had previously received chemotherapy. The primary end point was 24-week progression-free survival. Secondary end points included safety, tolerability, and the proportion of patients with a prostate-specific antigen (PSA) decline.
IV panobinostat (20 mg/m2) was administered to patients on days 1 and 8 of a 21-day cycle. Tumor response was assessed by imaging every 12 weeks (4 cycles) according to modified Response Evaluation Criteria In Solid Tumors (Scher HI et al, 2005), and PSA response was defined as a 50% decrease from baseline maintained for ≥ 4 weeks. Safety monitoring was routinely performed and included electrocardiogram monitoring.
Of 35 enrolled patients, 4 (11.4%) were alive without progression of disease at 24 weeks. PSA was evaluated in 34 (97.1%) patients: 5 (14.3%) patients demonstrated a decrease in PSA but none ≥ 50%; 1 patient (2.9%) had carcinoembryonic antigen as a marker of his prostate cancer, which declined by 43%. Toxicities regardless of relationship to panobinostat included fatigue (62.9%), thrombocytopenia (45.7%), nausea (51.4%), and decreased appetite (37.1%).
Despite promising preclinical data and scientific rationale, treatment with IV panobinostat did not show a sufficient level of clinical activity to pursue further investigation as a single agent in CRPC.
Prostate cancer; Deacetylase inhibitor; Panobinostat; Prostate-specific antigen
The mammalian target of rapamycin (mTOR) pathway is associated with castration-resistant prostate cancer (CRPC). Thirty-nine taxane-treated CRPC patients were enrolled in a phase II trial assessing the safety and efficacy of targeted therapy with the mTOR inhibitor, Ridaforolimus (Merck & Co, Inc/ARIAD Pharmaceuticals, Inc). Treatment with Ridaforolimus was generally well tolerated. No objective responses were observed, but some patients experienced disease stabilization. Ridaforolimus may be an option in combination therapy.
Few options are available after taxane-based therapy in men with CRPC. Genetic alterations involving the mTOR pathway have been associated with CRPC development, raising the hypothesis that blocking mTOR signaling may be an effective targeted approach to treatment.
Patients and Methods
In this open-label phase II study, the mTOR inhibitor Ridaforolimus was administered at a dose of 50 mg intravenous once weekly to 38 patients with taxane-treated CRPC. The primary end point was best overall response according to modified Response Evaluation Criteria in Solid Tumors guidelines. Serum prostate-specific antigen levels were prospectively monitored as a biomarker for cancer activity.
No objective responses were observed, but 18 patients (47.4%) had stable disease as their best response. Based on progression-free survival analysis, median time to progression with Ridaforolimus was 28 days (95% confidence interval, 27–29). Eight patients (21.1%) had stable disease as their best overall prostate-specific antigen response. The median number of days from first to last dose was 109.5 days (range, 1–442 days). Ridaforolimus was generally well tolerated, with a safety profile similar to that observed in patients with advanced malignancies. The most common side effects were typically mild or moderate in severity.
Ridaforolimus was generally well tolerated. Treatment did not produce objective responses, but stable disease was observed in some patients with taxane-treated CRPC. Alternative treatment regimens, such as combination therapy with a taxane or in a maintenance treatment paradigm, should be considered for further evaluation in this patient population.
Combination therapy; Disease stabilization; Phase II; Prostate-specific antigen; Targeted therapy
Vorinostat is a small molecule inhibitor of class I and II histone deacetylase (HDAC) enzymes which alters expression of target genes including the cell cycle gene p21, leading to cell cycle arrest and apoptosis.
Patients enrolled in a phase I trial were treated with vorinostat alone on day 1 and vorinostat and bortezomib in combination on day 9. Paired biopsies were obtained in eleven subjects. Blood samples were obtained on days 1 and 9 of cycle 1 prior to dosing, and 2 hours and 6 hours post dosing in all 60 subjects. Gene expression of p21, HSP70, AKT, nur77, ERB1 and ERB2 were evaluated in peripheral blood mononuclear cells and tissue samples. Chromatin immunoprecipitation of p21, HSP70 and Nur77 was also performed in biopsy samples.
In peripheral blood mononuclear cells, Nur77 was significantly and consistently decreased two hours after vorinostat administration on both days 1 and 9, median ratio of gene expression relative to baseline of 0.69 with interquartile range (IQR) 0.49-1.04 (p<0.001); 0.28 (0.15-0.7) (p<0.001), respectively, with more pronounced decrease on day 9, when patients received both vorinostat and bortezomib. p21, a downstream target of nur77, was significantly decreased on day 9 two hours and six hours after administration of vorinostat and bortezomib, 0.67 (0.41-1.03) (p<0.01); 0.44 (0.25-1.3) (p<0.01), respectively. The ChiP assay demonstrateed a protein DNA interaction, in this case interaction of Nur77, HSP70 and p21 with acetylated histone H3, at baseline and at day 9 after treatment with vorinostat in tissue biopsies in most patients.
Vorinostat inhibits Nur77 expression, which in turn may decrease p21 and AKT expression in PBMCs. The influence of vorinostat on target gene expression in tumor tissue was variable, however, most patients demonstrated interaction of acetylated H3 with Nur77, HSP70 and p21 which provides evidence of interaction with the transcriptions active acetylated H3.
SAHA; vorinostat; PS-341; bortezomib; phase I
Activation of the epidermal growth factor pathway is important in prostate cancer development and the transcription of androgen receptor regulated genes. This study evaluated the potential activity of lapatinib in men with biochemically-relapsed androgen-dependent (stage D0) prostate cancer.
Patients with a rising PSA after primary therapy for prostate cancer were enrolled. A PSA doubling time (PSADT) <12 months was required. Lapatinib was administered at 1,500 mg orally daily. Outcome measures were changes in PSA kinetics. Primary tumor blocks were obtained and assessed for EGFR expression, EGFR Q787Q polymorphism, and Kras 38 mutational status.
49 patients were enrolled (14 ineligible), resulting in 35 pts for analysis. No PSA response was observed; best response was stable disease (n=28, 80.0%). Pre-treatment average slope was 0.19 log (PSA)/month (PSADT=3.70 months), in contrast to on-treatment average slope of 0.13 log (PSA)/month (PSADT=5.44 months) using linear mixed effects models (p=0.006). Median progression-free survival (PFS) was 17.4 months for the high EGFR group and 6.0 months for the low EGFR group (p=0.50). Patients with Kras 38 mutation had shorter PFS than those without Kras 38 mutation (p=0.09).
Although no PSA responses (primary endpoint) was observed, lapatinib may have biologic activity in men with stage D0 prostate cancer as evidenced by a decrease in PSA slope in this non-randomized study. Additional trials assessing the role of EGFR overexpression and Kras wild type status in prostate cancer should be investigated.
Epidermal growth factor receptor; tyrosine kinase inhibitors; clinical trial
Prostate cancer is the most common malignancy and second leading cause of cancer related deaths in American men supporting the study of prostate cancer chemoprevention. Major risk factors for this disease have been associated with low serum levels of vitamin D. Here, we evaluate the biologic activity of a less calcemic vitamin D analog 1α-hydroxyvitamin D2 [1α-OH-D2] (Bone Care International, Inc.) in patients with prostate cancer and high grade prostatic intraepithelial neoplasia (HG PIN).
Patients with clinically organ-confined prostate cancer and HG PIN were randomized to 1α-OH-D2 versus placebo for 28 days prior to radical prostatectomy. Intermediate endpoint biomarkers included serum vitamin D metabolites, TGFß 1/2, free/total PSA, IGF-1, IGFBP-3, bFGF, and VEGF. Tissue endpoints included histology, MIB-1 and TUNEL staining, microvessel density and factor VIII staining, androgen receptor and PSA, vitamin D receptor expression and nuclear morphometry.
The 1α-OH-D2 vitamin D analog was well tolerated and could be safely administered with good compliance and no evidence of hypercalcemia over 28 days. While serum vitamin D metabolite levels only slightly increased, evidence of biologic activity was observed with significant reductions in serum PTH levels. TGF-ß2 was the only biomarker significantly altered by vitamin D supplementation. Whether reduced TGF-ß2 levels in our study is an early indicator of response to vitamin D remains unclear.
While further investigation of vitamin D may be warranted based on preclinical studies, results of the present trial do not appear to justify evaluation of 1α-OH-D2 in larger clinical prostate cancer prevention studies.
prostate cancer; vitamin D; chemoprevention
Castration resistance occurs in most patients with metastatic hormone-sensitive prostate cancer who are receiving androgen-deprivation therapy. Replacing androgens before progression of the disease is hypothesized to prolong androgen dependence.
Men with newly diagnosed, metastatic, hormone-sensitive prostate cancer, a performance status of 0 to 2, and a prostate-specific antigen (PSA) level of 5 ng per milliliter or higher received a luteinizing hormone–releasing hormone analogue and an antiandrogen agent for 7 months. We then randomly assigned patients in whom the PSA level fell to 4 ng per milliliter or lower to continuous or intermittent androgen deprivation, with patients stratified according to prior or no prior hormonal therapy, performance status, and extent of disease (minimal or extensive). The coprimary objectives were to assess whether intermittent therapy was noninferior to continuous therapy with respect to survival, with a one-sided test with an upper boundary of the hazard ratio of 1.20, and whether quality of life differed between the groups 3 months after randomization.
A total of 3040 patients were enrolled, of whom 1535 were included in the analysis: 765 randomly assigned to continuous androgen deprivation and 770 assigned to intermittent androgen deprivation. The median follow-up period was 9.8 years. Median survival was 5.8 years in the continuous-therapy group and 5.1 years in the intermittent-therapy group (hazard ratio for death with intermittent therapy, 1.10; 90% confidence interval, 0.99 to 1.23). Intermittent therapy was associated with better erectile function and mental health (P<0.001 and P = 0.003, respectively) at month 3 but not thereafter. There were no significant differences between the groups in the number of treatment-related high-grade adverse events.
Our findings were statistically inconclusive. In patients with metastatic hormone-sensitive prostate cancer, the confidence interval for survival exceeded the upper boundary for noninferiority, suggesting that we cannot rule out a 20% greater risk of death with intermittent therapy than with continuous therapy, but too few events occurred to rule out significant inferiority of intermittent therapy. Intermittent therapy resulted in small improvements in quality of life. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00002651.)
Frequent PSA testing in screening and monitoring of prostate cancer has led to significant stage migration. We evaluated if overall survival (OS) in hormone naïve, metastatic prostate cancer patients has improved during the era of PSA use. We also assessed whether any subsets of patients benefited differentially during this period.
Materials and Methods
We compared OS in three sequential phase III trials of men with hormone naïve, metastatic prostate cancer receiving similar androgen deprivation therapy (n=3096): two conducted prior to the ‘PSA era’ (S8494 and S8894), and the other during this era (S9346). OS was adjusted for patient and disease risk factors in the latter two trials. Subgroups were evaluated by interactions of risk factors with trial.
Median OS in S8494 was 30 months, 33 months in S8894; and 49 months in S9346. Adjusting for risk factors, there was a 22% lower risk of death in S9346 compared to S8894 (hazard ratio 0.78, 95% confidence interval 0.70, 0.87, p<0.001). The improvement in OS was greater in African Americans (AA) (p=0.008 for test of interaction). In both S8494 and S8894, median survival for AA was 27 months and 34 and 35 months for non-AA, respectively; this racial difference disappeared in S9346 (AA OS=48 months, non-AA OS=49 months).
Adjusting for risk factors, OS was significantly improved in the post-PSA era trial. However, attributing this solely to PSA monitoring cannot be concluded. AA men now have comparable OS to Caucasians. Current estimates of survival should be used for designing new trials in this population.
Heterogeneous expression of drug target proteins within tumor sites is a major mechanism of resistance to anticancer therapies. We describe a strategy to selectively inhibit, within tumor sites, the function of a critical intracellular protein, the sarcoplasmic/endoplasmic reticulum calcium adenosine triphosphatase (SERCA) pump, whose proper function is required by all cell types for viability. To achieve targeted inhibition, we took advantage of the unique expression of the carboxypeptidase prostate-specific membrane antigen (PSMA) by tumor endothelial cells within the microenvironment of solid tumors. We generated a prodrug, G202, consisting of a PSMA-specific peptide coupled to an analog of the potent SERCA pump inhibitor thapsigargin. G202 produced substantial tumor regression against a panel of human cancer xenografts in vivo at doses that were minimally toxic to the host. On the basis of these data, a phase 1 dose-escalation clinical trial has been initiated with G202 in patients with advanced cancer.
CTLA-4 blockade has demonstrated antitumor efficacy in human clinical trials. The antitumor mechanism is presumably mediated in part by the expansion of tumor-specific T cells. Androgen deprivation, the cornerstone of treatment for patients with metastatic prostate cancer, has been shown to elicit prostate tissue apoptosis and lymphocytic inflammation. We hypothesized that treatment with androgen deprivation, followed by an anti-CTLA-4 antibody, could augment a tumor-specific immune response elicited by androgen deprivation. We report here the results of a phase I trial evaluating a humanized monoclonal antibody targeting CTLA-4, CP-675,206 (tremelimumab), in combination with androgen deprivation using an antiandrogen. Eligible patients were those with PSA-recurrent prostate cancer after primary surgery and/or radiation therapy, not previously treated with androgen deprivation, and without radiographic evidence of metastatic disease. Subjects were treated in two cycles, 3 months apart, in which they received bicalutamide 150 mg daily days 1–28 and tremelimumab on day 29. The primary endpoint of the trial was safety. Secondary endpoints included measures of PSA kinetics and identification of a maximum tolerated dose. Eleven patients were enrolled and completed at least 1 year of follow-up. Dose-limiting toxicities included grade 3 diarrhea and skin rash. No favorable changes in PSA doubling time were observed in a period shortly after completing treatment; however, three patients experienced a prolongation in PSA doubling time detectable several months after completing treatment. The identification of delayed, prolonged favorable changes in serum PSA suggests that future studies could explore this combination in studies evaluating time to disease progression.
Tremelimumab; Anti-CTLA-4 monoclonal antibody; Bicalutamide; Prostate cancer; Clinical trial
Ixabepilone is an epothilone B analogue with activity in a variety of solid malignancies, including prostate cancer. The main dose-limiting toxicity of ixabepilone is myelosuppression when administered by using an every 3-week schedule. Here we evaluate the activity of a weekly ixabepilone in men with metastatic castrate-resistant prostate cancer to minimize hematologic toxicity.
BMS-247550 (ixabepilone) is an epothilone B analogue with activity in taxane-resistant cancer cell lines. Here we report the activity and toxicity of ixabepilone, administered by using a weekly schedule, in men with metastatic castrate-resistant prostate cancer (CRPC).
Patients with metastatic CRPC received ixabepilone at 20 mg/m2 intravenous weekly × 3, in 4-week cycles. This noncomparative study stratified patients to either a chemotherapy naive (CN), prior taxane (Tax) only, or 2 prior cytotoxic (TCx) chemotherapy arm. The primary endpoint was prostate-specific antigen response by using PCWG (Prostate Cancer Working Group) 1 criteria. Secondary endpoints included radiographic response when using RECIST (Response Evaluation Criteria In Solid Tumors).
In total, 124 patients were enrolled, of whom, 109 were eligible (35 CN, 42 Tax, and 32 TCx) for the primary response determination in this study. Prostate-specific antigen responses were seen in 12 (34.3%) of 35, 12 (28.6%) of 42, and 7 (21.9%) of 32 patients with the partial objective response in 5 (22.7%) of 22, 2 (8.0%) of 25, and 0 (0.0%) of 24 patients for the CN, Tax, and TCx arms, respectively. Significant (grade 3/4) neutropenia was seen in 6 (15.4%), 7 (14.6%), and 9 (25.0%); and grade 3/4 sensory neuropathy was seen in 8 (20.5%), 12 (25.0%), and 12 (33.3%) for CN, Tax, and TCx, respectively. Grade 3/4 thrombocytopenia was infrequent and seen in only one patient on the CN and the TCx arm.
Ixabepilone was found to have an acceptable toxicity profile when administered by using a weekly schedule with less myelosuppression compared with prior studies when using the every 3-week schedule. Single-agent activity was observed and met prespecified activity levels for the Tax treated arm.
BMS-247550; Chemotherapy; Epothilone; Microtubule-inhibitor
Sarcomatoid features can arise in renal cell carcinoma of any subtype and are associated with a poor prognosis. Doxorubicin and gemcitabine in a limited series showed activity in aggressive renal tumors and we wished to formally assess the combination in patients with renal cell carcinoma specifically containing sarcomatoid features. The Eastern Cooperative Oncology Group (ECOG) conducted a phase II trial of doxorubicin 50 mg/m2 IV push and gemcitabine 1,500 mg/m2 IV over 30 min every 2 weeks in 39 patients with locally advanced or metastatic renal cell carcinoma with sarcomatoid features. Ten patients (26%) had grade 3 toxicity, and four patients (11%) had grade 4 toxicities. Although most toxicity was from myelosuppression, one patient died on study from cardiac dysfunction after a cumulative dose of 450 mg/m2 doxorubicin. Six (16%) patients experienced responses (5 partial responses and 1 complete response), and ten (26%) patients had stable disease. In addition, another patient had an unconfirmed partial response and an additional patient experienced over 50% decrease in her tumor burden after an initial progression. The median overall survival was 8.8 months, and the median progression-free survival was 3.5 months. We conclude that the combination of doxorubicin and gemcitabine, inactive in patients with mostly clear cell histology, demonstrated responses in patients with RCC with sarcomatoid features. We acknowledge the toxicity of this combination but note that limited treatment options exist for this aggressive histology. Only through prospective multicenter trials with comprehensive central pathology review will better treatment options be identified.
Sarcomatoid; Gemcitabine; Doxorubicin; Renal cell cancer; Kidney cancer
Satraplatin is an oral platinum with potential advantages over other platinum agents. This study investigated the combination of satraplatin and docetaxel in a phase 1 study of patients with advanced solid tumor malignancies followed by a phase 1b study in men with chemotherapy naïve metastatic castrate-resistant prostate cancer (CRPC).
In this single institution phase 1/1b study, patients received docetaxel on day 1 and satraplatin on days 1–5 of a 21-day cycle ± granulocyte colony stimulating factor (GCSF). For phase 1b, prednisone 10 mg daily was added.
Twenty-nine patients received treatment. Based on 3 dose limiting toxicities (DLT) (grade 4 neutropenia) in 13 patients at dose levels 1 and −1 (docetaxel 60 mg/m2 plus satraplatin 40 mg/m2 and docetaxel 60 mg/m2 plus satraplatin 50 mg/m2) GCSF was administered with subsequent cohorts. A dose level of docetaxel 60 mg/m2 plus satraplatin 50 mg/m2 with GCSF was the starting dose level for phase 1b. At the highest dose in the phase 1b (docetaxel 75 mg/m2 plus satraplatin 50 mg/m2) there were no DLTs.
The combination of satraplatin and docetaxel is feasible in solid tumor malignancies. In advanced malignancies, the recommended phase 2 dose is docetaxel 60 mg/m2 IV day 1 with satraplatin 40 mg/m2/d PO days 1–5, without G-CSF, and Docetaxel 70 mg/m2 IV day 1 with Satraplatin 50 mg/m2/day PO days 1–5, with G-CSF support, repeated in 3-week cycles. For patients with CRPC the recommended phase 2 dose is docetaxel 75 mg/m2 IV day 1 with satraplatin 50 mg/m2/d PO days 1–-5, with G-CSF and prednisone 10 mg daily, repeated in 3-week cycles.
Satraplatin; Docetaxel; Phase 1; Castrate-resistant; Prostate; Cancer
ATN-224 (choline tetrathiomolybdate) is an oral Cu2+/Zn2+-superoxide dismutase 1 (SOD1) inhibitor with preclinical antitumor activity. We hypothesized that ATN-224 may induce antitumor effects as an antiangiogenic agent at low dose-levels while possessing direct antitumor activity at higher dose-levels. The objective of this study was to screen its clinical activity in patients with biochemically recurrent hormone-naïve prostate cancer.
Biochemically-recurrent prostate cancer patients with prostate specific antigen doubling times (PSADT) <12 months, no radiographic evidence of metastasis, and no hormonal therapy within 6 months (with serum testosterone levels >150 ng/dL) were eligible. ATN-224 was administered at two dose-levels, 300 mg (n=23) or 30 mg (n=24) daily, by way of randomization. PSA progression was defined as a ≥50% increase (and >5 ng/mL) in PSA from baseline or post-treatment nadir. Endpoints included the proportion of patients who were free of PSA progression at 24 weeks, changes in PSA slope/PSADT, and safety. The study was not powered to detect differences between the two treatment groups.
At 24 weeks, 59% (95% CI 33–82%) of men in the low-dose arm and 45% (95% CI 17–77%) in the high-dose arm were PSA progression-free. Median PSA progression-free survival was 30 weeks (95% CI 21–40+) and 26 weeks (95% CI 24–39+) in the low-dose and high-dose groups, respectively. Pre- and on-treatment PSA kinetics analyses showed a significant mean PSA slope decrease (p=0.006) and a significant mean PSADT increase (p=0.032) in the low-dose arm only. Serum ceruloplasmin levels, a biomarker for ATN-224 activity, were lowered in the high-dose group, but did not correlate with PSA changes.
Low-dose ATN-224 (30 mg daily) may have biologic activity in men with biochemically-recurrent prostate cancer, as suggested by an improvement in PSA kinetics. However, the clinical significance of PSA kinetics changes in this patient population remains uncertain. The absence of a dose-response effect also reduces enthusiasm, and there are currently no plans to further develop this agent in prostate cancer.
To characterize proliferative changes in tumors during the sunitinib malate exposure/withdrawal using 3′-Deoxy-3′-[18F]fluorothymidine (FLT) PET/CT imaging.
Patients and Methods
Patients with advanced solid malignancies and no prior anti-VEGF exposure were enrolled. All patients had metastatic lesions amenable to FLT PET/CT imaging. Sunitinib was initiated at the standard dose of 50 mg PO daily either on a 4/2 or 2/1 schedule. FLT PET/CT scans were obtained at baseline, during sunitinib exposure, and after sunitinib withdrawal within cycle #1 of therapy. VEGF levels and sunitinib pharmacokinetic data were assessed at the same time points.
16 patients (8 pts on 4/2 schedule; 8 pts on 2/1 schedule) completed all three planned FLT PET/CT scans, and were evaluable for pharmacodynamic imaging evaluation. During sunitinib withdrawal (change from scan 2 to 3), median FLT PET SUVmean increased +15% (range −14% to +277%) (p=0.047) for the 4/2 schedule and +19% (range −5.3% to +200%) (p=0.047) for the 2/1 schedule. Sunitinib PK and VEGF ligand levels increased during sunitinib exposure, and returned towards baseline during the treatment withdrawal.
The increase of cellular proliferation during sunitinib withdrawal in patients with renal cell carcinoma and other solid malignancies is consistent with a VEGFR TKI withdrawal flare. Univariate and multivariate analysis suggest that plasma VEGF is associated with this flare, with an exploratory analysis implying that patients who experience less clinical benefit have a larger withdrawal flare. This might suggest that patients with a robust compensatory response to VEGFR TKI therapy experience early “angiogenic escape”.
Angiogenesis; molecular imaging; VEGFR TKI
MKC-1 is an oral cell-cycle inhibitor with broad antitumor activity in preclinical models. Clinical studies demonstrated modest antitumor activity using intermittent dosing schedule, however additional preclinical data suggested continuous dosing could be efficacious with additional effects against the mTor/AKT pathway. The primary objectives were to determine the maximum tolerated dose (MTD) and response of continuous MKC-1. Secondary objectives included characterizing the dose limiting toxicities (DLTs) and pharmacokinetics (PK).
Patients with solid malignancies were eligible, if they had measurable disease, ECOG PS ≤1, and adequate organ function. Exclusions included brain metastases and inability to receive oral drug. MKC-1 was dosed twice daily, continuously in 28-day cycles. Other medications were eliminated if there were possible drug interactions. Doses were assigned using a TITE-CRM algorithm following enrollment of the first 3 pts. Disease response was assessed every 8 weeks
Between 5/08-9/09, 24 patients enrolled (15 M/9 F, median 58 years, range 44-77). Patients 1-3 received 120 mg/d of MKC-1; patients 4-24 were dosed per the TITE-CRM algorithm: 150 mg [n=1], 180 , 200 , 230 , 260 , 290 , 320 . The median time on drug was 8 weeks (range 4-28). The only DLT occurred at 320 mg (grade 3 fatigue). Stable disease occurred at 150 mg/d (28 weeks; RCC) and 320 mg/d (16 weeks; breast, parotid). Escalation halted at 320 mg/d. Day 28 pharmacokinetics indicated absorption and active metabolites.
Continuous MKC-1 was well-tolerated; there were no RECIST responses, although clinical benefit occurred in 3/24 pts. Dose escalation stopped at 320 mg/d, and this is the MTD as defined by the CRM dose escalation algorithm; this cumulative dose/cycle exceeds that determined from intermittent dosing studies. A TITE-CRM allowed for rapid dose escalation and was able to account for late toxicities with continuous dosing via a modified algorithm.
MKC-1; TITE-CRM; Solid malignancy; Novel dose escalation designs
Prior to the advent of VEGF-targeted therapies, renal cell carcinoma (RCC) was among the few solid tumors shown to respond to cytokine-based therapies such as interleukin-2 (IL-2) and interferon alpha. Previous work has shown that aminobisphosphonates, including zoledronic acid (ZA), are capable of activating human Vγ9 Vδ2 T cells in vitro, and these cells can be further expanded with IL-2. Moreover, these Vγ9 Vδ2 T cells have cytolytic activity in vitro to multiple human tumor cell lines. In the current report, we have conducted a pilot trial in patients with metastatic RCC, evaluating different doses of ZA in combination with low-dose IL-2 to determine whether combining these agents can promote in vivo proliferation of Vγ9 Vδ2 T cells and elicit an antitumor response. In 12 patients evaluated, no objective clinical responses were observed by RECIST criteria; however, two patients experienced prolonged stable disease. A modest increase in Vγ9 Vδ2 T-cell frequency could be detected by Day 8 of therapy in four of the nine patients who received at least one cycle of therapy, but not to the magnitude anticipated from preclinical models. Repeated administration of IL-2 and ZA resulted in both a diminished in vivo percentage of Vγ9 Vδ2 T cells as well as impaired expansion in vitro after the first cycle of therapy. These results suggest that repeated administration of IL-2 and ZA, at the doses and schedules used in this trial, may actually inhibit the proliferative capacity of Vγ9 Vδ2 T cell in patients with metastatic RCC.
Vγ9 Vδ2 lymphocyte; Interleukin-2; Zoledronic acid; Renal cell carcinoma
To evaluate the maximum tolerated dose (MTD), safety, and antitumor activity of sunitinib combined with paclitaxel and carboplatin.
Successive cohorts of patients with advanced solid tumors received oral sunitinib (25, 37.5, or 50 mg) for 2 consecutive weeks of a 3-week cycle (Schedule 2/1) or as a continuous daily dose for 3-week cycles (CDD schedule) in combination with paclitaxel (175–200 mg/m2) plus carboplatin (AUC 6 mg•min/mL) on day 1 of each of 4 cycles. Dose-limiting toxicities (DLTs) and adverse events (AEs) were evaluated to determine the MTD. Efficacy parameters were analyzed in patients with measurable disease.
Forty-three patients were enrolled (n = 25 Schedule 2/1; n = 18 CDD schedule). Across all doses, 6 DLTs were observed (grade 4 papilledema, grade 5 GI hemorrhage, grade 3 neutropenic infection, grade 4 thrombocytopenia [n = 3]). The MTD for Schedule 2/1 was sunitinib 25 mg plus paclitaxel 175 mg/m2 and carboplatin AUC 6 mg•min/mL. The MTD was not determined for the CDD schedule. Treatment-related AEs included neutropenia (77%), thrombocytopenia (56%), and fatigue (47%). Of 38 evaluable patients, 4 (11%) had partial responses and 12 (32%) had stable disease. PK data indicated an increase in maximum and total plasma exposures to sunitinib and its active metabolite when given with paclitaxel and carboplatin compared with sunitinib monotherapy.
Myelosuppression resulting in prolonged dose delays and frequent interruptions was observed, suggesting that this treatment combination is not feasible in the general cancer population.
Sunitinib; Phase I; Solid tumor; NSCLC; Antiangiogenesis; Chemotherapy
In 2005, the US Department of Defense, through the US Army Medical Research and Materiel Command, Office of the Congressionally Directed Medical Research Programs, created a funding mechanism to form a clinical trials consortium to conduct phase I and II studies in prostate cancer. This is the first report of the Prostate Cancer Clinical Trials Consortium (PCCTC).
Patients and Methods
The Department of Defense award supports a consortium of 10 prostate cancer research centers. Memorial Sloan-Kettering Cancer Center was awarded the Coordinating Center grant for the consortium and charged with creating an infrastructure to conduct early-phase multicenter clinical trials. Each participating center was required to introduce ≥ 1 clinical trial per year and maintain accrual of a minimum of 35 patients per year.
The PCCTC was launched in 2006 and now encompasses 10 leading prostate cancer research centers. Fifty-one trials have been opened, and 1386 patients have been accrued at member sites. Members share an online clinical trial management system for protocol tracking, electronic data capture, and data storage. A legal framework has been instituted, and standard operating procedures, an administrative structure, editorial support, centralized budgeting, and mechanisms for scientific review are established.
The PCCTC fulfills a congressional directive to create a clinical trials instrument dedicated to early-phase prostate cancer studies. The member institutions have built an administrative, informatics, legal, financial, statistical, and scientific infrastructure to support this endeavor. Clinical trials are open and accruing in excess of federally mandated goals.
Clinical consortium; Collaborative; Infrastructure; Phase I/II trial
Sunitinib malate is an oral, multitargeted tyrosine kinase inhibitor that has demonstrated superior efficacy over interferon (IFN)–α in a phase III trial in first-line, metastatic renal cell carcinoma (RCC). Herein, we report the results of a phase I dose-finding study of sunitinib in combination with IFN-α as first-line treatment in patients with metastatic RCC.
Patients and Methods
Treatment-naive patients with clear-cell metastatic RCC received sunitinib at a starting dose of 50 mg or 37.5 mg orally once daily in 6-week cycles (schedule 4/2) plus IFN-α at a starting dose of 3 MU subcutaneously 3 times a week, with weekly intrapatient dose escalation to a maximum of 9 MU as tolerated. Patients who did not tolerate either drug received lower doses of either or had dose interruptions.
Twenty-five patients were enrolled; their median age was 64 years (range, 45–77 years). All patients experienced grade 3/4 treatment-emergent adverse events; the most common were neutropenia, fatigue, and thrombocytopenia. After a median of 4 cycles (range, 1–9 cycles), 3 patients (12%) had a partial response, and 20 (80%) had stable disease.
Although reduced starting doses were tolerated (37.5 mg for sunitinib and 3 MU for IFN-α), even these lower doses might not be well tolerated for long-term treatment of patients with meta-static RCC. Based on historical data, sunitinib on schedule 4/2 appears to be more effective as single-agent therapy. Further study of sunitinib plus IFN-α on this schedule is not being pursued in RCC.
Combination therapy; First-line therapy; Karnofsky performance status; Schedule 4/2; Targeted therapy
This study aimed to assess the safety and feasibility of administering volociximab, a chimeric monoclonal antibody that specifically binds to α5β1 integrin, and to determine the pharmacokinetics, pharmacodynamics, and preliminary evidence of antitumor activity.
Patients with advanced solid malignancies were treated with escalating doses of volociximab i.v. administered over 60 minutes. Blood samples were assayed to determine plasma pharmacokinetic parameters, detect human antichimeric antibody formation, and determine the saturation of α5β1 sites on peripheral blood monocytes.
Twenty-one patients received 223 infusions of volociximab at doses ranging from 0.5 to 15 mg/kg i.v. on days 1, 15, 22, 29, and 36; and weekly thereafter. Treatment was well tolerated, and dose-limiting toxicity was not identified over the range examined. Mild (grade 1 or 2), reversible fatigue was the principal toxicity of volociximab at the highest dose levels of 10 and 15 mg/kg. Nausea, fever, anorexia, headache, vomiting, and myalgias were mild and infrequent, and there was no hematologic toxicity. Volociximab had biexponential distribution; clearance was inversely related to increasing dose, and the half-life at 15 mg/kg was estimated as being 30 days. Three patients tested positive for anti-volociximab antibodies. Saturation of monocyte α5β1 integrin sites was dose-dependent up to 15 mg/kg. There was one minor response (renal, 7 months) and one durable stable disease (melanoma, 14 months).
Volociximab can be safely administered at 15 mg/kg i.v. per week. The absence of severe toxicities and preliminary activity at the highest dose level warrants further disease-directed studies.
The kinesin spindle protein (KSP) is essential for separation of spindle poles during mitosis. Its inhibition results in mitotic arrest. This phase I trial examined safety, tolerability, dose-limiting toxicity (DLT), maximum tolerated dose (MTD), pharmacokinetic parameters, and anti-tumor activity of MK-0731, a potent inhibitor of KSP.
In part 1, patients with advanced solid tumors received MK-0731 intravenously over 24 h every 21 days starting at 6 mg/m2, escalating until MTD was reached. In part 2, patients with taxane-resistant tumors received the MTD. Plasma samples were collected to analyze the pharmacokinetics of MK-0731. Tumor response was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) v1.0.
In part 1, 21 patients (median age 63 years) were treated with MK-0731 at doses ranging from 6 to 48 mg/m2/24 h for median four cycles. The dose-limiting toxicity was neutropenia and the MTD was 17 mg/m2/24 h. At the MTD, AUC (±SD) was 10.5 (±7.3) μM × hour, clearance (±SD) was 153 mL/min (±84), and t1/2 was 5.9 h. In part 2, 22 patients received the MTD and there were no DLTs. Although there were no objective tumor responses, four patients (with cervical, non-small cell lung, and ovarian cancers) had prolonged stable disease.
MK-0731 at the MTD of 17 mg/m2/day every 21 days in patients with solid tumors had few grade 3 and 4 toxicities with the major DLTs at higher doses being myelosuppression. Anti-tumor efficacy was suggested by the length of stable disease in selected patients with taxane-resistant tumors.
Kinesin spindle protein; Oncology; Neutropenia
Antiproliferative and antiosteoclastic activity from preclinical models show potential for dasatinib, an oral SRC and SRC family kinase inhibitor, as a targeted therapy for patients with prostate cancer. This phase II study investigated the activity of dasatinib in patients with metastatic castration-resistant prostate cancer (CRPC).
Chemotherapy-naive men with CRPC and increasing prostate-specific antigen were treated with dasatinib 100 or 70 mg twice daily. Endpoints included changes in prostate-specific antigen, bone scans, measurable disease (Response Evaluation Criteria in Solid Tumor), and markers of bone metabolism. Following Prostate Cancer Working Group 2 guidelines, lack of progression according to Response Evaluation Criteria in Solid Tumor and bone scan was determined and reported at 12 and 24 weeks.
Forty-seven patients were enrolled and received dasatinib (initial dose 100 mg twice daily, n = 25; 70 mg twice daily, n = 22), of whom 41 (87%) had bone disease. Lack of progression was achieved in 20 (43%) patients at week 12 and in 9 (19%) patients at week 24. Of 41 evaluable patients, 21 (51%) patients achieved ≥40% reduction in urinary N-telopeptide by week 12, with 33 (80%) achieving some level of reduction anytime on study. Of 15 patients with elevated urinary N-telopeptide at baseline, 8 (53%) normalized on study. Of 40 evaluable patients, 24 (60%) had reduction in bone alkaline phosphatase at week 12 and 25 (63%) achieved some reduction on study. Dasatinib was generally well tolerated and treatment-related adverse events were moderate.
This study provides encouraging evidence of dasatinib activity in bone and reasonable tolerability in chemotherapy-naive patients with metastatic CRPC.
To determine the activity and tolerability of 100-mg once-daily (QD) dasatinib in patients with metastatic castration-resistance prostate cancer (CRPC). Dasatinib, an oral Src family kinase inhibitor, has demonstrated both preclinical and clinical activity with twice-daily dosing in patients with metastatic CRPC.
Chemotherapy-naive men with metastatic CRPC and increasing prostate-specific antigen levels were treated with dasatinib 100 mg QD. The primary measurement was a composite lack of disease progression, according to the Prostate Cancer Working Group 2 criteria, determined every 12 weeks during the study. The other analyses included changes in the prostate-specific antigen level, bone lesions, soft tissue disease, and bone turnover markers (urine N-telopeptide and bone alkaline phosphatase).
The present trial was designed before the publication of the recent Prostate Cancer Working Group 2 criteria; however, the analyses are presented to conform to the updated guidelines. A total of 48 patients received dasatinib. A lack of disease progression was observed in 21 patients (44%) at week 12 and in 8 (17%) at week 24. Urine N-telopeptide was reduced by ≥40% from baseline in 22 (51%) of 43 patients, and bone alkaline phosphatase was decreased in 26 (59%) of 44 patients. Dasatinib was well-tolerated, with only 6 patients (13%) with drug-related grade 3–4 adverse events and 3 (6%) with grade 3 adverse events. The most common treatment-related adverse events (≥20%) were fatigue, nausea, diarrhea, headache, and anorexia.
Dasatinib 100 mg QD has a favorable safety profile and maintains a similar degree of activity as the previously reported twice-daily dosing schedules. These data support additional study of dasatinib 100 mg QD for metastatic CRPC.
Current treatment for metastatic renal cell cancer with vascular endothelial growth factor (VEGF) tyrosine kinase inhibitors (TKI) have provided improved overall survival, but complete responses are rare. We conducted a multicenter phase II study to evaluate the objective response rate of 2-methoxyestradiol (2ME2 NCD) alone and in combination with sunitinib for patients with metastatic renal cell carcinoma who have progressed on sunitinib alone.
Adults with metastatic kidney cancer were stratified depending on whether they were still taking sunitinib or had discontinued sunitinib therapy at the time of registration. Patients were treated with 2ME2 NCD alone or in combination with sunitinib. The primary endpoint was objective response rate.
In total, 17 patients were enrolled, and 12 were evaluable for response (arm A, n=7; arm b, n=5). In arm A, four patients had the best response of stable disease, and three patients developed disease progression. In arm B, three patients had a best response of stable disease, and two patients had disease progression. One patient continued to receive treatment for a total of 14 cycles before developing disease progression. Fatigue was the most common observed toxicities. Thirty five percent of patients required discontinuation of therapy secondary to toxicities.
2ME2 NCD had minimal anti-tumor activity, with no observed objective responses. The study was terminated because 2ME2 NCD was not found to be tolerable at the recommended phase 2 dose in this patient population. A newer 2ME2 analog is in development with a more favorable toxicity profile and increased potency.
Renal cell carcinoma; Clinical trials; Phase II; 2-methoxyestradiol; Sunitinib malate; Antiangiogenic agent
BMS-641988 is an androgen receptor antagonist with increased potency relative to bicalutamide in both in vitro and in vivo prostate cancer models. A first-in-man phase I study was conducted to define the safety and tolerability of oral BMS-641988 in patients with castration-resistant prostate cancer (CRPC).
Doses were escalated from 5 to 150 mg based on discrete pharmacokinetic parameters in cohorts of 3 to 6 subjects. After establishing safety with 20 mg of BMS-641988 in the United States, a companion study was opened in Japan to assess differences in drug metabolism between populations.
Sixty-one men with CRPC were treated with daily BMS-641988. The pharmacokinetics of BMS-641988 and its active metabolites were proportional to dose. One patient experienced an epileptic seizure at a dose of 60 mg administered twice. Despite achieving target drug exposures, anti-tumor activity was limited to 1 partial response. Seventeen of 23 evaluable patients (74%) exhibited stable disease on imaging (median 15 weeks; range 8–32), and 10 of 61 patients (16%) achieved a ≥30%. decline in levels of prostate-specific antigen (PSA). Partial agonism was seen within the context of this study upon removal of the drug as evidenced by a decrease in PSA.
Although the clinical outcomes of predominantly stable disease and partial agonism were similar to what was observed in the preclinical evaluation of the compound, the limited anti-tumor activity of BMS-641988 at therapeutic dose levels coupled with an episode of seizure activity led to study closure.