Phase II study of tailored S-1 monotherapy with a 1-week interval after a 2-week dosing period in elderly patients with advanced non-small cell lung cancer

S-1 eliminates MDSCs and enhances the efficacy of PD-1 blockade via regulation of tumor-derived Bv8 and S100A8 in thoracic tumor

Myeloid-derived suppressor cells (MDSCs) have been known to play a pivotal role in the induction of immune tolerance, which limits the benefits of immune checkpoint inhibitors (ICIs). Recent studies revealed that several chemotherapeutic agents decreased tumor-infiltrating MDSCs. Therefore, combination therapy with cytotoxic chemotherapeutic agents and ICIs was approved for first-line treatment for lung cancer. However, the impact of chemotherapeutic agents on MDSCs and an optimal partner of ICIs has not been fully investigated in thoracic tumors, including lung cancer and malignant pleural mesothelioma. In the present study, we found that treatment with 5-FU and its oral formulation, S-1, suppressed tumor progression and inhibited the accumulation of MDSCs in thoracic tumor-bearing mice. Tumor-infiltrating T cells and dendritic cells were significantly expanded in S-1-treated mice. 5-FU suppressed the ability of tumor cells to recruit MDSCs, while it did not suppress the survival and differentiation of mouse MDSCs in vitro. We also revealed that 5-FU or S-1 significantly downregulated the expression of tumor-derived Bv8 and S100A8. The knockdown of Bv8 or S100A8 in tumor cells suppressed tumor growth and MDSC recruitment in vivo. Furthermore, in comparison with pemetrexed, administration of S-1 improved the synergistic therapeutic efficacy of anti-PD-1 antibodies with or without carboplatin. Our findings revealed a novel mechanism wherein S-1 primed a favorable tumor microenvironment to provide the rationale for combination therapy with S-1 and ICIs as the optimal therapy for thoracic cancer.

Efficacy and safety of S-1 monotherapy in previously treated elderly patients (aged ≥75 years) with non-small cell lung cancer: A retrospective analysis

BACKGROUND

S-1 monotherapy is effective and feasible for previously treated patients with advanced non-small cell lung cancer (NSCLC). However, it is not clear whether its effectiveness and tolerability in elderly patients are equivalent to those in younger patients. Hence, this study aimed to evaluate the efficacy and feasibility of S-1 monotherapy in elderly patients with NSCLC who had previously received other treatments.

METHODS

We included 96 elderly patients (aged ≥75 years) with advanced NSCLC treated with S-1 alone as a subsequent-line treatment at 12 medical facilities between January 2005 and March 2018 in this study. The baseline characteristics of the patients, response to S-1 monotherapy, and adverse events (AEs) were investigated, retrospectively.

RESULTS

A total of 68 male and 28 female patients (median age, 78 [range: 75-86] years) were analyzed. In elderly patients who were treated with S-1 monotherapy as a subsequent-line treatment, the objective response rate, disease control rate, median progression-free survival (PFS), and overall survival (OS) were 8.3%, 43.8%, 3.4 months, and 9.6 months, respectively. Observed AEs included anorexia, anemia, nausea, fatigue, reduced platelet count, and skin hyperpigmentation. Treatment-related death was observed in one patient because of pneumonitis. In patients who experienced no progressive disease, subsequent-line S-1 alone was associated with longer PFS and OS.

CONCLUSIONS

S-1 monotherapy is effective and feasible as a subsequent-line treatment in elderly patients who were previously treated for NSCLC, and it produces results. S-1 monotherapy could be one of the treatment choices for elderly patients with previously treated NSCLC.

Oral Chemotherapy for Treatment of Lung Cancer

The global COVID-19 pandemic has disrupted healthcare delivery, particularly for patients with advanced lung cancer. While certain aspects of care can be safely omitted or delayed, systemic therapy plays an important role in survival and quality of life for patients with advanced lung cancer; limiting access to systemic therapy will compromise cancer-related outcomes. This can be at odds with strategies to mitigate risk of COVID-19 exposure, which include reducing hospital and clinic visits. One important strategy is implementation of oral cancer therapies. Many standard regimens require intravenous infusions but there are specific circumstances where an oral agent could be an acceptable alternative. Integrating oral therapeutics can permit patients to receive effective systemic treatment without the exposure risks associated with frequent infusions. Here, we review currently available oral cytotoxic agents with a potential role in the treatment of lung cancer.

A phase I and extension study of S-1 and carboplatin for previously untreated patients aged 75 years or more with advanced non-small cell lung cancer -TCOG 1101

PURPOSE

Combination carboplatin and S-1 is active in the treatment of non-small cell lung cancer (NSCLC). However, data on this combination for elderly patients with NSCLC are insufficient.

METHODS

Eligibility criteria were no prior chemotherapy, Stage IIIB or IV NSCLC, performance status 0-1, age ≥ 75 years, and adequate hematological, hepatic, and renal functions. Carboplatin was administered on day 1 and S-1 was administered orally, twice a day, between days 1 and 14, repeated every 3 weeks. In phase I, the primary purpose was determination of the recommended dose. Starting doses of carboplatin and S-1 were area under the curve (AUC) of 4 and 80 mg/m²/day, respectively. In the extension study, the effects and tolerability of this combination therapy of recommended dose were confirmed.

RESULTS

A total of 10 patients were entered into phase I and 14 patients were entered into the extension study. The recommended doses for this drug combination are AUC 5 for carboplatin and 80 mg/m²/day every 3 weeks for S-1. With carboplatin and S-1 combination therapy at the recommended dose, the response rate was 30.0% [95% confidence interval (CI) 12-54%] and the disease control rate was 90.0% (95% CI 68-99%). Thrombocytopenia and neutropenia were major adverse events.

CONCLUSIONS

The recommended doses for this combination therapy are carboplatin AUC 5 and S-1 80 mg/m²/day every 3 weeks, and this combination is effective with tolerable toxicities for advanced NSCLC patients ≥ 75 years old.

Phase II study of S-1 in patients with previously-treated invasive thymoma and thymic carcinoma: North Japan lung cancer study group trial 1203

OBJECTIVES

Invasive thymoma (IT) and thymic carcinoma (TC) are rare epithelial neoplasms arising in the anterior mediastinum. Platinum-based chemotherapies are widely used for first-line treatment of unresectable IT and TC, but no standard treatment has been established for previously-treated IT and TC thus far. Because promising efficacy of S-1 (tegafur, gimeracil and oteracil combination) has been reported in some retrospective studies, we conducted the first prospective phase II trial to evaluate its efficacy in previously-treated patients with advanced IT and TC.

MATERIALS AND METHODS

Patients progressing after at least one regimen of systemic chemotherapy received S-1 orally at a dose based on body surface area for 2 weeks followed by one week of rest until tumor progression or unacceptable toxicity. The primary endpoint was overall response rate (ORR) and secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity profile. We defined an ORR of 25% as indicating potential usefulness while ORR of 10% was the lower limit of interest.

RESULTS

Forty patients were enrolled (IT, n = 20; TC, n = 20). ORR was 17.5% (95% CI 7.3-32.8; IT, 10%; TC, 25%), disease control rate was 85% (IT, 95%; TC, 75%). Median PFS was 7.0 months (IT, 11.3 months; TC, 5.4 months), and median OS was 40.3 months (IT, 58.5 months; TC, 22.7 months) with a median follow-up of 51.9 months. Major toxicities (grade 3-4) were anorexia (10%), neutropenia (7.5%) and pneumonitis (5%). No treatment-related death was observed.

CONCLUSION

Although the primary endpoint was not met, S-1 monotherapy did have effects similar to recently reported immunotherapies for TC but at much lower cost. S-1 could represent a treatment option for previously-treated advanced TC. This trial was registered as UMIN 000008174.

Alternate-day administration of S-1 for elderly patients with advanced non-small-cell lung carcinoma: A prospective feasibility study

S-1 is an oral fluoropyrimidine agent used for the treatment of non-small-cell lung cancer (NSCLC). Although S-1 monotherapy has been reported to exhibit lesser hematotoxicity compared with other third-generation chemotherapeutics, digestive toxicity was also frequently observed. Alternate-day administration of S-1 has shown a lower rate of severe digestive toxicity than the daily standard administration in patients with NSCLC. However, the safety of alternate-day S-1 therapy in elderly patients aged 75 years or older has not been investigated. The present study was a multi-center and prospective feasibility study aimed to evaluate the safety of alternate-day S-1 therapy in elderly patients with NSCLC. The patients received S-1 orally twice daily for 4 days (Monday, Wednesday, Friday, and Sunday) every week until disease progression or unacceptable toxicity. The primary endpoint was safety, which was evaluated as the number of grade ≥3 adverse events, and the secondary endpoints were progression-free survival (PFS), 1-year survival, and disease control rate (DCR). A total of 10 patients were enrolled, but 2 patients failed to initiate the treatment protocol. Finally, 8 patients were treated with the study protocol regimen. No grade 3 or higher adverse events were observed. Four (50%) and 1 (12.5%) patient had grade 2 or lower digestive symptoms such as anorexia, diarrhea, or stomatitis and grade 1 lacrimation, respectively. Moreover, 2 (25%), 1 (12.5%), and 1 (12.5%) patients had grade 2 renal dysfunction, grade 2 ileus, and elevated blood bilirubin, respectively. The median PFS was 1.5 months (95% confidence interval: 0.9-1.8), and the 1-year survival rate was 42.9%. The DCR was 12.5%. In conclusion, alternate-day S-1 administration can be a safe treatment regimen for elderly patients with NSCLC, but its therapeutic efficacy and safety for elderly patients with NSCLC should be compared against the standard S-1 administration in a large-scale study.

Phase I study of S-1 plus paclitaxel combination therapy as a first-line treatment in elderly patients with advanced non-small cell lung cancer

This phase I study was aimed at determining the maximum tolerated dose (MTD) and recommended dose (RD) for oral S-1 plus paclitaxel combination therapy in elderly patients with non-small cell lung cancer (NSCLC). Chemotherapy-naïve patients (age, >70 years) with stage III/IV NSCLC were treated with paclitaxel intravenously at four dose levels (DLs), 60, 70, 80, and 90 mg/m², on day 1 and 8, and with S-1 (80 mg/m²) orally on days 1-14 every 3 weeks. MTD was defined as the dose at which two of the initial three patients experienced dose-limiting toxicities (DLTs). Three patients were added when the initial three patients experienced DLTs. The dose administered in three of the six patients with DLTs met the definition of MTD. The RD was defined as a dose 1 DL below the MTD. Fifteen patients including six on DL 1 and three each on DLs 2, 3, and 4 were enrolled. One patient experienced a DLT (febrile neutropenia) at DL 1. The remaining DLTs were noted at DL 4 (in one patient each): febrile neutropenia, grade (G) 3 skin rash, G3 diarrhea, G3 stomatitis, and G3 international normalized ratio (INR) elevation. The MTD of paclitaxel was 90 mg/m². The RD for both S-1 and paclitaxel was 80 mg/m² (DL 3). The response rate was 45.5% (8 of 15 patients achieved a partial response). In conclusion, the RD of both S-1 and paclitaxel was 80 mg/m² in the combination therapy for chemotherapy-naïve patients with advanced NSCLC.