Targeting Neovasculature with Multitargeted Antiangiogenesis Tyrosine Kinase Inhibitors in Non-small Cell Lung Cancer

Chemotherapy has reached a plateau in the efforts for survival improvement in non-small cell lung cancer (NSCLC). The growing knowledge of NSCLC molecular pathobiology has led to the development of new treatments that target specific tumor functions. Angiogenesis is a tumor function leading to the formation of new tumor vessels that are crucial for its survival. Although vascular endothelial growth factor (VEGF) plays a primary role in angiogenesis, the inhibition of the VEGF pathway with VEGF-receptor (VEGFR) tyrosine kinase inhibitors (TKIs) is associated with a modest survival benefit due to the development of resistance by the tumor that has been mainly attributed to the up-regulation of other stimulators of angiogenesis. Thus, the use of multitargeted antiangiogenesis TKIs (MATKIs) for simultaneous inhibition of multiple angiogenic pathways has been proposed. This review summarizes data about novel treatment strategies incorporating the inhibition of angiogenesis with MATKIs in NSCLC. The data from all relevant studies shows that MATKIs do not offer additional survival benefit to currently available chemotherapeutic options in unselected NSCLC patients. However, the diversity in disease response to MATKI-containing regimens implies that specific patient subgroups may benefit from or be harmed by these agents. In this context, most studies agree that the VEGFR-targeting MATKIs are harmful in squamous NSCLC while specific MATKIs (i.e., motesanib, vandetanib and nintedanib) are associated with improved progression free survival in non-squamous NSCLC. However, overall survival benefit was found only in adenocarcinoma and Asian non-squamous NSCLC patients with the use of nintedanib and motesanib, respectively.

[Anti-angiogenic agents in the treatment of lung cancer: indications and toxicities]

Lung cancer is the leading cause of cancer-related death. Targeting the vascular endothelial growth factor (VEGF) pathways in combination with standard chemotherapy can improve response rate and survival in non-small cell lung cancer. Since October 2006, a new class of drugs targeting angiogenesis has been introduced for the treatment of advanced lung cancer. Bevacizumab, an antibody directly targeting VEGF was the first agent to be approved. Other small molecule tyrosine kinase inhibitors targeting the VEGF receptor are also active in the treatment of advanced lung cancer and are currently under development. Most of these new drugs are well tolerated though potentially significant toxicities such as haemoptysis and hypertension have been observed. This article will review these new-targeted anti-angiogenic agents with a focus on their use in lung cancer and on their important side effects.

Phase II, multicenter, uncontrolled trial of single-agent sorafenib in patients with relapsed or refractory, advanced non-small-cell lung cancer

PURPOSE

Sorafenib is an oral multikinase inhibitor that targets the Ras/Raf/MEK/ERK mitogenic signaling pathway and the angiogenic receptor tyrosine kinases, vascular endothelial growth factor receptor 2 and platelet-derived growth factor receptor beta. We evaluated the antitumor response and tolerability of sorafenib in patients with relapsed or refractory, advanced non-small-cell lung cancer (NSCLC), most of whom had received prior platinum-based chemotherapy.

PATIENTS AND METHODS

This was a phase II, single-arm, multicenter study. Patients with relapsed or refractory advanced NSCLC received sorafenib 400 mg orally twice daily until tumor progression or an unacceptable drug-related toxicity occurred. The primary objective was to measure response rate.

RESULTS

Of 54 patients enrolled, 52 received sorafenib. The predominant histologies were adenocarcinoma (54%) and squamous cell carcinoma (31%). No complete or partial responses were observed. Stable disease (SD) was achieved in 30 (59%) of the 51 patients who were evaluable for efficacy. Four patients with SD developed tumor cavitation. Median progression-free survival (PFS) was 2.7 months, and median overall survival was 6.7 months. Patients with SD had a median PFS of 5.5 months. Major grades 3 to 4, treatment-related toxicities included hand-foot skin reaction (10%), hypertension (4%), fatigue (2%), and diarrhea (2%). Nine patients died within a 30-day period after discontinuing sorafenib, and one patient experienced pulmonary hemorrhage that was considered drug related. CONCLUSION Continuous treatment with sorafenib 400 mg twice daily was associated with disease stabilization in patients with advanced NSCLC. The broad activity of sorafenib and its acceptable toxicity profile suggest that additional investigation of sorafenib as therapy for patients with NSCLC is warranted.

Efficacy and safety of axitinib in patients with advanced non-small-cell lung cancer: results from a phase II study

PURPOSE

This phase II study evaluated efficacy and safety of single-agent axitinib, an oral, potent, selective inhibitor of vascular endothelial growth factor receptors (VEGFR) -1, -2, and -3, in patients with advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

This was an open-label, single-arm, multicenter, phase II study with a Simon two-stage minimax design. Patients received a starting dose of axitinib 5 mg orally BID. The primary end point was Response Evaluation Criteria in Solid Tumors (RECIST) -defined objective response rate. Secondary end points included safety and tolerability, overall survival (OS), and progression-free survival (PFS).

RESULTS

Thirty-two patients were enrolled, with a median age of 66.5 years. The majority of patients (75%) had adenocarcinoma. Nine patients (28%) had received no prior chemotherapy for metastatic disease, and 23 (72%) had received > or = one regimen. Three patients (9%) had a RECIST investigator-assessed, confirmed partial response (PR); disease control rate (PR + stable disease) was 41%. Median PFS was 4.9 months overall (95% CI, 3.6 to 7.0 months). Median OS was 14.8 months (95% CI, 10.7 months to not estimable) overall and 14.8 months (95% CI, 12.5 months to not estimable) in patients receiving first-line axitinib. One-year survival rates for patients with or without prior therapy for metastatic disease were 57% and 78%, respectively. Grade 3 treatment-related adverse events in > or = 5% of patients comprised fatigue (22%), hypertension (9%), and hyponatremia (9%).

CONCLUSION

Axitinib demonstrated single-agent activity in patients with advanced NSCLC. Therapy was well tolerated with manageable toxicities. Further investigation of this VEGFR inhibitor in NSCLC is of interest.