Drug-induced thrombocytopenia induced by trastuzumab: a special challenge in a curable disease

Trastuzumab Associated With Recurrent Severe Thrombocytopenia and Successful Use of Pertuzumab Monotherapy

Trastuzumab is a mainstay chemotherapeutic agent used in the treatment of human epidermal growth factor receptor 2 (HER2)/neu-positive breast cancer that, though generally well-tolerated, is classically associated with side effects like cardiotoxicity. Cytopenias can be seen but are generally secondary to other chemotherapeutic agents used in conjunction with trastuzumab. Herein, we present a case of recurrent severe thrombocytopenia following trastuzumab use that resolved following discontinuation. Our patient then finished a year of maintenance therapy with pertuzumab alone and is still in remission four years later. This is the eleventh report of this severe adverse effect described in the literature. This report contributes to the body of work describing this severe side effect by illustrating a clear temporal relationship between trastuzumab and severe thrombocytopenia, while also providing an alternate treatment option with chemotherapy and pertuzumab monotherapy. Given that pertuzumab is typically only used in addition to trastuzumab, evidence of its successful independent use is of clinical value to patients who may not be able to tolerate trastuzumab.

Drug-induced thrombocytopenia associated with trastuzumab in a patient with HER2-positive recurrent gastric cancer

Here, we report a 57-year-old female patient with HER2-positive recurrent gastric cancer who experienced drug-induced thrombocytopenia associated with trastuzumab, a humanized anti-HER2 monoclonal antibody. Shortly after the initiation of S-1, oxaliplatin, and trastuzumab chemotherapy, the patient experienced severe thrombocytopenia and did not respond to platelet transfusions. Based on the findings of increased numbers of polynuclear megakaryocytes in the bone marrow and an elevated level of platelet-associated IgG (PA-IgG), the patient was diagnosed with drug-induced thrombocytopenia (DITP). The platelet count recovered rapidly with oral prednisolone (1 mg/kg). Since we initially suspected oxaliplatin as the causal agent, S-1 was restarted as a monotherapy, followed by trastuzumab after a 3-week interval, without oxaliplatin. On the second day after the addition of trastuzumab, severe thrombocytopenia occurred again, which suggests that trastuzumab was responsible for the DITP. The patient no longer experienced severe thrombocytopenia during the subsequent S-1 and oxaliplatin chemotherapy, which supports this hypothesis.

Severe thrombocytopenia induced by trastuzumab rechallenge: a case report and literature review

WHAT IS KNOWN AND OBJECTIVE

Trastuzumab can significantly prolong the survival of patients with human epidermal growth factor receptor-2 (HER-2)-positive breast cancer. Trastuzumab-induced thrombocytopenia is a rare adverse effect. There have been no reports of acute, grade 4 thrombocytopenia after weekly trastuzumab therapy. The study reports a case of a breast cancer patient with severe thrombocytopenia due to trastuzumab infusion (8 mg/kg). Moreover, the patient experienced recurrence of severe thrombocytopenia after receiving weekly trastuzumab therapy (4 mg/kg).

CASE SUMMARY

A 52-year-old woman with HER-2-positive breast cancer developed diffuse petechial haemorrhages and ecchymosis on the lower limbs and gingival bleeding within 24 hours of trastuzumab infusion (8 mg/kg). She was confirmed to have severe thrombocytopenia, which quickly recovered after corticosteroid therapy and platelet transfusion. When her platelet count recovered, we attempted weekly trastuzumab therapy (4 mg/kg); however, thrombocytopenia recurred within 24 hours. Thus, we did not attempt further treatment with trastuzumab.

WHAT IS NEW AND CONCLUSION

We are the first to attempt weekly trastuzumab therapy after thrombocytopenia induced by its initial administration. Reducing the trastuzumab dose did not prevent trastuzumab-induced thrombocytopenia. Unlike other reports with administration of high-dose corticosteroid, we found that a standard dose of corticosteroid combined with platelet transfusion was effective in treating trastuzumab-induced thrombocytopenia.

Trastuzumab-induced thrombocytopenia after eight cycles of trastuzumab treatment

Trastuzumab, a humanized monoclonal antibody derived from recombinant DNA, is used in patients with breast cancer with HER2 gene amplification. The survival benefit from trastuzumab has been well established in patients with early and metastatic breast cancer who had over expression of HER2. We reported a case of severe thrombocytopenia after eight cycles of trastuzumab treatment for breast cancer. Before the 9th trastuzumab treatment, the patient’s platelet decreased to 48 × 10⁹/L. Recombinant human thrombopoietin was used, and the platelet level increased to normal level. Before the 10th treatment, the platelet count of the patient was 99 × 10⁹/L. However, during the 10th and 11th trastuzumab treatment, the platelet count decreased to 5 × 10⁹/L in 24 h. After treatment with TPO and corticosteroids, the platelet levels increased to the normal level in 7 days. Trastuzumab-induced thrombocytopenia is rare but still occurred even after 8 cycles of trastuzumab treatment.

Severe Thrombocytopenia Related to Long-Term Trastuzumab Exposure

Drug-induced immune thrombocytopenia may occur secondary to several chemotherapeutic agents or new targeted monoclonal antibodies, but thrombocytopenia induced by trastuzumab is a very rare occurrence. We report a case of severe thrombocytopenia related to the administration of trastuzumab six months after the first exposure.

Unexpected hematologic effects of biotherapeutics in nonclinical species and in humans

Biotherapeutics are expanding the arsenal of therapeutics available for treating and preventing disease. Although initially thought to have limited side effects due to the specificity of their binding, these drugs have now been shown to have potential for adverse drug reactions including effects on peripheral blood cell counts or function. Hematotoxicity caused by a biotherapeutic can be directly related to the activity of the biotherapeutic or can be indirect and due to autoimmunity, biological cascades, antidrug antibodies, or other immune system responses. Biotherapeutics can cause hematotoxicity primarily as a result of cellular activation, cytotoxicity, drug-dependent and independent immune responses, and sequelae from initiating cytokine and complement cascades.  The underlying pathogenesis of biotherapeutic-induced hematotoxicity often is poorly understood. Nonclinical studies have generally predicted clinical hematotoxicity for recombinant cytokines and growth factors.  However, most hematologic liabilities of biotherapeutics are not based on drug class but are species specific, immune-mediated, and of low incidence. Despite the potential for unexpected hematologic toxicity, the risk-benefit profile of most biotherapeutics is favorable; hematologic effects are readily monitorable and managed by dose modification, drug withdrawal, and/or therapeutic intervention.  This article reviews examples of biotherapeutics that have unexpected hematotoxicity in nonclinical or clinical studies. 

Adverse events to monoclonal antibodies used for cancer therapy: Focus on hypersensitivity responses

Fifteen monoclonal antibodies (mAbs) are currently registered and approved for the treatment of a range of different cancers. These mAbs are specific for a limited number of targets (9 in all). Four of these molecules are indeed directed against the B-lymphocyte antigen CD20; 3 against human epidermal growth factor receptor 2 (HER2 or ErbB2), 2 against the epidermal growth factor receptor (EGFR), and 1 each against epithelial cell adhesion molecule (EpCAM), CD30, CD52, vascular endothelial growth factor (VEGF), tumor necrosis factor (ligand) superfamily, member 11 (TNFSF11, best known as RANKL), and cytotoxic T lymphocyte-associated protein 4 (CTLA4). Collectively, the mAbs provoke a wide variety of systemic and cutaneous adverse events including the full range of true hypersensitivities: Type I immediate reactions (anaphylaxis, urticaria); Type II reactions (immune thrombocytopenia, neutopenia, hemolytic anemia); Type III responses (vasculitis, serum sickness; some pulmonary adverse events); and Type IV delayed mucocutaneous reactions as well as infusion reactions/cytokine release syndrome (IRs/CRS), tumor lysis syndrome (TLS), progressive multifocal leukoencephalopathy (PML) and cardiac events. Although the term "hypersensitivity" is widely used, no common definition has been adopted within and between disciplines and the requirement of an immunological basis for a true hypersensitivity reaction is sometimes overlooked. Consequently, some drug-induced adverse events are sometimes incorrectly described as "hypersensitivities" while others that should be described are not.

Severe thrombocytopenia after trastuzumab retreatment: a case report

Background

Trastuzumab prolongs survival of human epidermal growth factor receptor 2-positive breast cancer patients in both the adjuvant and metastatic settings. Currently toxicity data are not available on retreatment of metastatic breast cancer patients who relapse after adjuvant trastuzumab. We report one patient with metastatic breast cancer who developed acute thrombocytopenia after trastuzumab infusion. This patient had trastuzumab treatment in the adjuvant setting.

Case presentation

A 70-year-old Caucasian woman received a diagnosis of metastatic breast cancer four years after her initial diagnosis of locally advanced, hormone receptors-positive, human epidermal growth factor receptor 2-positive breast cancer. Trastuzumab retreatment was planned. Less than 24 hours after trastuzumab infusion, the patient was admitted to the hospital for the appearance of diffuse petechial hemorrhages and ecchymosis. The patient was confirmed to have a severe trastuzumab-induced thrombocytopenia. A rapid and complete recovery was observed after high-dose intravenous corticosteroids and immunoglobulin. No trastuzumab retreatment was attempted.

Conclusion

Among the reported cases of trastuzumab-induced thrombocytopenia, this is the first report in the literature occurring in a patient retreated with trastuzumab after adjuvant therapy.

Severe thrombocytopenia related to trastuzumab infusion

BACKGROUND

Trastuzumab is a humanized, monoclonal antibody that interferes with the HER2/neu receptor and binds selectively to the HERB2 protein which causes uncontrolled proliferation of malignant breast cells.

CASE REPORT

We report a case of severe thrombocytopenia related to trastuzumab administration. Three days after the first dose of single-agent trastuzumab, the patient was admitted to the hospital with nose bleeding, petechiae and platelet counts of 5 × 10⁹/L.

CONCLUSIONS

The patient showed a self-limiting trastuzumab-related thrombocytopenia. Among the reported cases of trastuzumab-induced severe thrombocytopenia, this patient is the only one who did not interrupt trastuzumab treatment. It is possible that our patient showed progressive reduction of immune-mediated thrombocytopenia caused by trastuzumab administration.