Herombopag for low platelets caused by T‑DM1 in breast cancer

A Multicenter, Single-arm Exploratory Clinical Study Evaluating the Efficacy and Safety of T-DM1 in Patients With Breast Cancer Who Developed Thrombocytopenia.

This will test whether herombopag tablets can raise or stabilize platelet counts in breast cancer patients who developed low platelets after T‑DM1 so they can continue planned T‑DM1 cycles.

Quick facts

• Phase: Phase 2
• Study type: Interventional
• Enrollment: 56 (estimated)
• Ages: 18 Years to 75 Years
• Sex: All
• Sponsor: Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University (Academic / other)
• Drugs / interventions: chemotherapy
• Locations: 1 site (Guangzhou, Guangdong)
• Trial ID: NCT07257809 on ClinicalTrials.gov

What this trial studies

This is a single-arm Phase 2 trial planned to enroll about 56 breast cancer patients who experienced grade 2 or higher thrombocytopenia during prior T‑DM1 treatment but whose platelet counts recovered to between 100 and 200 × 10^9/L before the next cycle. Enrolled patients will receive oral herombopag while continuing at least two additional scheduled T‑DM1 cycles, with regular blood counts and safety monitoring. The study will record whether herombopag prevents recurrent thrombocytopenia, reduces treatment delays or dose reductions, and is tolerable in this setting. Safety signals and treatment continuity measures will guide conclusions about utility for managing T‑DM1–related platelet reduction.

Who should consider this trial

Good fit: Adults 18–75 with histologically confirmed breast cancer who had grade ≥2 thrombocytopenia during prior T‑DM1 but recovered to 100–200 × 10^9/L, have ECOG 0–2, and are scheduled for at least two more T‑DM1 cycles are the intended candidates.

Not a fit: Patients whose platelet counts are still below 100 × 10^9/L or already above 200 × 10^9/L before treatment, those with recent other malignancies or significant comorbidities, or those unable to tolerate further T‑DM1 are unlikely to benefit.

Why it matters

Potential benefit: If successful, herombopag could help patients keep safer platelet levels and avoid dose delays or reductions of T‑DM1.

How similar studies have performed: Other thrombopoietin-receptor agonists have shown benefit for chemotherapy-induced thrombocytopenia in prior studies, but applying this approach specifically to T‑DM1–induced thrombocytopenia has limited direct evidence.

Eligibility criteria

Inclusion：

* Age 18-75 years, any gender;
* Pathologically diagnosed with breast cancer based on histological or cytological examination, and previously treated with neoadjuvant anti-HER-2 therapy followed by T-DM1 adjuvant therapy;
* Experienced grade 2 or higher tumor treatment-related thrombocytopenia during the previous T-DM1 treatment cycle, with platelet count restored to ≥100 × 109/L and ≤200 × 109/L prior to the next treatment;
* ECOG performance status score: 0-2;
* Planned to undergo at least two additional treatment cycles including T-DM1 administration, with the dose of T-DM1 in the current cycle consistent with the previous cycle;
* Expected survival of ≥12 weeks and able to tolerate the current treatment regimen for at least two cycles or more;
* Expected to have good compliance, able to follow up on treatment efficacy and adverse reactions as required by the protocol.

Exclusion:

* A history of other malignant tumors diagnosed within the past 3 years;
* Patients with mental or neurological disorders who are unable to cooperate;
* Patients who are scheduled to undergo or have previously undergone organ or bone marrow transplantation;
* Patients with hematopoietic system disorders other than chemotherapy-induced thrombocytopenia (CTIT), including but not limited to leukemia, primary immune thrombocytopenia, myeloproliferative disorders, multiple myeloma, and myelodysplastic syndrome;
* Patients with a history of any arterial or venous thrombotic events within the past 6 months prior to screening;
* Severe bleeding manifestations within 2 weeks prior to screening, such as gastrointestinal or central nervous system bleeding;
* Participation in a clinical trial of the same type of drug within 4 weeks prior to enrollment;
* Pregnant or lactating women;
* Patients with a history of hypersensitivity to the study drug;
* Patients deemed ineligible by the investigator.

Where this trial is running

Guangzhou, Guangdong

• Sun Yat-sen Memorial Hospital — Guangzhou, Guangdong, China (Recruiting)

Study contacts

• Principal investigator: Yinduo Zeng, MD — Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University
• Study coordinator: Tao Qin, MD

Conditions Thrombocytopenia