1 Division of Oncology/Hematology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC; 2 Investigational Drug Branch, Cancer Treatment Evaluation Program, National Cancer Institute, Bethesda, MD; 3 Division of Hematology/Oncology, Department of Medicine, University of Michigan Health System, Ann Arbor, MI; 4 Medical Operations, Genta Inc., Berkeley Heights, NJ, USA
* Correspondence to: Dr J. L. Marshall, Lombardi Comprehensive Cancer Center, 3800 Reservoir Rd NW, Washington, DC 20007, USA. Tel: +1-202-444-7064; Fax: +1-202-444-1229; Email: marshalj{at}georgetown.edu
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Abstract |
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Patients and methods: We performed a phase I trial to determine the maximum tolerated dose (MTD) and safety profile of combined therapy with G3139 and weekly docetaxel in patients with advanced Bcl-2-positive solid tumors. Cohorts of three to six patients were enrolled to escalating doses of G3139 and a fixed dose of weekly docetaxel using either of two schedules. In part I, G3139 was administered by continuous infusion for 21 days (D122), and docetaxel (35 mg/m2) was given weekly on days 8, 15 and 22. In part II, G3139 was given by continuous infusion for 5 days before the first weekly dose of docetaxel, and for 48 h before the second and third weekly docetaxel doses. For both schedules, cycles were repeated every 4 weeks.
Results: Twenty-two patients were enrolled. Thirteen patients were treated on the part I schedule with doses of G3139 escalated from 1 to 4 mg/kg/day. Nine patients were on the part II schedule of shorter G3139 infusion at G3139 doses of 59 mg/kg/day. Hematologic toxicities were mild, except for one case of persistent grade 3 thrombocytopenia in part I. The most common adverse events were cumulative fatigue and transaminase elevation, which prevented further dose escalation beyond 4 mg/kg/day for 21 days with the part I schedule. In part II of the study, using the abbreviated G3139 schedule, even the highest daily doses were tolerated without dose-limiting toxicity or the need for dose modification. Objective tumor response was observed in two patients with breast cancer, including one whose cancer previously progressed on trastuzumab plus paclitaxel. Four patients had stable disease. Pharmacokinetic results for G3139 were similar to those of other trials.
Conclusions: G3139 in combination with standard-dose weekly docetaxel was well tolerated. The shortened and intermittent G3139 infusion had less cumulative toxicities and still allowed similar total G3139 delivery as the longer infusion. Further studies should examine the molecular effect of the regimen, as well as clinical activities in malignancies for which taxanes are indicated.
Key words: advanced breast cancer, Bcl-2, docetaxel, G3139, solid tumors
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Introduction |
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G3139 [Oblimersen (GenasenseTM); Genta, Inc., Berkeley Heights, NJ] is an 18-mer phosphorothioate antisense oligodeoxynucleotide (ASO) complementary to the first six codons of the Bcl-2 mRNA. ASOs have been pursued as a therapeutic approach to specifically modulate single gene expression, mainly by triggering mRNA degradation of the ASO/mRNA hybrids and translational arrest [15, 16
]. In vivo stability of ASO is conferred by the phosphorothioate backbone. Preclinically, G3139 induces downregulation of Bcl-2 protein in vivo in a dose-dependent and sequence-specific manner [17
]. Complete tumor regression was observed in human lymphoma models in mice after treatment with G3139, especially when administered by continuous infusion [17
]. The effect of G3139 on solid tumor models is modest as a single agent. However, antitumor activity is significantly enhanced in the presence of external apoptotic signals provided by the addition of chemotherapeutic agents, such as docetaxel [18
], dacarbazine [19
] or anthracyclines [20
].
G3139 has undergone clinical evaluation as a single agent or in combination with chemotherapy. In a phase I trial in patients with relapsed or refractory non-Hodgkin's lymphoma (NHL), administration of G3139 up to 147 mg/m2/day by 14-day subcutaneous infusion was well tolerated, with the main side-effects being thrombocytopenia and fatigue [21, 22
]. Combinations of G3139 with several chemotherapy regimens, including dacarbazine [23
], irinotecan [24
], mitoxantrone [25
], paclitaxel [26
], fludarabine and cytarabine [27
], are feasible without much added toxicity. Importantly, single-agent activity, including induction of a complete remission, has been observed in patients with NHL. Target gene downregulation has been demonstrated in tumor tissues from some patients with lymphoma [22
], melanoma [28
] and acute myeloid leukemia [27
].
Docetaxel is an active agent for the treatment of many advanced malignancies. The mechanism of resistance to docetaxel may include tubulin mutation [29], multidrug resistance gene overexpression [30
] and/or impairment of apoptotic pathways [31
, 32
]. In vitro studies have indicated that Bcl-2 is one of the main factors that protects cells from apoptosis triggered by microtubule-damaging agents [33
]. Combination docetaxelG3139 has been studied in several Bcl-2-overexpressing human breast cancer models (MDA-MB-231 and MDA-MB-361). While G3139 or low-dose docetaxel (7.5 mg/kg) alone only partially retarded tumor growth, combination of the two resulted in complete regression of established tumors lasting up to 5 months following 14-day treatment [18
].
We report a phase I trial in which we evaluate the feasibility and safety profile of increasing doses of G3139 in combination with standard weekly docetaxel.
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Patients and methods |
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Patient population
Eligible patients had histologically confirmed measurable or evaluable advanced solid tumors for which treatment with docetaxel was appropriate. Priority was given to patients with breast cancer, but tumors of all histology could be included. To be eligible, patients' tumors must have exhibited Bcl-2 overexpression defined by immunohistochemical staining of the Bcl-2 protein in 20% of tumor cells using anti-Bcl-2 antibody M887 (DAKO, Inc., Carpenteria, CA) [7
]. Bcl-2 expression was measured on previously obtained tumor specimens in the majority of cases. There was no restriction of the number of previous therapies, and previous exposure to paclitaxel or docetaxel was permitted. Eligibility criteria also included age
18 years, Eastern Cooperative Oncology Group (ECOG) performance status
2, and life-expectancy
12 weeks. Adequate organ functions were required using standard criteria. Patients were excluded if they had active tumor metastasis in the central nervous system, had previous myeloablative chemotherapy requiring stem cell support, or had grade >2 peripheral neuropathy.
Study drug
G3139 [oblimersen sodium (GenasenseTM)] was supplied by Genta, Inc. It is an 18-mer phosphorothioate oligodeoxynucleotide (5'-TCTCCCAGCGTGCGCCAT-3') that is complementary to the first six codons of the Bcl-2 mRNA. Infusion pump cassettes were filled with the total dose of G3139 to be delivered over up to 7 days through a central venous catheter.
Docetaxel (TaxotereTM) used in this study was a marketed product obtained from commercial suppliers.
Treatment plan
Treatment was carried out on an outpatient basis and consisted of standard weekly docetaxel (35 mg/m2) over 3060 min and escalating doses of G3139 by continuous infusion. The initial plan was to determine the maximum tolerated dose (MTD) of the 21-day continuous infusion schedule combined with docetaxel, but, in addition, a second, shorter infusion schedule was tested to determine if further escalations in dose could be achieved (Table 1). In part I of the trial, G3139 was given by continuous infusion for 21 days (days 122) and docetaxel was given weekly on days 8, 15 and 22; each cycle consisted of 28 days. Part II was initiated after a protocol amendment to reduce the duration of G3139 infusion. In each 28-day cycle, G3139 was infused for 5 days before the first dose of docetaxel, then for 48 h each before the second and third doses of weekly docetaxel. Prophylactic medication for docetaxel included dexamethasone 8 mg at 12 h before, 1 h before and 12 h after docetaxel administration.
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DLT for this study was defined as grade 3 toxicity persisting for 2 weeks, or any grade 4 non-hematologic toxicity. For hepatic toxicity, DLT was defined as grade 3/4 transaminase or alkaline phosphatase (ALP) elevation, or grade 2 abnormality for >1 week. Hematologic DLTs included grade 3/4 neutropenia or grade 1/2 thrombocytopenia persisting for >2 weeks.
Patient monitoring and dose modification
Clinical and laboratory evaluations for safety profile were performed on day 3 of the first cycle and weekly for all cycles. Grading of toxicities was based on the National Cancer Institute Common Toxicity Criteria version 2.0. The disease status was assessed every 8 weeks using standard criteria by bidimensional measurement [34].
Dose modifications were required for either hematologic or hepatic toxicities: first, grade 3/4 neutropenia or thrombocytopenia lasting >1 week resulted in a 25% reduction in docetaxel dose, and any occurrence of grade 4 neutropenia or grade 2 thrombocytopenia led to a 25% reduction in G3139 dose. Secondly, grade 2 transaminase elevation or grade 3 ALP elevation or new-onset grade 2 ALP elevation required a 25% dose reduction for both docetaxel and G3139.
Pharmacokinetic analysis of G3139
Plasma was collected for pharmacokinetic measurement on days 1, 3, 8, 15, 22 and 28 for part I, and days 1, 6, 12, 14, 19 and 21 for part II (Table 1). Plasma levels of G3139 were measured by anion-exchange high-performance liquid chromatography and performed by Oread, Inc. (Lawrance, KS) in compliance with the US Food and Drug Administration's Good Laboratory Practice Regulations. The lower limit of quantitation was 0.2 µg/ml. Pharmacokinetic parameters were determined using non-compartmental methods based on the individual plasma concentrationtime data of G3139. The non-compartment analysis was performed using WinNonlin® Professional (version 3.2). Descriptive statistics (e.g. means, standard deviations) were calculated using Excel (version 97-SR-2; Microsoft) [35]. Samples for pharmacokinetic analysis of docetaxel clearance were not obtained in this trial.
Measurement of the biological effect of G3139
Assessment of the effect of G3139 on Bcl-2 gene expression was performed on peripheral blood mononuclear cells (PBMNs) obtained from patients using fluorescence-activated cell sorting (FACS). The time points of PBMN collection were the same as those for pharmacokinetic (PK) samples (Table 1), including a sample from day 0 for use as a baseline control. All samples of different time points from a single patient were analyzed simultaneously under the same conditions. Flow cytometry was performed using a fluorescent isothiocyanate (FITC)-labeled monoclonal antibody against Bcl-2 (Bcl-2 124; DAKO Inc., Denmark). Briefly, PBMNs were isolated by FicollHypaque density centrifugation and stored in DMSO at 70°C. Thawed cells were fixed by suspension in 70% (w/v) ice-cold ethanol, and were then stained for Bcl-2 expression by incubation in a buffer (phosphate-buffered saline, 5% goat serum, 0.5% Tween 80, 20 mM EDTA) containing a primary mouse monoclonal FITC-conjugated anti-Bcl-2 antibody (Bcl-2 124; DAKO, Inc., Denmark) and subsequent incubation with a FITC-conjugated secondary antibody (anti-mouse FITC immunoglobulin G). Cells were then subjected to standard FACS analysis in the Lombardi Comprehensive Cancer Center's Flow Cytometry Shared Resource for Bcl-2 expression. An internal control was provided by labeling unfixed samples with a FITC-labeled HLA-A,B,C antibody (Harlan Sera Laboratory, UK) using the same technique as above.
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Results |
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Patient characteristics
Twenty-three patients were registered on this study. One patient withdrew consent before receiving any treatment, therefore a total of 22 patients were evaluable (Table 2), including 13 patients in the part I schedule and nine patients in the part II schedule. The most common tumor type was breast. Of the 10 patients with breast cancer, six had previous treatment with taxanes. All tumors were Bcl-2-positive, with immunostaining in 20100% of tumor cells. Twenty patients had received systemic chemotherapy previously, including taxanes in 11 patients.
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Mild and isolated transaminase elevation was the most common laboratory abnormality in this study, and was associated with dose and duration of the treatment. At dose levels of 3 and 4 mg/kg/day (part I), transaminase elevation frequently occurred at the end of the first or second cycles of the 21-day infusion, while higher doses in part II (59 mg/kg/day) were associated with similar transaminase changes at the end of 5 days. Although all transaminase elevations were reversible within 12 weeks, dose reduction by 25% of both G3139 and docetaxel was necessary in part I in order to maintain the 21-day administration of G3139. With the shorter and intermittent schedule in part II, however, full delivery of higher daily doses was possible for all the dose levels tested (5, 7 and 9 mg/kg/day).
Most of the hematologic toxicities were mild and reversible, except for a grade 3 thrombocytopenia in one patient at the dose level of 3 mg/kg/day (21-day G3139 infusion, part I). This patient had small-cell carcinoma of the cervix with liver and bone marrow involvement, and she had previously been treated with pelvic radiation, cisplatin and topotecan. The patient had normal platelet counts and liver function tests at baseline, but began to develop thrombocytopenia after 12 days of G3139 infusion and one dose of docetaxel. Despite discontinuation of all treatments at that point, the platelet count continued to decline to a nadir of 17 000/mm3. A bone marrow biopsy revealed extensive tumor involvement and no detectable hematopoietic cells. The patient subsequently developed liver function abnormalities and died 30 days after the last dose of the study treatment. It was felt that the history of pelvic radiation and myelophthisis had rendered the patient susceptible to G3139-induced thrombocytopenia, and the final clinical decompensation was precipitated by progressive disease. In the other five patients with thrombocytopenia, the effect was mostly grade 1 or 2 and was rapidly revised upon discontinuation of therapy. Only seven patients developed neutropenia, with two being grade 3 or 4 (both in part II, at 5 and 9 mg/kg/day). In this trial, lymphopenia was present at baseline in most of the patients and did not change significantly with the treatment. Grade 1 aPTT prolongation was observed at doses of 5 mg/kg/day. Paralleling the short plasma half-life of oligonucleotides, aPTT prolongation was transient in all cases and no hemorrhagic events were associated with aPTT prolongation.
MTD has not been reached for either of the two schedules according to the definition of the protocol. In view of the cumulative side-effects, the part II schedule with abbreviated and intermittent G3139 infusion may be preferred, and the highest dose tested in this trial was well tolerated: docetaxel 35 mg/m2 weekly for 3 weeks every 4 weeks, and G3139 9 mg/kg/day given for 5 days (days 15) before the first dose of docetaxel and then for 2 days (days 12 and 13, and 19 and 20, respectively) before the second and third doses of docetaxel (Table 1). Alternatively, G3139 2 mg/kg/day by continuous infusion for 21 days (days 122) and docetaxel 35 mg/m2 weekly for 3 weeks with 1-week rest was also tolerated without the need for dose reduction or interruption.
Pharmacokinetics
Plasma pharmacokinetics of G3139 was performed for both part I (Table 5) and part II. Significant interpatient variability was observed, probably due to the small sample size. The plasma concentrations of G3139 were proportional to dose. At 2 mg/kg/day, the steady-state level (Css) reached 2.02.6 µg/ml, surpassing the concentration (1.5 µg/ml) required to downregulate Bcl-2 expression in vitro [17
]. Combination with weekly docetaxel did not appear to alter the plasma levels of G3139. In part II of the trial, where higher daily doses of G3139 were used, the plasma levels were proportionally higher. Due to the shorter infusion, only the peak levels on the last day of infusion rather than the Css levels were obtained. At the end of the 5 days of infusion (day 6), the plasma levels of G3139 reached 6.7 µg/ml, 9.52±5.1 µg/ml and 12±4.3 µg/ml at dose levels of 5, 7 and 9 mg/kg/day, respectively. At the end of the 2-day infusion (days 14 and 21), the plasma levels were quite variable and ranged from 4.6 to 6.9 µg/ml at dose level 7 mg/kg/day, and 5.0 to 13.0 µg/ml at dose level 9 mg/kg/day. As the plasma half-life of phosphorothioate ASOs has been well established (12 h), it was not measured in this trial.
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Discussion |
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Most of the G3139-related toxicities were typical of those reported with other phosphorothioate oligonucleotides (PS oligos) [40, 41
], and included fatigue, thrombocytopenia, aPTT prolongation and transaminase elevation. These toxicities are likely related to the polyanionic nature of the phosphorothioate backbones. Thrombocytopenia had clearly been associated with G3139 as well as other ASOs, and patients with poor marrow reserve at baseline are particularly at risk. In the G3139 single-agent study in lymphoma, severe thrombocytopenia was reported in patients with a history of bone marrow transplant or extensive lymphoma infiltration in the marrow [21
]. In this study, the only case of persistent grade 3 thrombocytopenia occurred in a patient with previous pelvic radiation and concurrent tumor progression in the bone marrow. Cumulative toxicities were more prominent with the 21-day infusion of G3139. Although mostly mild, fatigue was the main reason for treatment withdrawal in four of the 13 patients in part I, and cumulative transaminitis necessitated dose reduction of both G3139 and docetaxel for patients at the dose levels of
3 mg/kg/day in order to maintain the 21-day infusion. The shortened G3139 infusion in part II appeared to improve the tolerability of the regimen, and all patients were able to complete the planned dose and schedule. It should be noted that although infusion of G3139 at doses of up to 9 mg/kg/day (as per the schedule in part II) appeared to be well tolerated, due to the relatively small size of this trial, the number of patients treated at the highest dose level was limited, and as only two patients received two or more cycles of the 9 mg/kg/day dose, the cumulative toxicity of this dosage could not be optimally addressed. However, 510 day administration of G3139 at a dose of 7 mg/kg/day is being used in ongoing phase II/III trials with no DLTs reported [27
].
The hypothesis underlying the conduct of this study was that G3139 would enhance the effect of chemotherapy by downregulating the Bcl-2 protein before and around the time of chemotherapy administration. Most other clinical trials of G3139 combination regimens have used an every-3-week schedule of chemotherapy, and G3139 has been given for 57 days before chemotherapy [28, 42
]. In a phase I/II trial in hormone-refractory prostate cancer, docetaxel 75 mg/m2 every 3 weeks and G3139 7 mg/kg/day for 5 days was tolerable, with the main side-effects being neutropenia and fatigue [42
]. In the current study, docetaxel was given weekly, a regimen known to have less hematologic side-effects compared with the every-3-week schedule of chemotherapy. However, the design for the G3139 schedule was more complicated and had to take into account the half-lives of the oligonucleotide, the onset and duration of target gene downregulation, and safety and feasibility. For the two schedules tested in the current trial, the total delivery of G3139 before the administration of cytotoxic agent was similar, since a much higher daily dose of G3139 can be given using the part II schedule (9 mg/kg/day x 25 days before weekly docetaxel) compared with the 21-day infusion (3 mg/kg/day x 21 days with weekly docetaxel). It was undetermined, however, which schedule was superior in terms of effect on target gene expression. However, in light of the better tolerability, the part II regimen can serve as a basis for further exploration of G3139 in combination with weekly docetaxel or other chemotherapies.
Assessment of pharmacodynamics at the molecular level is a crucial but challenging task in the clinical development of molecular targeted agents. Given the difficulty in obtaining repeated biopsies for most solid tumors, PBMNs have been explored as a surrogate tissue for monitoring molecular changes. In this study, Bcl-2 protein was measured in PBMNs from patients participating in part I of this trial. There are various ways to detect alterations in Bcl-2 protein expression, including western blot, immunohistochemical staining, FACS analysis and RTPCR. Each of these methods has advantages and disadvantages. For instance, both western blotting and immunohistochemical staining can be performed with relative ease in the clinical laboratory, however, neither of these methods provides for an easily quantifiable measure of protein changes. Whereas FACS analysis, although easily quantifiable, is technically more complicated and requires a large number of cells. We chose to measure changes in Bcl-2 protein expression via FACS analysis in this study. We have previously tested and validated this method in both human cancer cell lines, expressing various levels of the Bcl-2 protein, and PBMNs from normal donors, and have confirmed the FACS results with western blotting. Similar studies using FACS analysis of PBMNs have been reported by other laboratories and are consistent with our observations [43, 44
].
Although Bcl-2 downregulation was demonstrated in a subset of patients, the pattern did not correlate with dose or duration of the ASO administration. Our inability to demonstrate consistent Bcl-2 downregulation could be due to interexperimental variability in sample processing or assay. Alternatively, the dose and schedule used in this trial may have been suboptimal. Additionally, circulating mononuclear cells are biologically and pharmacodynamically different from tumor tissues, and it is unknown whether PBMN data correlate with the target gene status in tumors. Intracellular uptake of ASO varies with specific cell types and status, with monocytes being more efficient than lymphocytes, and dividing cells being more efficient than their resting counterparts [45]. Physiological expression of Bcl-2 also differs among subsets of PBMNs. Therefore, assessment of antisense-induced Bcl-2 modulation in whole PBMNs may be confounded by a shift in the relative abundance of different leukocyte subsets or the kinetics of leukocyte turnover. Further, although antisense-mediated Bcl-2 mRNA downregulation occurs within 24 h, 7296 h are required to see a decrease in protein expression [46
]. We are currently performing studies to optimize assays for Bcl-2 expression as well as methods to determine gene expression profiles that may better serve as predictive markers for anti-Bcl-2 therapies.
In this phase I study, clinical efficacy was not the primary end point. Only seven breast cancer patients were evaluable for response, five of whom had previous exposures to taxanes. Two patients achieved partial responses (4 and 6.5 months) and two patients with unmeasurable diseases remained progression-free for 4 and 9 months. The durable tumor response (6.5 months) in the patient with paclitaxel-resistant disease was encouraging, although it is recognized that docetaxel alone could induce a response in a subset of paclitaxel-resistant breast cancers, especially if previous paclitaxel was given by 3 h infusion [47]. The unequivocal role of G3139 in the combination regimen remains to be elucidated in randomized trials or in a cohort of patients with taxane-refractory tumors.
The frequency of Bcl-2 overexpression was 47% among the 30 breast cancer specimens screened for this study, which is comparable to observations in other reports [7, 48
]. Although Bcl-2 expression in breast cancer has been associated with hormonal receptor positivity and better prognosis, its clinical implication in relation to chemotherapy is unclear. Nevertheless, preclinical studies have supported the hypothesis that Bcl-2 inhibition enhances the antitumor activity of DNA-damaging and microtubule-disturbing agents such as paclitaxel or docetaxel [18
, 33
, 49
]. In addition, non-antisense mechanisms of action may also contribute to the enhanced antitumor activity [50
]. Given the current phase I experience with G3139 and weekly docetaxel, as well as other pilot studies of G3139 with 3-week cycles of docetaxel, further clinical trials of this combination should be pursued in diseases such as breast and prostate cancers. In addition to clinical evaluation, efforts should be continued to optimize and validate assays for assessment of intermediate molecular end points. As with all molecularly targeted therapeutics, knowledge of target effects in patients is essential for optimizing the dose and schedule of G3139 and for rational development of this novel agent.
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Acknowledgements |
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Received for publication December 17, 2003. Revision received April 14, 2004. Accepted for publication April 16, 2004.
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References |
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![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
2. Green DR, Evan GI. A matter of life and death. Cancer Cell 2002; 1: 1930.[CrossRef][ISI][Medline]
3. Reed JC. Apoptosis-targeted therapies for cancer. Cancer Cell 2003; 3: 1722.[ISI][Medline]
4. Tsujimoto Y, Croce CM. Analysis of the structure, transcripts, and protein products of bcl-2, the gene involved in human follicular lymphoma. Proc Natl Acad Sci USA 1986; 83: 52145218.[Abstract]
5. Pezzella F, Turley H, Kuzu I et al. bcl-2 protein in non-small-cell lung carcinoma. N Engl J Med 1993; 329: 690694.
6. Yan JJ, Chen FF, Tsai YC et al. Immunohistochemical detection of Bcl-2 protein in small cell carcinomas. Oncology 1996; 53: 611.[ISI][Medline]
7. Bhargava V, Kell DL, van de Rijn M et al. Bcl-2 immunoreactivity in breast carcinoma correlates with hormone receptor positivity. Am J Pathol 1994; 145: 535540.[Abstract]
8. Colombel M, Symmans F, Gil S. Detection of the apoptosis-suppressing oncoprotein bcl-2 in hormone refractory human prostate cancers. Am J Pathol 1993; 143: 390399.[Abstract]
9. McDonnell T, Troncoso P, Brisbay S. Expression of the protooncogene bcl-2 in the prostate and its association with emergence of androgen-independent prostate cancer. Cancer Res 1992; 52: 69406944.[Abstract]
10. Schmitt CA, Rosenthal CT, Lowe SW. Genetic analysis of chemoresistance in primary murine lymphomas. Nat Med 2000; 6: 10291035.[CrossRef][ISI][Medline]
11. Tu SM, McConnell K, Marin MC et al. Combination adriamycin and suramin induces apoptosis in bcl-2 expressing prostate carcinoma cells [published erratum appears in Cancer Lett 1996; 99: 247]. Cancer Lett 1995; 93: 147155.[CrossRef][ISI][Medline]
12. Koty PP, Zhang H, Levitt ML. Antisense bcl-2 treatment increases programmed cell death in non-small cell lung cancer cell lines. Lung Cancer 1999; 23: 115127.[CrossRef][ISI][Medline]
13. Ziegler A, Luedke GH, Fabbro D et al. Induction of apoptosis in small-cell lung cancer cells by an antisense oligodeoxynucleotide targeting the Bcl-2 coding sequence. J Natl Cancer Inst 1997; 89: 10271036.
14. Zangemeister-Wittke U, Schenker T, Luedke GH et al. Synergistic cytotoxicity of bcl-2 antisense oligodeoxynucleotides and etoposide, doxorubicin and cisplatin on small-cell lung cancer cell lines. Br J Cancer 1998; 78: 10351042.[ISI][Medline]
15. Monia BP, Sasmor H, Johnston JF et al. Sequence-specific antitumor activity of a phosphorothioate oligodeoxyribonucleotide targeted to human C-raf kinase supports an antisense mechanism of action in vivo. Proc Natl Acad Sci USA 1996; 93: 1548115484.
16. Mukhopadhyay T, Roth JA. Antisense regulation of oncogenes in human cancer. Crit Rev Oncol 1996; 7: 151190.
17. Cotter FE, Johnson P, Hall P et al. Antisense oligonucleotides suppress B-cell lymphoma growth in a SCID-hu mouse model. Oncogene 1994; 9: 30493055.[ISI][Medline]
18. Yang D, Ling Y, Amazan M et al. Tumor regression of human breast carcinomas by combination therapy of anti-bcl-2 antisense oligonucleotide and chemotherapeutic drugs. Proc Am Assoc Cancer Res 1999; 40: 729 (Abstr 4814).
19. Jansen B, Schlagbauer-Wadl H, Brown B et al. bcl-2.antisense therapy chemosensitizes human melanoma cells in SCID mice. Nat Med 1998; 4: 232234.[ISI][Medline]
20. Kitada S, Takayama S, De Riel K et al. Reversal of chemoresistance of lymphoma cells by antisense-mediated reduction of bcl-2 gene expression. Antisense Res Dev 1994; 4: 7179.[ISI][Medline]
21. Webb A, Cunningham D, Cotter F et al. BCL-2 antisense therapy in patients with non-Hodgkin lymphoma. Lancet 1997; 349: 11371141.[CrossRef][ISI][Medline]
22. Waters JS, Webb A, Cunningham D et al. Phase I clinical and pharmacokinetic study of bcl-2 antisense oligonucleotide therapy in patients with non-Hodgkin's lymphoma. J Clin Oncol 2000; 18: 18121823.
23. Jansen B, Schlagbauer-Wadl H, Brown BD et al. bcl-2 antisense therapy chemosensitizes human melanoma in SCID mice. Nat Med 1998; 4: 232234.[ISI][Medline]
24. Ochoa L, Kuhn J, Salinas R et al. G3139 downregulates the expression of Bcl-2 in patients with metastatic colorectal cancer treated with irinotecan (CPT-11). Proc Am Assoc Cancer Res 2001; 42: 848 (Abstr).
25. Chi KN, Gleave ME, Klasa R et al. A phase I dose-finding study of combined treatment with an antisense Bcl-2 oligonucleotide (Genasense) and mitoxantrone in patients with metastatic hormone-refractory prostate cancer. Clin Cancer Res 2001; 7: 39203927.
26. Rudin CM, Otterson GA, Mauer AM et al. A pilot trial of G3139, a bcl-2 antisense oligonucleotide, and paclitaxel in patients with chemorefractory small-cell lung cancer. Ann Oncol 2002; 13: 539545.
27. Marcucci G, Byrd JC, Dai G et al. Phase 1 and pharmacodynamic studies of G3139, a Bcl-2 antisense oligonucleotide, in combination with chemotherapy in refractory or relapsed acute leukemia. Blood 2003; 101: 425432.
28. Jansen B, Wacheck V, Heere-Ress E et al. Chemosensitization of malignant melanoma by BCL2 antisense therapy. Lancet 2000; 356: 17281733.[CrossRef][ISI][Medline]
29. Monzo M, Rosell R, Sanchez JJ et al. Paclitaxel resistance in non-small-cell lung cancer associated with beta-tubulin gene mutations. J Clin Oncol 1999; 17: 17861793.
30. Ling V, Charles F, Kettering Prize. P-glycoprotein and resistance to anticancer drugs. Cancer 1992; 69: 26032609.[ISI][Medline]
31. Sumantran VN, Ealovega MW, Nunez G et al. Overexpression of Bcl-XS sensitizes MCF-7 cells to chemotherapy-induced apoptosis. Cancer Res 1995; 55: 25072510.[Abstract]
32. Tang SC, Shaheta N, Chernenko G et al. Expression of BAG-1 in invasive breast carcinomas. J Clin Oncol 1999; 17: 17101719.
33. Haldar S, Basu A, Croce C. Bcl2 is the guardian of microtubule integrity. Cancer Res 1997; 57: 229233.[Abstract]
34. Miller AB, Hoogstraten B, Staquet M et al. Reporting results of cancer treatment. Cancer 1981; 47: 207214.[ISI][Medline]
35. Raynaud FI, Orr RM, Goddard PM et al. Pharmacokinetics of G3139, a phosphorothioate oligodeoxynucleotide antisense to bcl-2, after intravenous administration or continuous subcutaneous infusion to mice. J Pharmacol Exp Ther 1997; 281: 420427.
36. Burstein HJ, Manola J, Younger J et al. Docetaxel administered on a weekly basis for metastatic breast cancer. J Clin Oncol 2000; 18: 12121219.
37. Piccart MJ, Klijn J, Paridaens R et al. Corticosteroids significantly delay the onset of docetaxel-induced fluid retention: final results of a randomized study of the European Organization for Research and Treatment of Cancer Investigational Drug Branch for Breast Cancer. J Clin Oncol 1997; 15: 31493155.[Abstract]
38. Jansen B, Wacheck V, Heere-Ress E et al. Clinical, pharmacologic and pharmacodynamic study of Genasense (G3139, Bcl-2 antisense oligonucleotide) and Dacarbazine in patients with malignant melanoma. Proc Am Soc Clin Oncol 2001; 20: 357.
39. Morris MJ, Tong WP, Cordon-Cardo C et al. Phase I trial of Bcl-2 antisense oligonucleotide (G3139) administered by continuous intravenous infusion in patients with advanced cancer. Clin Cancer Res 2002; 8: 679683.
40. Yuen AR, Halsey J, Fisher GA et al. Phase I study of an antisense oligonucleotide to protein kinase C-alpha (ISIS 3521/CGP 64128A) in patients with cancer. Clin Cancer Res 1999; 5: 33573363.
41. Adjei AA, Dy GK, Erlichman C et al. A phase I trial of ISIS 2503, an antisense inhibitor of H-ras, in combination with gemcitabine in patients with advanced cancer. Clin Cancer Res 2003; 9: 115123.
42. Tolcher AW. Preliminary phase I results of G3139 (bcl-2 antisense oligonucleotide) therapy in combination with docetaxel in hormone-refractory prostate cancer. Semin Oncol 2001; 28: 6770.
43. Dragowska WH, Lopes de Menezes DE, Sartor J et al. Quantitative fluorescence cytometric analysis of Bcl-2 levels in tumor cells exhibiting a wide range of inherent Bcl-2 protein expression: correlation with Western blot analysis. Cytometry 2000; 40: 346352.[CrossRef][ISI][Medline]
44. Chi KN, Gleave ME, Klasa R et al. A phase I dose-finding study of combined treatment with an antisense Bcl-2 oligonucleotide (Genasense) and mitoxantrone in patients with metastatic hormone-refractory prostate cancer. Clin Cancer Res 2001; 7: 39203927.
45. Zhou D, Clarke P, Wang J et al. Identification of a promoter that controls aromatase expression in human breast cancer and adipose stromal cells. J Biol Chem 1996; 271: 1519415202.
46. van de Donk NW, Kamphuis MM, van Dijk M et al. Chemosensitization of myeloma plasma cells by an antisense-mediated downregulation of Bcl-2 protein. Leukemia 2003; 17: 211219.[CrossRef][ISI][Medline]
47. Valero V, Jones SE, Von Hoff DD et al. A phase II study of docetaxel in patients with paclitaxel-resistant metastatic breast cancer. J Clin Oncol 1998; 16: 33623368.[Abstract]
48. Silvestrini R, Veneroni S, Daidone M. The bcl-2 protein: a prognostic indicator strongly related to p53 protein in lymph node negative breast cancer patients. J Natl Cancer Inst 1994; 86: 499504.[Abstract]
49. Miayake H, Tolcher A, Gleave ME. Chemosensitization and delayed androgen-independent recurrence of prostate cancer with the use of antisense Bcl-2 oligodeoxynucleotides. J Natl Cancer Inst 2000; 92: 3441.
50. Benimetskaya L, Miller P, Benimetsky S et al. Inhibition of potentially anti-apoptotic proteins by antisense protein kinase C-alpha (Isis 3521) and antisense bcl-2 (G3139) phosphorothioate oligodeoxynucleotides: relationship to the decreased viability of T24 bladder and PC3 prostate cancer cells. Mol Pharmacol 2001; 60: 12961307.