Non-platinum gemcitabine combinations in non-small cell lung cancer

A Novel Strategy to Improve the Therapeutic Efficacy of Gemcitabine for Non-Small Cell Lung Cancer by the Tumor-Penetrating Peptide iRGD

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, comprising approximately 75–80% of all lung cancers. Gemcitabine is an approved chemotherapy drug for NSCLC. The objective of this study was to develop a novel strategy to improve the therapeutic efficacy of Gemcitabine for NSCLC by the co-administered iRGD peptide. We showed that the rates of positive expression of αvβ3, αvβ5 and NRP-1 in the A549 cell line were 68.5%, 35.3% and 94.5%, respectively. The amount of Evans Blue accumulated in the tumor of Evans Blue+iRGD group was 2.5 times that of Evans Blue group. The rates of growth inhibition of the tumors of the iRGD group, the Gemcitabine group and the Gemcitabine+iRGD group were 8%, 59.8% and 86.9%, respectively. The results of mechanism studies showed that PCNA expression in the Gemcitabine+iRGD group decreased 71.5% compared with that in Gemcitabine group. The rate of apoptosis in the Gemcitabine+iRGD group was 2.2 time that of the Gemcitabine group. Therefore, the tumor-penetrating Peptide iRGD can enhance the tumor-penetrating ability and therapeutic efficacy of Gemcitabine in the A549 xenograft. The combined application of Gemcitabine with iRGD may be a novel strategy to enhance the clinical therapeutic efficacy of Gemcitabine in patients with NSCLC.

The C-terminal region of Bfl-1 sensitizes non-small cell lung cancer to gemcitabine-induced apoptosis by suppressing NF-κB activity and down-regulating Bfl-1

Gemcitabine is used to treat several cancers including lung cancer. However, tumor cells often escape gemcitabine-induced cell death via various mechanisms, which include modulating bcl-2 family members and NF-κB activation. We previously reported that the C-terminal region of Bfl-1 fused with GFP (BC) is sufficient to induce apoptosis in 293T cells. In the present study, we investigated the anti-tumor effect of combined BC gene therapy and gemcitabine chemotherapy in vitro and in vivo using non-small cell lung cancer cell lines and a xenograft model. Cell lines were resistant to low dose gemcitabine (4-40 ng/ml), which induced NF-κB activation and concomitant up-regulation of Bfl-1 (an NF-κB-regulated anti-apoptotic protein). BC induced the apoptosis of A549 and H157 cells with caspase-3 activation. Furthermore, co-treatment with BC and low dose gemcitabine synergistically and efficiently induced mitochondria-mediated apoptosis in these cells. When administered alone or with low dose gemcitabine, BC suppressed NF-κB activity, inhibited the nuclear translocation of p65/relA, and down-regulated Bfl-1 expression. Furthermore, direct suppression of Bfl-1 by RNA interference sensitized cells to gemcitabine-induced cell death, suggesting that Bfl-1 importantly regulates lung cancer cell sensitivity to gemcitabine. BC and gemcitabine co-treatment also showed a strong anti-tumor effect in a nude mouse/A549 xenograft model. These results suggest that lung cancer cells become resistant to gemcitabine via NF-κB activation and the subsequent overexpression of Bfl-1, and that BC, which has both pro-apoptotic and NF-κB inhibitory effects, could be harnessed as a gene therapy to complement gemcitabine chemotherapy in non-small cell lung cancer.

Gemcitabine plus docetaxel as first-line chemotherapy in patients with advanced non-small cell lung cancer: a lung cancer Galician group phase II study

BACKGROUND

Numerous phase II and III clinical trials have demonstrated a higher activity of combined gemcitabine plus docetaxel schedules against non-small cell lung cancer (NSCLC) than that of both agents in monotherapy.

METHODS

This phase II study evaluated a 3-week based schedule of docetaxel 85 mg/m(2) (1-h i.v. infusion, d8) combined with gemcitabine 1,000 mg/m(2) (30-min i.v. infusion; d1,8) as first-line chemotherapy for patients with advanced NSCLC.

RESULTS

Forty-one patients with non-resectable, stage IIIB/IV, and bidimensionally measurable disease were enrolled. A total of 182 chemotherapy cycles (median 6, range 1-6) was administered to 40 patients during the study; one patient did not receive chemotherapy due to a protocol deviation. Two patients were not evaluable for treatment efficacy. The overall response rate found was 44% (95% CI, 29-59%): three patients (7%) had a complete response and 15 patients (37%) had a partial response (median duration of response = 4.0 months). With a median follow-up of 8.7 months, the median time to disease progression was 4.4 months and the median overall survival was 7.3 months. The combined gemcitabine plus docetaxel chemotherapy was well tolerated except for pulmonary toxicity. The main grade 3-4 hematological toxicity was neutropenia (28% of patients, 9% of cycles). Two cases of febrile neutropenia were reported. The main grade 3-4 non-hematological toxicity was pulmonary toxicity (23% of patients, 6% of cycles).

CONCLUSION

Gemcitabine 1,000 mg/m(2) on days 1 and 8 in combination with docetaxel 85 mg/m(2) on day 8 given in 3-week cycles is an active and well-tolerated first-line chemotherapeutic regimen for advanced NSCLC.