Management of Diarrhea in Patients with HER2-Positive Breast Cancer Treated with Neratinib: A Case Series and Summary of the Literature

Preclinical and clinical evaluation through serial colonoscopic evaluation of neratinib-induced diarrhea in HER2-positive breast cancer-A pilot study

The irreversible pan-HER tyrosine kinase inhibitor neratinib is approved for patients with HER2-positive, early-stage and metastatic breast cancer (BC). Neratinib-associated diarrhea is the most common reason for early discontinuation. Preclinical studies identified mechanisms of neratinib-induced diarrhea and rationale for prophylactic and preventive measures. We studied effects of neratinib on rat intestines and conducted a phase 2 study of colon pathogenesis in patients with HER2-positive BC treated with neratinib (NCT04366713). Colon samples from female albino Wistar rats receiving neratinib or vehicle were examined for histopathological changes. Patients with HER2-positive BC received neratinib 240 mg once daily for up to 1 year. Colonoscopy biopsies were collected at baseline and at Day 28 to identify changes consistent with rat pathologies. Rat colons were markedly altered in appearance, with similar short circuit currents (Isc) and responses to carbachol and forskolin. Mucosal barrier loss and/or significant increase in secretory propensity in neratinib- versus control-treated animals were not seen. Two of four endpoint-evaluable patients presented with mild pathological changes, largely comparable with the rat model. Preclinical evidence supports an inflammatory component of neratinib-induced diarrhea without mucosal barrier function loss. Colonoscopy findings in patients with BC indicate mild or no pathological changes in the colon due to neratinib treatment.

Mechanism and treatment of diarrhea associated with tyrosine kinase inhibitors

Tyrosine kinase inhibitors (TKIs) have become first-line drugs for cancer treatment. However, their clinical use is seriously hindered since many patients experience diarrhea after receiving TKIs. The mechanisms of TKI-associated diarrhea remain unclear. Most existing therapies are symptomatic treatments based on experience and their effects are unsatisfactory. Therefore, clarification of the mechanisms underlying diarrhea is critical to develop effective anti-diarrhea drugs. This article summarizes several potential mechanisms of TKI-associated diarrhea and reviews current treatment progress.

Pyrotinib versus placebo in combination with trastuzumab and docetaxel as first line treatment in patients with HER2 positive metastatic breast cancer (PHILA): randomised, double blind, multicentre, phase 3 trial

OBJECTIVE

To assess the efficacy and safety of pyrotinib (an irreversible pan-HER (human epidermal growth factor receptor) inhibitor), trastuzumab, and docetaxel compared with placebo, trastuzumab, and docetaxel for untreated HER2 positive metastatic breast cancer.

DESIGN

Randomised, double blind, placebo controlled, multicentre, phase 3 trial.

SETTING

40 centres in China between 6 May 2019 and 17 January 2022.

PARTICIPANTS

590 female patients (median age 52 (interquartile range 46-58) years) with untreated HER2 positive metastatic breast cancer.

INTERVENTIONS

Eligible patients were randomised 1:1 to receive either oral pyrotinib (400 mg once daily) or placebo, both combined with intravenous trastuzumab (8 mg/kg in cycle 1 and 6 mg/kg in subsequent cycles) and docetaxel (75 mg/m2) on day 1 of each 21 day cycle. Randomisation was stratified by treatment history of trastuzumab in the (neo)adjuvant setting and hormone receptor status. Patients, investigators, and the sponsor's study team were masked to treatment assignment.

MAIN OUTCOME MEASURES

The primary endpoint was progression-free survival as assessed by the investigator.

RESULTS

Of the 590 randomised patients, 297 received pyrotinib, trastuzumab, and docetaxel treatment (pyrotinib group), and 293 received placebo, trastuzumab, and docetaxel treatment (placebo group). At data cut-off on 25 May 2022, the median follow-up was 15.5 months. The median progression-free survival according to the investigator was significantly longer in the pyrotinib group than in the placebo group (24.3 (95% confidence interval 19.1 to 33.0) months versus 10.4 (9.3 to 12.3) months; hazard ratio 0.41 (95% confidence interval 0.32 to 0.53); one sided P<0.001). Treatment related adverse events of grade 3 or higher were reported in 267 (90%) of the 297 patients in the pyrotinib group and 224 (76%) of the 293 patients in the placebo group. No treatment related deaths occurred in the pyrotinib group, and one (<1%; diabetic hyperosmolar coma) treatment related death occurred in the placebo group. Survival and toxicities are still under assessment with longer follow-up.

CONCLUSIONS

Pyrotinib, trastuzumab, and docetaxel showed superiority by significantly improving progression-free survival compared with placebo, trastuzumab, and docetaxel in patients with untreated HER2 positive metastatic breast cancer. The toxicity was manageable. The findings support this dual anti-HER2 regimen as an alternative first line treatment option in this patient population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03863223.

Efficacy of the Whole-Course Case Management Model on Compliance and Satisfaction of Breast Cancer Patients with Whole-Course Standardized Treatment

Objective

To explore the influence of the whole-course case management model on the compliance and satisfaction of breast cancer patients with the whole-course standardized treatment.

Methods

Eighty breast cancer patients admitted to our hospital between April 2020 and June 2021 were assigned to receive either conventional nursing (routine group, n = 40) or whole-process case management (experimental group, n = 40) according to different nursing methods. Outcome measures included self-rating anxiety scale (SAS) scores, self-rating depression scale (SDS) scores, adverse reactions, treatment compliance, and nursing satisfaction.

Results

After nursing, the SAS and SDS scores of the experimental group were significantly lower than those of the routine group (P < 0.05). The whole case management mode was associated with a significantly lower incidence of adverse reactions versus routine nursing (P < 0.05). The whole case management resulted in higher compliance of patients versus routine nursing (P < 0.05). The experimental group had a significantly higher nursing satisfaction versus the routine group (P < 0.05).

Conclusion

The whole-process case management mitigates patients' negative emotions, strengthens their treatment compliance, lowers the incidence of postoperative adverse reactions, and improves nursing satisfaction, which may provide a viable nursing alternative for patients with breast cancer.