Soft Tissue Sarcoma Pipeline Highlights Phase II and Late-Stage Programs

Soft tissue sarcoma pipeline activity includes 70+ companies and 75+ pipeline drugs, with a phase II trial evaluating ADI-PEG 20 in combination with gemcitabine and docetaxel in sarcomas. A report on the pipeline landscape also highlighted recent studies in synovial sarcoma, advanced and/or metastatic soft tissue sarcoma, and unresectable locally advanced or metastatic disease.

The phase II ADI-PEG 20 trial was designed after investigators demonstrated that argininosuccinate synthase 1 (ASS1) expression is silenced in 88% of all sarcomas (n=708), and that this loss is associated with a decreased overall survival. Using the extracellular arginine depleting enzyme PEGylated arginine deiminase (ADI-PEG20), investigators demonstrated ADI-PEG20 induces a prosurvival metabolic reprogramming in ASS1-deficient sarcomas that redirects glucose into the serine/folate pathway directing the carbons from glucose into pyrimidine biosynthesis, thus sensitizing cells to death by the pyrimidine antimetabolite gemcitabine by using metabolomics. The synthetic lethality was increased by the addition of docetaxel.

The trial was to determine if the clinical benefit rate of gemcitabine and docetaxel, a standard second line therapy for soft tissue sarcoma, is improved by the metabolic changes induced by ADI-PEG20. Recently published data showed that priming ASS1-deficient tumors with ADI-PEG 20 and docetaxel improves the effect of gemcitabine. An exploratory cohort was to include ten patients diagnosed with either osteosarcoma or Ewing's sarcoma, ideally five of each, and five patients diagnosed with small cell lung cancer. The site was not currently accepting new patients for this trial and was listed as not recruiting.

The pipeline report said the soft tissue sarcoma space has 70+ active players working to develop 75+ pipeline therapies. It highlighted a study initiated on February 18, 2026, to verify the safety and the efficacy of TBI-1301 for NY-ESO-1 expressing synovial sarcoma when administered following cyclophosphamide/fludarabine pre-treatment, and a phase IIa open-label study announced on February 17, 2026, evaluating preliminary efficacy of intratumoural tigilanol tiglate in advanced and/or metastatic soft tissue sarcoma of the extremities and body wall.

The report also cited a study conducted on February 11, 2026, to find out whether retifanlimab, combined with gemcitabine and docetaxel, is a safe and effective treatment for soft tissue sarcoma that is either locally advanced or has spread beyond its original location and cannot be removed with surgery. Among therapies highlighted in the report, Fibromun (L19TNF) was described as being in Phase III development for soft tissue sarcoma, while chiauranib was described as being in Phase II development.