Joyce O’Shaughnessy, MD

At the European Society for Medical Oncology (ESMO) Breast Cancer Virtual Meeting 2020, Joyce O’Shaughnessy, MD, of Baylor University Medical Center, reported results from an interim analysis of the PHranceSCa study (Abstract 80O). The study investigators found that over 80% of patients preferred a subcutaneous fixed-dose combination of pertuzumab and trastuzumab, packaged in one ready-to-use vial, to pertuzumab plus trastuzumab given intravenously, and chose the subcutaneous formulation to complete their treatment.

Subcutaneous treatment was generally well tolerated, and the safety profile was consistent with intravenous treatment. No new safety signals were seen.

Dr. O’Shaughnessy said that a subcutaneous fixed-dose combination of pertuzumab plus trastuzumab may offer patients less invasive treatment in comparison to the same combination given intravenously. Subcutaneous treatment may reduce time in the clinic for patients, as well as free up resources at the practice.

Furthermore, patient-reported outcomes are increasingly important for decision-making. PHranceSCa provides insights into patients’ perspective on subcutaneous treatment with pertuzumab plus trastuzumab and provides supportive information to the pivotal FeDeriCa pharmacokinetic study.

PHranceSCa Methods

PHranceSCa is an open-label, randomized crossover study evaluating patient preference and satisfaction with subcutaneous vs intravenous treatment with pertuzumab plus trastuzumab. Patients enrolled had to have histologically confirmed, HER2-positive early breast cancer, and had to have completed neoadjuvant therapy with pertuzumab plus trastuzumab plus chemotherapy and had surgery.

Patients were randomly assigned to either group A, who received three cycles of pertuzumab plus trastuzumab given intravenously every 3 weeks then three cycles of the subcutaneous fixed-dose combination of pertuzumab and trastuzumab every 3 weeks; or to group B, who received three cycles of the subcutaneous fixed-dose combination of pertuzumab and trastuzumab every 3 weeks and then three cycles of pertuzumab plus trastuzumab given intravenously every 3 weeks. Patients then chose the subcutaneous fixed-dose combination of pertuzumab and trastuzumab or pertuzumab plus trastuzumab given intravenously to complete anti-HER2 therapy up to 18 cycles.

The primary objective was to evaluate patient preference for the subcutaneous fixed-dose combination of pertuzumab and trastuzumab. At clinical cutoff in August 2019, 118 patients had been randomly assigned: 56 patients to group A and 62 patients to group B. All patients were female, and the median age was 49 years.

Findings

In total, 42 (82%) of 51 patients who completed the crossover therapy preferred the subcutaneous fixed-dose combination of pertuzumab and trastuzumab. The main reasons given for preference of subcutaneous treatment were spending less time in the clinic and more comfortable therapy administration.

In total, 46 of 51 patients (90%) were very satisfied or satisfied with subcutaneous treatment, compared with 34 of 51 patients (67%) who reported satisfaction with the intravenous combination. The majority of patients (84%) chose the subcutaneous fixed-dose combination of pertuzumab and trastuzumab to complete their therapy.

In total, 81 of 116 patients reported one adverse event. One patient had a serious adverse event (pyrexia), and five patients had a grade 3 adverse event—in particular, three patients who had undergone subcutaneous treatment had ejection fraction decrease, diarrhea, and device-related infection, respectively, while two patients who received intravenous treatment had ejection fraction decrease and lymphopenia, respectively. However, there were no deaths and no adverse events led to study discontinuation.

In total, 16 of 116 patients (13.8%) had diarrhea, mainly low-grade. Systemic administration-related reaction rates were reported in 2 of 116 patients (1.7%) for subcutaneous treatment and in 3 of 116 patients (2.6%) for intravenous treatment. In total, 21 of 116 patients (18.1%) had local injection site reactions. There were no local infusion–related reactions.

The authors concluded that most patients preferred subcutaneous over intravenous treatment. The main reasons for preference of subcutaneous treatment in the PHranceSCa study are consistent with findings from the PrefHer trial.

Disclosure: The study was funded by F. Hoffman-La Roche. For full disclosures of the study authors, visit cslide.ctimeetingtech.com.