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A. Dietz
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OA13 - Immunotherapy in Malignant Pleural Mesothelioma: Current Status of Trials and New Approaches (ID 392)
- Event: WCLC 2016
- Type: Oral Session
- Track: Mesothelioma/Thymic Malignancies/Esophageal Cancer/Other Thoracic Malignancies
- Presentations: 1
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OA13.07 - Intrapleural Modified Vaccine Strain Measles Virus Therapy for Patients with Malignant Pleural Mesothelioma (ID 5655)
14:20 - 15:50 | Author(s): A. Dietz
- Abstract
- Presentation
Background:
Malignant pleural mesothelioma (MM) remains an almost universally fatal disease with limited treatment options. Preclinical models indicate the preferential oncolytic activity of the modified vaccine strain measles virus carrying the gene for the human sodium-iodine symporter (NIS) – MV-NIS. Intraperitoneal and intravenous administration of MV-NIS was recently found to be potentially effective in patients with refractory ovarian cancer and multiple myeloma. However, whether MV-NIS is directly oncolytic or triggers an anti-tumor immune response remains unclear.
Methods:
We conducted a phase I dose escalation study with 3+3 design and ongoing maximal tolerated dose (MTD) expansion cohort. MV-NIS was administered as first or second line therapy via a tunneled intrapleural catheter to patients with MM. MV-NIS dose ranged from 10[8] TICID~50~ to 9 x 10[9] TICID~50~. In the absence of dose limiting toxicity and disease progression, patients received up to 6 cycles of MV-NIS therapy (Phase I). Currently additional patients are being randomized between a single and multiple cycles. MV-NIS infection and replication are monitored by Iodine[123] SPECT/CT (Phase I only) as well as by RT-PCR and/or plaque-assay. Anti-tumor immunity is monitored in the blood and pleural fluid and patients are followed clinically by chest CT using the modified RECIST criteria.
Results:
Twelve patients (3/dose level) received MV-NIS therapy. There were no dose limiting adverse events and therapy was well tolerated. The best therapeutic response was stable disease, which was achieved at 1 month by 8/12 evaluable patients (67%). Median overall survival was 449 days (95%CI: 221, 484) (~15 months) (4/12 patients remain alive), and median progression free survival was 63 days (95% CI: 33, 174) (~2 months). MV infection and replication were detectable by RT-PCR and plaque assay in the pleural fluid between 24-72 hours after treatment. I[123] SPECT-CT demonstrated only marginal viral gene expression in a single patient treated with the highest dose level. MV-NIS therapy effectively boosted pre-existing anti-MV neutralizing antibody responses in the plasma and pleural fluid of most patients. We observed a transient inflammatory response in the pleural space after MV-NIS administration. In addition, induction or boosting of anti-tumor antibody responses was observed.
Conclusion:
The intrapleural administration of MV-NIS is safe, resulted in stable disease for 67% of patients and may be associated with favorable overall survival in MM. While there was only transient infection and viral replication, we observed the induction of anti-tumor immune responses supportive of potential long-term therapeutic impact. The study continues with the MTD expansion cohort.
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P3.03 - Poster Session with Presenters Present (ID 473)
- Event: WCLC 2016
- Type: Poster Presenters Present
- Track: Mesothelioma/Thymic Malignancies/Esophageal Cancer/Other Thoracic Malignancies
- Presentations: 1
- Moderators:
- Coordinates: 12/07/2016, 14:30 - 15:45, Hall B (Poster Area)
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P3.03-034 - Comprehensive Immunophenotyping of the Blood and Pleural Fluid from Patients with Malignant Pleural Mesothelioma by Flow Cytometry (ID 6294)
14:30 - 15:45 | Author(s): A. Dietz
- Abstract
Background:
Malignant pleural mesothelioma (MM) remains an almost universally fatal disease with limited treatment options. Immunotherapy represents a rapidly emerging therapeutic strategy for multiple malignancies including MM. However durable therapeutic responses occur in a minority (~30%) of patients. Better understanding of the quantities and immunophenotype of circulating and intrapleural immune cells is essential to design and apply personalized immunotherapeutic strategies.
Methods:
We used a comprehensive flow cytometry panel (PLoS One. 2015 Mar 23;10 (3):e0121546) to prospectively characterize circulating and pleural fluid immune cells in patients with MPM (n=12) and normal volunteers (circulating cells only, n=50). Matched blood and pleural samples were available from 11 patients, including samples from 9 patients enrolled into a Phase I study investigating the intrapleural administration of the modified vaccine strain measles virus (MV-NIS), MC1023. Pre- and post-treatments samples were available from 7 patients. The immune cell counts and cell fractions were compared using a false discovery rate (FDR) of 10% and the non-parametric Mann-Whitney test and the Wilcoxon matched-pairs signed rank test (blood versus pleural fluid and different time points). (p ≤ 0.05)
Results:
Cell counts and immune phenotype of circulating immune cells differ between of patients with MPM differ from normal volunteers (31 of 86 cell types). Patients with MPM had fewer B-lymphocytes, more pro-inflammatory monocytes (CD14+CD16+) and exhausted CD4 and CD8 T-lymphocytes (CD4 and CD8 PD1+TIM3+ double positive cells). As expected we observed characteristic differences between blood and pleural fluid in MPM patients. For example there are a higher numbers of antigen experienced, PD-1 expressing CD4 and CD8-memory cells within the pleural fluid compared to the peripheral blood. The intrapleural administration of a modified vaccine strain measles (MV-NIS) triggered changes in pleural and circulating immune cells. While these changes varied among patients, we observed increased CD80 and CD86 expression on CD14+ monocytes in the pleural fluid down.
Conclusion:
Comprehensive flow-cytometric immunophenotying of blood and pleural fluid is feasible in patients with MPM. This approach may help to identify patients who may respond favorably to specific immunotherapeutic interventions such as immune checkpoint inhibitors or facilitate longitudinal immune monitoring during clinical trials. Additional data is needed and we are continuing to prospectively analyze samples from patients with MPM.
