Small cell lung cancer: will recent progress lead to improved outcomes?

Small cell lung cancer (SCLC) is an aggressive neuroendocrine malignancy with a unique natural history characterized by a short doubling time, high growth fraction, and early development of widespread metastases. Although a chemotherapy- and radiation-sensitive disease, SCLC typically recurs rapidly after primary treatment, with only 6% of patients surviving 5 years from diagnosis. This disease has been notable for the absence of major improvements in its treatment: Nearly four decades after the introduction of a platinum-etoposide doublet, therapeutic options have remained virtually unchanged, with correspondingly little improvement in survival rates. Here, we summarize specific barriers and challenges inherent to SCLC research and care that have limited progress in novel therapeutic development to date. We discuss recent progress in basic and translational research, especially in the development of mouse models, which will provide insights into the patterns of metastasis and resistance in SCLC. Opportunities in clinical research aimed at exploiting SCLC biology are reviewed, with an emphasis on ongoing trials. SCLC has been described as a recalcitrant cancer, for which there is an urgent need for accelerated progress. The NCI convened a panel of laboratory and clinical investigators interested in SCLC with a goal of defining consensus recommendations to accelerate progress in the treatment of SCLC, which we summarize here.

Southwest Oncology Group S0802: a randomized, phase II trial of weekly topotecan with and without ziv-aflibercept in patients with platinum-treated small-cell lung cancer

PURPOSE

Development of new therapies for previously treated small-cell lung cancer (SCLC) is a major unmet need. Here, we describe a randomized, phase II trial of weekly topotecan with or without ziv-aflibercept (VEGF-trap) in this clinical setting.

PATIENTS AND METHODS

Patients with previously treated SCLC (one line of platinum-based chemotherapy), performance status of 0 to 1, adequate organ function, treated brain metastases, and no recent vascular events or bleeding diatheses were eligible. Eligible patients were stratified as platinum-sensitive or platinum-refractory and randomly assigned to receive weekly topotecan 4 mg/m(2) intravenously (IV) with or without ziv-aflibercept 6 mg/kg IV every 21 days. Progression-free survival (PFS) at 3 months was the primary end point.

RESULTS

In 189 randomly assigned patients, treatment arms were well balanced with regard to clinical characteristics. The 3-month PFS was significantly improved with the addition of ziv-aflibercept in patients who had platinum-refractory disease (27% v 10%; P = .02) but not in patients with platinum-sensitive disease (24% v 15%; P = .22). Although response rate was low, disease control rate was higher with combination therapy than with topotecan alone in patients who had platinum-sensitive disease (37% v 18%; P = .05) and in those who had platinum-refractory disease (25% v 15%; P = .14). Overall survival (OS) was not significantly improved in either strata. Grades 3 to 5 toxicities were more common with the addition of ziv-aflibercept.

CONCLUSION

Ziv-aflibercept improved the 3-month PFS in patients who had platinum-refractory SCLC, but its addition increased toxicity. OS was similar with combined ziv-aflibercept and topotecan compared with topotecan in both strata.

Phase II study of maintenance sunitinib following irinotecan and carboplatin as first-line treatment for patients with extensive-stage small-cell lung cancer

BACKGROUND

Inhibition of angiogenesis may be effective in the treatment of small-cell lung cancer (SCLC). Sunitinib, an oral agent that inhibits the VEGF signaling pathway, may delay progression in sequence with chemotherapy. This phase II trial was designed to evaluate the role of sunitinib monotherapy following 6 cycles of irinotecan and carboplatin in patients with newly diagnosed extensive-stage (ES) SCLC.

METHOD

Patients aged ≥18 years with previously untreated ES-SCLC were eligible. Additional criteria included: ECOG PS 0-1, no active brain metastases, and adequate organ function. Patients received 28-day cycles of irinotecan (60 mg/m(2), days 1, 8, 15) and carboplatin (AUC=4, day 1), and were assessed for response every 8 weeks. After 6 cycles of chemotherapy, patients with stable disease or responding disease proceeded to sunitinib monotherapy (25 mg orally daily) until disease progression or unacceptable toxicity. The primary endpoint was 1-year overall survival (OS).

RESULTS

Between 2/09 and 10/09, 34 patients (median age 65 years [range, 41-80]) were enrolled. 53% of patients were male, 47% had ECOG PS 0.21 patients (62%) completed 6 cycles of chemotherapy, and 17 (50%) initiated sunitinib monotherapy (median duration: 9 weeks; range, 2-28+weeks). After a median follow-up of 50 weeks (range: 37-68 weeks), 22 (62%) of the patients remain alive. The objective response rate with chemotherapy was 59%, and an additional 20% had stable disease. 1-year OS was 54% and median time to progression was 7.6 months. Grade 3/4 toxicity was rare during sunitinib monotherapy.

CONCLUSIONS

This phase II trial provides support for further study of sunitinib maintenance therapy following platinum-doublet chemotherapy in patients with ES-SCLC. The 1 year OS of 54% is encouraging, and a randomized trial would be appropriate to assess sunitinib's impact following chemotherapy.

Novel strategies for the treatment of small-cell lung carcinoma

Small-cell lung cancer (SCLC) is a disease with a poor prognosis and limited treatment options. Over the past 30 years, basic and clinical research have translated to little innovation in the treatment of this disease. The Study of Picoplatin Efficacy After Relapse (SPEAR) evaluated best supportive care with or without picoplatin for second-line SCLC treatment and failed to meet its primary end point of overall survival. As the largest second-line, randomized study in patients with SCLC, SPEAR provides an opportunity to critically examine the drug development model in this disease. In this Review, we discuss the current standard approach for the management of SCLC that progresses after first-line therapy, analyze the preliminary data that supported the evaluation of picoplatin in this setting, and critically evaluate the SPEAR trial design and results. Lastly, we present advances in the understanding of the molecular biology of SCLC that could potentially inform future clinical trials and hopefully lead to the successful development of molecular targeted agents for the treatment of this disease.

Randomized phase II study of bevacizumab in combination with chemotherapy in previously untreated extensive-stage small-cell lung cancer: results from the SALUTE trial

PURPOSE

Because of promising efficacy signals in single-arm studies, a placebo-controlled, double-blind, randomized phase II trial was designed to assess the efficacy and safety of adding bevacizumab to first-line standard chemotherapy for treatment of extensive-stage small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients with SCLC were randomly assigned to receive bevacizumab or placebo, with cisplatin or carboplatin plus etoposide, for four cycles followed by single-agent bevacizumab or placebo until progression or unacceptable toxicity. The primary end point was progression-free survival (PFS).

RESULTS

Fifty-two patients were randomly assigned to the bevacizumab group and 50 to the placebo group; 69% versus 66%, respectively, completed four cycles of therapy. Median PFS was higher in the bevacizumab group (5.5 months) than in the placebo group (4.4 months; hazard ratio [HR], 0.53; 95% CI, 0.32 to 0.86). Median overall survival (OS) was similar for both groups (9.4 v 10.9 months for bevacizumab and placebo groups, respectively), with an HR of 1.16 (95% CI, 0.66 to 2.04). Overall response rates were 58% (95% CI, 43% to 71%) for the bevacizumab group and 48% (95% CI, 34% to 62%) for the placebo group. Median duration of response was 4.7 months for the bevacizumab group and 3.2 months for the placebo group. In the bevacizumab and placebo groups, 75% versus 60% of patients, respectively, experienced one or more grade 3 or higher adverse events. No new or unexpected safety signals for bevacizumab were observed.

CONCLUSION

The addition of bevacizumab to cisplatin or carboplatin plus etoposide for treatment of extensive-stage SCLC improved PFS, with an acceptable toxicity profile. However, no improvement in OS was observed.

Paclitaxel plus bevacizumab in patients with chemosensitive relapsed small cell lung cancer: a safety, feasibility, and efficacy study from the Hoosier Oncology Group

INTRODUCTION

Bevacizumab when combined with carboplatin and paclitaxel improves response rates (RRs) and overall survival in patients with advanced non-small cell lung cancer. Paclitaxel has single-agent activity in relapsed small cell lung cancer (SCLC). Angiogenesis seems to play an important role in the pathogenesis of SCLC. This study evaluated the safety and efficacy of paclitaxel plus bevacizumab in patients with chemosensitive relapsed SCLC.

METHODS

Patients with relapsed chemosensitive SCLC with an Eastern Cooperative Oncology Group performance status of 0 to 1 were eligible. They received paclitaxel 90 mg/m intravenously on days 1, 8, and 15. Bevacizumab was administered at 10 mg/kg intravenously on days 1 and 15. Cycles were every 28 days. The primary endpoint was progression-free survival (PFS). Secondary endpoints included RRs, toxicity, and overall survival. Correlative studies evaluated vascular endothelial growth factor polymorphisms.

RESULTS

Thirty-four patients were enrolled in the study. Median age was 66.5 (range, 38-88) years, male:female: 61.8%:38.2%, Eastern Cooperative Oncology Group performance status 0:1 47.1%:52.9%. Median progression-free survival was 14.7 weeks (equivalent to historical controls). Median survival time was 30 weeks. The overall RR was 18.1%. Stable disease rate was 39.3%, and 45.4% of patients had progressive disease. No unexpected toxicities were noted, and grade 3/4 toxicities were limited to neutropenia, fatigue, and dyspnea. None of the vascular endothelial growth factor polymorphisms evaluated were significantly associated with response.

CONCLUSIONS

The addition of bevacizumab to paclitaxel does not improve outcomes in relapsed chemosensitive SCLC.

Phase II study of cisplatin/etoposide and endostar for extensive-stage small-cell lung cancer

PURPOSE

To investigate the efficacy and safety of endostar, a novel recombinant human endostatin, plus cisplatin, and etoposide in patients with extensive-stage small-cell lung cancer (ED-SCLC).

PATIENTS AND METHODS

Chemotherapy-naïve patients with histologically confirmed, measurable ED-SCLC were enrolled. Treatment consisted of cisplatin (25 mg/m(2)) administered intravenously (IV) on days 1-3; etoposide (120 mg/m(2)) administered intravenously (IV) on days 1-3; endostar (15 mg) administered intravenously (IV) on days 1-14 every 21 days for up to four cycles. The primary objective was to assess the progression-free survival (FPS). Secondary objectives were to assess the objective response rate, median overall survival (OS), and treatment-related toxicity.

RESULTS

Thirty-three patients were enrolled, the median age of the patients was 53 years (range, 29-74), twenty-three patients (69.7%) were men and 10 patients were women. Eastern Cooperative Oncology Group performance status scores were 0, 1,and 2 in 30.3, 60.6, and 9.1% of the patients, respectively. The overall response rate was 69.7%, one patient (3%) had a complete response, and 22 patients (66.7%) had partial responses. Five patients (15.1%) had stable disease; the median PFS was 5.0 months (95% CI, 4.2-5.6 months), and the 6-month PFS was 33.3%. The median OS was 11.5 months (95% CI, 9.6-13.4 months), and the 1-year OS was 38.1% (95% CI, 26-50.1%). Sixteen patients (48.5%) had at least one grade 3/4 adverse events; the most common grade 3/4 hematologic toxicity included neutropenia in 57.6%, thrombocytopenia in 12.1% of patients. The most common grade 3/4 non-hematologic toxicities included fatigue in 15.2%, nausea/vomiting in 9.1%, diarrhea in 6.1%, anorexia in 6.1%, mucositis in 6.1% of patients.

CONCLUSION

The addition of rh-endostain to cisplatin and etoposide in patients with ED-SCLC results in slightly improved PFS and OS relative to historical controls who received this chemotherapy regimen alone. This regimen appears to be well tolerated; the promising results suggest the further randomized phase III trial to define endostar's impact on SCLC treatment.

Sorafenib in platinum-treated patients with extensive stage small cell lung cancer: a Southwest Oncology Group (SWOG 0435) phase II trial

INTRODUCTION

Sorafenib is a multikinase inhibitor affecting pathways involved in tumor progression and angiogenesis. We conducted a phase II trial of sorafenib in platinum-treated patients with extensive stage small cell lung cancer to determine the tumor response rate, toxicity, and overall survival.

METHODS

Patients with histologically confirmed, measurable disease, Zubrod performance status 0 to 1, and no more than 1 prior platinum-based treatment were eligible. Patients were stratified by platinum-sensitivity status: sensitive (progression >90 days after platinum) or refractory (progression during or ≤90 days after platinum). Patients were treated with sorafenib 400 mg orally twice a day continuously on a 28-day cycle.

RESULTS

Of 89 patients registered, 82 were evaluable for toxicity assessment, and 83 were evaluable for response. There were four partial responses seen among the 38 patients in the platinum-sensitive stratum, for an estimated response rate of 11% (95% confidence interval: 3-25%), and one partial response among the 45 patients in the platinum-refractory stratum, for an estimated response rate of 2% (95% confidence interval: 0-12%). The median overall survival estimates were 6.7 months (95% confidence interval: 6.1-9.1 months) for the platinum-sensitive stratum and 5.3 months (95% confidence interval: 3.3-7.5 months) in the platinum-refractory stratum. Nineteen patients discontinued treatment because of adverse events or side effects from therapy.

CONCLUSIONS

Based on the lack of disease control seen in our trial, further investigation of single-agent sorafenib in the small cell lung cancer population is not recommended. Combination trials of sorafenib and chemotherapy are ongoing.

Phase II study of Cediranib (AZD 2171), an inhibitor of the vascular endothelial growth factor receptor, for second-line therapy of small cell lung cancer (National Cancer Institute #7097)

BACKGROUND

Inhibition of angiogenesis is a novel strategy for the treatment of cancer. We evaluated the safety and efficacy of cediranib, a potent small molecule inhibitor of the vascular endothelial growth factor receptor, in patients with refractory or recurrent small cell lung cancer (SCLC).

METHODS

Patients with SCLC with progression after prior platinum-based chemotherapy only; performance status (PS) of 0 to 2; and adequate bone marrow, renal, and hepatic function were included. The dose of cediranib was 45 mg PO once a day for the first 12 patients and was reduced to 30 mg PO once a day for the subsequent patients because of intolerance of the higher dose. Treatment was given on a daily continuous schedule. The primary end point was determination of the response rate.

RESULTS

Twenty-five patients were enrolled. Patient characteristics were as follows: 13 men; median age 61 years; PS 0 (12 pts), PS 1 (12 pts). A median of two cycles were administered. Salient grade 3/4 toxicities were fatigue, diarrhea, hypertension, proteinuria, and elevated liver enzymes. Tolerability was better with the 30 mg dose once a day. Nine patients had stable disease, but none had a confirmed partial response. The median progression-free survival and overall survival were 2 and 6 months, respectively. Response criteria to proceed to full accrual were not met. Increase in circulating endothelial cell count was noted at the time of progression in several patients.

CONCLUSIONS

Cediranib failed to demonstrate objective responses in recurrent or refractory SCLC at the dose and schedule evaluated. The 45 mg dose was intolerable in a majority of SCLC patients.

[Molecular targeted therapies in small-cell lung cancer]

Small-cell lung cancers (SCLC) are aggressive malignancies, however, characterized by high primary chemosensitivity. Unfortunately, for the vast majority of patients, relapse is the rule with emergence of secondary resistance mechanisms. In the era of molecular targeted therapies, characterization of a number of molecular abnormalities has encouraged implementation of several clinical trials. This literature review summarizes the various pharmacological approaches used in SCLC to improve survival in localized and extensive forms of the disease. Initial trials with molecular targeted therapies have not been able to improve clinical outcome compared to the standard etoposide-cisplatin chemotherapy regimen in extensive forms. However, new targets continue to be identified and many treatments are currently being assessed, including blockade of angiogenesis, signal transduction, cell cycle or induction of apoptosis.

Emerging drugs for small-cell lung cancer

Small-cell lung cancer (SCLC) is a rapidly progressing tumor in which chemotherapy has a limited impact on survival. Unfortunately, little progress has been made in the medical management of SCLC during the last 30 years, which is best exemplified by the fact that standard first-line chemotherapy has remained platinum-based over time. On the other hand, improvements in survival have been obtained only with the introduction of innovative radiation strategies such as accelerated hyperfractionation to the thorax for limited-stage disease and prophylactic cranial irradiation for both limited- and extensive-stage disease. However, recent advances in the understanding of SCLC biology have renewed the interest in the clinical development of active drugs for SCLC. In this review, we address the most promising agents under clinical evaluation, discussing both novel chemotherapeutic agents and targeted agents. Particularly, amrubicin, a fully synthetic anthracycline, is a very active agent for SCLC, and ongoing Phase III trials are evaluating this agent either in the first-line setting of extensive-stage or relapsed disease. Among targeted agents, anti-angiogenic strategies and Bcl-2 inhibitors represent the most promising approaches, and they are being specifically tested in combination with and/or as maintenance therapy after first-line platinum-based chemotherapy.

Treatment options for small cell lung cancer - do we have more choice?

Small cell lung cancer (SCLC) is a significant health problem worldwide because of its high propensity for relapse. This review discusses existing and future therapies for the treatment of SCLC.

Targeted therapies in small cell lung cancer: a review

Small cell lung cancer (SCLC) is an aggressive form of lung cancer that is characterized by a rapid doubling time, early onset of dissemination and high sensitivity to chemotherapy. Despite the potential for cure in patients with limited disease with concurrent chemoradiation and an initial good response to chemotherapy in extensive disease, there is a high chance of disease relapse with an overall poor median survival for both stages. With increasing translational research and a better understanding of the molecular basis of cancer, a number of molecular targets have been identified in various preclinical studies. This review summarizes potentially viable targets and new agents that have been developed and employed in recent, ongoing and future clinical trials to attempt to improve clinical outcomes in this disease.

Phase II study of cisplatin plus etoposide and bevacizumab for previously untreated, extensive-stage small-cell lung cancer: Eastern Cooperative Oncology Group Study E3501

PURPOSE

To investigate the efficacy and safety of bevacizumab plus cisplatin and etoposide in patients with extensive-stage disease, small-cell lung cancer (ED-SCLC).

PATIENTS AND METHODS

In this phase II trial, 63 patients were treated with bevacizumab 15 mg/kg plus cisplatin 60 mg/m(2) and etoposide 120 mg/m(2), which was followed by bevacizumab alone until death or disease progression occurred. The primary end point was the proportion of patients alive at 6 months without disease progression (ie, progression-free survival [PFS]). Secondary end points included overall survival (OS), objective response rate, and toxicity. Correlative studies were performed to explore the relationship between baseline and changes in plasma vascular endothelial growth factor (VEGF), soluble cell adhesion molecules (ie, vascular cell adhesion molecule [VCAM], intercellular cell adhesion molecule [ICAM], and E-selectin) and basic fibroblast growth factor and outcome.

RESULTS

The 6-month PFS was 30.2%, the median PFS was 4.7 months, and OS was 10.9 months. The response rate was 63.5%. The most common adverse event was neutropenia (57.8%). Only one patient had grade 3 pulmonary hemorrhage. Patients who had high baseline VCAM had a higher risk of progression or death compared with those who had low baseline VCAM levels. No relationships between outcome and any other biomarkers were seen.

CONCLUSION

The addition of bevacizumab to cisplatin and etoposide in patients with ED-SCLC results in improved PFS and OS relative to historical controls who received this chemotherapy regimen without bevacizumab. This regimen appears to be well tolerated and has minimal increase in toxicities compared with chemotherapy alone. Baseline VCAM levels predicted survival, but no other relationships among treatment, biomarkers, and outcome were identified.