Phase I Trial of Vididencel in CML-CP Patients With MRD Under TKI Treatment

Inclusion Criteria:

* Male or female aged ≥ 18 years at the time of informed consent.

Signed and dated informed consent document indicating that the participant has been informed of all the pertinent aspects of the trial prior to any study-related activities.

Willing to comply with clinical trial instructions and requirements.

Confirmed Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML) in chronic phase (CP) (according to ELN 2025) treated with the same TKI for minimum 24 months.

MRD positive meaning BCR::ABL1 \<10% - \>0.01% IS at a stable level over the last 6 months. A value must not increase to ≥ 3 fold from baseline or a value must not decrease to ≤ 1/3 fold from baseline. All three measurements must fall within a 3-fold range, i.e., the ratio between the highest and lowest of the three values must be \<3.

Adequate performance status: Eastern Cooperative Oncology Group (ECOG) performance status 0-1.

Expected co-operation of participant regarding treatment and follow-up procedures according to the treating physician.

Women of childbearing potential (WOCBP) defined as all women physiologically capable of becoming pregnant, must present a negative serum pregnancy test result within 3 days prior to first dosing and a negative urine pregnancy test on the day of first dosing. Additionally,they must use a highly effectiveform of contraception (with Pearl index \< 1%) throughout the study and for at least 3 months after the last dose of study medication.

Men with partners of childbearing potential must be willing to use condoms during intercourse while on study and should not father a child in this period. A condom is required to be used also by vasectomized men

Exclusion Criteria:

* Participants who are scheduled for allogeneic stem cell transplantation (allo HSCT) or participants who have undergone allo HSCT less than 5 years ago. Participants who have undergone allo HSCT more than 5 years ago and had any sign of graft-versus-host disease.

Uncontrolled or serious infections.

Ongoing systemic immunosuppressive therapy, other than short use of low dose steroids, i.e. equivalent to an average dose of ≤10 mg of prednisone/day.

Use of any other experimental drug or therapy within 28 days or 5 half-lives of the investigational drug, whichever is longer of baseline.

Active autoimmune disease or participants with recent history, except for well controlled diabetes and stable thyroid disease.

Inadequate liver function (AST and ALT \> 3 x upper limit of normal (ULN), serum bilirubin \>3 x ULN).

Other active malignancies within the last 5 years, except for adequately treated carcinoma in situ of the cervix or non-melanoma carcinoma of the skin.

Pregnant or lactating females.

Major surgical procedure (including open biopsy) within 28 days prior to the first study treatment, or anticipation of the need for major surgery during the course of the study treatment.

Evidence of any other medical conditions (such as psychiatric illness, physical examination or laboratory findings) that may interfere with the planned treatment, affect participant compliance or place the participant at high risk from treatment-related complications.

Known HIV, Hepatitis B and/or Hepatitis C infections.

Known hypersensitivity to vididencel, or any of the ingredients or excipient in the formulation.

Participants who, in the opinion of the Investigator, would clinically benefit from switching to an alternative TKI therapy