Emerging from the Company’s proprietary ATAK™ CAR receptor library, Myeloid’s novel in vivo engineering platform specifically targets and activates myeloid cells to elicit broader anti-tumor adaptive immunity. Through this approach, Myeloid demonstrates that delivery of lipid-nanoparticles (LNPs) encapsulating mRNA results in uptake and selective expression by myeloid cells in vivo, leading to potent tumor killing in multiple cold tumor models.

The Company’s lead in vivo program, MT-302, is a TROP2-targeting in vivo CAR designed for expression within the myeloid compartment. TROP2 is a tumor associated antigen expressed widely on epithelial tumors, including some of the most difficult to treat cancers. Treatment with MT-302 has demonstrated monotherapy activity in a TROP2/TNBC model, confirming the potency of programmed myeloid cells in the absence of T cells. Myeloid believes that MT-302 has significant advantages over TROP2-ADC approaches through its ability to engage the full immune response. In 2023, Myeloid expects to initiate a Phase 1/2 clinical study with MT-302 for patients with TROP2-expressing tumors.

MT-101 is the Company’s first autologous CAR monocyte. This candidate was derived from the Company’s proprietary ATAK™ platform and designed to harness the ability of myeloid cells to penetrate into tumors and promote broad anti-tumor activity. MT-101 targets CD5, a surface receptor that is present in greater than 75% of peripheral T cell lymphomas. To create MT-101, the patient’s cells are engineered ex vivo with the mRNA-strand coding for the CAR. The engineered cells are delivered back to the patient with a vein-to-vein time of eight days. The ATAK™ CAR is proprietary to Myeloid and manufactured using the Company’s patented processes.

The IMAGINE study (NCT05138458) is a Phase 1/2, multicenter, open-label, first-in-human, multiple ascending dose study to evaluate MT-101 in patients with refractory or relapsed PTCL and CTCL. The dose-escalation portion of this study, conducted with and without conditioning therapy, is open and enrolling patients.

Retrotransposons are genetic elements that replicate through reverse transcription of an RNA transposition intermediate. Retrotransposons contribute to structural changes and more importantly, to gene regulation. Myeloid’s RetroT™ technology relies on a single-strand mRNA to deliver genetic sequences and integration enzymes. This breakthrough technology offers the potential to deliver gene-sized pieces of DNA into the genome in a virus-free manner. The payload realizable with RetroT™ is larger than currently possible with all known existing gene editing technologies. As a result, the Company’s RetroT™ platform holds the potential to significantly expand the type and scope of genetic errors that can be reversed in situ. In March 2022, Myeloid entered into an exclusive option and research collaboration agreement with Prime Medicine, Inc. to develop and accelerate RetroT™.