Second-line chemotherapy for gastric cancer: a new issue lies ahead in global trials

Taxanes in the Treatment of Advanced Gastric Cancer

Although rapid advances in treatment options have improved the prognosis of advanced gastric cancer (AGC), it remains a major public health problem and the second leading cause of cancer-related deaths in the world. Taxanes (paclitaxel and docetaxel) are microtubule stabilizing agents that inhibit the process of cell division, and have shown antitumor activity in the treatment of AGC as a single or combination chemotherapy. Accordingly, this review focuses on the efficacy and tolerability of taxanes in the first- or second-line chemotherapy setting for AGC.

Systemic therapy beyond first-line in advanced gastric cancer: An overview of the main randomized clinical trials

Following progression on first-line platinum and fluoropyrimidine-based chemotherapy, prognosis for advanced gastric cancer patients is extremely poor. Thus, new and effective treatments are required. Based on positive results of recent randomized controlled trials, second-line monochemotherapies with either irinotecan or taxanes confer a median overall survival of approximately 5 months in gastro-esophageal and gastric adenocarcinoma. Combination of weekly paclitaxel and ramucirumab, a novel anti-angiogenic VEGFR2 antibody, pushes the overall survival up to over 9.5 months, whereas apatinib, a novel oral VEGFR2 tyrosine kinase inhibitor, seems to be promising in heavily pretreated patients. In contrast, the role of EGFR/HER2 and mTOR inhibitors is controversial. Studies are heterogeneous for tumor population, geographical areas, quality of life assessment, type of first-line therapy and response to that, making clinical practice application of the trial results difficult. Furthermore, sustainability is challenging due to high cost of novel biotherapies.

Pemetrexed for previously treated patients with metastatic gastric cancer: a prospective phase II study

Background:

Gastric cancer is one of the leading causes of cancer-related death worldwide. There were debates on the value of the second-line and beyond chemotherapy by the time we designed this trial. So we designed this phase II trial to assess the efficacy and safety of pemetrexed in patients with pretreated metastatic gastric cancer.

Methods:

Thirty-four patients with pretreated metastatic gastric cancer were enroled in the study. Patients received pemetrexed 500 mg m⁻² every 21 days until the presence of progressive disease (PD) or unacceptable toxicity.

Results:

A total of 34 patients were enroled in the study; 34 were eligible for toxicity and 30 for response. The response rate was 13.3%, 13.3% patients achieved a partial response, 50.0% achieved stable disease and 36.7% had a PD as the best response. The median overall survival time and median progression-free survival time was 6.4 months (95% confidence interval (CI) 5.8–9.5 months) and 2.2 months (95% CI 2.0–5.5 months), respectively. Most haematologic and non-haematologic toxicity were grade 1/2. Grade 3/4 toxicity included fatigue, neutropenia, thrombocytopenia, weight loss, anorexia and transaminase elevation.

Conclusions:

The monochemotherapy of pemetrexed is active and well tolerated when used in previously treated patients with metastatic gastric cancer.

Biweekly S-1 plus paclitaxel (SPA) as second-line chemotherapy after failure from fluoropyrimidine and platinum in advanced gastric cancer: a phase II study

PURPOSE

Second-line chemotherapy is now considered a standard therapy option in patients with advanced gastric cancer (AGC) who failed from first-line chemotherapy. Single agents, such as irinotecan, docetaxel or paclitaxel, provided an overall response rate of about 10 %. However, the efficacy was not satisfactory. The authors conducted a phase II study to investigate biweekly regimen of S-1 plus paclitaxel in Chinese AGC in second-line setting, with response rate as the primary end point.

PATIENTS AND METHODS

Patients with AGC failed from first-line chemotherapy with fluoropyrimidine/platinum who had measurable lesions were enrolled. Paclitaxel was administered intravenously on day 1 at a dose of 120 mg/m(2), and oral S-1 was administered twice a day from days 1 to 7, followed by a 7-day drug-free interval.

RESULTS

A total of 30 patients with pretreated AGC were accrued. No complete responses were observed. Partial responses were documented in 10 (33.3 %) patients. Ten (33.3 %) patients had stable disease. The median progression-free survival was 3.6 months and the overall survival was 7.2 months. The main toxicity was bone marrow suppression. The most frequent grade 3/4 hematological toxicities were neutropenia and anemia, which were observed in 8 (26.7 %) and 6 (20 %) patients, respectively. The most common grade 3/4 non-hematological toxicity was neuropathy, which was reported in 4 (13.3 %) patients.

CONCLUSION

Biweekly S-1 plus paclitaxel showed promising activity with acceptable toxicities as second-line chemotherapy in pretreated patients with AGC. This regimen deserves further investigation in a phase III trial.

Geographic differences in approach to advanced gastric cancer: Is there a standard approach?

Gastric cancer is one of the leading causes of cancer related deaths worldwide. Regional differences in gastric cancer are evident between Asian and Western societies with respect to etiology, prevalence, clinicopathologic features as well as treatment pattern of the disease. For patients with advanced gastric cancer (AGC), chemotherapy has been found to improve survival and quality of life compared to best supportive care alone. But contrast to other tumors such as colon or pancreatic cancer, there are regional differences in outcome in gastric cancer. Various geographic/ethnic, biology and treatment strategies may contribute to these differences. In the first line setting, cisplatin and fluoropyrimidine based therapies remain the backbone of treatment for advanced gastric cancer in Asian and Western patients, although there is preference for S1 in Asia and 5FU in the West. A third agent may be added in patients with good performance status. Recent trials from Asia and Europe demonstrate an advantage for second line chemotherapy. Irinotecan and taxanes are the most commonly used agents. The introduction of trastuzumab into the frontline therapy of AGC has ushered the age of targeted therapy and personalized medicine in this disease. In this article, we will review the various first and second line chemotherapy regimens in AGC, taking into account regional differences including potential biomarkers.

A randomized phase II study of biweekly irinotecan monotherapy or a combination of irinotecan plus 5-fluorouracil/leucovorin (mFOLFIRI) in patients with metastatic gastric adenocarcinoma refractory to or progressive after first-line chemotherapy

BACKGROUND

The aim of this study was to evaluate the efficacy of irinotecan (CPT-11) monotherapy and CPT-11 plus 5-fluorouracil (5-FU)/leucovorin (LV) combination (mFOLFIRI) as second-line treatment in patients with advanced gastric cancer (AGC).

METHODS

A total of 59 patients were randomly assigned to either CPT-11 (150 mg/m(2) iv on day 1) or mFOLFIRI (CPT-11 150 mg/m(2) plus LV 20 mg/m(2) on day 1 followed by 5-FU 2,000 mg/m(2) over 48 h), every 2 weeks. The primary end point was objective response rate (ORR).

RESULTS

Following random assignment, 29 patients received CPT-11 and 30 patients mFOLFIRI. The ORR was 17.2 % [95 % confidence interval (CI) 3.4-30.9] and 20.0 % (95 % CI 5.6-34.3) for the CPT-11 and mFOLFIRI arms, respectively (P = 0.525). There was no significant difference in median progression-free survival: 2.2 months (95 % CI 0.2-4.3) for CPT-11 versus 3.0 months (95 % CI 2.0-3.7) for mFOLFIRI (P = 0.481) or in median overall survival: 5.8 months (95 % CI 3.0-8.7), compared with 6.7 months (95 % CI 5.3-8.2) (P = 0.514). Grade 3/4 toxicity was observed in 21 and 28 events in the CPT-11 and mFOLFIRI arms, respectively.

CONCLUSIONS

Although this study had a small sample size and limited statistical power, CPT-11 monotherapy and mFOLFIRI appear to be equally active and tolerable as second-line chemotherapy for AGC. The addition of 5-FU/LV to CPT-11 did not significantly improve efficacy.

Advanced HER2-positive gastric cancer: current and future targeted therapies

The prognostic value of human epidermal growth factor receptor 2 (HER2) in gastric cancer is controversial. Consensus guidelines have standardized the testing of HER2 status in gastric cancer. Overexpression of this receptor occurs in approximately 20% of gastric and gastro-esophageal junction adenocarcinomas, predominantly those of the intestinal type. Recently, trastuzumab has emerged as the first targeted drug to improve overall survival when combined with chemotherapy in advanced HER2-positive gastric cancer. Primary and secondary resistance to trastuzumab has become a major problem and new strategies to overcome this resistance are needed. A high percentage of advanced HER2-positive gastric cancer patients who progress on trastuzumab therapy are candidates for second-line therapy. New families of targeted drugs, including tyrosine kinase inhibitors (TKIs) such as lapatinib and PF-00299804, mammalian target of rapamycin (mTOR) pathway inhibitors such as everolimus, heat-shock protein 90 (HSP90) inhibitors such as AUY922, HER dimerization inhibitors such as pertuzumab, and antibody-chemotherapy conjugates such as trastuzumab-emtansine (T-DM1), could offer alternative second-line treatments when trastuzumab-based first-line therapy fails.

A phase II trial of ixabepilone in Asian patients with advanced gastric cancer previously treated with fluoropyrimidine-based chemotherapy

PURPOSE

The highest rates of gastric cancer occur in Eastern Asia. Fluoropyrimidine-based therapy is used initially in unresectable and metastatic disease, but no single standard of care exists following disease progression. Ixabepilone, an epothilone B analog, is a non-taxane microtubule-stabilizing agent with clinical activity across multiple tumor types approved by the United States Food and Drug Administration for treatment of metastatic breast cancer.

METHODS

Asian patients with unresectable or metastatic gastric adenocarcinoma who had failed fluoropyrimidine-based chemotherapy received ixabepilone 40 mg/m(2) by 3-h intravenous infusion every 3 weeks. The primary endpoint was objective response rate (ORR).

RESULTS

Fifty-two patients were treated (65.4 % men; median age: 56.5 years). The ORR was 15.4 % (95 % confidence interval [CI] 6.9-28.1); 8 patients achieved partial responses for a median duration of 3.1 months (95 % CI 2.6-4.1 months) and 26 patients (50.0 %) had stable disease. Median progression-free survival was 2.8 months (95 % CI 2.1-3.5 months). The most common grade 3 non-hematological toxicities were fatigue (9.6 %), decreased appetite (7.7 %), sensory neuropathy (5.8 %), and diarrhea (5.8 %). Grade 3/4 neutropenia occurred in 46.2 % of patients.

CONCLUSIONS

Ixabepilone is active in Asian patients with advanced gastric cancer and shows a toxicity profile similar to those previously reported in other tumor types.