Untenable dosing: A common pitfall of modern DLT-targeting Phase I designs in oncology

BACKGROUND

There is increasing use of Phase I statistical designs to find a dose that causes rapidly emerging and particularly concerning severe or life-threatening toxicities (dose-limiting toxicities, DLTs) in a specified percent of patients most commonly 25%. While a convenient statistical framework, the foundation for selecting any specified target DLT rate, and its relevance to the recommended Phase II dose is generally lacking.

METHOD

We surveyed 78 medical oncologists, most (69%) with experience as a principal investigator on a Phase I study, to ascertain their opinions related to this approach to Phase I studies and the targets often chosen.

RESULTS

Eighty-seven percent of respondents preferred severe toxicities in only 5%-10% of patients, consistent with 58% of respondents noting that 10% or fewer patients experience severe toxicities in the first cycle with standard outpatient treatments. The survey also documented in an example that the majority (62%) of physicians modify their patient selection during the conduct of the study based on observed toxicity and 78% note that higher toxicity is acceptable in patients where a cure is more likely.

CONCLUSION

DLT-target rate designs search for a single target that is rarely well-supported in a patient population that is not stable. The most common target used is inconsistent with the toxicity of most clinically used drugs and investigator preference and can lead to the pursuit of unacceptable doses. Use of Phase I trial designs with a target DLT rate should be limited to settings with a well-justified target and should specify how the target relates to the recommended Phase II dose.

Angiogenic markers during bevacizumab-based treatment in metastatic renal cell carcinoma (RCC)

522

Background: Targeting the vascular endothelial growth factor (VEGF) pathway delays progression in mRCC, however innate and acquired resistance limit success. CD105 (endoglin) is a TGFb family receptor which is upregulated after VEGF inhibition, possibly mediating resistance. We studied serum CD105 and TGFb at baseline and after treatment, and tissue levels of TGFbR1 & 2 plus AVCRL, to discover biomarkers for treatment response as part of a randomized trial of bevacizumab (Bev) +/- the anti-endoglin antibody TRC105. Clinical data from the trial were presented at ASCO 2015 (Dorff et al, abstr 4542). Methods: Serum was collected at baseline and before cycles 2&4. ELISA was performed using kits from Abcam. Changes from baseline were evaluated and compared overall and between arms using a general linear mixed effects model. Immunohistochemistry was performed on paraffin embedded tissue samples using antibodies from R&D systems; tissue and baseline ELISA data were evaluated for association with PFS using Kaplan-Meier analysis and the logrank test. Results: 54 subjects (24 on Bev and 28 on Bev+TRC105) had at least one analyzed serum sample; 14 and 19 respectively had both baseline and cycle 2 samples. Mean CD105 was 82.8 (95%CI 64.6, 106.2) at baseline and 59.0 (95%CI 43.2, 80.7) at cycle 2; for 16 patients with cycle 4 data the mean was 39.8, significantly lower than baseline (p = 0.024), but not different between treatment arms. Cycle 2 TGFb levels were not different from baseline (p = 0.66) or between arms (p = 0.17). Baseline serum TGFb below the median ( < 10.6) was associated with higher likelihood of PFS at 12 and 24 weeks; (0.78 vs 0.3 and 0.49 vs 0.19, respectively, p = 0.022); baseline CD105 was not (p = 0.83). Tissue was available for 29 subjects. No tissue markers (TGFbR1 &2 or AVCRL) were associated with longer PFS except, in exploratory analysis, higher TGFbR2 staining in patients treated with TRC105 (p = 0.017). Conclusions: No pharmacodynamics markers for TRC105 therapy were identified. Lower baseline serum TGFb levels may be prognostic of PFS during Bev therapy, supporting the notion that this pathway contributes to resistance. Better PFS in TRC105-treated patients with higher tissue TGFbR2 expression warrants further study. Clinical trial information: NCT01727089.

Phase II Study of the AKT Inhibitor MK-2206 plus Erlotinib in Patients with Advanced Non-Small Cell Lung Cancer Who Previously Progressed on Erlotinib

PURPOSE

Preclinical modeling in non-small cell lung cancer (NSCLC) showed that stimulation with hepatocyte growth factor (HGF), the ligand for MET, could reverse the cytostatic and cytotoxic effects of the EGFR inhibitor erlotinib in erlotinib-sensitive cell lines. Inhibitors of AKT signaling mitigated this HGF-mediated resistance, partially restoring erlotinib activity. We conducted a phase II trial of erlotinib plus MK-2206, a highly selective inhibitor of AKT, in NSCLC patients.

EXPERIMENTAL DESIGN

Eligible patients must have progressed following prior benefit from erlotinib, defined as response or stable disease > 12 weeks. Treatment consisted of erlotinib 150 mg orally every day + MK-2206 45 mg orally every alternate day on a 28-day cycle. Primary endpoints were RECIST response rate > 30% (stratum 1: EGFR mutant) and disease control rate (DCR) > 20% at 12 weeks (stratum 2: EGFR wild-type).

RESULTS

Eighty patients were enrolled, 45 and 35 in stratum 1 and 2, respectively. Most common attributable adverse events (all grade 3) were rash, diarrhea, fatigue, and mucositis. Response and DCR were, respectively, 9% and 40% in stratum 1; 3% and 47% in stratum 2. Median progression-free survival was 4.4 months in stratum 1 and 4.6 months in stratum 2.

CONCLUSIONS

Combination MK-2206 and erlotinib met its primary endpoint in erlotinib-pretreated patients with EGFR wild-type NSCLC. Although activity was seen in EGFR-mutated NSCLC, this did not exceed a priori estimates. AKT pathway inhibition merits further clinical evaluation in EGFR wild-type NSCLC.

A mismatch between methods and objectives in phase I drug development: Statistical limitations and personalized medicine—A California Cancer Consortium (CCC) study

2538

Background: Patient variation in drug response and toxicity impacts all phases of drug development. While detailed sample-size calculations and analysis based on statistical methodology are critical for addressing variation in late stage trials, phase I studies pose unique and largely unsolved challenges related to variability. Changes in patient selection during the study, small sample-sizes and large patient variation in toxicity are exactly the kind of problems that statistical methods cannot address in small, isolated phase I studies, regardless of apparent mathematical rigor. We have documented these problems via a physician survey. Methods: A 10-question anonymous survey was sent to 670 oncologists at National Comprehensive Cancer Network (NCCN) and CCC institutions via an online survey. 19 % (126/670) of the oncologists polled responded. 78/126 (62%) specialized in Medical Oncology. The number of years in practice varied from 2-45 yrs with a median of 17 yrs. Results: a) 66% of all respondents stated that non-DLT toxicities on one dose level would impact their patient selection on the following dose level, conflicting with the assumption of random patient selection implicit in simulations used in evaluating statistical designs. b) Only 13% stated a desire to target a non-heme toxicity as high as 20% grade 3, while 87% desired a 10% or less grade 3 rate; c) More than half the respondents would prefer not to escalate if 3/3 patients experienced grade 2 LFTs; d) 82% of the respondents thought the appropriate target toxicity differed for patients depending on their potential for becoming a surgical candidate, furthering the need for personalized dosing. Conclusions: Statistical methods in phase I trials are unable to address many of the salient features of phase I study conduct and investigator goals. We will present several approaches we have initiated to address these limitations, and present future plans to help produce a more reliable estimate of a recommended dose. Supported in part by NCI grants U01CA062505, N01-CM-62209, and NCCN data collection assistance.

Clinical evaluation of safety and immunogenicity of PADRE-cytomegalovirus (CMV) and tetanus-CMV fusion peptide vaccines with or without PF03512676 adjuvant

BACKGROUND

It has been reported that cytomegalovirus (CMV) pp65-specific T cells can protect hematopoietic cell transplant (HCT) recipients from CMV complications. Two candidate CMV peptide vaccines composed of the HLA A*0201 pp65(495-503) cytotoxic CD8(+) T-cell epitope fused to 2 different universal T-helper epitopes (either the synthetic Pan DR epitope [PADRE] or a natural Tetanus sequence) were clinically evaluated for safety and ability to elicit pp65 T cells in HLA A*0201 healthy volunteers.

METHODS

Escalating doses (0.5, 2.5, 10 mg) of PADRE or Tetanus pp65(495-503) vaccines with (30 adults) or without (28 adults) PF03512676 adjuvant were administered by subcutaneous injection every 3 weeks for a total of 4 injections.

RESULTS

No serious adverse events were reported, although vaccines used in combination with PF03512676 had enhanced reactogenicity. Ex vivo responses were detected by flow cytometry exclusively in volunteers who received the vaccine coadministered with PF03512676. In addition, using a sensitive in vitro stimulation system, vaccine-elicited pp65(495-503) T cells were expanded in 30% of volunteers injected solely with the CMV peptides and in all tested subjects receiving the vaccines coinjected with PF03512676.

CONCLUSIONS

Acceptable safety profiles and vaccine-driven expansion of pp65(495-503) T cells in healthy adults support further evaluation of CMV peptide vaccines combined with PF03512676 in the HCT setting.

CLINICAL TRIALS REGISTRATION

NCT00722839.

A phase I and pharmacokinetic study of oral 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, NSC #663249) in the treatment of advanced-stage solid cancers: a California Cancer Consortium Study

BACKGROUND

3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) is a novel small-molecule ribonucleotide reductase inhibitor. This study was designed to estimate the maximum tolerated dose (MTD) and oral bioavailability of 3-AP in patients with advanced-stage solid tumors.

METHODS

Twenty patients received one dose of intravenous and subsequent cycles of oral 3-AP following a 3 + 3 patient dose escalation. Intravenous 3-AP was administered to every patient at a fixed dose of 100 mg over a 2-h infusion 1 week prior to the first oral cycle. Oral 3-AP was administered every 12 h for 5 consecutive doses on days 1-3, days 8-10, and days 15-17 of every 28-day cycle. 3-AP was started at 50 mg with a planned dose escalation to 100, 150, and 200 mg. Dose-limiting toxicities (DLT) and bioavailability were evaluated.

RESULTS

Twenty patients were enrolled. For dose level 1 (50 mg), the second of three treated patients had a DLT of grade 3 hypertension. In the dose level 1 expansion cohort, three patients had no DLTs. No further DLTs were encountered during escalation until the 200-mg dose was reached. At the 200 mg 3-AP dose level, two treated patients had DLTs of grade 3 hypoxia. One additional DLT of grade 4 febrile neutropenia was subsequently observed at the de-escalated 150 mg dose. One DLT in 6 evaluable patients established the MTD as 150 mg per dose on this dosing schedule. Responses in the form of stable disease occurred in 5 (25%) of 20 patients. The oral bioavailability of 3-AP was 67 ± 29% and was consistent with the finding that the MTD by the oral route was 33% higher than by the intravenous route.

CONCLUSIONS

Oral 3-AP is well tolerated and has an MTD similar to its intravenous form after accounting for the oral bioavailability. Oral 3-AP is associated with a modest clinical benefit rate of 25% in our treated patient population with advanced solid tumors.

Primary response against cytomegalovirus during antiviral prophylaxis with valganciclovir, in solid organ transplant recipients

Antiviral prophylaxis has proved successful for prevention of cytomegalovirus (CMV) disease in solid organ transplant (SOT) patients; though emerging data suggest that antiviral agents interfere with immunity, and may inhibit immune priming. In this context, we investigated levels and phenotype of primary CMV-specific immune responses that developed during antiviral prophylaxis in a cohort of CMV seronegative recipients (R(-) ) of a SOT from a seropositive donor (D(+) ). We longitudinally monitored CMV viral load, antibodies and levels of the negative immuno-modulator IL-10. PBMC were stimulated with CMV-specific peptide libraries to measure CD137 activation marker on CMV-specific T-cells and levels of PD-1 receptor, which is over expressed on exhausted T-cells. Unexpectedly, the majority (13/18) of D(+) R(-) patients who developed a primary CMV response showed early post-transplant CMV-specific responses, though levels of PD-1 on CMV-specific T-cells remained elevated throughout prophylaxis. A strong inverse association was found between levels of plasma IL-10 and CMV-specific cellular immune responses. Our study suggests that during prophylaxis, subclinical CMV infection might have occurred in the D(+) R(-) patients, and primary CMV-specific responses were detected early post-transplant when levels of plasma IL-10 were low. Extended prophylaxis or antiviral treatment did not appear to suppress CMV-specific antibodies or T-cells, which, however, showed exhaustion phenotypes.

Randomized phase II trial of concurrent versus sequential bortezomib plus docetaxel in advanced non-small-cell lung cancer: a California cancer consortium trial

BACKGROUND

The proteasome inhibitor bortezomib sensitizes tumor cells to chemotherapy-induced apoptosis. In preclinical non-small-cell lung cancer (NSCLC) models, p53-dependent growth arrest after bortezomib treatment resulted in reduced cytotoxicity if bortezomib preceded docetaxel. The reverse sequence of docetaxel before bortezomib was associated with increased apoptosis, cleavage of caspase-3 and PARP (poly [ADP-ribose] polymerase), and reduction in Bcl-2. A prospective randomized phase II trial of concurrent versus sequential docetaxel and bortezomib was conducted to assess whether administration sequence resulted in measurable clinical differences.

PATIENTS AND METHODS

Previously treated patients with advanced NSCLC were randomized to concurrent (CON) or sequential (SEQ) docetaxel (75 mg/m² intravenous [I.V.]) followed by bortezomib, every 3 weeks. In the CON arm, bortezomib (1.6 mg/m² I.V.) was given on days 1 and 8, and in the SEQ arm, it was given on days 2 and 8. Previous erlotinib as well as treated or controlled brain metastases were allowed. The primary endpoint was objective response rate (RR); progression-free (PFS) and overall survival (OS) were secondary endpoints.

RESULTS

Eighty-one patients were randomized (40 CON and 41 SEQ). Grade 3+ toxicities were mostly due to myelosuppression. One patient each had grade 4 hyponatremia and syncope. Toxicities were similar between the arms. There was 1 treatment-related death in the SEQ arm. There were 8 partial responders, 4 in each arm, for an overall RR of 10%. Disease control rate was similar in both arms (50% vs. 49%). Median PFS was 12 weeks in the CON arm and 11 weeks in the SEQ arm. Median OS times in the CON and SEQ arms were 13.3 and 10.5 months, respectively.

CONCLUSION

Docetaxel plus bortezomib given sequentially or concurrently has similar RR and PFS. Median survival in the SEQ arm exceeds published survival estimates for either agent alone or in combination. Any further studies in this population would require molecular characterization of a phenotype most likely to benefit from proteasome inhibitor therapy.

A phase II trial of gefitinib and pegylated IFNα in previously treated renal cell carcinoma

BACKGROUND

This study was conducted to evaluate the efficacy of the epidermal growth factor receptor tyrosine kinase inhibitor gefitinib with pegylated-IFNα (PEG-IFNα) in patients with advanced renal cell carcinoma.

METHODS

Progression-free survival (PFS) rate at 6 months >50% was considered promising for further evaluation. Patients with unresectable or metastatic disease, unlimited prior therapies, and adequate performance status and end-organ function were eligible. PEG-IFNα was dosed subcutaneously once weekly (initially 6 μg/kg/week, later reduced to 4 μg/kg/week) for 12 weeks. Gefitinib was given 250 mg orally once daily until progression or intolerance.

RESULTS

Twenty-one patients were accrued. Fourteen patients had a prior nephrectomy, and twelve had prior systemic therapy. The 6-month PFS was 29% (95%CI 15-56%). Best responses by RECIST criteria: complete, partial (1, plus 3 unconfirmed) stable (Uhlman et al. Clin Cancer Res 1:913-920, 1995), and progression (Sirotnak et al. Clin Cancer Res 6:4885-4892, 2000). Response duration: complete response (35+ months) and partial response (2, 3, 3, 37 months). Median PFS and overall survival were 5.3 (95%CI 3-10.1) and 13.6 (95%CI 10.3-NA) months, respectively. Most common toxicities included myelosuppression, rash, and nausea.

CONCLUSIONS

Although generally well tolerated, gefitinib plus PEG-IFNα did not meet the pre-specified 6-month PFS rate >50%. Further evaluation of similar regimens would require appropriate molecular selection of subjects most likely to benefit. Thus, preclinical studies to determine candidate predictive markers for this combination are warranted.

Identification of high risk DISC1 protein structural variants in patients with bipolar spectrum disorder

In a large Scottish pedigree, a balanced translocation t (1;11)(q42.1;q14.3) disrupting the DISC1 and DISC2 genes segregates with major mental illness, including schizophrenia and depression. A frame-shift carboxyl-terminal deletion was reported in DISC1 in an American family with schizophrenia, but subsequently found in two controls. Herein, we test one hypothesis utilizing a large scale case-control mutation analysis: uncommon DISC1 variants are associated with high risk for bipolar spectrum disorder. We have analyzed the regions of likely functional significance in the DISC1 gene in 504 patients with bipolar spectrum disorder and 576 ethnically similar controls. Five patients were heterozygous for ultra-rare protein structural variants not found in the 576 controls (p=0.02, one-sided Fisher's exact test) and shown to be ultra-rare by their absence in a pool of 10,000 control alleles. In our sample, ultra-rare (private) protein structural variants in DISC1 are associated with an estimated attributable risk of about 0.5% in bipolar spectrum disorder. These data are consistent with: (i) the high frequency of depression in the large Scottish family with a translocation disrupting DISC1; (ii) linkage disequilibrium analysis demonstrating haplotypes associated with relatively small increases in risk for bipolar disorder (<3-fold odds ratio). The data illustrate how low/moderate risk haplotypes that might be found by the HapMap project can be followed up by resequencing to identify protein structural variants with high risk, low frequency and of potential clinical utility.

A phase II trial of the Src-kinase inhibitor AZD0530 in patients with advanced castration-resistant prostate cancer: a California Cancer Consortium study

Prostate cancer cells undergo neuroendocrine differentiation during androgen deprivation and secrete neuropeptides, hence activating androgen receptor-regulated genes. Src-family protein kinases are involved in neuropeptide-induced prostate cancer growth and migration. A phase II trial of AZD0530, an oral Src-family kinase inhibitor, in patients with advanced castration resistant prostate cancer was conducted. The primary endpoint was prostate cancer-specific antigen (PSA) response rate, defined as a 30% or greater decrease. A two-stage Simon design was used. Eligibility criteria included documentation of castration resistance (including antiandrogen withdrawal), adequate end-organ function, and performance status, and not more than one prior taxane-based chemotherapy regimen. AZD0530 was given at 175 mg orally once daily continuously. Rapid accrual led to 28 patients registering in the first stage. Median age was 67 years. Sixteen patients had performance status (PS) 0, eight patients had PS 1, and four patients had PS 2. Nine patients (32%) had prior docetaxel-based chemotherapy. Five patients had transient PSA reductions not meeting PSA response criteria. Median progression-free survival time was 8 weeks. Treatment was generally well tolerated. AZD0530, a potent oral Src kinase inhibitor, is feasible and tolerable in this pretreated patient population but possessed little clinical efficacy as monotherapy. Strong preclinical evidence warrants further investigation of AZD0530 in earlier-stage prostate cancer or as combination therapy.

Evidence for X-chromosomal schizophrenia associated with microRNA alterations

Background

Schizophrenia is a severe disabling brain disease affecting about 1% of the population. Individual microRNAs (miRNAs) affect moderate downregulation of gene expression. In addition, components required for miRNA processing and/or function have also been implicated in X-linked mental retardation, neurological and neoplastic diseases, pointing to the wide ranging involvement of miRNAs in disease.

Methods and Findings

To explore the role of miRNAs in schizophrenia, 59 microRNA genes on the X-chromosome were amplified and sequenced in males with (193) and without (191) schizophrenia spectrum disorders to test the hypothesis that ultra-rare mutations in microRNA collectively contribute to the risk of schizophrenia. Here we provide the first association of microRNA gene dysfunction with schizophrenia. Eight ultra-rare variants in the precursor or mature miRNA were identified in eight distinct miRNA genes in 4% of analyzed males with schizophrenia. One ultra-rare variant was identified in a control sample (with a history of depression) (8/193 versus 1/191, p = 0.02 by one-sided Fisher's exact test, odds ratio = 8.2). These variants were not found in an additional 7,197 control X-chromosomes.

Conclusions

Functional analyses of ectopically expressed copies of the variant miRNA precursors demonstrate loss of function, gain of function or altered expression levels. While confirmation is required, this study suggests that microRNA mutations can contribute to schizophrenia.

A phase II trial of gefitinib and pegylated interferon alfa 2b (PEG-IFN) in previously-treated renal cell carcinoma (RCC)

e16115

Background: Modulation of the epidermal growth factor receptor (EGFR) pathway is relevant to IFN activity in RCC. Cell lines sensitive to IFN's antiproliferative effects downregulate EGFR, while IFN treatment of resistant cells precludes such an effect. (Eisenkraft et al, Cancer Res. 1991) Lack of EGFR down-regulation may thus be responsible in part for IFN resistance. To explore this hypothesis, we conducted a trial of the EGFR tyrosine kinase inhibitor gefitinib plus PEG-IFN in RCC patients (pts). Methods: Unresectable or metastatic RCC pts (no limit on prior therapies; performance status 0–2, and adequate end-organ function) were eligible. Prior IFN was allowed. Dose schedule: PEG-IFN SQ weekly (6μg/kg/week or 4 μg/kg/week) × 12 weeks and gefitinib 250 mg po daily until progression. A 6-month progression free survival (PFS) rate of 50% was considered promising (vs. 30%) in a two-stage design incorporating the Green-Dahlberg rule. We accrued 21 patients in the first-stage of accrual. Results: Pt characteristics: Males -16; median age - 56 years; Prior nephrectomy - 12. All had > 1 prior systemic therapy . Accrual slowed with increased use of small molecule kinase inhibitors, bevacizumab, and temsirolimus for RCC. At 6 months, PFS was 26% (95% CI: 9%, 49%); 20% (4 pts) had died. Best responses by RECIST: complete (1), partial (4), stable (8); progression (4). Response duration: CR (35+ months) and PR (3, 5, 5, 38+ months). Median time to treatment failure was 18.4 weeks (95%CI: 7.4, 24.9). Median PFS and overall survival were 23 and 53 weeks, respectively. Most common treatment-related toxicities were leucopenia, thrombocytopenia, rash, nausea, diarrhea, and hyperglycemia. Conclusions: Although gefitinib plus PEG-IFN did not meet the pre-specified 6-month PFS of 50%, it appears to have activity similar to other first-line therapies even in this previously-treated setting. (Supported by Astra Zeneca)

[Table: see text]

The AKT inhibitor perifosine in biochemically recurrent prostate cancer: a phase II California/Pittsburgh cancer consortium trial

BACKGROUND

Perifosine is an oral alkylphospholipid that inhibits cancer cell growth through decreased Akt phosphorylation. We conducted a phase II trial of perifosine in patients with biochemically recurrent, hormone-sensitive prostate cancer.

PATIENTS AND METHODS

Eligible patients had histologically confirmed prostate cancer, previous prostatectomy and/or radiation therapy, and rising prostate-specific antigen (PSA) without radiographic evidence of metastasis. Previous androgen deprivation therapy < 9 months in duration (completed >or= 1 year before registration) was allowed. The primary endpoint was PSA response, defined as a decrease by >or= 50% from the pretreatment value. Treatment was composed of a loading dose of perifosine 900 mg orally on day 1, then 100 mg daily starting 24 hours later.

RESULTS

Of 25 patients, 24 were evaluable for response. After a median follow-up of 8 months, 5 patients (20%) had a reduction in serum PSA levels, but none met criteria for PSA response. Three patients immediately progressed with no response to therapy. Median progression-free survival was 6.64 months (range, 4.53-12.81 months). No change in the PSA doubling time (7 months) was observed before and after treatment initiation. Dose-limiting toxicities (all grade 3) included hyponatremia, arthritis, hyperuricemia, and photophobia.

CONCLUSION

Although well tolerated, perifosine did not meet prespecified PSA criteria for response as a single agent in biochemically recurrent prostate cancer. However, 20% of patients had evidence of PSA reduction, suggesting modest single-agent clinical activity. The role of perifosine in combination with androgen deprivation or chemotherapy is currently under investigation.

Programmed death-1 expression in liver transplant recipients as a prognostic indicator of cytomegalovirus disease

Immunological parameters that distinguish solid-organ transplant (SOT) recipients at risk for life-threatening cytomegalovirus (CMV) disease are being actively pursued to aid posttransplant management. A candidate marker is programmed death (PD)-1 receptor, whose overexpression has been associated with disease progression during persistent viral infections. To determine whether levels of this negative regulator of T cell activity are altered in SOT recipients with symptoms of CMV disease, a comparative PD-1 expression analysis was done in healthy, CMV-positive individuals and in liver transplant recipients. PD-1 levels were measured among the total population of CD8(+) and CD8(+) T cells binding to CMV-specific major histocompatibility complex class I tetramers. Minimal PD-1 expression was found in the healthy, CMV-positive cohort, and symptomatic SOT recipients had significantly higher PD-1 levels. PD-1 up-regulation was significantly associated with incipient and overt CMV disease and with viremia. Our findings suggest that PD-1 could be developed as a prognostic tool to predict CMV disease and guide therapeutic interventions.

Phase II trial of carboplatin and infusional cyclosporine with alpha-interferon in recurrent ovarian cancer: a California Cancer Consortium Trial

The purpose of this study was to estimate the response rate of 26-h continuous infusion cyclosporine A (CSA) combined with carboplatin (CBDCA) and subcutaneous alpha-interferon (IFN), in recurrent ovarian cancer (OC), and to measure their effects on CBDCA pharmacokinetics. OC patients relapsing following platinum-based chemotherapy received CBDCA area under the curve (AUC 3) with CSA and IFN, every 3 weeks. The pharmacokinetics of CSA and CBDCA were determined in a subset of patients. Thirty patients received 84 courses of therapy. Three partial responses were observed. Nine patients were stable for >4 months. Toxicity was similar to that observed in our previously reported phase I study and consisted of myelosuppression, nausea, vomiting, and headache. The mean end of infusion CSA level (high-performance liquid chromatographic assay [HPLC]) was 1109 +/- 291 microg/mL (mean +/- SD). CBDCA pharmacokinetics revealed a measured AUC of 3.61 versus a targeted AUC of 3, suggesting a possible effect of IFN on CBDCA levels versus errors in the estimation of CBDCA clearance using measured creatinine clearance. Steady-state levels of >1 microg/mL CSA (HPLC assay) are achievable in vivo. Insufficient clinical resistance reversal was observed in this study to warrant further investigation of this combination.

Longitudinal Assessment of Cytomegalovirus (CMV)–Specific Immune Responses in Liver Transplant Recipients at High Risk for Late CMV Disease

Cytomegalovirus (CMV)-seronegative recipients (R(-)) of a liver transplant from CMV-positive donors (D(+)) are at high risk for developing late CMV disease after discontinuation of antiviral prophylaxis. Levels of viremia and CMV-specific interferon (IFN)- gamma -producing CD4(+) and IFN- gamma -producing CD8(+) T cell responses were prospectively measured from discontinuation of antiviral prophylaxis until 1 year after transplantation in 17 consecutive D(+)/R(-) patients. CMV loads of >1000 copies/mL were strongly associated with CMV disease in the 6 symptomatic patients. Despite immunosuppression, broadly diverse T cells specific for CMV lysate or peptide libraries spanning pp65 and immediate early (IE) 1 immunodominant CMV antigens developed in all patients. A vigorous CD8(+) T cell response to pp65 and IE1 antigens characterized the D(+)/R(-) cohort. Unexpectedly, none of these responses were predictive of CMV disease or viremia. No significant lymphopenia or functional impairment of CMV-specific T cells was detected in the symptomatic patients, whose morbidity was resolved after antiviral treatment while measurable CMV immunity was maintained during the 1-year observation period.

Functional comparison of T cells recognizing cytomegalovirus pp65 and intermediate-early antigen polypeptides in hematopoietic stem-cell transplant and solid organ transplant recipients

The functional status of cytotoxic T lymphocyte (CTL) populations recognizing cytomegalovirus intermediate-early antigen (IE1) and pp65 polypeptides was investigated in peripheral blood mononuclear cells from hematopoietic stem-cell transplant (HSCT) and solid organ transplant recipients. Combined flow-based CD107a/b degranulation/mobilization and intracellular cytokine (ICC) assays using peptide libraries as antigens indicated that a significantly higher proportion of pp65-specific CTLs were in a more mature functional state, compared with IE1-specific CTLs. Degranulation/multiple cytokine ICC assays also indicated that a significantly higher proportion of pp65-specific than IE1-specific CTLs secreted both interferon- gamma and tumor necrosis factor- alpha and possessed greater cytotoxic potential. These results support our earlier findings of functional differences between CTLs recognizing individual epitopes within the IE1 and pp65 antigens in healthy donors and HSCT recipients and extend them to a broader array of human leukocyte antigen-restricted responses to those antigens. We also provide evidence of a relationship between cytotoxic function and the ability of cytomegalovirus-specific CTLs to secrete multiple cytokines.

Phase II study of lapatinib, a dual inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase 1 and 2 (Her2/Neu) in patients (pts) with advanced biliary tree cancer (BTC) or hepatocellular cancer (HCC). A California Consortium (CCC-P) Trial

4010

Background: Advanced BTC (gallbladder, bile duct) and HCC respond poorly to systemic chemotherapy. Lapatinib is an oral inhibitor of EGFR and Her/2-neu with evidence of activity in a number of tumor types. Both BTC and HCC overexpress EGFR 1 and 2. In addition, Her2/neu somatic mutations have been reported in HCC, and may predict response to EGFR targeted agents (Bekaii-Saab et al, A 4037, ASCO 2005). This trial conducted by the CCC-P and Univ. Chicago, is designed to determine the efficacy of lapatinib in BTC and HCC pts. Methods: A two-stage design is utilized and pts are stratified by tumor type (BTC or HCC); the study has a 90% power to detect a true response rate ≥20%. Two initial groups of 17 patients for BTC and HCC were accrued; one response from each was required to proceed with accrual to a total of 37 patients in each group. Adequate hematologic, renal, and hepatic function is required. Eligible pts are in Child A group and have ECOG PS of 0–2. One prior treatment regimen is allowed. Lapatinib dose is 1,500 mg/d orally without interruption. One cycle is 28 days and radiological assessment is done every 8 weeks. Results: 49 pts have been accrued (BTC 19 and HCC 30). Pt Characteristics: Male 59%, ECOG PS 0 (18 pts), ECOG PS 1 (22 pts). Median age 66 yrs (range19–82). Median cycles 2 (range 1–12). Grade 3/4 toxicity was noted in 19 pts and included fatigue in 4 pts, elevation of liver enzymes in 4 pts and diarrhea in 2 pts. Nausea, vomiting, rash, anemia and thrombocytopenia were noted in 1 pt each. There was no evidence of cardiac dysfunction. In 17 evaulable pts with BTC, no responses were observed, 5 had stable disease (SD). Among the first 17 pts with HCC, 2 confirmed partial responses have been recorded. In addition 8 pts have SD. The progression free survival is 1.8 mo for both BTC and HCC. Tumor and blood specimens are being analyzed for expression of EGFR, HER-2/neu, status of downstream signal pathway molecules, and correlation to response. Conclusions: Lapatinib is well-tolerated. No activity in BTC was noted and that cohort is closed. Lapatinib activity in HCC is encouraging, and study is close to completion. Source of support: NCI-NO1-CM-57018–16.

[Table: see text]

In vitro expansion of polyclonal T-cell subsets for adoptive immunotherapy by recombinant modified vaccinia Ankara

OBJECTIVE

Adoptive cellular therapy of cytomegalovirus (CMV)-specific T cells in allogeneic hematopoietic stem cell transplantation (HSCT) patients is a promising approach for controlling CMV viremia and its morbidity. We sought to develop a clinically suitable strategy to dually expand infusible CD8(+) and CD4(+) T-cell subsets specific for CMV.

METHODS

Polyclonal CMV T-cell lines were generated using peripheral blood mononuclear cell (PBMCs) treated with synthetic single-stranded CpG motif-containing oligodeoxynucleotides (ODNs) and infected with recombinant (r) modified vaccinia Ankara (MVA) expressing CMV antigens. Cultures derived from 12 healthy CMV-positive donors were analyzed using chromium release and lymphoproliferation assays, intracellular staining for interferon-gamma (IFN-gamma), and HLA tetramers.

RESULTS

A 3-day incubation with a combination of ODN 2006 and 2216 was found to reproducibly generate a highly rMVA infectable population of PBMCs with concomitant high expression of CMV antigens. CpG ODN-treated autologous PBMCs infected with rMVA elicited a 30-fold average expansion of both CMV-specific CD4(+) and CD8(+) T cells in 10 days. The enriched T-cell populations showed minimal alloreactivity, high levels of CMV-specific HLA class I tetramer binding, cytotoxic activity, and IFN-gamma production from both CD8(+) and CD4(+) T cells.

CONCLUSIONS

The ability to quickly produce autologous professional antigen-presenting cells, capable of stimulating clinically useful amounts of CMV-specific CD4(+) and CD8(+) T-cell lines, enhances the attractiveness of using rMVA for immunotherapeutic interventions to manage HSCT-related CMV disease.

A randomized phase II trial of the matrix metalloproteinase inhibitor BMS-275291 in hormone-refractory prostate cancer patients with bone metastases

BACKGROUND

BMS-275291 is a selective matrix metalloproteinase inhibitor (MMPI) that does not inhibit sheddases implicated in the dose-limiting arthritis of older MMPIs. We conducted a randomized phase II trial of two doses of BMS-275291 (1,200 versus 2,400 mg) in hormone-refractory prostate cancer (HRPC) patients with bone metastases to probe for a dose-response relationship and to assess differential toxicities. Serial serum and urine specimens were collected to assess for markers of bone metabolism.

METHODS

The primary end point was 4-month progression-free survival (PFS). Eligibility criteria included documentation of androgen-independent disease (including anti-androgen withdrawal), skeletal metastasis, adequate end-organ function and performance status, and no more than one prior chemotherapy regimen. Patients were randomized to 1,200 mg orally once daily (arm A) or 1,200 mg orally twice daily (arm B). Response was assessed every 56 days.

RESULTS

Eighty patients were enrolled: 39 in arm A and 41 in arm B. There were no responders by prostate-specific antigen or measurable disease to treatment. Stable disease was noted at 8 weeks in 39% of patients in arm A and in 17% of patients in arm B. Progression of disease at 8 weeks was seen in 61% of patients in arm A versus 83% of patients in arm B. Median survival time was 21.6 months (95% confidence interval, 17.5; not reached), whereas median PFS time was 1.8 months (95% confidence interval 1.74; 2) for all patients. Patients in arm A had a median survival time that was not reached, whereas patients on arm B has a median survival time of 21 months (P = 0.2). PFS at 4 months favored arm A: 22% versus 10% (log-rank, P = 0.008). Grade 3 toxicities occurred in 5 (13%) patients in arm A and in 9 (22%) patients in arm B. Grade 4 toxicities were uncommon (only 4% of patients): one each of thrombosis, fatigue, and motor neuropathy was seen in the arm B. Bone marker studies showed that baseline serum levels of N-telopeptide, osteocalcin, procollagen I NH2-terminal propeptide, and PICP had prognostic significance for PFS and/or overall survival.

CONCLUSIONS

Regardless of dose schedule, BMS-275291 was well tolerated in HRPC patients and had no dose-limiting arthritis. Toxicities differed modestly according to the dose schedule employed. As overall survival and PFS favored the once daily schedule, this dose schedule is recommended for future studies. Baseline markers of bone metabolism may have prognostic value in HRPC patients with bone metastases.

Bortezomib plus docetaxel in advanced non-small cell lung cancer and other solid tumors: a phase I California Cancer Consortium trial

BACKGROUND

This phase I study was performed to determine the dose-limiting toxicity and maximum tolerated dose (MTD) of docetaxel in combination with bortezomib in patients with advanced non-small cell lung cancer (NSCLC) or other solid tumors.

METHODS

Patients were enrolled in cohorts of three over six dose levels. Each treatment cycle was 3 weeks long and consisted of one docetaxel infusion (day 1) and four bortezomib injections (days 1, 4, 8, and 11). Dose escalation and MTD determination were based on the occurrence of dose-limiting toxicities in cycle 1 only.

RESULTS

A total of 36 patients were enrolled, 26 of whom had NSCLC. All patients received at least one dose of study drug at one of five dose levels. The MTD of the combined regimen was determined to be 1.0/75 mg/m bortezomib/docetaxel. The combination was generally well tolerated. Toxicities were manageable, and no additive toxicities were observed. The most common adverse events were fatigue (67% of patients), nausea (50%), diarrhea (39%), and neutropenia (39%). Two patients with NSCLC achieved a partial response, and seven (19%) patients achieved stable disease (including six patients with NSCLC).

CONCLUSION

The combination of bortezomib and docetaxel was feasible and well tolerated in patients with advanced NSCLC or other solid tumors. The recommended phase II dose is bortezomib 1.0 mg/m on days 1, 4, 8, and 11 plus docetaxel 75 mg/m on day 1, cycled every 21 days. Therapeutic doses of docetaxel and bortezomib are achievable for this combination.

Cytomegalovirus immune reconstitution occurs in recipients of allogeneic hematopoietic cell transplants irrespective of detectable cytomegalovirus infection

The question of when immune reconstitution of cytomegalovirus (CMV)-specific CD8 T cells occurs after hematopoietic cell transplantation and, more specifically, to which CMV targets this immunity is likely to be directed remains poorly understood. The dependence of immune reconstitution on CMV reactivation is even less clear. To better understand these events, 44 CMV-seropositive HLA-A*0201 subjects were followed up at approximately days 40, 90, 120, 150, 180, and 360 after hematopoietic cell transplantation for CMV immunity as measured by 2 types of assays: (1) an HLA-A*0201 tetramer-binding assay for both CMV pp65 (pp65) and immediate-early 1 (IE-1) or (2) intracellular cytokine interferon gamma responses induced by pp65 or IE-1-derived peptides. To verify the reliability of IE-1-specific assays relative to the pp65-based assays, a pilot study first compared the development of IE-1-specific immunity in a subgroup by using multiple HLA-A*0201-restricted peptides, and then these recipients were followed up for 1 year for immunologic function and for CMV infection. The IE-1-specific response occurred to each of the 3 HLA-A*0201-restricted peptides studied (IE-1-256, -297, and -316), and there was no predominant IE peptide response. However, the immunodominant HLA-A*0201-restricted pp65 peptide was recognized significantly more frequently than these IE-1 peptides. When this was compared with the occurrence of CMV infection, the overall immune reactivity, as measured by the mean or median number of CD8+ T cells reactive to either pp65 or IE-1 peptides by intracellular cytokine or tetramer binding assay, was not significantly different in those with and without CMV infection. For patients who demonstrated reconstituted immunity to CMV at 1 year, all were reconstituted by 6 months, and the timing of the first observed immune reactivity to either of the pp65 or the IE peptides was not different in those with and without detectable CMV infection.

Novel conjugates of epitope fusion peptides with CpG-ODN display enhanced immunogenicity and HIV recognition

Vaccination strategies remain elusive that are effective against viral disease pathogens yet remain gentle enough for widespread human use. We developed a model system that relies on the recognition of specific T-cell epitopes from immunodominant antigens of HIV to explore single-stranded CpG-oligodeoxynucleotides (ODN) (CpG) as an adjuvant. We improved upon current strategies of utilizing CpG in combination with peptide vaccines by covalently modifying epitope fusion peptides with CpG motifs. Characterization of the immune recognition of DNA-peptide conjugates was carried out in a murine model of human HLA A2. Immunogenicity of DNA-peptide conjugates was superior in sensitivity to non-covalently linked mixtures of the same functional molecules as measured by peptide-mediated cytotoxicity and IFN-gamma release, as well as protection against viral infection. Enhancement of sensitivity of immune recognition by covalent attachment of DNA to epitope peptides should be further evaluated as a novel prophylactic vaccine strategy for HIV infection and other infectious diseases.

Improved Hepatic Toxicity Profile of Portal Vein Adjuvant Hepatic Infusional Chemotherapy

Purpose

To determine whether floxuridine (FUDR) can be delivered with low hepatic toxicity through the portal vein (PV) as an adjuvant to surgically treated colorectal metastases.

Patients and Methods

Fifty-one patients undergoing complete resection and/or ablation for colorectal hepatic metastases were prospectively enrolled at a National Cancer Institute–designated comprehensive cancer center. Two sequential phase II trials were performed. Each trial included complete surgical treatment followed by sequential, alternating (22 patients) or concurrent (29 patients) regional PV FUDR and systemic fluorouracil (FU) with leucovorin chemotherapy.

Results

Fifty percent of patients were male. The mean age at diagnosis was 57 years. The mean number of lesions resected was three (range, one to 11 lesions). The stage at diagnosis was II, III, and IV in 16.9%, 52.8%, and 28.3% of patients, respectively. One- and 3-year overall survival rates were 92.7% and 41.8%, respectively. The 1- and 3-year disease-free survival rates were 64.5% and 19%, respectively. The site of first recurrence was hepatic in 35.9% of patients. Treatment was terminated early in 24 patients (17 patients progressed, two refused treatment, and five had nonhepatic toxicities). Fifty-five percent of patients received 75% to 100% of the planned FUDR courses, and 72% received greater than 50% of the planned FUDR dose. Only four patients required dose reductions of FUDR because of grade 3 hepatic toxicity. No patient required biliary stenting or had discontinuation of PV infusion because of hepatic toxicity.

Conclusion

The delivery of PV FUDR and FU with leucovorin can be performed with a high percentage of expected drug delivery and a low drug-induced hepatic toxicity rate, while achieving acceptable overall and disease-free survival.

The Cyclin-Dependent Kinase Inhibitor UCN-01 Plus Cisplatin in Advanced Solid Tumors: A California Cancer Consortium Phase I Pharmacokinetic and Molecular Correlative Trial

BACKGROUND

UCN-01 (7-hydroxy-staurosporine) is a novel antineoplastic agent targeting cyclin-dependent kinases, which shows potent in vitro and in vivo activity against a broad range of tumor types. Our group has previously shown that UCN-01 potentiates the apoptotic response of agents such as cisplatin in vitro by preventing sequence-specific abrogation of G2 arrest caused by DNA-damaging chemotherapies.

PATIENTS AND METHODS

This National Cancer Institute-sponsored phase I trial was designed to determine the safety, maximum tolerated dose, and pharmacokinetics of escalating doses of cisplatin in combination with UCN-01 in patients with advanced malignant solid tumors, as well as to do molecular correlative studies on tumor specimens. Cisplatin was infused over 1 hour before UCN-01 (45 mg/m2/d) given as a 72-hour continuous infusion. Escalation of cisplatin was planned through five dose levels at 20, 30, 45, 60, and 75 mg/m2.

RESULTS

Ten patients were accrued. Accrual was halted at dose level 2 (cisplatin, 30 mg/m2) due to dose-limiting toxicities consisting of grade 5 sepsis with respiratory failure associated with grade 3 creatinine (one patient) and grade 3 atrial fibrillation (one patient). Plasma and salivary pharmacokinetics of UCN-01 were unaffected by cisplatin. Pretreatment and posttreatment tumor biopsies showed that UCN-01 was active against a key molecular target, the checkpoint kinase Chk1.

CONCLUSIONS

This phase I trial failed to achieve targeted therapeutic dose levels of cisplatin when combined with prolonged infusion UCN-01. However, because preclinical data indicate that UCN-01 potentiates response to platinum, further studies with alternative dose schedules of the combination, or with other platinum analogues, are warranted.

Predominant type 1 CMV-specific memory T-helper response in humans: evidence for gender differences in cytokine secretion

Cell-mediated memory immune responses to viral antigens are important for protection against viruses causing persistent or acute infections. This study compared the cytokine profile of memory T-helper cells specific for cytomegalovirus (CMV) in healthy CMV-seropositive men and women. The cytokine response reflected T(H)1 bias, with dominant secretion of interferon (IFN)-gamma along with moderate levels of tumor necrosis factor-alpha, interleukin (IL)-10, and IL-2. Analyzed by gender, women had higher and significant spontaneous release of IFN-gamma and CMV-specific IL-2 secretion. Similar analysis with herpes simplex virus-1 showed a trend toward higher cytokine responsiveness in women, but the differences were not statistically significant. In contrast, men had statistically significant higher influenza virus-specific tumor necrosis factor-alpha secretion. IL-4 and IL-5, both T(H)2 cytokines, were low for all three viruses. The results show a predominant T(H)1 antiviral cytokine T-help memory response with significant differences linked to gender. Such differences may have an impact in the design of immunization strategies against CMV.

Simultaneous reconstitution of multiple cytomegalovirus-specific CD8+ cell populations with divergent functionality in hematopoietic stem-cell transplant recipients

A panel of 7 human cytomegalovirus (CMV) epitope peptides and corresponding major histocompatibility class 1 tetramers was used to evaluate cellular immunity in healthy seropositive donors and in hematopoietic stem-cell transplant recipients. Broad CMV-specific T cell responses to epitopes were found within several CMV polypeptides and were restricted by multiple human leukocyte antigen alleles. Their cytotoxic functionality was evaluated by use of an assay that measures transient surface levels of lysosomal membrane proteins LAMP-1 (CD107a) and LAMP-2 (CD107b) after peptide stimulation. This assay can be combined with tetramer staining of antigen-specific CD8(+) T lymphocytes and has potential as a surrogate marker for cytotoxic function. CD8(+) T lymphocytes specific for epitopes within the pp65 or pp50 gene products exhibited significantly higher functionality, compared with populations recognizing CMV major immediate early-1 epitopes. These functional differences between T lymphocyte populations within the same individual may have implications for protection against CMV.

Gemcitabine in patients with non-small-cell lung cancer previously treated with platinum-based chemotherapy: a phase II California cancer consortium trial

A phase II trial was designed to evaluate the efficacy and toxicity of gemcitabine in patients with non-small-cell lung cancer (NSCLC) previously treated with platinum-containing regimens and prospectively categorized for platinum response status. Treatment consisted of gemcitabine 1000 mg/m2 given intravenously on days 1 and 8 of a 21-day cycle. The status of p53 in pretreatment tumor tissue was assessed by immunohistochemistry (IHC). Sixty-one patients who progressed or recurred following platinum-based therapy were enrolled, 26 platinum-sensitive and 35 platinum-refractory. A median of 4 treatment courses (range, 2-7 courses) was delivered. Of the 55 patients assessable for response, there was 1 confirmed complete response and 3 with a confirmed partial response for an overall response proportion of 7%. Twenty-one patients had stable disease while 28 progressed and 2 patients had an unconfirmed partial response. Three of the responders (2 confirmed, 1 unconfirmed) were platinum-refractory. Median progression-free survival (PFS) and overall survival for all patients were 4.1 months and 8.6 months, respectively. Median PFS and overall survival for the platinum-sensitive and platinum-refractory cohorts were 5.4 months versus 3.1 months, and 11.9 months versus 7.1 months, respectively. Toxicity was principally hematologic with grade 3/4 neutropenia in 21% and grade 4 platelets in 8%. There were no treatment-related deaths. Twenty-four of 33 patients (73%) had p53-positive tumors. Although no significant association between platinum sensitivity and p53 status was seen, patients with platinum-sensitive disease and negative p53 by IHC had a trend toward longer survival compared to those with platinum-refractory disease and/or p53 positivity (P = 0.06). We concluded that salvage gemcitabine in this dose and schedule is safe and tolerable in previously platinum-treated patients with NSCLC.

Neurophysiological study of peripheral neuropathy after high-dose Paclitaxel: lack of neuroprotective effect of amifostine

PURPOSE

To determine if there is a beneficial effect of amifostine in preventing or reducing the neuropathy induced by high-dose paclitaxel.

METHODS

Breast cancer patients receiving high-dose infusional paclitaxel (725 mg/m(2)/24 h) in combination with doxorubicin (165 mg/m(2)/96 h) and cyclophosphamide (100 mg/kg/2 h; ACT) were studied on two autologous peripheral blood stem cell transplant protocols, one with and one without amifostine (740 mg/m(2) administered over 10 min before and 12 h after initiation of the paclitaxel infusion). Patients were evaluated before ACT and 20-40 days later with neurological examination, a composite peripheral neuropathy score, peroneal and sural nerve conduction studies, and quantitative sensory testing.

RESULTS

There was no significant difference in paclitaxel maximum concentration, systemic clearance, or area under the curve determinations. Narcotic requirement as well as recovery of hematopoietic counts were also similar in subjects with or without amifostine. After ACT was administered, there was a decrease in peroneal nerve compound muscle action potential amplitude and sural nerve sensory action potential amplitude, as well as an increase in vibratory and cold detection thresholds. Clinical composite peripheral neuropathy scores were similar despite amifostine treatment; and logarithm to the base 2 ratios post/pre ACT showed no significant effect of amifostine on peroneal nerve compound muscle action potential, sural nerve sensory action potential, vibratory detection thresholds, or cold detection thresholds. All subjects had acroparesthesias and lost their ankle deep-tendon reflexes after administration of ACT.

CONCLUSIONS

Single high-dose paclitaxel produces predictable clinical and neurophysiological changes so that patients receiving high-dose therapy are ideal subjects to test the effectiveness of neuroprotective agents. Amifostine was ineffective in preventing or reducing the neurotoxicity of high-dose paclitaxel.

Two distinct pathways of immuno-modulation improve potency of p53 immunization in rejecting established tumors

The p53 gene product is overexpressed by almost 50% of cancers, making it an ideal target for cancer immunotherapy. We previously demonstrated rejection of established p53-overexpressing tumors without stimulating autoimmunity by immunization with modified vaccinia Ankara-expressing murine p53 (MVAp53). Tumor rejection was enhanced through antibody-mediated CTL-associated antigen 4 (CTLA-4) blockade. We examined the role of synthetic oligodeoxynucleotides (ODN) containing unmethylated cytosine-phosphate-guanine (CpG) motifs (CpG ODN) in enhancing MVAp53-mediated tumor rejection. CpG ODN with MVAp53 resulted in tumor rejection in BALB/c mice bearing poorly immunogenic 11A-1 murine mammary carcinomas or Meth A sarcomas and C57Bl/6 mice bearing MC-38 colon carcinomas. The effect was similar to that seen in tumor-bearing mice treated with MVAp53 along with CTLA-4 blockade. Monoclonal antibody depletion experiments demonstrated that the adjuvant effects of CpG ODN and CTLA-4 blockades were CD8 dependent. CpG ODN were partially natural killer cell dependent and ineffective in Toll-like Receptor 9(-/-) and interleukin 6(-/-) mice, whereas CTLA-4 blockade was partially CD4 dependent and functional in Toll-like Receptor 9(-/-) and interleukin 6(-/-) mice. In addition, when administered with MVAp53, both adjuvants enhanced p53-specific cytotoxicity and demonstrated an additive effect when combined. The combination of CpG ODN and CTLA-4 blockade worked synergistically to reject palpable 11A-1 and MC-38 tumors. These experiments demonstrate the potential for augmenting MVAp53-mediated antitumor immunity using CpG ODN and CTLA-4 blockade. This cell-free immunotherapy approach is a candidate for evaluation in cancer patients.

A study of radiotherapy modalities combined with continuous 5-FU infusion for locally advanced gastrointestinal malignancies

AIM

We describe the feasibility of combining infusional 5-fluorouracil (5-FU) with intraoperative radiation therapy (IORT).

METHODS

Patients with surgically resectable locally advanced gastrointestinal cancers were treated concurrently during surgery with IORT and a 72 h infusion of 5-FU. Patients without previous external beam radiation therapy (EBRT) were subsequently treated with EBRT (40-50Gy) concurrent with a 21-day continuous infusion of 5-FU. Pancreatic, gastric, duodenal, ampullary, recurrent colorectal, and recurrent anal cancer were included.

RESULTS

During IORT/5-FU, no chemotherapy-related grade III or IV hematologic or gastrointestinal toxicity was noted. Post-surgical recovery or wound healing was not affected. One of nine patients who received post-operative radiation required a treatment break. During follow-up, there were more complications in patients with pelvic tumours, especially those with previous radiation. Nine patients have had local and/or local regional recurrences, two of these in the IORT field.

CONCLUSIONS

Treatment with a combination of IORT and 5-FU followed by EBRT and 5-FU is feasible. However, long-term complications may be increased in previously irradiated recurrent pelvic tumours.

Trastuzumab plus docetaxel in HER2/neu-positive non-small-cell lung cancer: a California Cancer Consortium screening and phase II trial

HER2 is reported to be overexpressed in 20% of cases of non-small-cell lung cancer (NSCLC), principally adenocarcinoma. Trastuzumab is a monoclonal antibody against HER2 that, when combined with a taxane, improves survival compared with chemotherapy alone in advanced breast cancer. In view of these observations, we conducted a phase II HER2 screening and efficacy trial of trastuzumab plus weekly docetaxel in cases of advanced NSCLC in which primary platinum-based therapy had failed. Patients with advanced or metastatic NSCLC were screened for HER2 overexpression by immunohistochemistry. Patients with HER2-positive tumors (2+ or 3+) were initially randomized to either single-agent trastuzumab or docetaxel. After completing 2 treatment cycles, all patients went on to receive the trastuzumab/docetaxel combination regardless of response to the single agents. Treatment consisted of docetaxel 30 mg/m2 weekly for 6 weeks followed by a 2-week break and trastuzumab 4 mg/kg intravenously on week 1 followed by 2 mg/kg per week thereafter. Cycle length was 8 weeks. Sixty-nine patients with NSCLC (33 men, 36 women) were screened between August 1999 and March 2001. Only 13 patients (19%) had HER2-positive disease; all 13 enrolled in the efficacy trial. Of 9 patients receiving docetaxel alone, 1 partial response (PR) was seen. None responded to trastuzumab alone. The overall outcomes to the sequence of single-agent therapy followed by combination therapy included a PR rate in 8% of cases, stable disease in 23%, progression in 46%, and nonassessable disease in 23%. Estimated event-free and overall survival times were 4.3 and 5.7 months, respectively. Treatment was well tolerated. The screening component of this trial demonstrated that the target population for trastuzumab therapy in NSCLC is relatively small. Because of the limited clinical activity of trastuzumab-based therapy in this cohort and the similar disappointing reports from other studies of trastuzumab in NSCLC, this trial was closed to further accrual. In view of the limited target population for HER2 inhibition, future efforts and resources should be directed toward molecular targets other than HER2 in NSCLC.

Phase II trial of carboplatin and infusional cyclosporine in platinum-resistant recurrent ovarian cancer

PURPOSE

To determine the response rate to 26-h continuous infusion cyclosporine A (CSA) combined with a fixed dose level of carboplatin (CBDCA) in patients with recurrent ovarian cancer, and to determine the effect of CSA on the pharmacokinetics of CBDCA.

EXPERIMENTAL DESIGN

To examine the effect of duration of CSA exposure on reversal of CBDCA resistance, clonogenic assays were performed in vitro in platinum-resistant A2780 cells. CBDCA (AUC 4) with CSA repeated every 3 weeks was then administered to patients on this phase II study. Pharmacokinetics of CSA and CBDCA were determined in a subset of patients.

RESULTS

Preincubation of platinum-resistant A2780 cells with CSA reversed CBDCA resistance in a concentration-dependent and time-dependent manner. A group of 23 patients received 58 courses of CBDCA/CSA therapy. One partial response was observed. Eight patients achieved disease stabilization. Toxicity was similar to that observed in our previous phase I study and consisted of myelosuppression, nausea, vomiting, and headache. The mean +/- SD end-of-infusion CSA level (HPLC assay) was 1253 +/- 400 microg/ml. The pharmacokinetic studies suggest that CSA does not increase CBDCA AUC.

CONCLUSIONS

Steady-state levels of >1 microg/ml CSA (HPLC assay) are achievable in vivo. Modest partial reversal of platinum resistance (in one patient with an objective response and in eight patients with stable disease noted) is achievable in vivo in patients pretreated with CSA. This phenomenon is not explained by alterations in CBDCA pharmacokinetics.

Trastuzumab plus docetaxel in HER-2/neu-positive prostate carcinoma: final results from the California Cancer Consortium Screening and Phase II Trial

BACKGROUND

Overexpression of the HER-2/neu oncoprotein has been reported to occur in </= 60% of patients with prostate carcinoma and to correlate with shortened survival. Trastuzumab is a humanized monoclonal antibody to the HER-2 receptor and has activity against HER-2-positive breast carcinoma, more so when combined with a taxane. The authors screened for HER-2 overexpression in patients developing hormone-refractory prostate carcinoma (HRPC) and conducted a Phase II trial of trastuzumab plus docetaxel in HER-2-positive patients.

METHODS

Paraffin-embedded tumor specimens from potentially eligible patients were screened for HER-2 expression by immunohistochemistry (IHC) and/or amplification by fluorescent in situ hybridization (FISH). Shed HER-2 was also assessed by enzyme-linked immunoradsorbent assay (ELISA). Patients with HER-2-positive tumor specimens (IHC 2+ or 3+ or FISH ratio > 2) were initially randomized to receive either single-agent trastuzumab or docetaxel. After two treatment cycles, nonresponding patients received the trastuzumab/docetaxel combination. Treatment was comprised of 30 mg/m(2) of docetaxel weekly for 6 weeks followed by a 2-week break and 4 mg/kg of trastuzumab intravenously during Week 1 then 2 mg/kg per week thereafter. The cycle length was 8 weeks.

RESULTS

One hundred patients with HPRC were screened. IHC results were as follows: 3+ (n = 1), 2+ (n = 6), 1+ (n = 26), 0 (n = 39), and insufficient tissue specimen/not tested (n = 28). Only 3 of 37 patients had elevated shed HER-2 by ELISA (> 15 mg/mL). None overexpressed HER-2 by IHC. FISH amplification was found in 0 of 34 tissue samples. Of seven patients with IHC 3+ or 2+, four were tested by ELISA and two by FISH. None were abnormal. Age and Gleason score did not correlate with IHC status. Of the seven patients eligible for the Phase II study, only four agreed to participate. The trial was thus closed for nonfeasibility (the overall HER-2 positivity rate was < 20%). No patient responded to trastuzumab alone. The median survival was not reached and the median progression-free survival was 7 months.

CONCLUSIONS

HER-2 overexpression by IHC in archival prostate carcinoma specimens was infrequent. There was no apparent correlation among IHC, ELISA, and FISH, although the sample size was limited. Conclusions regarding the predictive value of HER-2 status on outcome after trastuzumab-based therapy were not reached and were only drawn after larger-scale screening efforts. The authors estimated that 1000 patients need to be screened to complete accrual to a 40-patient efficacy trial.

Recombinant modified vaccinia virus Ankara expressing a soluble form of glycoprotein B causes durable immunity and neutralizing antibodies against multiple strains of human cytomegalovirus

Human cytomegalovirus (CMV) is a viral pathogen that infects both genders, who remain asymptomatic unless they receive immunosuppressive drugs or acquire infections that cause reactivation of latent virus. CMV infection also causes serious birth defects following primary maternal infection during gestation. A safe and effective vaccine to limit disease in this population continues to be elusive. A well-studied antigen is glycoprotein B (gB), which is the principal target of neutralizing antibodies (NAb) towards CMV in humans and has been implicated as the viral partner in the receptor-mediated infection by CMV in a variety of cell types. Antibody-mediated virus neutralization has been proposed as a mechanism by which host immunity could modify primary infection. Towards this goal, an attenuated poxvirus, modified vaccinia virus Ankara (MVA), has been constructed to express soluble CMV gB (gB680-MVA) to induce CMV NAb. Very high levels of gB-specific CMV NAb were produced after two doses of the viral vaccine. NAb were durable within a twofold range for up to 6 months. Neutralization titers developed in immunized mice are equivalent to titers found clinically after natural infection. This viral vaccine, expressing gB derived from CMV strain AD169, induced antibodies that neutralized CMV strains of three different genotypes. Remarkably, preexisting MVA and vaccinia virus (poxvirus) immunity did not interfere with subsequent immunizations of gB680-MVA. The safety characteristics of MVA, combined with the robust immune response to CMV gB, suggest that this approach could be rapidly translated into the clinic.