leiomyosarcoma of soft tissue

This is an open-label, non-randomized, single-institution, single arm Phase II study conducted using a Simon two-stage design with an additional safety lead-in. The overall objective is to determine the efficacy of combination doxorubicin with dual checkpoint blockade with anti-CTLA-4 antibody AGEN1884 and anti-PD-1 antibody AGEN2034. The investigators will estimate the progression-free survival rate at 6 months (PFS6mo) of doxorubicin plus AGEN1884/AGEN2034 in comparison to historical PFS6mo with doxorubicin monotherapy, calculated as the mean from two large randomized Phase 3 clinical trials.

The objective of LMS04 study is to better define the treatment strategy for patients with metastatic leiomyosarcoma (uterine or soft tissue), as well as identifying the best first line therapeutic option for these patients. LMS04 will test a new strategy for first line therapy LMS sarcoma compare to the reference therapy (6 cycles of doxorubicin alone): the interest of the association of trabectedin to doxorubicin in first line treatment followed by trabectedin alone for non-progressive patients after 6 cycles of the association of trabectedin and doxorubicin (the LMS02 design).
LMS04 will be the first phase III randomized study specifically dedicated to soft tissue leiomyosarcoma in first line metastatic disease.
It is planned to compare a new doxorubicin combination (including trabectedin) with very encouraging results followed by trabectedin maintenance therapy for non-progressive patients to doxorubicin alone. Prospective ancillary translational studies will attempt to define profiles of patients who could benefit from this new chemotherapy in an exploratory way.
The validation of a new first line option specific for LMS, identifying clinical factors that characterize aggressiveness and responsiveness to treatment aims to have an important in the spirit of personalized medicine in this rare and deadly disease.

Uterine leiomyosarcomas and soft tissues are rare tumors with a poor prognosis when metastatic or locally advanced. They have an average chemosensitivity mainly to doxorubicin, ifosfamide, cisplatin, gemcitabine and trabectedin but response rates in combination in first line does not exceed 55% for uterine leiomyosarcomas and 35% for leiomyosarcomas of soft tissue.
The trabectedin is a new cancer drug that has obtained marketing authorization after failure of anthracyclines and ifosfamide in the treatment of soft tissue sarcomas (STM) in Europe. It has especially shown efficacy in myxoid liposarcomas, leiomyosarcomas and synoviosarcoma.
This study aims to evaluate the usefulness of the combination of trabectedin with doxorubicin in first-line treatment of uterine or soft tissue leiomyosarcoma.