Intravenous administration of CP-4055 (ELACYT) in patients with solid tumours. A Phase I study

PURPOSE

Cytarabine (ara-C) has limited activity in solid tumours. CP-4055 (ELACYT) is a novel ara-C-5'-elaidic acid ester that may circumvent this limitation. CP-4055 maximum tolerated dose (MTD), pharmacokinetics and antitumor activity have been investigated in patients with solid tumours.

MATERIAL AND METHODS

Thirty-four patients (19 malignant melanoma, 8 ovarian cancers and 7 NSCLC) received CP-4055 as a 30 min, or 2 hr intravenous (IV) infusion daily for 5 consecutive days every 3 or 4 weeks (D1-5 q3w or D1-5 q4w) in a dose escalation designed study with doses ranging from 30 to 240 mg/m(2)/day.

RESULTS

The most frequent CTC grade 1-2 adverse events (AEs) were nausea, fatigue, vomiting, anorexia and pyrexia. Most of the grade 3-4 AEs were neutropenia. The MTD was 200 mg/m(2)/day and 240 mg/m(2)/day for D1-5 q3w and D1-5 q4w, respectively. The MTD was independent of infusion time in the 4 week schedule. CP-4055 was maintained in plasma for up to 5-10 hr at dose levels >150 mg/m(2)/day. One objective partial response (PR) with time to progression (TTP) of 22 months was reported in an advanced malignant melanoma patient.

CONCLUSION

CP-4055 was well tolerated; the majority of the AEs were of CTC grade 1. The 3 week schedule was not recommended due to neutropenic nadir between days 18-26. The recommended dose was 200 mg/m(2)/day in a D1-5 q4w schedule. Efficacy data suggest that CP-4055 might be active in treatment of solid tumours.

Autoimmune antibodies and recurrence-free interval in melanoma patients treated with adjuvant interferon

BACKGROUND

Appearance of autoantibodies and clinical manifestations of autoimmunity in melanoma patients treated with adjuvant interferon (IFN)-alpha2b was reported to be associated with improved prognosis. We assessed the association of the appearance of autoantibodies after initiation of treatment with recurrence-free interval in two randomized trials that compared intermediate doses of IFN with observation for the treatment of melanoma patients.

METHODS

Serum levels of anticardiolipin, antithyroglobulin, and antinuclear antibodies were determined using enzyme-linked immunosorbent assays in 187 and 356 patients in the European Organization for Research and Treatment of Cancer (EORTC) 18952 and Nordic IFN trials, respectively, immediately before and up to 3 years after random assignment. The association of the presence of at least one of the three autoantibodies with risk of recurrence was assessed by three Cox models in patients negative for all three autoantibodies at baseline (125 from the EORTC 18952 trial and 230 from the Nordic IFN trial): 1) a model that considered appearance of autoantibodies as a time-independent variable, 2) one that considered a patient autoantibody positive once a positive test for an autoantibody was obtained, and 3) a model in which the status of the patient was defined by the most recent autoantibody test. All statistical tests were two-sided.

RESULTS

When treated as a time-independent variable (model 1), appearance of autoantibodies was associated with improved relapse-free interval in both trials (EORTC 18952, hazard ratio [HR] = 0.41, 95% confidence interval [CI] = 0.25 to 0.68, P < .001; and Nordic IFN, HR = 0.51, 95% CI = 0.34 to 0.76, P < .001). However, on correction for guarantee-time bias, the association was weaker and not statistically significant (model 2: EORTC 18952, HR = 0.81, 95% CI = 0.46 to 1.40, P = .44; and Nordic IFN, HR = 0.85, 95% CI = 0.55 to 1.30, P = .45; model 3: EORTC 18952, HR = 1.05, 95% CI = 0.59 to 1.87, P = .88; and Nordic IFN, HR = 0.78, 95% CI = 0.49 to 1.24, P = .30).

CONCLUSIONS

In two randomized trials of IFN for the treatment of melanoma patients, appearance of autoantibodies was not strongly associated with improved relapse-free interval when correction was made for guarantee-time bias.

Extended TME- and MRI-assisted pathology show high incidence of pt4 after neoadjuvant treatment

e15033

Background: The clinical ability of pre- and post neoadjuvant MRI to predict the necessary extension of TME (ETME) in evaluation of the areas at risk in locally advanced rectal cancer (LARC). Evaluation of treatment response to chemo/ radiation in T4 tumours is difficult. MRI cannot discriminate between different tissue components within a voxel. Increasing rate of late local relapses are reported from different studies. Methods: Prospective registration of 92 MRI evaluated T4a cancers undergoing multimodal treatment for rectal cancer between 2002 and 2007 in a tertiary referral cancer centre. MRI was found to predict T- downstaging in 10% after neoadjuvant treatment. In 35% both MRI and histopathological examination staged the patients as T4 after treatment. 55% (n=51) of the patients were downstaged after the routine postoperative pathology work-up. A new technique with MRI- based sampling of areas of infiltration was introduced and dedicated histopathological evaluation of these threatened areas was performed. Results: ETME was performed in 95% of the patients, mostly as en-bloc resections. After MRI focused pathology 50% were reclassified and up scaled to have pT4. Accordingly, at least 2/3 of the MRI staged T4 tumours before treatment still were pT4 after multimodal treatment. Conclusions: The tumours were downsized, but to lesser amount downstaged. If cure is the goal of the treatment, extended TME as en-bloc resections has to be performed. It is necessary to remove tumour as shown in pre-treatment MRI, as well as tumour, fibrosis and mucus as shown in MRI after post neoadjuvant treatment. MRI assisted pathology is an important option for right T-stage classification and for planning the extent of surgical resection.

No significant financial relationships to disclose.

First-in-human study of a novel nucleoside analogue, CP-4126, in patients with advanced solid tumors

2577

Background: CP-4126 (gemcitabine 5'-elaidic acid ester) is a novel nucleoside analogue with proven preclinical antitumor activity. Unlike gemcitabine, the intracellular uptake of CP-4126 is independent of nucleoside transporters. The aims of this study were to determine the safety, toxicity, MTD and the RD of CP-4126, to describe its pharmacokinetic (PK) characteristics, and to assess its preliminary antitumor activity. Methods: Patients (pts) with refractory solid tumors, performance status ECOG < 2, with adequate haematologic, renal and hepatic function were enrolled in this dose escalation study (1–6 pts per dose level (DL)). CP-4126 was administered on days (d) 1, 8 and 15 every 4 week by a 30 min IV infusion. Start dose was 30 mg/m2/d and the dose was increased by 100% until toxicity > CTCAE grade 2 occurred. Standard DLT definitions were used. Activity was assessed at the end of every 2nd cycle (cy). Plasma and urine PK were determined during d1 (24 hrs) of cy1; plasma at all DLs and urine at DL= 1400 mg/m2/d. Results: 39 pts have been included, (m =24; f =15 ), median age 60 (range 19–78), receiving 96 cycles (range 1–9) of treatment, with 1 pt/DL from 30 to 240 mg/m2/d. The first grade 2 AE (neutropenia) was reported at 480 mg/m2/d. Most frequent toxicities include nausea, vomiting, fatigue and anorexia, the majority of mild severity (grade 1–2). 5 DLTs have been reported; 800 mg/m2/d (1 pt - d8 dose delay >2 weeks due to grade 3 thrombocytopenia and anaemia); 1000 mg/m2/d (1 pt died 48 hrs after treatment start due to acute lung damage); 1400 mg/m2/d (1 pt - fatigue grade 3); 2 pts at 1600 mg/m2/d (grade 3 ALT/AST elevation [1 pt]; 1 pt grade 4 neutropenia and grade 3 fatigue). Stabilisation of disease (≥ 3 months) reported in 5 pts (pancreas, colon and ovarian cancer) lasting between 3.5 to 8 months. One ovarian pt had a 28.3% reduction in tumor mass. CP-4126 was detected in plasma up to 24 hrs post-dosing. AUC for dFdC exposure was significantly higher than reported with gemcitabine at comparable dose levels. Urinary excretion of the main metabolite dFdU during the first 24 hrs was approximately 60% of dose. Conclusions: CP-4126 is well tolerated and accrual is ongoing at 1400 mg/m2/d to establish RD for phase II studies. Updated results including plasma and urine PK will be presented.

[Table: see text]

Assessing quality of life in a randomized clinical trial: correcting for missing data

Background

Health-related quality of life is a topic of current interest. This paper considers a randomized phase III study of radiation therapy with concurrent chemotherapy (docetaxel) versus radiation therapy alone in non-small cell lung cancer, stage III A/B. Longitudinal data on quality of life have been obtained through repeated administration of a multi-item questionnaire (EORTC QLQ-C30) developed by the European Organisation for Research and Treatment of Cancer. Missingness in the data is owing to patients having failed to complete the questionnaire at some of the scheduled filling-in times.

Methods

We have analysed a monotone (in terms of missingness) subset of the data as regards estimation of the mean score of a summary measure of self-reported quality of life in a hypothetical drop-out-free population at different points in time. Missingness is a difficult issue of great importance. We have therefore chosen to compare three different methods that are relatively easy to implement: the linear-increments method, the inverse-probability-weighting method and the Markov-process method. Single imputation has been applied in a supplementary analysis to fill in for all the non-consecutive missing score values prior to the execution of the estimation procedure.

Results

For the response in focus, the observed mean score at a certain time is larger than the estimated mean scores, which implies that the true mean score is easily overestimated unless the missingness is appropriately adjusted for. Comparison of the treatment arms shows a significant difference in mean score at the end of treatment.

Conclusion

Use of proper methodology developed for analysing data subject to missingness is necessary to reduce potential estimation bias. The quality of life of patients receiving radiation therapy with concurrent chemotherapy (docetaxel) appears somewhat worse than that of patients receiving radiation therapy alone in the period during which treatment is given. The conclusions are robust for the choice of statistical methods.

Population-based prevalence of CDKN2A and CDK4 mutations in patients with multiple primary melanomas

The presence of multiple primary cutaneous melanomas (MPM) has been advocated as guidance to identifying melanoma families. Frequencies of CDKN2A mutations in materials of sporadic MPM cases from pigmented lesion clinics vary between 8 and 15%. Patients with MPM have therefore been regarded as good candidates for CDKN2A mutational screening. We describe a population-based study where all persons in Norway diagnosed with MPM between 1953 and 2004 (n = 738 alive per April 2004) were invited to participate. Three-hundred-and-ninety patients (52.8%) responded confidentially. Mutations in CDKN2A were found in 6.9% of the respondents. Eighty-one MPM patients (20.8%) reported that they belonged to melanoma families, and 17 (21.0%) of these harboured a CDKN2A mutation, compared to 3.2% of the nonfamilial cases. The probability of finding a CDKN2A mutation increased when the patients had three or more melanomas, or a young age of onset of first melanoma. We identified five novel CDKN2A variants (Ala57Gly, Pro81Arg, Ala118Val, Leu130Val, and Arg131Pro) and four that previously have been reported in melanoma families (Glu27X, Met53Ile, Arg87Trp, and Ala127Pro). A large deletion (g.13623_23772del10150) encompassing exon 1alpha and the 5' part of exon 2 was detected in six patients with a family history of melanoma. Three patients, belonging to the same family, had the CDK4 Arg24His mutation. The frequency of CDKN2A mutations was lower than previously reported in other studies, an observation which probably is due to the population-based design of our study.

The prognostic role of blood lymphocyte subset distribution in patients with resected high-risk primary or regionally metastatic melanoma

The aim of this study was to investigate whether the profile of peripheral blood lymphocyte subsets of patients with high-risk malignant melanoma is associated with prognosis. Blood samples were systematically obtained from 31 patients with high-risk melanoma eligible for the Nordic Melanoma Cooperative Group adjuvant interferon study. The frequencies of peripheral blood lymphocyte subsets were monitored by flow cytometry using CD3, CD4, CD8, CD56, and CD69 monoclonal antibodies. Patients with low proportions of CD3+CD4+CD69+ cells and of CD3+CD56+ cells before treatment had an improved disease-free survival compared to those with high proportions [77.7 vs. 16.8 mo, hazard ratio (HR) 0.25, confidence interval (CI) 0.09-0.71, P=0.005 and 77.2 vs. 16.0 mo, HR: 0.25, CI 0.086-0.73, P=0.001, respectively]. Low pretreatment levels of these cell populations also correlated with a better overall survival (79.2 vs. 22.6 mo, HR: 0.17, CI 0.05-0.52, P=0.0005 and 78.2 vs. 21.4 mo, HR: 0.2, CI 0.07-0.59, P=0.001, respectively). In the multivariate analysis both the pretreatment proportion of CD3+CD4+CD69+ cells (P=0.01, HR: 0.21, CI 0.07-0.67) and CD3+CD56+ cells (P=0.01, HR: 0.22, CI 0.062-0.65) were independent prognostic factors for overall survival. Our data show that both the proportions of CD3+CD4+CD69+ cells and of CD3+CD56+ cells seem to have a prognostic potential in the natural course of melanoma. These results need to be confirmed in larger studies.

Pharmacokinetic analysis of two different docetaxel dose levels in patients with non-small cell lung cancer treated with docetaxel as monotherapy or with concurrent radiotherapy

Background

Previous pharmacokinetic studies with docetaxel have mostly used 3-weekly (75 mg/m² and 100 mg/m²) or weekly regimens (35–40 mg/m²). The pharmacokinetics and radiosensitizing efficacy of weekly 20 mg/m² docetaxel, has however not been well characterized. We examined the pharmacokinetics of weekly docetaxel when administered with concurrent radiotherapy and compared the results with a 3-weekly 100 mg/m² regimen.

Methods

Thirty-four patients with non small cell lung cancer (NSCLC) were included in this study, 19 receiving 100 mg/m² docetaxel 3-weekly as single therapy, and 15 receiving 20 mg/m² docetaxel weekly with concurrent radiotherapy. A newly developed HPLC method was used for measuring docetaxel levels, capable of quantifying docetaxel in plasma down to the nanomolar level.

Results

The HPLC method showed detectable concentrations of docetaxel in plasma even after 72 hours. In the present study we have demonstrated that median docetaxel plasma levels of 3 nM can be obtained 72 hours after a dose of 20 mg/m².

Conclusion

The pharmacokinetics of docetaxel is characterized by great inter-individual variability and at some time points plasma concentrations for 20 mg/m² and 100 mg/m² docetaxel were overlapping. Extrapolation of these results indicates that radio sensitizing docetaxel concentrations may be present for as long as 1 week, thus supporting the use of 20 mg/m² weekly docetaxel.

T cell responses in melanoma patients after vaccination with tumor-mRNA transfected dendritic cells

We have developed an individualized melanoma vaccine based on autologous dendritic cells (DCs) transfected with autologous tumor-mRNA. The vaccine targets the unique spectrum of tumor antigens in each patient and may recruit multiple T cell clones. In a recent phase I/II trial, we demonstrated T cell responses against vaccine antigens in 9/19 patients evaluable by T cell assays. Here, we report a follow-up study that was conducted to characterize interesting T cell responses and to investigate the effects of long-term booster vaccination. Two patients were selected for continued vaccine therapy. The clinical follow-up suggested a favorable clinical development in both patients. The immunological data (T cell proliferation/IFNgamma ELISPOT/Bioplex cytokine assays) indicated sustained T cell responses and suggested an enhancing effect of booster vaccinations. Both CD4(+) and CD8(+) T cell responses were demonstrated. From post-vaccination samples, we generated 39 T cell clones that responded specifically to stimulation by mRNA-transfected DCs and 12 clones that responded to mock-transfected DCs. These data clearly indicate a two-component vaccine response, against transfected and non-transfected antigens. T cell receptor (TCR) clonotype mapping, performed on 11 tDC-specific clones, demonstrated that 10/11 clones had different TCRs. The results thus indicate a broad spectrum T cell response against antigens encoded by the transfected tumor-mRNA. We generally observed mixed Th1/Th2 cytokine profiles, even in T cell clones that were confirmed to be derived from a single cell. This finding suggests that cytokine patterns after cancer vaccination may be more complex than indicated by the classic Th1/Th2 dichotomy.

Telomerase peptide vaccination: a phase I/II study in patients with non-small cell lung cancer

PURPOSE

A phase I/II study was conducted to investigate the safety, tolerability and clinical response to vaccination with a combination of telomerase peptides GV1001 (hTERT: 611-626) and HR2822 (hTERT: 540-548) in patients with non-small cell lung cancer.

EXPERIMENTAL DESIGN

Twenty-six patients with non-small cell lung cancer received intradermal administrations of either 60 nmole (112 microg) or 300 nmole (560 microg) GV1001 in combination with 60 nM (68.4 microg) HR2822 and granulocyte macrophage-colony stimulating factor. The treatment period was 10 weeks. Booster vaccinations with 300 nM GV1001 were offered as follow-up. Monitoring of blood samples, clinical examination and radiological staging were performed regularly. Immune responses were measured as delayed-type hypersensitivity skin reaction and in vitro T cell proliferation. Bone marrow function was monitored in long time survivors.

RESULTS

The treatment was well tolerated with minor side effects. No bone marrow toxicities were observed in long time survivors with immune responses. Immune responses against GV1001 were detected in 11 of 24 evaluable patients during the primary regimen and in additional two patients following booster injections. Two patients responded to HR2822. Cloned GV1001-specific CD4+ T cells displayed a Th1 cytokine profile and recognized autologous antigen presenting cells pulsed with recombinant telomerase protein. A complete tumor response was observed in one patient who developed GV1001-specific cytotoxic T cells that could be cloned from peripheral blood.

CONCLUSION

The results demonstrate that GV1001 and HR2822 are immunogenic and safe to use in patients with NSCLC. Induction of GV1001-specific immune responses may result in objective tumor responses. Based on these initial encouraging results, further clinical studies of GV1001 in NSCLC patients are warranted.

[Malignant melanoma--diagnosis and treatment]

BACKGROUND

Malignant melanoma is one of the most common forms of cancer in young adults in Norway. Early diagnosis and treatment is of vital importance for the prognosis.

MATERIAL AND METHODS

The article is based on articles obtained from Medline and PubMed and from the Norwegian guidelines for the treatment of malignant melanoma.

RESULTS AND INTERPRETATION

The depth of invasion of the melanoma is the most important prognostic factor. The thicker the primary tumour, the less chance there is of patient survival. Patients with a localized tumour should be controlled regularly for up to five years. Primary tumours, local recurrences and metastases should be treated by surgery whenever possible. Radical lymph node dissection should be performed in patients with regional lymph node metastases with the intention of curing the patient. There is no curative chemotherapy for metastatic disease. Dacarbazine has been the most used medication for many years. The treatment is effective for about 10 - 20 % of the patients, but the response does not last for long and the treatment does not prolong survival time. Isolated limb perfusion with melphalan and TNF-alpha (tumour necrosis factor-alpha) gives high response rates in patients with metastatic disease localised in the extremities, but the treatment is only palliative. Radiation therapy has been useful in selected patients postoperatively (e.g. after removed local recurrence) and in palliation of metastatic disease. Several clinical studies with chemotherapy, immunotherapy, vaccines and combinations are ongoing. Of preventive measures, avoiding sunburn is of particular importance.

[Retraction of: Diagnostics and treatment of early stages of oral cancer]

The undersigned, who are co-authors of the article Diagnostics and treatment of early stages of oral cancer, wish to retract it. The reason is that the basis for the review article has been shown to be false. A review committee, that has assessed the research activity of the main author, has concluded that the data in this article are fabricated. We can no longer stand behind the article and hereby retract it.

An open label phase I study of ABR-217620, a fusion protein of the 5T4 antibody moiety and an engineered superantigen, in patients with non-small cell lung, renal cell or pancreatic cancer

3083

Background: ABR-217620 (naptumomab estafenatox) is a recombinant fusion protein that consists of the 5T4Fab moiety genetically fused to the engineered superantigen variant SEA/E-120. This fusion protein is a new generation tumor-targeted superantigen based on the previously described ABR-214936 (anatumomab mafenatox). ABR-217620 was designed to reduce antigenicity and toxicity. The 5T4 antigen is expressed on more than 95 % of tumors from patients with non-small cell lung (NSCLC), renal cell (RCC) and pancreatic cancer (PC). In clinical PET studies 124I-labeled ABR-217620 has been shown to localize to 5T4 positive tumors. Methods: The compound was administered as a 5 min bolus infusion for 5 consecutive days. Patients with disease control at day 28 were offered a second cycle of therapy. Dose escalation has been performed using a Bayesian model starting at 0.5 μg/kg/day. The primary endpoint is determination of MTD. Secondary endpoints include characterization of side effects, immunological response, efficacy and pharmacokinetics. Results: 31 patients to date have been treated (19 NSCLC, 8 RCC, 4 PC). 3 patients have had dose limiting toxicities (fever, hypotension and nausea, grade 3) at doses between 23 and 28 μg/kg/day. The side effects were resolved quickly. Based on the experience from ABR-214936, these side effects were expected, but the MTD is ∼ 200 times higher. ABR-217620 leads to a dose dependent systemic increase of cytokines including IL-2 and IFN-γ after infusion. It also leads to an expansion of the superantigen reactive T cell population. 16/29 evaluable patients investigated had SD while 13 patients had PD. In contrast to ABR-214936, the first cycle of ABR-217620 treatment can be given without factoring in the titer of preformed anti-superantigen antibodies. Conclusions: ABR-217620 treatment had predicted and manageable side effects with fever, hypotension and nausea being dose limiting toxicities. Treatment with ABR-217620 resulted in a restricted systemic activation of the immune system. A large fraction of the patients have had stable disease.

[Table: see text]

A phase I/II study of telomerase peptide vaccination in combination with chemotherapy in patients with stage IV malignant melanoma

8031

Background: A phase I/II feasibility study was conducted to investigate the safety, tolerability and immunological response to vaccination with the telomerase peptide GV1001 (hTERT: 611–626) in combination with temozolomide (T). Methods: Twenty-five patients with malignant melanoma (15 stage M1c,10 stage M1b) received T day 1–5 every four weeks for 1–9 cycles. During the first cycle (4 weeks) they received i.d. injections of 560 μg GV1001 with local GM-CSF in week 2,3 and 4, followed by injections in week 6 and 7 in the second cycle and week 11 in the third cycle. The treatment period was 12 weeks (3 cycles). Booster vaccinations with 560 μg GV1001 were offered every third month. Monitoring of blood samples, clinical examination were performed regularly with radiological staging every 12th week. Immune responses were measured as DTH and in vitro T-cell proliferation. Results: The treatment was generally well tolerated with only grade 1–2 toxicity in most patients. Of 14 patients, 4 developed grade 3 toxicity and one grade 4 toxicity (neutropenia). Immune responses against GV1001 were detected in 17/21 patients (81%) at 12 weeks. Patients receiving up to 9 cycles of T exhibited stable proliferative responses to GV1001 throughout the treatment period. None of the patients had DTH response at trial entry and no DTH responses were observed in patients receiving T. This was not due to a shift in the cytokine profile since cloned GV1001-specific CD4+ T cells displayed a Th1 cytokine profile. Upon evaluation in week 12, 6 patients had SD, 10 PD. One patient had a PR with shrinkage or disappearance of multiple lung metastases. A patient continuing on vaccine alone developed significant DTH response when T therapy was stopped. Conclusions: Telomerase vaccination of patients receiving concomitant T treatment is feasible. The unexpected high proportion of patients showing an immune response indicates that regulatory T-cells may have been removed by T treatment. The chemotherapy may also have influenced effector cells required for development of skin reactions. In spite of lacking DTH response however, the majority of the patients demonstrated significant immune response indicating different regulation of DTH and T-cell response.

No significant financial relationships to disclose.

Phase I/II trial of melanoma therapy with dendritic cells transfected with autologous tumor-mRNA

We have developed an individualized melanoma vaccine based on transfection of autologous dendritic cells (DCs) with autologous tumor-mRNA. Dendritic cells loaded with complete tumor-mRNA may generate an immune response against a broad repertoire of antigens, including unique patient-specific antigens. The purpose of the present phase I/II trial was to evaluate the feasibility and safety of the vaccine, and the ability of the DCs to elicit T-cell responses in melanoma patients. Further, we compared intradermal (i.d.) and intranodal (i.n.) vaccine administration. Twenty-two patients with advanced malignant melanoma were included, each receiving four weekly vaccines. Monocyte-derived DCs were transfected with tumor-mRNA by electroporation, matured and cryopreserved. We obtained successful vaccine production for all patients elected. No serious adverse effects were observed. A vaccine-specific immune response was demonstrated in 9/19 patients evaluable by T-cell assays (T-cell proliferation/interferon-gamma ELISPOT) and in 8/18 patients evaluable by delayed-type hypersensitivity (DTH) reaction. The response was demonstrated in 7/10 patients vaccinated intradermally and in 3/12 patients vaccinated intranodally. We conclude that immuno-gene-therapy with the described DC-vaccine is feasible and safe, and that the vaccine can elicit in vivo T-cell responses against antigens encoded by the transfected tumor-mRNA. The response rates do not suggest an advantage in applying i.n. vaccination.

High sensitivity assays for docetaxel and paclitaxel in plasma using solid-phase extraction and high-performance liquid chromatography with UV detection

Background

The taxanes paclitaxel and docetaxel have traditionally been used in high doses every third week in the treatment of cancer. Lately there has been a trend towards giving weekly low doses to improve the therapeutic index. This article describes the development of high performance liquid chromatographic (HPLC) methods suitable for monitoring taxane levels in patients, focusing on patients receiving low-dose therapy.

Methods

Paclitaxel and docetaxel were extracted from human plasma by solid phase extraction, and detected by absorbance at 227 nm after separation by reversed phase high performance liquid chromatography. The methods were validated and their performance were tested using samples from patients receiving paclitaxel or docetaxel.

Results

The limits of quantitation were 1 nM for docetaxel and 1.2 nM for paclitaxel. For both compounds linearity was confirmed from the limit of quantitation up to 1000 nM in plasma. The recoveries ranged between 92% and 118% for docetaxel and between 76% and 104% for paclitaxel. Accuracy and precision were within international acceptance criteria, that is within ± 15%, except at the limit of quantitation where values within ± 20% are acceptable. Low-dose patients included in an on going clinical trial had a median docetaxel concentration of 2.8 nM at 72 hours post infusion. Patients receiving 100 mg/m² of paclitaxel had a mean paclitaxel concentration of 21 nM 48 hours after the end of infusion.

Conclusion

We have developed an HPLC method using UV detection capable of quantifying 1 nM of docetaxel in plasma samples. The method should be useful for pharmacokinetic determinations at all relevant doses of docetaxel. Using a similar methodology paclitaxel can be quantified down to a concentration of 1.2 nM in plasma with acceptable accuracy and precision. We further demonstrate that the previously reported negative influence of Cremophor EL on assay performance may be overcome by degradation of the detergent by incubation with lipase.

Weekly docetaxel with concurrent radiotherapy in locally advanced non-small cell lung cancer: a phase I/II study with 5 years' follow-up

This Phase I/II study investigated weekly docetaxel (Taxotere) with concurrent radiotherapy in 42 patients with untreated stage III non-small cell lung cancer (NSCLC). All patients were treated with chest irradiation: 2Gy administered 5 days/week for 5 weeks, to a total of 50Gy. Docetaxel (1-h infusion) was administered on days 1, 8, 22, and 29< or =2 h before radiation fractions 1, 6, 16, and 21 (i.e. every week excluding the third week of treatment). In the Phase I study (n=12), docetaxel was started at 20 mg/m2 per week (n=3) and escalated in 10 mg/m2 increments (30 mg/m2, n=3; 40 mg/m2, n=6). Dose-limiting toxicity (grade 3-4 esophagitis) occurred with docetaxel 40 mg/m2. The Phase II study (n=30), therefore, evaluated docetaxel 30 mg/m2 (considered recommended dose). All patients except one experienced asymptomatic grade 3-4 lymphopenia; four patients (9.5%) had grade 3-4 esophagitis. The overall response rate was 45.5%, with eight (24.2%) complete responses. The median time to progression at the recommended dose of 30 mg/m2 (n=33) was 12.0 months and the median survival time was 13.6 months. The 1-year survival rate was 60.6%. Five patients (one from Phase I and four from Phase II) were alive after >5 years. In conclusion, weekly docetaxel 30 mg/m2 plus radiotherapy is active and well tolerated in stage III NSCLC.

Immunotherapy with allotumour mRNA-transfected dendritic cells in androgen-resistant prostate cancer patients

Here, we present results from a clinical trial employing a new vaccination method using dendritic cells (DCs) transfected with mRNA from allogeneic prostate cancer cell lines (DU145, LNCaP and PC-3). In all, 20 patients were enrolled and 19 have completed vaccination. Each patient received at least four weekly injections with 2 × 10⁷ transfected DCs either intranodally or intradermally. Safety and feasibility of vaccination were determined. Immune responses were measured as delayed-type hypersensitivity and by in vitro immunoassays including ELISPOT and T-cell proliferation in pre- and postvaccination peripheral blood samples. Serum prostate-specific antigen (PSA) levels and bone scans were monitored. No toxicity or serious adverse events related to vaccinations were observed. A total of 12 patients developed a specific immune response to tumour mRNA-transfected DCs. In total, 13 patients showed a decrease in log slope PSA. This effect was strengthened by booster vaccinations. Clinical outcome was significantly related to immune responses (n=19, P=0.002, r=0.68). Vaccination with mRNA-transfected DCs is safe and results in cellular immune responses specific for antigens encoded by mRNA derived from the prostate cancer cell lines. The observation that in some patients vaccination affected the PSA level suggests that this approach may become useful as a treatment modality for prostate cancer patients.

Multi-centre Phase II trial of the polyamine synthesis inhibitor SAM486A (CGP48664) in patients with metastatic melanoma

PURPOSE

To determine the activity and tolerability of SAM496A, an inhibitor of S-adenosylmethionine decarboxylase (SAMDC), in patients with metastatic melanoma who had not received prior chemotherapy. Selected patients were offered participation in two sub-studies examining early changes in tumor metabolism with FDG-PET and changes in tumor polyamine content.

PATIENTS AND METHODS

Fifteen patients with measurable metastatic melanoma, normal cardiac function, and no known CNS metastases were eligible and received SAM486A by 1-hour IV infusion daily for 5 days every 3 weeks. Response was assessed by SWOG criteria.

RESULTS

No patient had a confirmed partial response. Fatigue/lethargy, myalgia and neutropenia were the main toxicities but no febrile neutropenia or grade 4 non-hematological toxicity occurred. Five patients had PET scans pre-treatment and on days 8-12 of cycle 1. No patient had reduction of tumor metabolism. Serial biopsy in one patient showed alterations in polyamines consistent with SAMDC inhibition.

CONCLUSIONS

Using the present dose and schedule of administration, SAM486A does not have significant therapeutic potential in patients with metastatic melanoma.

Preclinical full-scale evaluation of dendritic cells transfected with autologous tumor-mRNA for melanoma vaccination

Most cancer vaccines to date have made use of common tumor antigens or allogenic cancer cell lines. The majority of tumor antigens may, however, be unique patient-specific antigens. Dendritic cells (DCs) are the most potent antigen-presenting cells known. The present report is a full-scale preclinical evaluation of autologous DCs transfected with autologous tumor-mRNA (tDCs) for vaccination in malignant melanoma. By using autologous tumor-mRNA, we intend to make the DCs present a broad spectrum of tumor-associated antigens relevant to each individual patient. Previously, we have described effective methods for mRNA-transfection into DCs by square-wave electroporation and for generating large numbers of DCs. Here, we demonstrate the ability of tDCs, made under full-scale vaccine conditions, to generate in vitro T-cell responses specific for antigens encoded by the transfected tumor-mRNA. T-cell proliferation assays demonstrated tDC-specific responses for all six patients tested. Responses were further studied by IFNgamma ELISPOT and Bioplex cytokine assays (two patients) and by experiments on isolated CD4(+) and CD8(+) T cells, including HLA-blockage (one patient). Moreover, we describe the results of extensive tumor-RNA analysis using Agilent Bioanalyser, a method that we have implemented in the clinical protocol. Based on this preclinical evaluation, a vaccine trial has been started.