Docetaxel-based chemotherapy as second-line regimen for advanced thymic carcinoma

Second-line treatment options in advanced thymic carcinoma after failure of platinum-based chemotherapy: A multicenter retrospective study

BACKGROUND

Currently there is no standard therapy recommended for second-line treatment for thymic carcinoma. Our study compared multidrug chemotherapy, single-agent chemotherapy, and PD-1 inhibitors in patients diagnosed with advanced thymic carcinoma who had previous platinum-based chemotherapy at the clinic.

METHODS

The study included patients with thymic carcinoma who failed first-line platinum-based chemotherapy. Kaplan-Meier methods were applied in the study for estimating the progression-free survival (PFS) and overall survival (OS) curves. Pearson chi-square or Fisher's exact chi-square test was adopted to make comparisons of the objective response rate (ORR) between treatment groups. Cox regression was used for the multivariate analyses in PFS and OS.

RESULTS

Among the 92 patients enrolled, multidrug chemotherapy was used in 51 (55.4%) patients for second-line therapy. Thirty-six patients (35.9%) received single-agent chemotherapy, and eight patients (8.7%) underwent PD-1 inhibitors. The multidrug chemotherapy group showed better efficacy than the other two groups, with an ORR of 35.3% (p = 0.006). The median PFS of multidrug chemotherapy, single-agent chemotherapy and PD-1 inhibitors were 5.0 months, 3.0 months, and 4.0 months, respectively (p = 0.008). Patients in the multidrug chemotherapy group also showed an advantage in OS in comparison with the other two treatment groups (p = 0.045), with a median OS of 30.4 months. Multivariate analysis showed that second-line treatment was independent factor for both PFS (p = 0.035) and OS (p = 0.037). Grade 3-4 AEs were mostly detected in patients receiving multidrug chemotherapy and were primarily hematologic. Treatment-related mortality was not found in any of the groups.

CONCLUSIONS

Multidrug chemotherapy had a trend toward a more positive response rate and outcomes in longer survival time than single-agent chemotherapy and PD-1 inhibitors. Multidrug chemotherapy is a choice worth considering for second-line therapy in patients with thymic carcinoma if tolerable.

Apatinib in patients with recurrent or metastatic thymic epithelial tumor: a single-arm, multicenter, open-label, phase II trial

BACKGROUND

Thymic epithelial tumors (TETs) are rare malignancies and the treatment options are limited. We aimed to evaluate the efficacy and safety of apatinib, an angiogenesis inhibitor, in advanced TETs.

METHODS

This was an open-label, single-arm, phase II trial at three centers in China. Patients with TET who had progressed after failure of at least one line of platinum-based chemotherapy were enrolled. Patients received apatinib 500 mg orally per day. The primary endpoint was objective response rate (ORR). Secondary endpoints were progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and safety.

RESULTS

From June 29, 2017, to April 18, 2019, 25 patients were enrolled. At data cut off (September 30, 2021), one patient achieved complete response, nine achieved partial response, and 11 achieved stable disease, with an ORR of 40% (95% CI 21-61%) and DCR of 84% (95% CI 64-95%). The median PFS was 9.0 (95% CI 5.4-12.6) months. The median OS was 24.0 (95% CI 8.2-39.8) months. All patients reported treatment-related adverse events (TRAEs). Grade 3 TRAEs occurred 26 times in 15 patients. No grade 4 or 5 toxicities occurred.

CONCLUSIONS

This is the first trial of apatinib for the treatment of TETs. Apatinib showed promising antitumor activity and the toxicities were tolerable and manageable.

Salvage Chemotherapy in Patients with Previously Treated Thymic Carcinoma

Thymic carcinoma is a rare neoplasm, and it is difficult to achieve complete remission with systemic chemotherapy. In advanced or recurrent thymic carcinoma, platinum-based chemotherapy is chosen as the first-line setting; however, it remains unclear which regimen is better to improve its outcome. It remains unknown whether salvage chemotherapy should be administered to patients with platinum-based chemotherapy-refractory thymic carcinoma. Currently, several clinical studies have investigated the efficacy of second-line settings for advanced thymic carcinoma. As cytotoxic agents, S-1, amrubicin, pemetrexed, docetaxel, paclitaxel, and gemcitabine have been reported as prospective phase II studies or retrospective studies. The overall response rates (ORRs) of S-1, amrubicin, and pemetrexed were 25-50%, 11-44.4%, and 9-10%, respectively. Molecular targeting drugs, such as sunitinib, everolimus, and lenvatinib, also provide clinical effectiveness with tolerability after the failure of platinum-based regimens. Based on the results of the prospective phase II study, the ORR, median progression-free survival, and median overall survival were 16.6% and 5.6 months, respectively, in everolimus, 26% and 7.2 months, respectively, in sunitinib, and 38% and 9.3 months, respectively, in lenvatinib. Although it is difficult to compare each study, lenvatinib appears to be better in increasing efficacy as a second-line setting. However, each study had a small sample size, which may have biased the results of their studies. Further investigation is warranted to elucidate the therapeutic significance of salvage chemotherapy in advanced thymic carcinoma in a large-scale study.

Systemic treatments for thymic tumors: a narrative review

Thymic epithelial tumours (TETs) are rare tumours originating from the thymus. Considering the rarity of this disease, the management of TETs is still challenging and difficult. In fact, all the worldwide clinical practice guidelines are based on data from retrospective analyses, prospective single arm trials or experts' opinions. The results of combined modality therapy (chemotherapy, surgery, radiotherapy) in thymic malignancies are reasonably good in less advanced cases whereas in case of advanced (unsuitable for surgery) or metastatic disease, a platinum-based chemotherapy is considered standard of care. Unfortunately, chemotherapy in the palliative setting has modest efficacy. Moreover, due to the lack of known oncogenic molecular alterations, no targeted therapy has been shown to be efficient for these tumours. In order to offer the best diagnostic and therapeutic tools, patients with TETs should be managed with a continuous and specific multidisciplinary expertise at any step of the disease, especially in the era of a novel coronavirus disease (COVID-19). Current evidences show that cancer patients might have more severe symptoms and poorer outcomes from COVID-19 infection than general population. With the exception of the patients carrying a Good's syndrome, there is no evidence that patients with TETs present a higher risk of infection compared with other cancer patients and their management should be the same. The aim of this review is to summarize the existing literature about systemic treatments for TETs in all clinical setting (local and locally advanced/metastatic disease) exploring how these therapeutic strategies have been managed in the COVID-19 era.

Efficacy of pemetrexed-based regimen in relapsed advanced thymic epithelial tumors and its association with thymidylate synthetase level

Purpose

Due to the rarity of thymic epithelial tumors (TET), no standard chemotherapy regimen has been identified in the relapsed setting. The aim of this study was to investigate the activity of a pemetrexed-based regimen in advanced TET as palliative treatment after failure of previous chemotherapy, and to detect its association with thymidylate synthetase (TS) level.

Methods

Patients with pathologically confirmed TET and treated with pemetrexed-based regimen were evaluated from 2006 to 2014 in Zhejiang Cancer Hospital. TS mRNA level was detected by real-time polymerase chain reaction. The Kaplan–Meier method was used for survival analysis.

Results

A total of 22 TET patients were identified, of whom eight had thymoma and 14 had thymic carcinoma. In total, the objective response rate and disease control rate of the 22 patients were 22.7% and 68.2%, respectively. Median progression-free survival and overall survival were 4.5 months and 34.9 months, respectively. A trend of lower TS mRNA levels existed in patients with disease control compared to those with progressive disease (268.0±160.5×10⁻⁴ vs 567.0±445.0×10⁻⁴, P=0.065).

Conclusion

Patients with advanced TET may benefit from pemetrexed-based regimen therapy. TS mRNA level is valuable for predicting the efficacy of pemetrexed in TET.