• ECOG Performance status (PS) 0-1 (WHO)

• Unresectable Malignant Pleural Mesothelioma

• suffering from unresectable MPM (n=20), relapsing after one or 2 lines of treatment with platinum-based doublet of chemotherapy (including pemetrexed) \[Note: MPM patients having contra-indications for, or refusing chemotherapy may also be recruited\], and candidate for palliative pleural procedure (i.e. thoracoscopy for pleurodesis by talc or by insertion of indwelled pleural catheter, IPC)

• Documented progression after previous 1 or 2 lines of chemotherapy including Platinum/Pemetrexed chemotherapy\*

• Measurable disease according to modified RECIST 1.1. for MPM

• Malignant pleural lesion assessed to be accessible by local PDT treatment during thoracoscopy, as validated by expert MTB (MESOCLIN, Lille, France)

• Histological diagnosis confirmed by national expert pathology panel (MESOPATH - Institut Léon Bérard, Lyon, France)

• Weight loss \<10%

• available tumor tissue (archival or fresh)

• obtention of an informed written consent before any specific procedure of the study

• Decision to treat the patient within this clinical trial taken during MPM dedicated multidisciplinary board (RCP MESOCLIN in France )

• Patient affiliated to and covered by social security for standard care

• Women of child-bearing potential must use a highly effective method of contraception for 28 days prior to the first dose of investigational product, and must agree to continue using such precautions for 5 months after the final dose of investigational product

• Women of child-bearing potential must have a negative pregnancy test within 24h before administration of investigational product

• First line patients may also be recruited if they declined or if they have contra-indications for chemotherapy.