A phase 2, randomized, double-blind, placebo- controlled study of chemo-immunotherapy combination using motolimod with pegylated liposomal doxorubicin in recurrent or persistent ovarian cancer: a Gynecologic Oncology Group partners study

BACKGROUND

A phase 2, randomized, placebo-controlled trial was conducted in women with recurrent epithelial ovarian carcinoma to evaluate the efficacy and safety of motolimod-a Toll-like receptor 8 (TLR8) agonist that stimulates robust innate immune responses-combined with pegylated liposomal doxorubicin (PLD), a chemotherapeutic that induces immunogenic cell death.

PATIENTS AND METHODS

Women with ovarian, fallopian tube, or primary peritoneal carcinoma were randomized 1 : 1 to receive PLD in combination with blinded motolimod or placebo. Randomization was stratified by platinum-free interval (≤6 versus >6-12 months) and Gynecologic Oncology Group (GOG) performance status (0 versus 1). Treatment cycles were repeated every 28 days until disease progression.

RESULTS

The addition of motolimod to PLD did not significantly improve overall survival (OS; log rank one-sided P = 0.923, HR = 1.22) or progression-free survival (PFS; log rank one-sided P = 0.943, HR = 1.21). The combination was well tolerated, with no synergistic or unexpected serious toxicity. Most patients experienced adverse events of fatigue, anemia, nausea, decreased white blood cells, and constipation. In pre-specified subgroup analyses, motolimod-treated patients who experienced injection site reactions (ISR) had a lower risk of death compared with those who did not experience ISR. Additionally, pre-treatment in vitro responses of immune biomarkers to TLR8 stimulation predicted OS outcomes in patients receiving motolimod on study. Immune score (tumor infiltrating lymphocytes; TIL), TLR8 single-nucleotide polymorphisms, mutational status in BRCA and other DNA repair genes, and autoantibody biomarkers did not correlate with OS or PFS.

CONCLUSIONS

The addition of motolimod to PLD did not improve clinical outcomes compared with placebo. However, subset analyses identified statistically significant differences in the OS of motolimod-treated patients on the basis of ISR and in vitro immune responses. Collectively, these data may provide important clues for identifying patients for treatment with immunomodulatory agents in novel combinations and/or delivery approaches.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT 01666444.

A randomized phase II study of the telomerase inhibitor imetelstat as maintenance therapy for advanced non-small-cell lung cancer

BACKGROUND

Continuation or 'switch' maintenance therapy is commonly used in patients with advancd non-small-cell lung cancer (NSCLC). Here, we evaluated the efficacy of the telomerase inhibitor, imetelstat, as switch maintenance therapy in patients with advanced NSCLC.

PATIENTS AND METHODS

The primary end point of this open-label, randomized phase II study was progression-free survival (PFS). Patients with non-progressive, advanced NSCLC after platinum-based doublet (first-line) chemotherapy (with or without bevacizumab), any histology, with Eastern Cooperative Oncology Group performance status 0-1 were eligible. Randomization was 2 : 1 in favor of imetelstat, administered at 9.4 mg/kg on days 1 and 8 of a 21-day cycle, or observation. Telomere length (TL) biomarker exploratory analysis was carried out in tumor tissue by quantitative PCR (qPCR) and telomerase fluorescence in situ hybridization.

RESULTS

Of 116 patients enrolled, 114 were evaluable. Grade 3/4 neutropenia and thrombocytopenia were more frequent with imetelstat. Median PFS was 2.8 and 2.6 months for imetelstat-treated versus control [hazard ratio (HR) = 0.844; 95% CI 0.54-1.31; P = 0.446]. Median survival time favored imetelstat (14.3 versus 11.5 months), although not significantly (HR = 0.68; 95% CI 0.41-1.12; P = 0.129). Exploratory analysis demonstrated a trend toward longer median PFS (HR = 0.43; 95% CI 0.14-1.3; P = 0.124) and overall survival (OS; HR = 0.41; 95% CI 0.11-1.46; P = 0.155) in imetelstat-treated patients with short TL, but no improvement in median PFS and OS in patients with long TL (HR = 0.86; 95% CI 0.39-1.88; and HR = 0.51; 95% CI 0.2-1.28; P = 0.145).

CONCLUSIONS

Maintenance imetelstat failed to improve PFS in advanced NSCLC patients responding to first-line therapy. There was a trend toward a improvement in median PFS and OS in patients with short TL. Short TL as a predictive biomarker will require further investigation for the clinical development of imetelstat.

Phase II trial of nab-paclitaxel as first-line therapy of hormone refractory metastatic prostate cancer (HRPC)

5152

Background: Many patients with hormone refractory prostate cancer have poor tolerance to treatment. Docetaxel chemotherapy was shown to improve survival but has substantial toxicity, requires steroid administration, may cause poorly reversible neuropathy and requires long infusion times, all limiting its use. Nab-paclitaxel, an albumin-bound nanopaticle form of paclitaxel, delivers paclitaxel without steroids, requires only 30 minutes infusion time and has favorable toxicity profile that may be more tolerable but effective in patients with prostate cancer. The goal of this study was to evaluate the efficacy and toxicity of nab-paclitaxel in first line chemotherapy of men with castration resistant prostate cancer. Methods: nab-paclitaxel was given iv100 mg/m2 weekly x 3 of 4 weeks cycles. Main eligibility criteria include: hormone refractory metastatic prostate cancer, no prior chemotherapy, performance status 0–2. Primary endpoint was efficacy based on prostate-specific antigen (PSA) response. PSA response was PSA decrease of >50%, progressive disease (PD) was PSA increase of >25%, stable disease (SD) was <25% PSA increase or <50% decrease sustained longer that 8 weeks. Results: There are 38 patients enrolled, 35 were evaluable for response. Median age was 71 years old (range 57–86). One patient discontinued the treatment after 1 infusion due to toxicity (elevated ALT). PSA response was seen in 9 (25%) patients and SD in 15 patients (43%), with an overall response rate of 25% and clinical benefit of 68%. Seven patients received treatment for ≥ 6 months with minimal toxicity (range 6–10 months). Grade 3 related hematologic toxicity was reported in 7 (18%) patients (4 anemia, 4 neutropenia), grade 3 related non-hematologic toxicity was reported in 6 patients (1 hypokalemia, 1 muscle weakness, 2 fatigue, 1 fever, 1 neuropathy, 1 ALT elevation). Conclusions: Nab-paclitaxel has activity in patients with metastatic hormone refractory prostate cancer. This regimen was well tolerated, and may be useful in patients who are not suitable candidates for docetaxel based therapy.

[Table: see text]

Phase II trial of bevacizumab in combination with temozolomide and regional radiation therapy for up-front treatment of patients with newly diagnosed glioblastoma multiforme

2000

Background: Bevacizumab (BV) is a humanized monoclonal antibody directed against the vascular endothelial growth factor (VEGF). Based on the promising activity of BV in the treatment of recurrent glioblastoma, we are conducting a phase II trial to determine whether up-front treatment of newly diagnosed GBM with BV may be more advantageous than withholding BV until recurrence. In this trial, we evaluate the safety and efficacy of BV combined with standard of care radiation (RT) and temozolomide (TMZ) and radiation (RT) for newly-diagnosed GBM. Methods: This is a phase II trial with a 10-patient pilot and 60-patient expansion phases. Newly-diagnosed GBM patients with no prior treatments are eligible. Primary outcome measure is overall survival; the secondary outcome measure is TTP and 12-month survival. Therapy began between 3–5 weeks of surgery with BV (10 mg/kg every 2 weeks), TMZ (75 mg/m2 daily), and external beam RT (30 x 200 Gy) on the same day. After completion of radiation, patients are then placed on a maintenance phase of BV (10mg/kg every 2 weeks) and TMZ (150–200 mg/m2 5 out of every 28 days) until progression or 24 months in which patients are then maintained on BV only. Results: 70 of 70 projected GBM patients have been enrolled between August 2006 and November 2008 at UCLA and Kaiser Permanente (KP) (Northern and Southern California). All patients had resections to ensure that frozen tissue (>200mg) was collected. The median age was 57.4 years (range 31–75). MGMT methylation analysis has been performed on 52/70 patients with ∼40% showing methylation. Severe adverse events to date have included ischemic stroke, pulmonary embolus, wound breakdown, GI bleeding/perforation, and renal dysfunction. Isolated cases of retinal detachment and optic neuropathy have also been observed. As of now, 35/70 patients are off study (26 due to progression and 9 due to SAE). Preliminary TTP by Kaplan-Meier analysis is promising compared to that of a UCLA/KP control group of patients that received the conventional RT/TMZ regimen. Conclusions: Addition of BV to the standard regimen of TMZ and RT for newly-diagnosed GBM is well-tolerated and shows promising efficacy. More detailed analysis of safety and efficacy will presented.

[Table: see text]

Phase 3 Study: Canfosfamide (C, TLK286) plus carboplatin (P) vs liposomal doxorubicin (D) as 2nd line therapy of platinum (P) resistant ovarian cancer (OC)

LBA5529

Background: Canfosfamide (C) is a novel glutathione analog prodrug activated by glutathione S-transferase P1–1. C has single agent activity in P resistant OC and is synergistic with P. Methods: Pts with P resistant OC following ≤ 2 P regimens, measurable disease (RECIST) were eligible. Pts received C (750 mg/m2) and P (AUC 5) or D (50 mg/m2) IV q4wks until progression. Randomization was stratified by ECOG PS, best prior P response and bulky disease (≥ 5cm). Results: All 247 P refractory or resistant pts received 505/494 cycles median 3 (range 1–17), CP/D respectively. Most common toxicities for CP were hematologic and as expected for each drug alone. By independent radiologic review (IRR), 25% of pts discontinued treatment without documented progression. Overall ORR varied between clinician and IRR assessments. Overall median PFS was 3.5 mos for both CP and D. Overall median survival (MS) has not been reached. Planned analysis of the effect of time from last P dose to study treatment (TFP; not from time of recurrence) identified a P resistant subgroup for TFP ≥ 6 mos (med 7.1) [ Table ]. Subgroup ORR for CP was 31.6% vs 10.5% for D. Subgroup median PFS for CP has not been reached vs 3.5 mos for D (p=0.0099). Subgroup MS for CP has not been reached vs 11.1 mos for D(p=0.0014). Subgroup CP had superior QOL outcomes per FACIT-FACT-O. Conclusions: Primary endpoint of overall PFS was comparable. Subgroup TFP ≥ 6 mos reported large differences in ORR and QOL and statistical significance in PFS and survival for CP. OC trials with C in combination with other standard agents are in progress.

[Table: see text] [Table: see text]

Phase II trial of paclitaxel in front-line therapy of hormone refractory metastatic prostate cancer

15628

Hormone refractory prostate cancer patients have poor prognosis with median survival of only 16 months. They are frequently elderly men with many co-morbid conditions unable to tolerate treatments with substantial toxicity. Docetaxel, the only drug shown to prolong survival causes significant toxicities, requires steroids administration, may cause poorly reversible neuropathy and requires long infusion times, all limiting its use in elderly men that are mostly affected by hormone refractory prostate cancer. Abraxane is a novel agent delivering paclitaxel without steroids, requires only 30 minutes infusion times and low toxicity potential that may be effective and more tolerable in patients with prostate cancer. The goal of our study is to evaluate the effectiveness and toxicity of Abraxane in first line chemotherapy of men with hormone refractory prostate cancer. Considering the favorable toxicity profile of Abraxane and in an effort to make our results applicable to the majority of prostate cancer patients we are including men with performance status of 2. Main eligibility criteria are: hormone refractory metastatic prostate cancer documented by PSA progression, no prior chemotherapy, PSA >5 and performance status 0–2. Primary endpoint is efficacy based on PSA response. Secondary endpoints are time to PSA progression, overall survival, and toxicities. The clinical trial has been opened at Kaiser Permanente Northern California since September 2005. There are 15 patients enrolled. All have been evaluable for toxicity and the drug is very well tolerated so far by this population of patients. Out of 15 patients 12 are evaluable for response. Two patients have recently started the protocol therapy and have not met the time point for disease assessment. One patient discontinued the treatment after one infusion due to toxicity (elevated LFTs). One patient completed 11 cycles of Abraxane, while maintaining stable disease on bone scan and achieved a PR by PSA. Ten patients have come off study due to progressive disease based on clinical presentation, rising PSA or signs of radiological progression. There are currently 4 patients actively receiving therapy. Updated results will be presented at the time of ASCO 2007 meeting.

No significant financial relationships to disclose.

Granulocyte-monocyte colony forming unit content of autologous bone marrow transplants in patients with haematological malignancy

Cell viability and number of granulocyte-monocyte colony forming units (CFU-GM) were systematically assessed in 57 patients who had undergone transplantation of the autologous bone marrow for treatment of haematologic malignancies. Bone marrow cell cultivation in agarose with feeder layers appeared inferior to that performed in agarose with recombinant human granulocyte-monocyte colony stimulating factor and methylcellulose with phytohaemaglutinin leukocyte-conditioned medium. Since the transplant cells were frozen in liquid nitrogen between harvesting and reinfusion, the following samples were tested: buffy coat cells, buffy coat cells immediately after addition of dimethylsulphoxide, cell sample that had been frozen for 24 hours, and frozen transplant cells at the time of thawing and transplantation. Each procedural step decreased both cell viability and the number of CFU-GM, but since the lymphohaematologic recovery in all patients followed the pattern reported in the literature for high-quality transplants, we concluded that our transplants retained the necessary number of progenitor cells. It appears that the best strategy for dynamic assessment of the transplant quality would be to perform tests after every step of the transplant processing. Cell viability and number of progenitors per body weight in transplants were also found to be associated with probability of neutrophil reconstitution after bone marrow reinfusion.

Characterization and partial purification of the Croatian national standard Dermatophagoides pteronyssinus allergen extract

Lyophilized Dermatophagoides pteronyssinus (Der p) allergen extract (AE) and partially purified Der p extract (PAE) were prepared and characterized. Partial purification of AE was performed by gel filtration on Sephadex G-100 and Sephacryl S-300. Crossed immunoelectrophoresis (CIE) disclosed the same precipitating lines in AE and PAE preparations. The relative potencies of AE and PAE were determined and compared with the WHO International Standard for Der p by the RAST inhibition method. The potencies were 6.5 x 10(5) IU and 1.5 x 10(6) IU, respectively. Biologic standardization by quantitative skin testing was performed with AE (20 selected patients) and PAE (12 patients). Median Ch was calculated by linear regression analysis (log-log model). One ampoule of AE contained 65,300 BU and 1 ml (vial) of PAE contained 166,000 BU. Der p AE could serve as a croatian national standard for further production of Der p allergenic extracts.

[Procollagen type 111 peptide levels in patients with bronchial asthma and COPD]

The aim of these study was to evaluate if the inflammatory injury of parenchymal cells can lead to proliferation of fibroblasts and deposition of increased amounts of collagen, measured by the increased concentration of procollagen in blood, in patients with asthma and COPD. We evaluated 22 patients with asthma that has lasted more than 5 years, 18 patients with COPD and 20 healthy subjects. RIA-gnost method (Behring) was used to measure the procollagen peptide concentrations in blood. Our results showed that the concentration of procollagen peptide in blood samples from patients with asthma was 5.8 +/- 2.4, 4.9 +/- 1.8 in patients with COPD and 11.1 +/- 3.6 in healthy subjects. There was no significant difference between patients with asthma, COPD and healthy subjects (p less than 0.01). It can be concluded that there is no increased deposition of collagen in patients with long lasting asthma and COPD. Further studies of active collagen deposition in the early acute forms of these diseases are in progress.

[Treatment of neoplastic hematologic diseases with intensive radio-chemotherapy and transplantation of cryopreserved autologous bone marrow]

Autologous bone marrow transplantation (ABMT) allows application of intensive myeloablative therapy aimed at eradication of neoplastic disease by facilitating haematopoietic reconstitution. Between March and June 1988, four patients (two with acute myelogenous leukaemia in first remission, one with acute lymphoblastic leukaemia in second remission, and one with Burkitt lymphoma, stage IV with CNS involvement in second remission) received this treatment. Methods of collecting, processing and freezing bone marrow as well as thawing and reinfusion of the marrow into patients after intensive chemoradiotherapy are described. Viability of bone marrow cells tested by the dye exclusion method after freezing and thawing process was 89, 88, 91 and 78%, respectively. CFU-GM recovery in culture, as a test of marrow stem cells clonogenicity was between 63,3 and 156,5%. Patients received between 1,7 and 3,0 x 10(8)/kg nucleated cells and 4,0 to 7,6 x 10(4)/kg CFU-GM, respectively. In all four patients stable haematopoietic reconstitution was achieved. The bone marrow function was evident mainly at 11th day after marrow reinfusion. Leukocyte count reached 1,0 x 10(0)/L in 11 to 15 days, and granulocyte count raised more than 0,5 x 10(9)/L in 19 to 37 days after transplantation. Platelet recovery was prolonged with the minimum of 29 days and maximum of more than 60 days to reach 20 x 10(9)/L. Side effects caused by the intensive radiochemotherapy were moderate. Bacterial, fungal and viral infections in early posttransplant period were successfully treated. All patients have survived and left the hospital 63, 54, 36 and 65 days after ABMT, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Accuracy of routine flow-cytometric bitmap selection for three leukocyte populations

A double-blind study was performed with peripheral blood of 41 human subjects to check the accuracy of determination of lymphocyte, monocyte, and granulocyte windows with which every flow cytometric analysis of leukocyte markers starts. White blood cell suspensions were prepared according to the whole blood method and analyzed on an EPICS-C flow cytometer using the two-parameter 90 degrees light scatter vs. forward angle light scatter (granularity vs. cell size) data distribution. Windows (bitmaps) for lymphocytes, monocytes, and granulocytes were drawn and numbers of cells determined in each. The proportions of lymphocytes, monocytes, and granulocytes were calculated in relation to total cell number, counted and in relation to the sum of cells in three bitmaps, and then compared with proportions determined by microscopic whole blood cell (WBC) differential and a WBC differential determined in an automated hematology analyzer. Average proportions of lymphocytes obtained by the flow cytometer were significantly lower than those obtained by either microscopic or automated differential, suggesting that some of the relevant cells were not included in the bitmaps. Granulocyte proportion related to total cell number was lower and that related to bitmap cell number higher than that obtained by microscopic and automatic differentials, suggesting that nongranulocytic cells were included in the granulocyte bitmaps. Proportions of lymphocytes and granulocytes obtained by the flow cytometer correlated well with those obtained by both microscopic and automatic differential. In contrast, the proportions of monocytes showed a poor correlation, which is probably due to their low number and delicate position in the distribution, and which makes them difficult to delineate.

Lymphocyte subsets in normal human bone marrow harvested for routine clinical transplantation

Bone marrow and peripheral blood of 25 healthy bone marrow donors from our allogeneic bone marrow transplantation program were assessed for cell subsets bearing T11(CD2), T4(CD4), T8(CD8), B1(CD20) J5(CALLA, CD10), Mo1(CD11b), MY7(CD13). Mo2(CD14), MY9(CD33) and NKH-1 antigens. Bone marrow cell samples were taken for analysis at the start or at the end of the harvesting procedure of aspiration from the iliac crest. All samples were analysed on a flow cytometer at the lymphocyte window as obtained on the two-parameter (L90oLSxFALS) scatter diagram. There were no differences in the lymphocyte subset composition of bone marrow samples taken at the start or at the end of the harvesting procedure. In contrast to the majority of literature data, a high CD4/CD8 ratio was detected in bone marrow samples: it did not differ from that in the peripheral blood. The proportions of CD2 and CD4 T cell markers in the bone marrow correlated with those in the peripheral blood, thus further documenting a substantial bone marrow contamination with peripheral blood cells. A relatively large aspirate volume (4-5 ml) obtained from individual aspiration sites was identified as the only factor possibly accounting for the high-level contamination of bone marrow samples with peripheral blood. This conclusion was corroborated by low T cell proportions and low CD4/CD8 ratios found in the bone marrow washed from bone fragments and in bone marrow samples aspirated at first bone puncture in a volume of 1.0 ml. Taken together, these findings imply that less vigorous suction may decrease the number of T lymphocytes in bone marrow harvested for transplantation purposes.