RPTR-168 is a cell therapy program that leverages our ability to localize key cytokine immunomodulators to the surface of our MTCs and deliver them to the tumor tissue. In this program, the cytokine is interleukin-12 (IL-12), a key immunomodulator of both T cells and the tumor microenvironment. We developed a loading technology designed to enable these immunomodulatory effects in the local environment of the MTC, so that IL-12 can activate both the loaded T cells and immune cells in the surrounding tumor microenvironment.
In this program, the design was to link a humanized, anti-human CD45 fragment (Fab) to IL-12 which binds to CD45 receptors on the MTC surface, given that IL-12 was not conducive to nanogel technologies. RPTR-168 comprises autologous MTCs that are surface-loaded with this CD45-targeted IL-12 cytokine fusion protein.
The Phase 1 dose-escalation, multi-center clinical trial of RPTR-168, also referred to as our PRIME-102 clinical trial, is designed to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary antitumor activity in patients with relapsed or refractory HPV-driven tumors or metastatic melanoma. The PRIME-102 clinical trial tests two product candidates:
- RPTR-168:1 is primed with Antigen Set 1.0, comprised of PRAME, Survivin, NY-ESO-1, SSX2, and WT-1
- RPTR-168:2 is primed with Antigen Set 2.0, comprised of HPV16+ viral antigens (HPV16 E6 and HPV16 E7) and three additional tumor-associated antigens, or TAAs, (PRAME, Survivin and MAGE-A4).