Lytix Biopharma has announced data from its ATLAS-IT-04 trial in patients with metastatic soft tissue sarcoma (STS).

The data from this Phase II proof of concept study shows that LTX-315 in combination with Adoptive Cell Therapy (ACT) was able to stabilize the disease in 3 out of 4 fully treated patients in this hard-to-treat patient population, and that the LTX-315 treatment generated tumor-specific T cells.

The ATLAS-IT-04 trial

The ATLAS-IT-04 trial was an open label, exploratory, Phase II trial assessing the effect of LTX-315 when used in combination with ACT in patients with metastatic STS. ACT with tumor infiltrating lymphocytes (TILs) is a potent treatment that can induce complete and durable tumor regression as documented in patients with melanoma. The use of ACT with TILs for patients with advanced STS has not previously been reported. Patients with advanced stages of STS have few effective treatment options and respond poorly to current treatment as well as to immunotherapy tested in clinical trials.

The trial design of ATLAS-IT-04 included intratumoral injections of LTX-315 ahead of surgical removal of tumors, followed by in vitro expansion of T cells as the first step. In a second step, the expanded T cells were infused back to the patients and the effect of LTX-315 on the tumor microenvironment was assessed.

LTX-315 is a first-in-class non-viral oncolytic molecule, representing a new and superior in situ therapeutic vaccination principle to boost the clonal expansion of T cells that kill tumor cells through a targeted immune response. In a recent Phase I/II study LTX-315 has been shown to increase TILs in malignant solid tumors after intratumoral injection. The immune response data from the ATLAS-IT-04 trial demonstrates that the treatment induce both new and tumor-specific T cells which provides proof to the concept that LTX-315 generates an immune response that targets the tumor. Moreover, the data shows that LTX-315 induce expansion of a heterogenous pool of T-cell clones in blood, and a pool of these are also present in tumor tissue after treatment.

“This trial demonstrates that the combination of LTX-315 and ACT is not only feasible and tolerable, but that tumor-specific T cells can be expanded in vitro from tumors that have been pretreated with the oncolytic molecule LTX-315.”

“This trial demonstrates that the combination of LTX-315 and ACT is not only feasible and tolerable, but that tumor-specific T cells can be expanded in vitro from tumors that have been pretreated with the oncolytic molecule LTX-315,” says Inge Marie Svane, PI and Professor at the National Center for Cancer Immune Therapy, Department of Oncology, Copenhagen University Hospital. “This combination therapy invokes tumor specific T cells that can be cultured and infused as part of an adoptive transfer regimen for several subtypes of soft tissue sarcoma, and its treatment schedule should be further optimized to achieve superior signs of efficacy.”

Photo of Oystein Rekdal, CEO, Lytix Biopharma