Trem-cel is a shielded transplant designed to enable multiple modalities and therapies, including ADCs and CAR-Ts

We are developing trem-cel as a Hematopoietic Stem Cell Transplant (HCT) product to replace the current standard of care in transplant settings. Once trem-cel has engrafted, patients can be treated with anti-CD33 therapies, such as Mylotarg™, with reduced on-target toxicity.

VBP101, a Phase 1/2a clinical trial in patients with CD33-positive AML or MDS who are at high risk of relapse, is actively enrolling patients. The key goals of the trial are to evaluate tolerability and feasibility of the trem-cel stem cell transplant, with a focus on confirming that trem-cel can engraft normally. Following engraftment, patients will be eligible to be treated with Mylotarg, a CD33-directed Antibody Drug Conjugate (ADC) therapy, to potentially prolong leukemia-free survival and to provide evidence that trem-cel protects healthy blood cells against the myelosuppression that typically accompanies treatment with Mylotarg.

Patients receiving a trem-cel transplant who become measurable residual disease (MRD) positive or relapse also have the option to receive induction-course Mylotarg or VCAR33.

Trem-cel has been granted Orphan Drug Designation and Fast Track designation from the U.S. Food and Drug Administration.

Trem-cel clinical data

The latest data update from VBP101, the Phase 1/2a clinical study of trem-cel, was released in December 2024 and showed that trem-cel in combination with Mylotarg demonstrated engraftment, shielding, broadened therapeutic window, and patient benefit.

Trem-cel and Myelodysplastic Syndrome

Other blood cancers overexpress CD33, such as myelodysplastic syndrome (MDS). MDS consists of a spectrum of bone marrow cancers that are characterized by a reduction in blood cell counts and an increase in immature blood cells in bone marrow.

MDS evolves into AML in up to 30% of cases. Patients with this condition can be segmented into different risk categories based on cell counts and cytogenetics, with intermediate- or high-risk patients often treated with HCT, and MDS is one of the most common indications for allogeneic HCT outside of AML. Scientific evidence produced by third parties shows that blast cells responsible for MDS express CD33 and other myeloid cell surface targets. We believe trem-cel has the potential to enable the use of anti-CD33-targeted therapies in those settings, and we are exploring the potential use of trem-cel in combination with targeted therapies in these indications.