JMIR Publications

ABSTRACT

Background:

Trastuzumab had a major impact on the treatment of HER2-positive breast cancer (BC). Anti-HER2 biosimilars, such as Ogivri®, have demonstrated safety and clinical equivalence to the reference product HerceptinTM in clinical trials. In patients treated with biosimilars, to our knowledge, no real-world reporting of side effects and quality of life (QoL) has been investigating using electronic patient-reported outcome (ePRO).

Objective:

The primary objective of the study was to evaluate ePRO data collected with the mediduxTM app in patients with HER2-positive BC treated with the trastuzumab biosimilar Ogivri® (prospective cohort) with respect to treatment side effects and to compare them with ePRO data obtained from a historical cohort of 38 patients treated with HerceptinTM in two previous studies (NCT02004496, NCT03578731).

Methods:

In this prospective observational study, patients with HER2-positive BC were treated with Ogivri® alone +/-pertuzumab, +/- chemotherapy and hormone therapy in (neo )adjuvant and palliative settings. Patients used the mediduxTM app to dynamically record symptoms (according to the CTCAE), well-being (according to the ECOG PS), QoL (using the EQ-5D-5L questionnaire), cognitive capabilities, and vital parameters over an observational period of 6 weeks. The primary endpoint was the mean CTCAE score. Key secondary endpoints included the mean well-being score and QoL (EQ-5D-5L questionnaire). A comparative analysis was performed between the prospective and the historical cohorts. Here we report on the primary endpoint and the secondary endpoint well-being.

Results:

Overall, 53 female patients with a median age of 54 years (range 31-87 years) were enrolled in the study. In the prospective cohort, the mean CTCTA score was analyzed in 50 patients with available data on symptoms, while the mean well-being score was evaluated in 52 patients with available data. Among the most common symptoms reported in both cohorts were fatigue, taste disorder, nausea, diarrhea, dry mucosa, joint discomfort, tingling, sleep disorder, headache, and appetite loss. Most patients experienced minimal (grade 0) or mild (grade 1) toxicities in both cohorts. The mean CTCAE score was comparable between prospective cohort and historical cohort (29.0% vs 30.3%, respectively; mean difference of - 1.27 [95%CI - 7.24, 4.70), P=0.678). Similarly, no significant difference was reported for the mean well-being score between the trastuzumab biosimilar Ogivri® and HerceptinTM (74.3 vs 69.8, respectively; mean difference of 4.45 [95%CI - 3.53, 12.44], P=0.277).

Conclusions:

The treatment of HER2-positive BC patients with trastuzumab biosimilar Ogivri® compared to HerceptinTM resulted in equivalent symptoms, adverse events and well-being reported by ePRO. Our findings indicate that the integration of ePRO into research and clinical practice provides reliable information when investigating real-world tolerability and outcomes of similar therapeutic compounds. Clinical Trial: ClinicalTrials.gov registration identifier NCT05234021