Testing YKST02 for patients with relapsed or refractory multiple myeloma

A Multicenter, Open-label, Phase I Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Preliminary Antitumor Efficacy of YKST02 in Participants With Relapsed or Refractory Multiple Myeloma

Phase 1 Interventional Excyte Biopharma Ltd · NCT06574568

This study is testing a new treatment called YKST02 to see if it can help people with relapsed or hard-to-treat multiple myeloma by boosting their immune system.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment70 (estimated)
Ages18 Years to 75 Years
SexAll
SponsorExcyte Biopharma Ltd Industry-sponsored
Drugs / interventionschimeric antigen receptor, Chemotherapy, prednisone
Locations12 sites (Beijing, Beijing Municipality and 11 other locations)
Trial IDNCT06574568 on ClinicalTrials.gov

What this trial studies

This clinical trial evaluates YKST02, a bispecific antibody designed to activate the immune system against relapsed or refractory multiple myeloma. It is a first-in-human study that focuses on assessing the safety, tolerability, pharmacokinetics, and preliminary efficacy of YKST02. The trial includes a dose escalation phase followed by a dose expansion phase to determine the optimal dosing strategy. Participants must have measurable disease and a history of prior treatments for multiple myeloma.

Who should consider this trial

Good fit: Ideal candidates are adults diagnosed with relapsed or refractory multiple myeloma who have received at least two prior classes of treatment.

Not a fit: Patients who have not been previously treated for multiple myeloma or have a performance status worse than ECOG 1 may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients with difficult-to-treat multiple myeloma.

How similar studies have performed: While this approach is novel, similar bispecific antibody therapies have shown promise in treating other hematological malignancies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Participants or their legally acceptable representative must sign an ICF indicating that the participants understand the purpose of, and procedures required for the study and are willing to participate in the study.
2. Diagnosis of multiple myeloma according to the IMWG criteria.
3. Receipt of at least two prior classes of drugs either in separate regimens or as combinations. The three classes are defined as: An immunomodulatory drug, a proteasome inhibitor, and an anti-CD38 drug.
4. Measurable disease at screening, as defined by at least 1 of the following:

   1. Serum M-protein ≥0.5 g/dL;
   2. Urinary M-protein excretion ≥200 mg/24 hours;
   3. Abnormal serum free light chain (FLC) ratio ( \<0.26 or \>1.65) and serum immunoglobulin FLC≥10 mg/dL.
5. Eastern Cooperative Oncology Group Performance Status (ECOG) of 0-1.
6. An estimated survival time of more than 12 weeks.
7. Recovery to Grade 0-1 (Graded by National Cancer Institute Common Toxicity Criteria for Adverse Events (NCI CTCAE) Version (v) 5.0) from adverse events related to prior therapy except alopecia.
8. Adequate hematological and organ function.
9. Female participants of childbearing potential must have a negative serum pregnancy test at screening. Female patients who are sexually active must use highly effective methods of contraception throughout the study and for 3 months following the last dose of study treatment.
10. Male participants must agree to use reliable methods of contraception (barrier methods or sexual abstinence) and avoid sperm donation throughout the study period and until 3 months after the last dose.

Exclusion Criteria:

1. Plasma cell leukemia (\>2.0×10\^9/L plasma cells by standard differential), Waldenstrom's Macroglobulinemia, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes), or primary light-chain amyloidosis.
2. History of antitumor therapy as follows, before the first dose of study drug:

   1. Targeted therapy with small molecule drug within 2 weeks or 5 half-lives, whichever is longer;
   2. Targeted therapy with macromolecular drug or Immunomodulatory agent therapy within 2 weeks;
   3. Chemotherapy within 2 weeks;
   4. Treatment with an investigational drug within 2 weeks or 5 half-lives, whichever is shorter;
   5. Radical/extensive radiotherapy within 4 weeks, or local palliative radiotherapy within 2 weeks, or acute toxicity induced by previous radiotherapy have not recovered to grade ≤1;
   6. Autologous stem cell transplantation within 12 weeks;
   7. History of organ transplant, or allogeneic stem cell transplantation within 6 months;
   8. Prior treatment with any B cell maturation antigen (BCMA) targeted therapy;
   9. Prior treatment with any BCMA targeted chimeric antigen receptor modified \[CAR\]-T cells therapy.
3. Any active acute graft-versus-host disease (GvHD), grade 2-4 (according to Glucksberg criteria) or active chronic GvHD requiring systemic treatment within 2 weeks.
4. Prior myelodysplastic syndrome or malignancy within 5 years, except for localized malignancies that have been adequately treated or free of the disease for ≥ 5 years, e.g., basal cell carcinoma of the skin, squamous cell carcinoma of the skin, non-muscle invasive bladder cancer, localized prostate cancer, carcinoma in situ of the cervix, carcinoma in situ of the breast.
5. Active central nervous system (CNS) involvement or exhibition of clinical signs of meningeal involvement of multiple myeloma, or other evidence of uncontrolled metastases to the CNS or meninges, judged by the investigator.
6. (a) History of or current relevant CNS pathology as epilepsy, seizure, paresis, aphasia, apoplexia, severe brain injuries, cerebellar disease, organic brain syndrome, psychosis; (b) Evidence for presence of inflammatory lesions and/or vasculitis on cerebral MRI.
7. History or evidence of cardiovascular disease, including:

   1. Acute coronary syndromes (eg, myocardial infarction, unstable angina) within 6 months prior to enrollment;
   2. Coronary angioplasty or stenting within 6 months prior to enrollment;
   3. Clinically significant unstable arrhythmias (eg, atrial fibrillation), however, atrial fibrillation has been controlled for over 30 days prior to the first dose of YKST02 were allowed;
   4. New York Heart Association (NYHA) stage III or higher congestive heart failure within 6 months prior to enrollment; Cardiac valve morphological abnormalities recorded by ECHO (≥ grade 2), note that grade 1 cardiac valve morphological abnormalities (such as mild regurgitation/stenosis) were allowed, but participants with moderate valve thickening were excluded;
   5. Left ventricular ejection fraction (LVEF) below lower limit of the study center, or LVEF\<50% if there is no lower limit at the study center;
   6. The Fridericia-corrected QT interval (QTcF) ≥ 470 msec (female) or ≥ 450 msec (male);
   7. Implantable defibrillator;
   8. Clinically uncontrollable hypertension (i.e., SBP≥160 mm Hg and/or DBP≥100 mm Hg).
8. Known allergy to monoclonal antibody drugs or exogenous immunoglobulin.
9. Any major organ surgery or significant trauma within 4 weeks prior to the first dose of YKST02, or those requiring elective surgeries during the study, and all AEs associated with surgery or significant trauma have not recovered before the first dose of the YKST02.
10. Regular dose of systemic corticosteroids during 4 weeks prior to initiation of study drug, or anticipated need of corticosteroids exceeding prednisone 20 mg/day or equivalent during the trial, or any other systemic immunosuppressive therapy within 4 weeks prior to study entry.
11. Virological tests: Hepatitis B virus surface antigen (HBsAg) positive and/or hepatitis B core antibody (HBcAb) positive, and hepatitis B virus (HBV) deoxyribonucleic acid (DNA) quantitative \>ULN of the testing institution; Hepatitis C antibody (HCV-Ab) positive and hepatitis C virus-RNA (HCV-RNA) quantitative \> ULN of the testing institution; Anti-human immunodeficiency virus (Anti-HIV) positive. Participants will be excluded from the study if any of the above criteria is met.
12. Uncontrolled active infections requiring oral or intravenous systemic therapy, except for local treatment.
13. Uncontrolled pleural effusion, pericardial effusion, or ascites requiring repeated drainage (once a month or more frequently).
14. Pregnant or lactating women.
15. Known mental disorder that may affect study compliance or poor compliance.
16. Receipt of any live attenuated vaccines or live virus vaccine within 4 weeks prior to the first dose of study treatment.
17. Other serious systemic diseases or laboratory abnormalities or other reasons that the investigator believes are not appropriate for participating the study.

Where this trial is running

Beijing, Beijing Municipality and 11 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Relapsed or Refractory Multiple Myeloma
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.