ClinicalTrials.gg
Not yet recruitingNCT07911748Updated Nov 4, 2026

A Study of MBS314 for Injection in Participants With Relapsed/Refractory Multiple Myeloma.

A Phase 1/2 interventional study of MBS314 for Injection in Multiple Myeloma, sponsored by Beijing Mabworks Biotech Co., Ltd.. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-04.

Sponsored by Beijing Mabworks Biotech Co., Ltd. · Phase 1/2, Interventional, and Treatment

Updated Nov 4, 2026Title changedNewly registeredGo to Updates ↓
Phase
Phase 1/2
Study type
Interventional
Enrollment
78
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

This is a Phase I/II, multicenter, open-label, dose-escalation and dose-expansion study designed to evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and efficacy of MBS314, a novel asymmetric trivalent trispecific humanized antibody targeting GPRC5D, BCMA and CD3, administered by subcutaneous (SC) injection in participants with relapsed or refractory multiple myeloma. The investigational drug is MBS314 for Injection (high-concentration lyophilized formulation, 90 mg/vial, reconstituted to 90 mg/mL); this study is the first-in-human (FIH) study of this formulation. The study is divided into 2 parts: a dose escalation part (Phase I) and a dose expansion part (Phase II). In Phase I, eligible participants will be sequentially assigned to 1 of the 3 planned dose cohorts and receive MBS314 by SC injection using a step-up dosing (SUD) strategy, and dose escalation follows the Bayesian Optimal Interval (BOIN) design with a target toxicity rate of 33%. In Phase II, 1 to 3 dose groups will be selected based on Phase I results to further evaluate the efficacy of MBS314 at the recommended dose(s).

02

Conditions studied

  • Multiple Myeloma

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Keywords

  • Trispecific antibody
  • MBS314
  • Multiple myeloma
03

In context

Multiple Myeloma

3,760 studies on the registry are indexed under Multiple Myeloma; 769 are open to participants now.

This study's planned enrollment of 78 is above the median of 41 across 3,005 interventional studies indexed under Multiple Myeloma.

Browse Multiple Myeloma studies →

Lead sponsor

Beijing Mabworks Biotech Co., Ltd. is the lead sponsor of 18 studies on the registry; 11 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Able and willing to provide written and to comply with the study protocol;
  2. Phase I: 18-70 years of age (inclusive) at the time of signing ICF; Phase II: ≥18 years of age;
  3. Documented diagnosis of active or symptomatic multiple myeloma according to the 2014 IMWG diagnostic criteria; Phase I: at least 3 prior lines of systemic anti-myeloma therapy including at least one proteasome inhibitor (PI), one immunomodulatory drug (IMiD) and one anti-CD38 antibody, or no available standard treatment per investigator judgment, and to the last or intolerant to prior treatment; Phase II: at least 2 prior lines including at least one PI, one IMiD and one anti-CD38 antibody, and relapsed or refractory to the last line of therapy or intolerant to prior treatment;
  4. At least one at screening: Serum monoclonal paraprotein (M-protein) ≥5 g/L or Urine M-protein ≥200 mg/24 hours or Serum immunoglobulin free-light chains (FLCs) ≥100 mg/L and abnormal kappa/lambda FLC ratio (\<0.26 or >1.65)
  5. (ECOG) Performance Status score of 0 or 1.
  6. ≥3 months.
  7. Toxicity from prior anti-myeloma therapy recovered to Grade ≤1 per v6.0 (except alopecia, fatigue and Grade 2 peripheral neuropathy);
  8. (LVEF) ≥50%;
  9. Adequate hematologic, hepatic, renal and coagulation function: count ≥75×10\^9/L (or ≥50×10\^9/L if ≥50% of bone marrow nucleated cells are plasma cells); (NEUT) ≥1.5×10\^9/L; ≥75 g/L; and ALT ≤2.5×; total ≤1.5×ULN (≤3×ULN for participants with Gilbert syndrome); serum creatinine ≤1.5×ULN or ≥40 mL/min; or PT ≤1.5×ULN; APTT ≤1.5×ULN; corrected serum calcium ≤14 mg/dL (≤3.5 mmol/L).

Exclusion criteria

Exclusion Criteria:

  1. Known active central nervous system (CNS) involvement or exhibits clinical signs of meningeal involvement of multiple myeloma.
  2. Active infection within 14 days prior to the first MBS314 administration requiring anti-infective treatment or hospitalization (including infections requiring IV antibiotics and/or hospitalization within 4 weeks, or oral antibiotics within 2 weeks prior to first dose); participants with a positive SARS-CoV-2 test result, with or without symptoms or suspected infection, are excluded;
  3. and/or HBcAb positive with HBV DNA above the ; antibody positive with HCV RNA above the upper limit of normal; seropositive; Treponema pallidum antibody (TP-Ab) positive;
  4. Received the following anti-myeloma treatments within the specified time frame prior to the first administration: targeted therapy, immunotherapy, antibody drugs, cytotoxic drugs, antibody-drug conjugates, radiotherapy, tumor embolization, epigenetic therapy or drugs (or invasive investigational medical devices) within 21 days or 5 half-lives (whichever is shorter); PIs within 14 days; IMiDs within 14 days; anti-tumor Chinese herbal medicines within 14 days; cell therapy (including but not limited to CAR-T, NK cells, neoantigen vaccines, etc.) or hematopoietic stem cell transplantation within 3 months; prior allogeneic hematopoietic stem cell transplantation;
  5. Live, attenuated vaccines within 28 days prior to the first administration of MBS314, or expected to receive live, attenuated vaccines during the study period;
  6. Major surgery within 28 days prior to the first administration of MBS314, or expected to undergo major surgery during the study treatment, or with serious unhealed wounds, trauma or ulcers (except diagnostic and central venous catheterization);
  7. History of diseases (except participants with autoimmune-related hypothyroidism on a stable dose of thyroid replacement therapy, and participants with well-controlled type 1 diabetes);
  8. History of severe allergic reactions (≥Grade 3 per v6.0) to other antibody drugs, or known allergies or to any components of MBS314;
  9. Smoldering multiple myeloma, plasma cell leukemia (plasma cells >2.0×10\^9/L), Waldenström macroglobulinemia, POEMS syndrome, or concurrent primary or secondary amyloidosis;
  10. Prior treatment with agents targeting both BCMA and GPRC5D, including but not limited to BCMA/GPRC5D-targeted trispecific antibodies, chimeric antigen receptor T-cell (CAR-T) therapy, or simultaneous or sequential treatment with BCMA- and GPRC5D-targeted drugs; participants previously treated with only one of the BCMA or GPRC5D targets may enroll;
  11. Other severe, poorly controlled comorbidities that may affect protocol compliance or interpretation of results, including but not limited to: valvular heart disease; history of congestive heart failure; angina requiring medication or unstable angina; Class III or higher cardiac dysfunction; ≥470 ms (female) or ≥450 ms (male) or history of congenital long QT syndrome; myocardial infarction or acute coronary syndrome within 6 months prior to screening; thromboembolic or vascular events within 6 months prior to screening; clinically significant arrhythmias; poorly controlled hypertension (SBP >160 mmHg or DBP >100 mmHg); poorly controlled diabetes (fasting glucose ≥10 mmol/L); clinically significant pulmonary disease; uncontrolled pleural, pericardial or peritoneal effusions requiring repeated drainage or medical intervention;
  12. Any other invasive within the past 3 years (except radically treated basal or squamous cell skin cancer, carcinoma in situ of the cervix, breast or bladder, or other malignancy with low or death risk [5-year survival >90%]); progressive multifocal leukoencephalopathy; severe bleeding disorders such as hemophilia A, hemophilia B, von Willebrand disease, or spontaneous bleeding requiring transfusion or other medical intervention;
  13. Pregnant or lactating women; women of who do not agree to use appropriate (e.g., oral contraceptives, intrauterine device, barrier contraception or spermicide) during the treatment period and for at least 6 months after the last dose of study drug;
  14. Men who do not agree to use barrier contraception during the treatment period and for at least 6 months after the last dose of study drug, and do not agree to have their partners use appropriate contraception;
  15. Any other condition that, in the judgment of the investigator, makes the participant unsuitable for participation in this study.
Terms in these criteria, in plain language(31)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Relapsed and refractory

Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.

Line of therapy

A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.

“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.

Measurable disease

The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.

The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

CTCAE grade

The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.

1
Mild.
2
Moderate.
3
Severe.
4
Life-threatening.
5
Death due to the event.

“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.

LVEF (left ventricular ejection fraction)

The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

Absolute neutrophil count (ANC)

The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.

It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

Creatinine clearance (CrCl)

How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.

INR, PT and aPTT (clotting tests)

Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.

Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Allogeneic and autologous transplant

Stem cell (bone marrow) transplants. Allogeneic uses cells from a donor; autologous uses your own cells, collected earlier and given back.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
78 participants (estimated)

Study arms

  • Experimental
    MBS314

    Drug: MBS314 for Injection

Interventions

  • DrugMBS314 for Injection

    Phase I: Eligible participants will be sequentially assigned to one of three dose groups under BOIN design (Dose Group 1: 3-step SUD \[0.5/3.0/15.0 mg\], target dose 90.0 mg; Dose Group 2 \[tentative\]: 3-step SUD \[1.5/9.0/45.0 mg\], target dose 135.0 mg; Dose Group 3 \[tentative\]: 3-step SUD \[2.5/15.0/90.0 mg\], target dose 180.0 mg). MBS314 is given subcutaneously (single injection volume ≤2.0 mL; injection sites ≥2 cm apart). Step-up dosing is used in Cycle 1: priming doses on C1D1, C1D4, C1D7 and target dose on C1D10. From Cycle 2 onwards, target dose is administered Q4W. Phase II: Based on Phase I findings, 1-3 dose groups will be selected for dose expansion (10-20 participants per group, total 10-60).

06

What researchers measure

Primary outcomes

  1. Phase I :Percentage of Participants with Adverse Events (AEs)

    Percentage of Participants with AEs and SAEs Assessed by NCI CTCAE v6.0.

    Time frame: From Baseline up to 28 (+7) days after the last dose of MBS314]

  2. Phase I:Incidence of Dose Limiting Toxicities (DLTs)

    Time frame: From Baseline up to 4 weeks

  3. Phase I:Maximum Tolerated Dose (MTD) (if any) or Optimal Biological Dose (OBD) of MBS314

    Time frame: Up to approximately 7 months

  4. Phase I:Recommended Phase Ⅱ Dose (RP2D) of MBS314

    Time frame: Up to approximately 7 months

  5. Phase II:Efficacy: Overall Response Rate (ORR) as Assessed by the Investigator

    ORR is defined as the proportion of participants who achieve sCR, CR, VGPR or PR according to the 2016 IMWG response criteria, as assessed by the investigator.

    Time frame: Up to approximately 15 months

07

Study locations

No study locations are listed for this record.

08

References and documents

Individual participant data

Plan to share: Yes

No publications or documents are linked to this record.

09

Updates

2 registry updates since Sep 25, 2026
Title
A Study of MBS314 for InjectioninInjection in Participants With Relapsed/Refractory Multiple Myeloma.
Nov 4, 2026
Registered
First appeared on the registry
Nov 3, 2026
Show all 2 updates
  1. Nov 4, 2026
    Title A Study of MBS314 for InjectioninInjection in Participants With Relapsed/Refractory Multiple Myeloma.
  2. Nov 3, 2026
    First appeared on the registry

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT07911748
Lead sponsor
Beijing Mabworks Biotech Co., Ltd.
Responsible party
Sponsor
First posted
Nov 3, 2026
Start date
Nov 2026 (estimated)
Primary completion
Dec 2027 (estimated)
Completion
Nov 2028 (estimated)
Last update
Nov 4, 2026

Study contacts

Juan Du, Doctor
Contact
Juan_du@live.com
86+021-58752345

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.

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