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
4658 - Patient-reported outcomes associated with switching to rivaroxaban for the treatment of venous thromboembolism (VTE) in patients with active cancer
Presenter: Alexander Cohen
Session: Poster Display session 1
Resources:
Abstract
5638 - Incidence of Vascular Thromboembolism Events in Cancer Patients Receiving Immunotherapy: A Single Institution Experience.
Presenter: Laura Gutiérrez Sainz
Session: Poster Display session 1
Resources:
Abstract
5182 - High Incidence of Venous Thromboembolic Events (VTE) in Patients with Diffuse Large B-Cell Lymphoma.
Presenter: Alaa Abufara
Session: Poster Display session 1
Resources:
Abstract
1504 - Weight Loss over Time in Non-Small Cell Lung Cancer: Results from a Landmark Analysis of 800+ Prospectively-Treated Patients
Presenter: Jennifer Le-rademacher
Session: Poster Display session 1
Resources:
Abstract
3972 - The prognostic significance of preoperative nutritional status in resected pancreatic ductal adenocarcinoma (PDAC).
Presenter: Salvatore Paiella
Session: Poster Display session 1
Resources:
Abstract
2313 - Impact of Timing and Technique of Gastrostomy Placement on the Outcome of Patients (pts) with Head and Neck Cancer (HNC)
Presenter: M Julia Lostes Bardaji
Session: Poster Display session 1
Resources:
Abstract
5219 - Clinical & nutritional determinants of quality of life in patients with incurable cancer
Presenter: Louise Daly
Session: Poster Display session 1
Resources:
Abstract
4075 - Loss of skeletal muscle mass during palliative chemotherapy is a poor prognostic factor in patients with advanced gastric cancer
Presenter: In Gyu Hwang
Session: Poster Display session 1
Resources:
Abstract
4159 - Impact of nutritional derangement on treatment outcome in advanced non-small-cell lung cancer (A-NSCLC) patients (pts).
Presenter: Ilaria Trestini
Session: Poster Display session 1
Resources:
Abstract
1210 - Sarcopenia and pretreatment anemia as prognostic factors for patients with localized muscle invasive bladder cancer treated by neoadjuvant chemotherapy and radical cystectomy
Presenter: Emilien Billon
Session: Poster Display session 1
Resources:
Abstract