2 August 2022 - - The first patient has been dosed with TAC-001 in a Phase 1/2 clinical trial for patients with advanced or metastatic solid tumors, US-based biopharmaceutical company Tallac Therapeutics, Inc said.

TAC-001 is the company's lead clinical candidate from its novel Toll-like Receptor Agonist Antibody Conjugate (TRAAC) platform and the first to enter the clinic.

The Phase 1/2 trial, known as INCLINE-101 (NCT05399654), is an open label, multicenter, dose escalation and expansion study of TAC-001 in patients with select advanced or metastatic solid tumors.

It is designed to evaluate the safety, pharmacokinetics and preliminary anti-tumor activity of TAC-001 administered intravenously.

Toll-like receptor 9 agonists are a class of immunotherapy that generate both innate and adaptive immune response, which may produce more robust and durable anti-cancer immunity to help overcome resistance to standard-of-care oncology treatments.

TLR9 agonists have demonstrated clinical activity in melanoma patients when administered intratumorally.

B cells express TLR9 and play pivotal roles in the immune system, and represent a major component of the tumor microenvironment, where they are predominantly associated with tertiary lymphoid structure.

The presence of B cells and TLS is a positive prognostic factor and predicts treatment response to checkpoint inhibitors in multiple solid tumor types.

Tallac Therapeutic's TRAAC platform is designed to deliver a potent and differentiated TLR9 agonist (T-CpG) for targeted immune activation via systemic administration.

TAC-001 is an antibody-oligonucleotide conjugate, comprised of T-CpG conjugated to an antibody against CD22, a receptor restricted to B cells, including tumor-infiltrating B cells. 

Preclinical studies demonstrate that the innate and adaptive immune responses triggered by TAC-001 leads to robust, curative and durable single agent anti-tumor activity in checkpoint inhibitor resistant and refractory tumor models.

Increased B cell infiltration, T cell effector functions and modulation of suppressive myeloid cells within the tumor microenvironment were observed following systemic TAC-001 administration.

These results support the development of TAC-001 for a broad range of solid tumor malignancies, particularly in the tumor types with B cell/TLS involvement.

TAC-001 is a Toll-like Receptor Agonist Antibody Conjugate (TRAAC) comprised of a potent toll-like receptor 9 agonist (T-CpG) conjugated to an antibody against CD22, a receptor restricted to B cells, including tumor-infiltrating B cells.

TAC-001 is designed to systemically deliver T-CpG to B cells by binding to CD22, leading to internalization of TAC-001, TLR9 signaling, B cell activation and a cascade of immune reactions. 

Preclinical studies demonstrate that the innate and adaptive immune responses triggered by TAC-001 leads to potent anti-tumor activity. TAC-001 is being developed for the potential treatment of solid tumors.

Tallac Therapeutics is a privately held biopharmaceutical company harnessing the power of innate and adaptive immunity to fight cancer.

Tallac's pipeline of immunotherapy candidates is derived from the company's novel Toll-like Receptor Agonist Antibody Conjugate (TRAAC) platform to deliver a potent toll-like receptor agonist (T-CpG) for targeted immune activation via systemic administration.

Several TRAAC molecules are in various stages of discovery and preclinical development.