Abstract 2469
Background
Soft-tissue sarcomas (STS) are life-threatening diseases, for which more efficient therapeutic options are necessary. Trabectedin (T) is an anti-tumor drug approved for the treatment of advanced STS. Synergistic drug combinations could improve T results in STS patients. Rapamycin (R) is an mTOR pathway inhibitor. Synergy with T has been described in ovary clear cell carcinoma. Of note, R suppresses DNA double-strand breaks repair, thus generating the perfect set-up for T activity. Altogether, we hypothesize that T+R combination (T+R) is synergistic in STS, and that mTOR inhibition enhances T activity.
Methods
Human STS cell lines (n = 9) were treated with increasing doses of T (1x10-7M to 1x10-11M) and/ or R (1x10-9 to 1x10-11) to determine IC50 and combination index (CI) values. Cells were initially exposed to R, 2 hours later T was added, under the assumption that R pre-treatment favors T cytotoxicity. Cell viability, at 72 h, was measured by MTS assay. Apoptosis was determined by Western Blot for PARP and Caspase 3 cleavage. In vivo experiments were performed in immunocompetent 3-methylcolanthrene fibrosarcoma mice: T was administrated via IV (0.15 mg/kg; q7dx1) and R via IP (0.50 mg/kg; q7dx2). Body weight and tumor volume were measured every 2 days for 15 days of treatment. Tumors were collected for analysis (snap frozen and paraffin embedding).
Results
T+R was synergistic in all STS cell lines: CP0024 primary leiomyosarcoma and 93T449 liposarcoma cell lines showed strong synergism with CI at the ED50 of 0.129 and 0.027, respectively. This synergy was followed by an increase of PARP and Caspase 3 cleavage. The synergism was confirmed in vivo: mice treated with R+T showed tumor growth delay in comparison to the drugs alone (p < 0.05). Stable disease was achieved in 7 out of 7 mice.
Conclusions
R+T is synergic in STS and deserves exploration in clinical setting. Further research will reveal the mechanisms underlying this synergy.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Javier Martín Broto.
Funding
PharmaMar.
Disclosure
D.S. Moura: Research grant / Funding (institution): PharmaMar; Research grant / Funding (institution): Eisai; Research grant / Funding (institution): Novartis; Travel / Accommodation / Expenses: PharmaMar; Travel / Accommodation / Expenses: Eisai. M. Lopez-Alvarez: Travel / Accommodation / Expenses: Eisai. N. Hindi: Travel / Accommodation / Expenses: PharmaMar; Research grant / Funding (institution): Eisai; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): PharmaMar; Honoraria (self): PharmaMar. J. Martin-Broto: Research grant / Funding (institution): PharmaMar; Research grant / Funding (institution): Eisai; Research grant / Funding (institution): Novartis; Honoraria (self): PharmaMar; Honoraria (self): Lilly; Honoraria (self): Novartis; Speaker Bureau / Expert testimony: PharmaMar. All other authors have declared no conflicts of interest.
Resources from the same session
6079 - Invasive fungal diseases in patients with Hodgkin’s lymphoma before and after allogeneic hematopoietic stem cell transplantation
Presenter: Marina Popova
Session: Poster Display session 1
Resources:
Abstract
5995 - Invasive fungal diseases caused by rare pathogens in patients after hematopoietic stem cell transplantation (HSCT) & chemotherapy
Presenter: Yuliya Rogacheva
Session: Poster Display session 1
Resources:
Abstract
2961 - Safety and pharmacokinetics of novel CXCR4 antagonist YF-H-2015005 in the mobilization of hematopoietic stem cells in patients with non-Hodgkin's lymphoma
Presenter: Weiping Liu
Session: Poster Display session 1
Resources:
Abstract
5771 - Chemotherapy associated Hyponatremia in Hematological Malignancies: A retrospective study of 189 patients treated in a single medical center
Presenter: Vadim Lesan
Session: Poster Display session 1
Resources:
Abstract
1165 - Risk factors for Bacteremia-Associated Mortality of Aeromona sobria in Hematologic Malignancies
Presenter: Gabriel De la Cruz-Kú
Session: Poster Display session 1
Resources:
Abstract
5287 - Use of droplet digital polymerase chain reaction for detecting minimal residual disease: a prospective, multi-institutional study
Presenter: Hyunkyung Park
Session: Poster Display session 1
Resources:
Abstract
1886 - RUBIH2 — Use of NGS in haematological malignancies: from real world data to national recommendations, an innovative program to evaluate the impact of healthcare technology on patient care
Presenter: Severine Coquerelle
Session: Poster Display session 1
Resources:
Abstract
1940 - Outcomes of chronic myeloid leukemia with T315I mutation in the absence of targeted therapy or hematopoietic stem cell transplantation
Presenter: Nageswara Palukuri
Session: Poster Display session 1
Resources:
Abstract
1946 - Is bone marrow examination indispensible in chronic myeloid Leukemia at diagnosis ?
Presenter: Nageswara Palukuri
Session: Poster Display session 1
Resources:
Abstract
1904 - Incidence of Imatinib Resistance in Chronic Myeloid Leukemia (CML) Patients: Experience from Resource Poor Centre of Eastern India
Presenter: Debmalya Bhattacharyya
Session: Poster Display session 1
Resources:
Abstract