oblimersen and Lung-Neoplasms

Bcl-2 protein inhibits apoptosis and confers resistance to treatment with traditional cytotoxic chemotherapy, radiotherapy, and monoclonal antibodies. Oblimersen sodium is an antisense oligonucleotide compound designed to specifically bind to human bcl-2 mRNA, resulting in catalytic degradation of bcl-2 mRNA and subsequent decrease in bcl-2 protein translation. Both small cell and non-small cell lung cancer show baseline and inducible expression of bcl-2, which may contribute to resistance to therapy. Preclinical studies have shown that combining bcl-2 antisense with chemotherapy improves antitumor response, increases apoptosis of tumor cells, and increases survival. Preliminary data from a large international randomized trial in melanoma show a trend toward increased survival and significantly improved response rates and response duration when oblimersen is added to dacarbazine. Phase I studies in small cell lung cancer patients demonstrate that oblimersen can be combined with paclitaxel or carboplatin and etoposide. The combination of docetaxel and oblimersen has been shown to be feasible in Phase I studies and is currently undergoing evaluation in comparison with docetaxel alone as first-line salvage therapy in patients refractory or relapsed after one prior chemotherapy regimen. Enhancement of the efficacy of anticancer treatments with oblimersen bcl-2 antisense therapy represents a promising new apoptosis-modulating strategy.

Topics: Apoptosis; Carcinoma, Non-Small-Cell Lung; Catalysis; Humans; Lung Neoplasms; Oligonucleotides, Antisense; Proto-Oncogene Proteins c-bcl-2; RNA, Messenger; Thionucleotides

Small cell lung cancer continues to recur and claim the lives of most of its victims. Thus, management of the patient with recurrent disease remains an active area of research. This review provides an update of clinical research experience over the past decade with relatively new conventional cytotoxins in this setting, such as the topoisomerase I inhibitors and the taxanes. Additionally, novel molecular targeted approaches with specific relevance for small cell lung cancer are discussed.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Small Cell; Clinical Trials as Topic; Gefitinib; Humans; Immunotoxins; Lung Neoplasms; Neoplasm Recurrence, Local; Oligonucleotides, Antisense; Prognosis; Quinazolines; Thionucleotides

To assess the efficacy and toxicity of carboplatin, etoposide, and the bcl-2 antisense oligonucleotide oblimersen as initial therapy for extensive-stage small-cell lung cancer (ES-SCLC). bcl-2 has been implicated as a key factor in SCLC oncogenesis and chemotherapeutic resistance.. A 3:1 randomized phase II study was performed to evaluate carboplatin and etoposide with (arm A) or without oblimersen (arm B) in 56 assessable patients with chemotherapy-naïve ES-SCLC. Outcome measures including toxicity, objective response rate, complete response rate, failure-free survival, overall survival, and 1-year survival rate.. Oblimersen was associated with slightly more grade 3 to 4 hematologic toxicity (88% v 60%; P = .05). Response rates were 61% (95% CI, 45% to 76%) for arm A and 60% (95% CI, 32% to 84%) for arm B. The percentage of patients alive at 1 year was 24% (95% CI, 12% to 40%) with oblimersen, and 47% (95% CI, 21% to 73%) without oblimersen. Hazard ratios for failure-free survival (1.79; P = .07) and overall survival (2.13; P = .02) suggested worse outcome for patients receiving oblimersen. These results hold when adjusted for other prognostic factors, such as weight loss, in multivariate regression analysis.. Despite extensive data supporting a critical role for Bcl-2 in chemoresistance in SCLC, addition of oblimersen to a standard regimen for this disease did not improve any clinical outcome measure. Emerging data from several groups suggest that this lack of efficacy may be due to insufficient suppression of Bcl-2 in vivo. Additional evaluation of this agent in SCLC is not warranted.

Topics: Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Carboplatin; Carcinoma, Small Cell; Disease-Free Survival; Etoposide; Female; Humans; Lung Neoplasms; Male; Middle Aged; Multivariate Analysis; Neoplasm Staging; Odds Ratio; Thionucleotides; Treatment Outcome

Bcl-2 is expressed in the majority of cases of small cell lung cancer (SCLC) and may contribute to chemotherapeutic resistance. Bcl-2 suppression by G3139 (oblimersen sodium), a phosphorothioate oligonucleotide complementary to the bcl-2 mRNA, has the potential to enhance the antitumor efficacy of standard cytotoxic chemotherapy. A dose-finding study was performed evaluating the combination of G3139, carboplatin, and etoposide in patients with previously untreated extensive stage SCLC.. Sixteen patients were treated in three consecutive cohorts. Cohort 1 (n=5) received G3139 5 mg/kg/d on days 1 to 8 of a 21 day cycle, with carboplatin area under the curve (AUC)=6 on day 6, and etoposide 80 mg/m2/d on days 6 to 8. In cohort 2 (n=4), carboplatin dose was reduced to AUC=5. In cohort 3 (n=7), G3139 dose was escalated to 7 mg/kg/d. G3139 plasma concentrations and Bcl-2 protein levels in peripheral blood mononuclear cells were evaluated.. Two of three assessable patients in cohort 1 experienced cycle 1 dose-limiting toxicity (grade 4 neutropenia). No cycle 1 dose-limited toxicity was observed in cohorts 2 or 3. Of 14 patients assessable for response, partial response was documented in 12 patients (86%), and stable disease in two. Median time to progression was 5.9 months. Carboplatin and etoposide administration did not appear to alter G3139 pharmacokinetics. No evidence of Bcl-2 suppression in peripheral blood mononuclear cells was observed.. The combination of G3139, carboplatin, and etoposide is well tolerated and results in an encouraging response rate and time to progression in patients with extensive stage SCLC.

Topics: Adult; Aged; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Carboplatin; Carcinoma, Small Cell; Disease-Free Survival; Dose-Response Relationship, Drug; Etoposide; Female; Humans; Lung Neoplasms; Male; Maximum Tolerated Dose; Middle Aged; Oligonucleotides, Antisense; Proto-Oncogene Proteins c-bcl-2; Survival Rate; Thionucleotides; United States

Chemorefractory small-cell lung cancer (SCLC) is defined as disease that progresses during primary therapy or within 3 months of completion of primary therapy. Patients with chemorefractory SCLC have a very poor prognosis, and no treatment has been shown to be of significant clinical benefit. Elevated expression of Bcl-2 is found in the majority of SCLCs and has been associated with therapeutic resistance. Suppression of Bcl-2 levels through the use of G3139, an antisense oligonucleotide complementary to the mRNA encoding Bcl-2, might increase the antitumor efficacy of cytotoxic therapy.. Twelve patients with chemorefractory SCLC participated in this pilot trial of paclitaxel combined with G3139. G3139 was given by continuous i.v. infusion over 7 days at a fixed dose of 3 mg/kg/day. Paclitaxel dose was initially 175 mg/m2 on day 6, but was decreased to 150 mg/m2 due to myelosuppression observed in two of the three patients treated in the first dose cohort.. The combination of paclitaxel at 150 mg/m2 and G3139 at 3 mg/kg/day was found to be feasible and well tolerated. No objective responses were observed, but two patients had stable disease, one remaining stable on therapy for >30 weeks. Plasma G3139 levels were determined, and were found to be highest in the patient with prolonged stable disease, suggesting that individual variation in metabolism and clearance of the antisense oligonucleotide may influence activity.. This study demonstrates that G3139 can be combined with paclitaxel in a cytotoxic dose range, and suggests that a similar combination be tested for activity in the context of chemoresponsive disease.

Topics: Adult; Aged; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Small Cell; Disease Progression; Drug Resistance, Neoplasm; Female; Genes, bcl-2; Humans; Infusions, Intravenous; Lung Neoplasms; Male; Middle Aged; Oligonucleotides, Antisense; Paclitaxel; Thionucleotides; Treatment Outcome

Bcl-2 is an anti-apoptotic gene that is frequently overexpressed in human cancers. G3139 is an antisense oligonucleotide against bcl-2 that has shown limited efficacy in clinical trials. Here, we report the synthesis of a new antisense oligonucleotide containing additional chemical modifications and its delivery using nanoparticles.. An oligonucleotide G3139-GAP was synthesized, which has 2'-O-methyl nucleotides at the 5' and 3' ends based on a "gapmer" design. Furthermore, G3139-GAP was incorporated into lipid nanoparticles (LNPs) composed of DOTAP/egg PC/cholesterol/Tween 80. The LNP-loaded G3139-GAP was evaluated in A549 lung cancer cells both in vitro and in a murine xenograft model for biological activity and therapeutic efficacy.. The LNPs showed excellent colloidal and serum stability, and high encapsulation efficiency for G3139-GAP. They have a mean particle diameter and zeta potential of 134 nm and 9.59 mV, respectively. G3139-GAP-LNPs efficiently downregulated bcl-2 expression in A549 cells, as shown by 40% and 83% reduction in mRNA and protein levels, respectively. Furthermore, G3139-GAP-LNPs were shown to inhibit tumor growth, prolong survival, and downregulate tumor bcl-2 expression in an A549 murine xenograft tumor model. These data indicate that G3139-GAP-LNPs have excellent anti-tumor efficacy and warrant further evaluation.

Topics: A549 Cells; Animals; Cell Line, Tumor; Down-Regulation; Humans; Lipids; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Nanoparticles; Oligonucleotides, Antisense; Particle Size; Proto-Oncogene Proteins c-bcl-2; RNA, Messenger; Thionucleotides

Oblimersen, an ODN targeting BCL-2 RNA, has been shown to be effective in reducing BCL-2 expression in vitro and in in vivo models engineered to overexpress BCL-2. The present study evaluated the efficacy of combining BCL-2 ODN and radiation in small-cell lung cancers (SCLC) cell lines.. The in vitro effect was determined using short term (cell viability) and long term (clonogenic) assays. Apoptosis, BCL-2 expression and intratumoural uptake of the FAM-ODN with or without prior radiation treatment were also evaluated. Combination of ODN and RT was also assessed in vivo.. Radiation was shown to increase intracellular and intratumoural penetration of oblimersen, confirming previous results obtained in prostate cancer xenograft models. Oblimersen decreased BCL-2 protein expression in vitro and in vivo. BCL-2 ODN sensitised H69 cells to radiation in vitro and in vivo. Oblimersen increased radiation-induced apoptosis and decreased in vivo tumoural vascularisation.. Oblimersen was shown to increase in vitro and in vivo effect of RT on SCLC cell lines. Radiation increases intracellular and intratumoural penetration of ODN. This pre-clinical study argues in favour of clinical development in localised SCLC.

Topics: Animals; Apoptosis; Carcinoma, Small Cell; Cell Line, Tumor; Cell Survival; Combined Modality Therapy; Female; Humans; Lung Neoplasms; Mice; Mice, Nude; Oligonucleotides, Antisense; Proto-Oncogene Proteins c-bcl-2; Thionucleotides; Xenograft Model Antitumor Assays

Several phosphorothioate antisense oligodeoxynucleotides (ODN) are developed to target factors potentially involved in tumor growth and apoptosis suppression. Among them, the 18-mer G3139 (Oblimersen), which targets Bcl-2, is currently being tested in phase II and phase III clinical trials for various tumors in combination with chemotherapy. On the other hand, ODNs containing CpG dinucleotides (CpG-ODN) within specific-sequence contexts (CpG motifs) have been shown to activate rodent or primate immune cells via toll-like receptor 9 (TLR9) and have demonstrated remarkable T cell-dependent antitumor efficacy in a series of murine tumor models. However, immune cell activation by CpG-ODN is largely diminished upon C-5 methylation at CpG cytosine. As G3139 contains CpG motifs, we questioned whether the antitumor effects seen in human tumor xenografts might be abrogated by cytosine C-5 methylation of G3139, which retained the ability of G3139 to suppress Bcl-2 expression in tissue culture, or by similar derivatization of other phosphorothioate ODNs developed for the immune activation of rodent or human cells. The in vivo antitumor efficacy of the immunostimulatory H1826 and H2006 ODNs was compared with that of G3139. Bcl-2 suppression achieved by G3139 purportedly sensitizes tumor cells toward cytotoxic agents, and some of the experiments employed combinations of ODN with such drugs as cisplatin or etoposide. H1826, H2006, and G3139 all produced similar, striking, growth inhibitory effects on either H69 SCLC, A2780 ovarian carcinoma, or A549 lung adenocarcinoma human tumor xenografts at doses of 0.3 mg/kg and 1 mg/kg (H1826, H2006) or 12 mg/kg (G3139) per day. In contrast, the H2006-mC (1 mg/kg) or G3139-mC (12 mg/kg) derivatives demonstrated no significant antitumor effects. The combination of G3139 (12 mg/kg) with cisplatin produced some additive antitumor efficacy, which was not seen in combinations of G3139-mC (12 mg/kg) or H1826 (1 mg/kg) with cisplatin. G3139, at a dose of 12 mg/kg, alone induced extensive enlargement of the spleen. Immunostimulation was evaluated in vitro by flow cytometric measurements of the CD80 and CD86 activation markers found on CD19+ murine splenocytes. The CpG-ODN producing strong antitumor effects in vivo also induced these activation markers in vitro, in contrast to the in vivo inactive G3139-mC. Our data indicate a significant contribution of the immunostimulatory properties of CpG-ODN (including G3139) to the antitumor effect

Topics: Adenocarcinoma; Adjuvants, Immunologic; Animals; Antineoplastic Agents; B-Lymphocytes; Carcinoma; Cell Line, Tumor; Cytosine; Female; Humans; Lung Neoplasms; Lymphocyte Activation; Methylation; Mice; Mice, Nude; Neoplasms; Oligodeoxyribonucleotides; Ovarian Neoplasms; Proto-Oncogene Proteins c-bcl-2; Thionucleotides; Xenograft Model Antitumor Assays

Overexpression of Bcl-2 protein in cancer cells can inhibit programmed cell death and engender chemoresistance. Reducing Bcl-2 protein levels by using antisense oligonucleotides targeting the gene message can increase the sensitivity of cancer cells to cytotoxic agents. The objective of this work was to investigate the antitumor efficacy of the Bcl-2 antisense oligonucleotide oblimersen (Genasense; G3139), alone and in combination with vinorelbine (VNB), in an ectopic and orthotopic xenograft model of NCI-H460 human non-small-cell lung cancer. In addition to assessing therapeutic effect, Bcl-2 protein expression in tumor tissue isolated from lung and heart was measured. In the ectopic xenograft model, oblimersen at 5 and 10 mg/kg significantly inhibited tumor growth compared with saline-treated control groups, and furthermore, the antitumor effect of oblimersen was associated with down-regulation of Bcl-2 protein in isolated tumor tissue. Moreover, the combination of oblimersen with VNB was more active in inhibiting tumor growth than either drug used alone. In the orthotopic model, oblimersen treatment (5 mg/kg) increased the median survival time of mice to 33 days in comparison with a median survival time of 21 days in the control animals. With this model, the anticancer effect was demonstrated by assessing tumor growth in lung and heart tissues by hematoxylin and eosin staining and Bcl-2 expression by immunohistochemistry. When VNB at 5 mg/kg was combined with oblimersen administered at 5 mg/kg, 33% of mice survived more than 90 days. These data suggest that the combination of oblimersen and VNB may provide enhanced antitumor activities against non-small-cell lung cancer.

Topics: Animals; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Humans; Immunohistochemistry; Lung Neoplasms; Male; Mice; Mice, SCID; Neoplasm Transplantation; Oligonucleotides, Antisense; Proto-Oncogene Proteins c-bcl-2; Thionucleotides; Time Factors; Vinblastine; Vinorelbine

Topics: Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Small Cell; Disease Progression; Drug Resistance, Neoplasm; Genes, bcl-2; Humans; Lung Neoplasms; Oligonucleotides, Antisense; Paclitaxel; Thionucleotides; Treatment Outcome

Topics: Acute Disease; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Small Cell; Clinical Trials, Phase I as Topic; Humans; Leukemia, Myeloid; Lung Neoplasms; Middle Aged; Multicenter Studies as Topic; Oligonucleotides, Antisense; Thionucleotides

Topics: Carcinoma, Small Cell; Clinical Trials as Topic; Disease Progression; Genes, bcl-2; Humans; Lung Neoplasms; Oligonucleotides, Antisense; Proto-Oncogene Proteins c-bcl-2; Thionucleotides; Treatment Outcome