Author of

• 11515

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  P2.05 - Poster Session 2 - Preclinical Models of Therapeutics/Imaging (ID 158)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Biology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11539

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    P2.05-024 - Prediction of drug sensitivity in second line treatment of patients with malignant pleural mesothelioma (ID 3397)

    09:30 - 09:30  |  Author(s): J. Neefjes
    • Abstract

    Background
    In second line setting there is no standard treatment for patients with mesothelioma, since all agents tested in clinical trials failed to improve survival. An individual patient however, may actually benefit from second line treatment, considering the patient population is heterogeneous. Yet, there are no predictive markers to identify those patients likely to respond to a certain drug. We developed protocols for in vitro drug sensitivity testing with several cytotoxic agents using primary tumor cells derived from pleural fluid of our patients. Recently, we implemented a personalized second line treatment protocol. Here we will report the outcome of the pilot study.

    Methods
    Cells were isolated from pleural fluid, drawn from patients with mesothelioma for symptom relief. Diagnosis of each mesothelioma patient was confirmed by regular pathological staining. Cells were plated and incubated with a five point concentration range of 5 single drugs and 2 two-drug combinations for 72 hours. Cell viability was determined by a metabolic assay. Each concentration point was measured in triplo and a biological duplo experiment was performed to check reproducibility. The drugs used in this screen were all previously tested in clinical mesothelioma trials. Patients with pleural fluid that were fit and progressed after standard first line treatment were considered for second line chemotherapy. Choice of second line treatment was based on screening results.

    Results
    Thirty-nine mesothelioma patients had pleural fluid drawn for culture of primary tumor cells and subsequent drug sensitivity screening. Drug screens were successful in 22 patients (56%). Drug sensitivity profiles were available within two weeks after isolation of tumor cells, which is appropriate for clinical decision making. Agents tested for were cisplatin or carboplatin, pemetrexed, gemcitabine, vinorelbine, oxaliplatin, a combination of cisplatin and pemetrexed and of oxaliplatin and gemcitabine. Individual dose-response curves showed different sensitivity to the various cytotoxic agents. Ten patients were chemo-naive at the time of the drug sensitivity screen. Five of them received first line chemotherapy (cisplatin and pemetrexed). Two of them had progressive disease. Both demonstrated evident resistance to cisplatin and pemetrexed in their drug sensitivity profile. Four patients received second line treatment based on the drug sensitivity profile of their primary tumor cells. To date, treatment response is evaluated for two patients. Both patients received a combination of oxaliplatin and vinorelbine. The first patient had a clinical response. For the second patient, oxaliplatin/vinorelbine was the best option, although her in vitro profile suggested a rather resistant tumor. She was progressive and showed an unusual large amount of necrosis on repeated CT imaging. Patient three and four are currently treated with oxaliplatin and gemcitabine and gemcitabine monotherapy, respectively. Their treatment responses have to be awaited.

    Conclusion
    Personalized drug screening using primary tumor cells is feasible within a clinically relevant time period and may yield new treatment combinations with better responses.