O-104 XYOTAXT™ vs. gemcitabine or vinorelbine for the treatment of performance status (PS) 2 patients with chemotherapy-naïve advanced non-small cell lung cancer (NSCLC): The STELLAR 4 Phase III study

Phase III trial comparing paclitaxel poliglumex (CT-2103, PPX) in combination with carboplatin versus standard paclitaxel and carboplatin in the treatment of PS 2 patients with chemotherapy-naïve advanced non-small cell lung cancer

INTRODUCTION

Performance status (PS) 2 patients with non-small cell lung cancer (NSCLC) experience more toxicity, lower response rates, and shorter survival times than healthier patients treated with standard chemotherapy. Paclitaxel poliglumex (PPX), a macromolecule drug conjugate of paclitaxel and polyglutamic acid, reduces systemic exposure to peak concentrations of free paclitaxel and may lead to increased concentrations in tumors due to enhanced vascular permeability.

METHODS

Chemotherapy-naive PS 2 patients with advanced NSCLC were randomized to receive carboplatin (area under the curve = 6) and either PPX (210 mg/m/10 min without routine steroid premedication) or paclitaxel (225 mg/m/3 h with standard premedication) every 3 weeks. The primary end point was overall survival.

RESULTS

A total of 400 patients were enrolled. Alopecia, arthralgias/myalgias, and cardiac events were significantly less frequent with PPX/carboplatin, whereas grade > or =3 neutropenia and grade 3 neuropathy showed a trend of worsening. There was no significant difference in the incidence of hypersensitivity reactions despite the absence of routine premedication in the PPX arm. Overall survival was similar between treatment arms (hazard ratio, 0.97; log rank p = 0.769). Median and 1-year survival rates were 7.9 months and 31%, for PPX versus 8 months and 31% for paclitaxel. Disease control rates were 64% and 69% for PPX and paclitaxel, respectively. Time to progression was similar: 3.9 months for PPX/carboplatin versus 4.6 months for paclitaxel/carboplatin (p = 0.210).

CONCLUSION

PPX/carboplatin failed to provide superior survival compared with paclitaxel/carboplatin in the first-line treatment of PS 2 patients with NSCLC, but the results with respect to progression-free survival and overall survival were comparable and the PPX regimen was more convenient.

Lung cancer in women: exploring sex differences in susceptibility, biology, and therapeutic response

Src tyrosine kinases regulate a large number of important mechanisms in normal and cancerous cells, are overexpressed in a broad range of tumors including lung cancer, and thus represent a potential target for cancer therapy. Preclinical experiments indicate that small-molecule inhibitors of Src block tumor growth, metastasis, and angiogenesis. Phase I data from healthy volunteers also suggest that inhibitors of Src prevent bone resorption. Several phase II trials with small-molecule inhibitors of Src are under way or have been initiated in lung cancer and in other malignancies, as discussed herein.

New developments in chemotherapy for advanced non-small cell lung cancer

PURPOSE OF REVIEW

The treatment of patients with advanced non-small cell lung cancer has changed considerably in the past decade. This paper reviews the most significant changes seen in chemotherapy and the most promising new agents in development for this disease.

RECENT FINDINGS

Chemotherapy prolongs survival and improves quality of life in patients with a good performance status and appears to alleviate disease-related symptoms in patients with a lower performance status. Platinum-based regimens became standard; none of the third-generation drug combinations seemed to be superior to the others. Nonplatinum combinations are reasonable alternatives now and offer a better toxicity profile in certain populations. Attempts to add molecular-targeted therapy to combination chemotherapy have failed except for bevacizumab. New compounds such as pemetrexed, bortezomib, TLK286, bevacizumab, and the epothilones are currently being evaluated in non-small cell lung cancer.

SUMMARY

Management of non-small cell lung cancer has improved considerably in the past decade. The overall benefit of chemotherapy over supportive care has been shown, platinum-based doublets have been established, nonplatinum regimens have been developed, chemotherapy has been used more broadly in subgroups of patients who have been previously neglected, and a shorter chemotherapy duration has been shown to be equally effective. After hitting a plateau in the benefit of chemotherapy, new drugs with novel action mechanisms such as the ones described here offer hope to improve therapy for this disease.

Neglected and underrepresented subpopulations: elderly and performance status 2 patients with advanced-stage non-small-cell lung cancer

Elderly patients and those with performance status (PS) of 2 with non-small-cell lung cancer (NSCLC) have been habitually underrepresented in clinical trials. Therapeutic neglect and legitimate concerns about toxicity are responsible. Yet randomized phase III data in the elderly have demonstrated a survival benefit for single-agent chemotherapy compared with best supportive care, and retrospective analyses of fit elderly patients enrolled on platinum agent-based trials have shown similar survival rates, albeit more toxicity, compared with younger counterparts. To date, however, there are no phase III trials specific to the elderly population demonstrating a survival benefit for platinum agent-based combinations compared with the constituent nonplatinum single agent; such efforts are ongoing. Performance status is a critical prognostic factor in advanced-stage NSCLC. Retrospective analyses of multiple trials conducted before 1995 suggested that patients with advanced-stage NSCLC and compromised PS experienced substantial toxicity and virtually no benefit from systemic chemotherapy, leading most cooperative groups to suspend research in this cohort. But this trend has changed. A subset analysis of patients with a PS of 2 enrolled on a recent Cancer and Leukemia Group B trial showed a significant survival benefit for carboplatin in combination with paclitaxel compared with paclitaxel alone, and recent randomized phase II efforts evaluating platinum agent-based combinations have yielded median survival times of > 6 months with acceptable toxicity rates. Although the Selective Targeting for Efficacy in Lung Cancer, Lower Adverse Reaction trials testing polyglutamated paclitaxel failed to show a survival advantage compared with standard agents, interest in testing new, less toxic agents continues. Future efforts will need to differentiate the reasons for compromised PS, be it tumor burden, comorbidity, or both.