Phase III study comparing oxaliplatin plus S-1 with cisplatin plus S-1 in chemotherapy-naïve patients with advanced gastric cancer

Serum levels of soluble programmed cell death ligand 1 as a prognostic factor on the first-line treatment of metastatic or recurrent gastric cancer

PURPOSE

Immune checkpoint molecules are key targets for the treatment of various malignancies. Due to the heterogeneity of advanced gastric cancer (GC), the role of programmed cell death ligand 1 (PD-L1) expression as a tumor biomarker remains controversial. In this study, the prognostic value of soluble PD-L1 (sPD-L1) levels in serum samples was assessed in patients with metastatic GC.

METHODS

All patients received first-line treatment with fluoropyrimidine and platinum chemotherapy, and trastuzumab was added for HER2-positive patients. Serum levels of sPD-L1 were measured by enzyme-linked immunosorbent assay.

RESULTS

Among 75 metastatic GC patients, the median serum sPD-L1 level was 0.704 ng/ml (range <0.156-3.214). Serum sPD-L1 was significantly higher in patients with a high versus a low white blood cell count at baseline. When the cutoff value was set as the median, multivariate analyses showed that high sPD-L1 levels were associated with worse overall survival compared with low sPD-L1 levels (HR 2.218, 95 % CI 1.139-4.320, P = 0.019). Regardless of HER2 status, overall survival tended to be shorter in patients with high sPD-L1 compared with low sPD-L1. There was no significant association between sPD-L1 level and progression-free survival on the first-line treatment of metastatic GC.

CONCLUSIONS

High serum levels of sPD-L1 correlated with worse overall survival on the first-line chemotherapy in metastatic GC patients.

Evolving treatments for advanced gastric cancer: appraisal of the survival trend

Introduction and areas covered: We analysed the results of the main clinical studies looking at patients with advanced gastric or esophagogastric junction cancer, in order to differentiate between what is already clinical evidence and what is a promise for the cure of such patients. Thus, achievements from key studies, which had been purposely directed at chemotherapy, molecular target therapies and immunotherapy in both first and second-line setting were analysed. Metronomic chemotherapy, which consists of the administration of continuative low-dose anticancer drugs, was considered also. Expert commentary: It was found that patients included in experimental arms of randomized trials compared with controls have often benefited from a statistically significant extension of overall survival. However, further studies are awaited to bring new drugs into clinical practice and to validate candidate biomarkers predictive of response.

Phase II study of docetaxel, oxaliplatin, and S-1 therapy in patients with metastatic gastric cancer

BACKGROUND

Although the docetaxel, 5-fluorouracil, and cisplatin triplet has yielded significant improvements in time to progression, overall survival, and overall response rate, the high incidence of severe adverse events limits the use of the docetaxel, 5-fluorouracil, and cisplatin triplet. To overcome this limitation, we evaluated the efficacy and safety of the combination of docetaxel, oxaliplatin, and S-1 for the treatment of metastatic gastric cancer.

METHODS

Chemotherapy-naive patients with pathologically proven unresectable recurrent or metastatic gastric adenocarcinoma were assessed for eligibility. Docetaxel at 52.5 mg/m(2) and oxaliplatin at 105 mg/m(2) were administered intravenously on day 1, and S-1 was administered orally at 80 mg/m(2) on days 1-14 of every 21-day cycle.

RESULTS

Forty-four patients (median age 54.5 years) were enrolled. All patients had metastatic disease. A total of 340 cycles of chemotherapy were administered (median of eight cycles per patient; range 1-36 cycles). Toxicities were evaluated in 43 patients, and the responses were evaluated in 40 patients. Major toxicities included grade 3/4 neutropenia (37.2 %) and leukopenia (27.9 %). The overall response rate was 54.5 % [95 % confidence interval (CI) 40.1-68.3 %] in the intention-to-treat population. The median progression-free survival and overall survival were 7.6 months (95 % CI 6.2-9.0 months) and 12.0 months (95 % CI 6.9-17.2 months), respectively.

CONCLUSION

These data suggest that the docetaxel, oxaliplatin, and S-1 combination regimen is effective and relatively well tolerable, and it seems to have potential to be a reasonable therapeutic strategy in patients with metastatic or recurrent gastric cancer.

Electrolyte disorders associated with the use of anticancer drugs

The use of anticancer drugs is beneficial for patients with malignancies but is frequently associated with the occurrence of electrolyte disorders, which can be hazardous and in many cases fatal. The review presents the electrolyte abnormalities that can occur with the use of anticancer drugs and provides the related mechanisms. Platinum-containing anticancer drugs induce hypomagnesemia, hypokalemia and hypocalcemia. Moreover, platinum-containing drugs are associated with hyponatremia, especially when combined with large volumes of hypotonic fluids aiming to prevent nephrotoxicity. Alkylating agents have been linked with the occurrence of hyponatremia [due to syndrome of inappropriate antidiuretic hormone secretion (SIADH)] and Fanconi's syndrome (hypophosphatemia, aminoaciduria, hypouricemia and/or glucosuria). Vinca alkaloids are associated with hyponatremia due to SIADH. Epidermal growth factor receptor monoclonal antibody inhibitors induce hypomagnesemia, hypokalemia and hypocalcemia. Other, monoclonal antibodies, such as cixutumumab, cause hyponatremia due to SIADH. Tyrosine kinase inhibitors are linked to hyponatremia and hypophosphatemia. Mammalian target of rapamycin inhibitors induce hyponatremia (due to aldosterone resistance), hypokalemia and hypophosphatemia. Other drugs such as immunomodulators or methotrexate have been also associated with hyponatremia. The administration of estrogens at high doses, streptozocin, azacitidine and suramin may induce hypophosphatemia. Finally, the drug-related tumor lysis syndrome is associated with hyperphosphatemia, hyperkalemia and hypocalcemia. The prevention of electrolyte derangements may lead to reduction of adverse events during the administration of anticancer drugs.

Advanced gastric cancer: Current treatment landscape and future perspectives

Gastric cancer currently ranks fourth in cancer-related mortality worldwide. In the western world, it is most often diagnosed at an advanced stage, after becoming metastatic at distant sites. Patients with advanced disease (locally advanced or metastatic) have a somber prognosis, with a median overall survival of 10-12 mo, and palliative chemotherapy is the mainstay of treatment. In recent years, novel approaches using inhibition of human epidermal growth factor receptor 2 (HER2) have demonstrated significant improvements in progression-free and overall survival, compared with chemotherapy alone, in first-line treatment of patients with overexpression of HER2. In addition, both second-line chemotherapy and treatment with the vascular endothelial growth factor receptor-inhibitor ramucirumab demonstrated significant benefits in terms of overall survival, compared with best supportive care, in randomized studies. Moreover, ramucirumab in combination with chemotherapy demonstrated further significant benefits in terms of progression-free and overall survival, compared with chemotherapy alone, in second-line treatment for patients with metastatic gastric cancer. A recently published molecular classification of gastric cancer is expected to improve patient stratification and selection for clinical trials and provide a roadmap for future drug development. Nevertheless, despite these developments the prognosis of patients with advanced gastric cancer remains poor. In this review we discuss current standards of care and outline major topics of drug development in gastric cancer.

Large-scale prospective pharmacogenomics study of oxaliplatin-induced neuropathy in colon cancer patients enrolled in the JFMC41-1001-C2 (JOIN Trial)

BACKGROUND

Peripheral sensory neuropathy (PSN) is a dose-limiting toxicity of oxaliplatin-based chemotherapy. Several genetic markers have been shown to predict oxaliplatin-induced PSN; however, results remain to be validated in a large-scale and prospective pharmacogenomics study.

PATIENTS AND METHODS

Among 882 patients enrolled in the JFMC41-1001-C2 (JOIN trial), which was designed to investigate the tolerability of adjuvant-modified FOLFOX6 (mFOLFOX6) in Japanese Patients with stage II or III colon cancers undergoing curative resection, 465 patients were eligible for this pharmacogenomics analysis. Twelve single-nucleotide polymorphisms (SNPs) were selected based on published data. The effect of each genotype on time to PSN onset was evaluated in all patients (n = 465) using the Cox proportional hazard model. For the association analysis between severity of PSN and 12 SNP markers, 84 patients who failed to complete 12 cycles of mFOLFOX6 from grade 0/1 PSN group were excluded because the termination of the protocol treatment had been caused by reasons other than PSN.

RESULTS

Comparison of grade 0/1 PSN with grade 2/3 PSN or grade 3 PSN showed no significant associations with any of the 12 SNP markers after adjustment for total dose of oxaliplatin. Time-to-onset analysis also failed to reveal any significant differences.

CONCLUSIONS

Our large-scale and prospective pharmacogenomics study of Japanese patients receiving protocol treatment of adjuvant mFOLFOX6 could not verify a role for any of the 12 SNP markers reported as being significantly associated with PSN. Considering the OR observed in this study (range: 0.76-1.89), further evaluation of these 12 SNP markers in the context of L-OHP-induced PSN is unlikely to be clinically informative.

Emerging role of S-1 in gastric cancer

Gastric cancer remains one of the most important malignancies worldwide in terms of incidence and mortality. The treatment is based on the combination of local surgery and radiation therapy as well as systemic chemotherapy and targeted molecules. Fluoropyrimidines and particularly 5-fluorouracil (FU) represent still the backbone for gastric cancer chemotherapy and new molecular versions of this molecule have been brought to clinical practice in order to improve benefits and reduce adverse effects. S-1 is an oral prodrug of 5-FU, which has demonstrated high effectiveness for gastric cancer treatment and a favorable safety profile. Currently, there are geographic differences in the treatment of gastric cancer and in the use of S-1, which is a mainstay of gastric cancer management in Eastern countries, but is not part of the standard care in the rest of the world. In this review, we gathered data from phase I, II, and III trials of S-1 in gastric cancer, in order to define its real benefit-risk ratio and assess whether geographic differences in S-1 use are justified by unchangeable factors.

Meta-analysis supporting noninferiority of oxaliplatin plus S-1 to cisplatin plus S-1 in first-line treatment of advanced gastric cancer (G-SOX study): indirect comparison with S-1 alone

BACKGROUND

The Randomized Phase III Study Comparing Oxaliplatin plus S-1 with Cisplatin plus S-1 in Chemotherapy-naïve Patients with Advanced Gastric Cancer (G-SOX) showed the noninferiority of S-1 (an oral fluoropyrimidine-derivative dihydropyrimidine dehydrogenase inhibitor) plus oxaliplatin combination therapy (SOX) to S-1 plus cisplatin therapy (CS) in overall survival [hazard ratio (HR) from proportional hazard model 0.958, 95 % confidence interval (CI) 0.803-1.142; noninferiority margin 1.15]. To further clarify the clinical position of SOX in advanced gastric cancer (AGC), a meta-analysis including information from other reported studies was conducted.

METHODS

In addition to G-SOX, Japanese phase III clinical trials including S-1 monotherapy were included in the analyses. Individual patient data for SOX (318 patients) and CS (324 patients) from G-SOX, as well as those for S-1 (160 patients) from the Randomized Phase III Study Comparing the Efficacy and Safety of Irinotecan plus S-1 with S-1 Alone as First-line Treatment for Advanced Gastric Cancer (GC0301/TOP-002), were available. Published clinical information for S-1 from other studies (total 705 patients) was also collected. A Weibull distribution was assumed for overall survival time, and parameters for SOX, CS, and S-1 were estimated parametrically. Posterior HR distributions were obtained with a Bayesian approach.

RESULTS

The HR of SOX to S-1 was 0.817 (95 % credible interval 0.704-0.939), and the probability of the HR <1.00 was 99.8 %. The HR of CS to S-1 was 0.871 (95 % credible interval; 0.754-0.998), and the probability of the HR <1.00 was 97.6 %. The HR of SOX to CS in G-SOX was 0.942 (95 % credible interval; 0.789-1.117), and the probability of HR <1.15 was 98.9 %.

CONCLUSION

This meta-analysis indicates that SOX was superior to S-1 and noninferior to CS in AGC.

Is conversion therapy possible in stage IV gastric cancer: the proposal of new biological categories of classification

Conversion therapy for gastric cancer (GC) has been the subject of much recent attention. It is defined as a surgical treatment aiming at an R0 resection after chemotherapy for tumors that were originally unresectable or marginally resectable for technical and/or oncological reasons. However, the indications for resection remain to be clarified. In the present review, we focus on the biology and heterogeneous characteristics of stage IV GC and propose new categories of classification. Stage IV GC patients can be divided based on the absence (categories 1 and 2) or presence (categories 3 and 4) of macroscopically detectable peritoneal dissemination, which has a different biological outcome compared to hematological metastasis. Category 1 is defined oncologically as stage IV but the metastasis is technically resectable. Category 2 includes a marginally resectable metastasis or patients for whom the operation would not necessarily be the best choice. Category 3 includes a potentially unresectable metastasis of peritoneal dissemination that is only macroscopically detectable. Category 4 includes noncurable metastasis with peritoneal and other organ metastasis. The indications for conversion therapy might include the patients from category 2, some patients from category 3 and a very small number of patients from category 4. The longer survival can be expected for patients corresponding to categories 1, 2 and, to a lesser extent, 3, while the treatment of other patients focuses on "care." The provision of conversion therapy for stage IV GC patients might be one of the main roles of surgical oncologists in the near future.

S-1 plus leucovorin versus S-1 plus leucovorin and oxaliplatin versus S-1 plus cisplatin in patients with advanced gastric cancer: a randomised, multicentre, open-label, phase 2 trial

BACKGROUND

Although leucovorin enhances the efficacy of fluorouracil, the anti-tumour activity of S-1 and leucovorin and their combination with oxaliplatin for patients with advanced gastric cancer is unknown. We compared the activity and safety of S-1 plus leucovorin, S-1 plus leucovorin and oxaliplatin, and S-1 plus cisplatin as first-line chemotherapy for advanced gastric cancer.

METHODS

In this multicentre, randomised, open-label, phase 2 trial, we recruited chemotherapy-naive patients with unresectable or recurrent gastric cancer with measurable lesions aged 20 years or older from 25 general hospitals and specialist centres in Japan. Patients were randomly assigned (1:1:1) centrally to receive S-1 plus leucovorin (S-1 40-60 mg orally plus oral leucovorin 25 mg twice a day for 1 week, every 2 weeks), S-1 plus leucovorin and oxaliplatin (S-1 plus leucovorin and intravenous oxaliplatin 85 mg/m(2) on day 1, every 2 weeks), or S-1 plus cisplatin (S-1 40-60 mg orally twice a day for 3 weeks, plus intravenous cisplatin 60 mg/m(2) on day 8, every 5 weeks). Randomisation was done with the minimisation method using performance status (0 vs 1) and tumour stage (stage IV vs recurrent) as stratification factors. The primary endpoint was independently reviewed overall response in the full analysis set. This trial is registered with Japic CTI, number 111635.

FINDINGS

Between Oct 20, 2011, and Dec 17, 2012, we enrolled and randomly assigned 145 patients: 49 patients were assigned to S-1 plus leucovorin, 47 to S-1 plus leucovorin and oxaliplatin, and 49 to S-1 plus cisplatin. An objective response assessed by the independent review committee was achieved in 20 (43% [95% CI 28·3-57·8]) of the 47 patients in the S-1 plus leucovorin group, 31 (66% [50·7-79·1]) of the 47 patients in the S-1 plus leucovorin and oxaliplatin group, and 22 (46% [31·4-60·8]) of the 48 patients in the S-1 plus cisplatin group (Fisher's exact test, p=0·84 for S-1 plus leucovorin vs S-1 plus cisplatin, p=0·063 for S-1 plus leucovorin and oxaliplatin vs S-1 plus cisplatin, and p=0·038 for S-1 plus leucovorin and oxaliplatin vs S-1 plus leucovorin). The most common grade 3-4 adverse events were neutropenia (three [6%] of 48 patients in the S-1 plus leucovorin group vs 12 [26%] of 47 patients in the S-1 plus leucovorin and oxaliplatin group vs 17 [35%] of 49 patients in the S-1 plus cisplatin group), decreased appetite (six [13%] vs 14 [30%] vs 12 [24%]), anaemia (five [10%] vs seven [15%] vs 13 [27%]), and hyponatraemia (two [4%] vs two [4%] vs nine [18%]).

INTERPRETATION

S-1 plus leucovorin and oxaliplatin was more active than S-1 plus leucovorin or S-1 plus cisplatin with acceptable toxic effects for patients with advanced gastric cancer. A phase 3 trial comparing S-1 plus leucovorin and oxaliplatin with S-1 plus cisplatin is underway.

FUNDING

Taiho Pharmaceutical.

Feasibility of neoadjuvant S-1 and oxaliplatin followed by surgery for resectable advanced gastric adenocarcinoma

PURPOSE

In Japan, the administration of S-1 following D2 gastrectomy is a standard treatment for stage II/III gastric cancer (GC). However, the survival of stage IIIB/IIIC GC remains unsatisfactory. To improve this, we conducted a multicenter phase II study to evaluate the safety and efficacy of a neoadjuvant S-1 and oxaliplatin regimen (SOX) followed by surgery targeted at stage III GC.

METHODS

Oxaliplatin was administered intravenously (130 mg/m(2)) on day 1, and S-1 was administered orally (40 mg/m(2), twice a day) for 14 days followed by a seven-day rest period. After three cycles of therapy, D2 gastrectomy was performed.

RESULTS

A total of 14 patients were enrolled and completed the protocol treatment. Grade 3/4 toxicities included thrombocytopenia (21.4 %), anorexia (14.3 %), and diarrhea (7.1 %). Seven patients (50 %) underwent total gastrectomy, and seven patients underwent distal gastrectomy. Grade 3/4 surgical complications included pancreatic fistula (21.4 %) and lung infection (7.1 %). The pathological response rate was 85.7 %.

CONCLUSION

Although our data are limited and preliminary, neoadjuvant SOX followed by surgery can be performed safely with a high pathological response rate in patients with resectable advanced GC. Further investigation of this neoadjuvant approach is warranted.

Advancing pharmacological treatment options for advanced gastric cancer

INTRODUCTION

Gastric cancer is the third most common cause of cancer-related deaths worldwide. Improvement of conventional chemotherapy has been modest in the past decades.

AREAS COVERED

We review recent important studies of metastatic or recurrent gastric cancer. For human epidermal growth factor receptors 2 (HER2) negative cancer, standard treatments are combinations of fluoropyrimidine and platinum with or without epirubicin or docetaxel in first-line therapy. Controversy exists regarding the use of triplet chemotherapies due to their toxicity. For HER2 positive cancer, standard treatments are combinations of fluoropyrimidine and cisplatin with trastuzumab. As second- or third-line treatment, taxanes or irinotecan prolonged survival compared with best supportive care alone, but the extension of overall survival was only 1 - 2 months. A recent study demonstrated that ramucirumab plus paclitaxel improved survival as a second-line therapy.

EXPERT OPINION

Most trials have failed to demonstrate a benefit of targeted agents. It is important to identify predictive biomarkers to enrich an appropriate patient population for targeted agents such as HER2 status for trastuzumab.

Low-dosed docetaxel showed equivalent efficacy but improved tolerability compared with oxaliplatin in the S-1-based first-line chemotherapy regimen for metastatic or recurrent gastric adenocarcinoma

Platinum-fluoropyrimidine combinations are the preferred first-line options for advanced gastric cancer (AGC) in East Asia. On the other hand, docetaxel-containing regimens without platinum have demonstrated promising activity in AGC. However, dose-related toxicity of docetaxel has limited its clinical adoption. This study compared the efficacy and safety of a modified low-dosed docetaxel plus S-1 (mDS) with oxaliplatin plus S-1 (SOX) in Chinese patients with AGC. Patients were assigned to receive either oxaliplatin (100 mg/m(2)) in the SOX arm or docetaxel (40 mg/m(2)) in the mDS arm on day 1 of every 3-week cycle. S-1 80-120 mg/day was administered orally on days 1-14 in the 3-week cycle in both groups. One hundred and eighty-eight patients (mDS regimen 101; SOX 87) showed similar overall survival (OS; 13.1 vs 12.8 months, P = 0.878), progression-free survival (PFS; 5.8 vs 5.5 months, P = 0.924), and overall response rate (39.7 vs 44.2%, P = 0.569) in the mDS and SOX arms, respectively. mDS was associated with significantly less grade 3/4 toxicities in thrombocytopenia (5.9 vs 16.1%) and gastrointestinal disturbances (1.0 vs 8.0%). Furthermore, in patients who had ever received oxaliplatin-based adjuvant chemotherapy (N = 40), mDS resulted in significantly superior OS (17.8 vs 9.5 months, P = 0.015) and PFS (7.0 vs 4.2 months, P = 0.008) compared with SOX. In conclusion, mDS was as effective as SOX in Chinese patients with AGC, but it resulted in a significantly improved tolerability. In patients who received oxaliplatin-based adjuvant chemotherapy before, mDS was associated with improved efficacy in the first-line setting.

Trial Watch: Immunogenic cell death inducers for anticancer chemotherapy

The term "immunogenic cell death" (ICD) is now employed to indicate a functionally peculiar form of apoptosis that is sufficient for immunocompetent hosts to mount an adaptive immune response against dead cell-associated antigens. Several drugs have been ascribed with the ability to provoke ICD when employed as standalone therapeutic interventions. These include various chemotherapeutics routinely employed in the clinic (e.g., doxorubicin, epirubicin, idarubicin, mitoxantrone, bleomycin, bortezomib, cyclophosphamide and oxaliplatin) as well as some anticancer agents that are still under preclinical or clinical development (e.g., some microtubular inhibitors of the epothilone family). In addition, a few drugs are able to convert otherwise non-immunogenic instances of cell death into bona fide ICD, and may therefore be employed as chemotherapeutic adjuvants within combinatorial regimens. This is the case of cardiac glycosides, like digoxin and digitoxin, and zoledronic acid. Here, we discuss recent developments on anticancer chemotherapy based on ICD inducers.

Surgical outcomes in patients with locally advanced gastric cancer treated with S-1 and oxaliplatin as neoadjuvant chemotherapy

BACKGROUND

We wished to evaluate the impact of S-1 combined with oxaliplatin (SOX regimen) as neoadjuvant chemotherapy on surgical outcomes after gastrectomy with D2 lymphadenectomy.

METHODS

From February 2012 to September 2013, 170 patients with American Joint Committee on Cancer (AJCC) stage II-III gastric cancer were assessed retrospectively. Eighty patients underwent neoadjuvant chemotherapy before radical gastrectomy, and 90 patients received surgical treatment with adjuvant chemotherapy. Patients received S-1 (80 mg/m(2)/day; days 1-14) and oxaliplatin (130 mg/m(2); day 1) as neoadjuvant or adjuvant chemotherapy, and this schedule was repeated every 3 weeks. Gastrectomy with D2 lymphadenectomy was standard therapy for each patient. Surgical outcomes between the two groups were analyzed statistically.

RESULTS

There was no significant difference in the total prevalence of complications between neoadjuvant and adjuvant groups (18.8% vs. 22.2%, P = 0.704). The most common postoperative complications were surgical site infection (6.5%) and gastrointestinal motility disorders (3.5%). The clinical response rate was 68.8%, and ten patients (12.5%) had a pathological complete response after neoadjuvant chemotherapy. The SOX regimen as neoadjuvant chemotherapy for AJCC stage II/III gastric cancer can be effective without increasing the risk of postoperative complications.

CONCLUSIONS

The SOX regimen could be a neoadjuvant chemotherapy for advanced gastric cancer worldwide in the future.