Epirubicin and Gemcitabine as First-Line Treatment in Malignant Pleural Mesothelioma

Advances in systemic therapy for malignant mesothelioma: future perspectives

Malignant mesothelioma is a rare and aggressive form of cancer affecting the mesothelium. This mainly occupational disease is becoming more common in those countries where asbestos has been used for industrial applications. Notwithstanding the progress made in the field, patients do not survive more than 12 months on average with standard treatment. With the advent of next generation sequencing, it is now possible to study the mutational landscape of each tumor with the aim of identifying the genetic aberrations driving tumorigenesis. This review encompasses the latest research in the field, with particular attention to new chemotherapy combinatorial regimens, molecular targets and immunotherapies, providing a comprehensive picture of the current and future treatment options for malignant mesothelioma patients.

Second-line gemcitabine-based chemotherapy regimens improve overall 3-year survival rate in patients with malignant pleural mesothelioma: a multicenter retrospective study

In the present study, we aimed to evaluate the effectiveness of second-line gemcitabine-based chemotherapy regimens on overall survival (OS) in malignant pleural mesothelioma (MPM) patients receiving first-line pemetrexed-based regimens. A total of 73 patients with MPM from Akdeniz University, Acibadem Kayseri Hospital, Kayseri Training and Research Hospital, and Erciyes University were analyzed and evaluated retrospectively as two groups: second-line gemcitabine-based chemotherapy and no second-line chemotherapy. The median OS of patients who received second-line gemcitabine-based chemotherapy was 11.3 (5.1-17.5) months, while it was 9.9 (2.1-17.7) months in the patients who did not receive chemotherapy in the second-line setting (p = 0.056). When we evaluated the survival rate at the 6th, 12th, 18th, 24th, and 36th month, the OS rate of the 36th month was significantly higher in patients who received gemcitabine-based second-line chemotherapy (p = 0.041). When evaluating the OS from diagnosis to death, the median OS values were 20.8 (17.5-24.1) months for first-line pemetrexed-based regimens then second-line gemcitabine alone and 13.1 (9.0-17.1) months supportive care after first-line pemetrexed-based regimens (p = 0.005). According to our results, we may consider gemcitabine-based regimens as second-line chemotherapy after treatment with pemetrexed plus platinum in patients with MPM.

Chemotherapy and radiotherapy for mesothelioma

Previously considered to be rare, malignant pleural mesothelioma (MPM) is a highly aggressive tumor with an increasing incidence linked to asbestos exposure, its main etiological factor. MPM is also a very important issue because patients have usually a short survival (median <12 months) despite current treatments. Moreover an optimal treatment for MPM is not defined yet, even if ERS/ESTS experts recently provided clear and up-to-date guidelines on MPM management. These guidelines on chemotherapy and radiotherapy for mesothelioma, as well as new therapeutic developments, are presented in this chapter.

Systemic treatments for mesothelioma: standard and novel

Systemic therapy is the only treatment option for the majority of mesothelioma patients, for whom age, co-morbid medical illnesses, non-epithelial histology, and locally advanced disease often preclude surgery. For many years, chemotherapy had a minimal impact on the natural history of this cancer, engendering considerable nihilism. Countless drugs were evaluated, most of which achieved response rates below 20% and median survival of <1 year. Several factors have hampered the evaluation of systemic regimens in patients with mesothelioma. The disease is uncommon, affecting only about 2500 Americans annually. Thus, most clinical trials are small, and randomized studies are challenging to accrue. There is significant heterogeneity within the patient populations of these small trials, for several reasons. Since all of the staging systems for mesothelioma are surgically based, it is almost impossible to accurately determine the stage of a patient who has not been resected. Patients with very early stage disease may be lumped together with far more advanced patients in the same study. The disease itself is heterogenous, with many different prognostic factors, most notably three pathologic subtypes—epithelial, sarcomatoid, and biphasic—that have different natural histories, and varying responses to treatment. Finally, response assessment is problematic, since pleural-based lesions are difficult to measure accurately and reproducibly. Assessment criteria often vary between trials, making some cross-trial comparisons difficult to interpret. Despite these limitations, in recent years, there has been a surge of optimism regarding systemic treatment of this disease. Several cytotoxic agents have been shown to generate reproducible responses, improve quality of life, or prolong survival in mesothelioma. Drugs with single-agent activity include pemetrexed, raltitrexed, vinorelbine, and vinflunine. The addition of pemetrexed or raltitrexed to cisplatin prolongs survival. The addition of cisplatin to pemetrexed, raltitrexed, gemcitabine, irinotecan, or vinorelbine improves response rate. The combination of pemetrexed plus cisplatin is considered the benchmark front-line regimen for this disease, based on a phase III trial in 456 patients that yielded a response rate of 41% and a median survival of 12.1 months. Vitamin supplementation with folic acid is essential to decrease toxicity, though recent data suggests that there may be an optimum dose of folic acid that should be administered; higher doses may diminish the effectiveness of pemetrexed. There are also several unresolved questions about the duration and timing of treatment with pemetrexed that are the subject of planned clinical trials. It is essential to recognize that the improvements observed with the pemetrexed/cisplatin combination, though real, are still modest. Other active drugs or drug combinations may be more appropriate for specific individuals, and further research is still needed to improve upon these results. Since the majority of mesotheliomas in the United States occur in the elderly, non-cisplatin-containing pemetrexed combinations may be more appropriate for some patients. Now that effective agents have been developed for initial treatment, several classical cytotoxic drugs and many novel agents are being evaluated in the second-line setting. These include drugs targeted against the epidermal growth factor, platelet-derived growth factor, vascular endothelial growth factor, src kinase, histone deacetylase, the proteasome, and mesothelin. Given the progress made in recent years, there is reason to believe that more effective treatments will continue to be developed.

Phase II trial of pemetrexed and gemcitabine in chemotherapy-naive malignant pleural mesothelioma

PURPOSE

Pemetrexed and gemcitabine have single-agent activity in malignant pleural mesothelioma (MPM). The combination of pemetrexed/gemcitabine has not previously been studied in MPM to our knowledge.

PATIENTS AND METHODS

Patients with histologic or cytologic diagnosis of MPM were included. Cohort 1 received gemcitabine 1,250 mg/m(2) on days 1 and 8, with pemetrexed 500 mg/m(2) on day 8, and cohort 2 received gemcitabine 1,250 mg/m(2) on days 1 and 8, with pemetrexed 500 mg/m(2) on day 1. Cycles were repeated every 21 days; all patients were supplemented with folic acid and vitamin B(12) and received dexamethasone.

RESULTS

One hundred eight patients (cohort 1, n = 56; cohort 2, n = 52) with pleural mesothelioma were enrolled. Among assessable patients, response rate was 26.0% in cohort 1 and 17.1% in cohort 2. Median time to disease progression was 4.34 months for cohort 1 and 7.43 months for cohort 2. Median survival was 8.08 months for cohort 1 (1-year survival = 31.14%) and 10.12 months for cohort 2 (1-year survival = 45.80%). In cohorts 1 and 2, incidence of grade 4 neutropenia was 25.0% and 29.4%, grade 4 thrombocytopenia was 14.3% and 3.9%, grade 3 or 4 anemia was 5.4% and 5.9%, and grade 3 or 4 fatigue was 23.2% and 15.7%, respectively.

CONCLUSION

The combination of pemetrexed and gemcitabine resulted in moderate clinical activity in MPM. However, the median survival times are similar to those with single-agent pemetrexed and inferior to outcomes observed with cisplatin in combination with an antifolate.

Single-arm, open label study of pemetrexed plus cisplatin in chemotherapy naïve patients with malignant pleural mesothelioma: Outcomes of an expanded access program

BACKGROUND

An expanded access program (EAP) provided patient access to pemetrexed prior to its commercial availability. The current report consists of US patients in the EAP who had chemotherapy naïve pleural mesothelioma.

METHODS

Eligible patients had a histologic or cytologic diagnosis of malignant mesothelioma that was not amenable to curative treatment with surgery. Study treatment consisted of pemetrexed 500mg/m(2) in combination with cisplatin 75mg/m(2) once every 21 days. Vitamin B12, folic acid, and dexamethasone were administered as prophylaxis. Serious adverse events (SAEs) were reported by investigators and compiled in a pharmacovigilance database for all patients enrolled in the EAP.

RESULTS

Of 1056 patients receiving at least one dose of pemetrexed in the EAP, 728 had chemotherapy naïve pleural mesothelioma. Median age of this group was 70 years (range 23-89 years) and 84% were male. Among 615 patients, overall response rate was 20.5%, including 12 complete responses (2.0%) and 114 partial responses (18.5%). An additional 290 patients (47.2%) had stable disease. Median survival for all 728 patients was 10.8 months (95% CI=9.8, 12.3; 60.3% censorship) and 1 year survival was 45.4%. The most commonly reported SAEs in the overall EAP irrespective of causality were dehydration (7.2%), nausea (5.2%), vomiting (4.9%), dyspnea (3.8%), and pulmonary embolism (2.4%).

CONCLUSIONS

In this large cohort, 67.7% of patients treated with first-line chemotherapy experienced a response or stable disease. Survival time and toxicity from this EAP were promising for this difficult-to-treat disease.