Efficacy, Safety, and Cost-Minimization Analysis of Continuous Infusion of Low-Dose Gemcitabine Plus Cisplatin in Patients With Unresectable Malignant Pleural Mesothelioma

Drug sensitivity tumor cell clusters in malignant peritoneal mesothelioma

BACKGROUND

To explore the most effective adjuvant chemotherapy regimen for malignant peritoneal mesothelioma (MPM) through patient derived tumor-like cell clusters (PTC) drug sensitivity test.

METHODS

PTC were cultured in vitro with intraoperative specimens, and drug sensitivity test was performed to calculate the most effective chemotherapy regimen for MPM. The patients were divided into conventional and individualized chemotherapy group according to whether they received PTC drug testing. Univariate and multivariate analyses were conducted to identify independent prognostic factors.

RESULTS

Among 186 MPM patients included, 63 underwent PTC culture and drug sensitivity test. The results showed that the most effective chemotherapy regimen was oxaliplatin + gemcitabine. After propensity score matching, a total of 64 patients were enrolled in the following study, including 32 patients receiving individualized chemotherapy guided by PTC drug results as group 1 and 32 patients receiving conventional chemotherapy as group 2. Survival analysis showed that the median OS of group 1 was not reached, significantly longer than that of group 2 (23.5 months) (p < 0.05).

CONCLUSIONS

Compared with conventional chemotherapy, individualized chemotherapy guided by PTC drug sensitivity tests can prolong patient survival, and oxaliplatin + gemcitabine + apatinib could be the optimal adjuvant treatment regimen for MPM.

PD-L1 expression complements CALGB prognostic scoring system in malignant pleural mesothelioma

Background

Programmed death ligand-1 (PD-L1) expression is a predictive biomarker in patients with lung cancer, but its role in malignant pleural mesothelioma (MPM) remains unclear. Evidence suggests that higher PD-L1 expression is correlated with worse survival. CALGB is the main scoring system used to predict the benefit of chemotherapy treatment. This study aimed to determine the prognostic value of PD-L1 expression and its addition to CALGB scoring system in patients with MPM.

Methods

In this retrospective analysis, we evaluated samples with confirmed locally advanced or metastatic MPM. PD-L1 Tumor Proportional Score (TPS) was determined by immunohistochemistry at diagnosis.

Results

73 patients were included in this study. A cutoff value of 15 was set for a high or low PD-L1 TPS. In total, 71.2% (n=52) and 28.8% (n=21) of individuals harbored low or high PD-L1 expression, respectively. PD-L1High was associated with worse median progression-free Survival (mPFS) [4.9 vs. 10.8 months; HR 2.724, 95% CI (1.44-5.14); p = 0.002] and Overall Survival (OS) [6.0 vs. 20.9 months; HR 6.87, 95% CI (3.4-8.7); p<0.001] compared to patients with PD-L1Low. Multivariate analysis confirmed that PD-L1 expression was an independent factor for PFS and OS in patients with MPM and CALGB score of 5-6.

Conclusion

PD-L1 addition to CALGB scale improves its prognostic estimation of MPM survival and should be considered in future research.

Cost-effectiveness analysis of nivolumab plus ipilimumab versus chemotherapy as the first-line treatment for unresectable malignant pleural mesothelioma

Introduction:

This study evaluated the cost-effectiveness of nivolumab plus ipilimumab (NI) versus pemetrexed plus cisplatin/carboplatin (C) as the first-line treatment for unresectable malignant pleural mesothelioma (MPM) from the perspective of US payers.

Methods:

A 10-year partitioned survival model was constructed using survival and safety data from the CheckMate 743 clinical trial. The output metrics of the model included the patient’s lifetime quality-adjusted life years (QALYs), lifetime costs, and incremental cost-effectiveness ratio (ICER). Only direct medical costs were considered. One-way and probabilistic sensitivity analyses were conducted to assess the robustness of the results.

Results:

Among all randomized patients, group NI had an ICER of $475,677/QALY relative to group C. Among patients with epithelioid histology, group NI had an ICER of $760,955/QALY. Among patients with non-epithelioid histology, group NI had an ICER of $418,348/QALY. The ICERs of all three populations exceeded the willingness-to-pay threshold ($150,000). The results of one-way sensitivity analysis revealed that the cost of nivolumab had a great influence on the results. The results of probabilistic sensitivity analysis demonstrated that the possibility of NI being more economical in all randomized patients and in patients with non-epidemiology histology was 0. In patients with epithelioid histology, the probability that NI had an economic advantage was 0.6%.

Conclusions:

From the perspective of US payers, in patients with unresectable MPM, NI has no economic advantage over C.