Subcutaneous injection of trastuzumab into the thigh versus abdominal wall in patients with HER2-positive early breast cancer: Pharmacokinetic, safety and patients' preference - Substudy of the randomised phase III GAIN-2 study

BACKGROUND

Trastuzumab given intravenously in combination with chemotherapy is standard of care for patients with early HER2-positive breast cancer (BC). Different randomised studies have shown equivalent efficacy of a subcutaneous injection into the thigh compared to the intravenous formulation. Other body regions for injection have not been investigated but might be more convenient for patients.

METHODS

After surgery, patients were randomised to receive either subcutaneous trastuzumab into the thigh or into the abdominal wall (AW). Patient preferences were evaluated using validated questionnaires (PINT). Primary objectives of this multicentre, non-blinded, randomised substudy of the GAIN-2 study were to investigate pharmacokinetics of the injection into the thigh versus AW and to determine patients' preferences of either administration site versus the previously received intravenous application.

RESULTS

226 patients were randomised and 219 patients (thigh: N = 110; AW: N = 109) formed the modified intent-to-treat (mITT). Overall, 83.5% (out of N = 182 with information about patients' preference) preferred subcutaneous over previous intravenous application or had no preference. Preference was similar between both administration sites (thigh: 80.6%; AW: 86.5; p = 0.322). Pharmacokinetic analysis included 30 patients. Geometric means of C_max and AUC_0-21d were higher in thigh than in AW group (geometric mean ratio with body weight adjustment: C_max: 1.291, 90%-CI 1.052-1.584; AUC_0-21d: 1.291, 90%-CI 1.026-1.626). Safety profile was in line with previous reports of subcutaneous trastuzumab.

CONCLUSION

Subcutaneous trastuzumab into the thigh showed an approximately 30% higher bioavailability. Injections were well tolerated and preferred over intravenous administration. The subcutaneous injection into the thigh should remain the standard of care.

Chemotherapy-induced ovarian failure in young women with early breast cancer: Prospective analysis of four randomised neoadjuvant/adjuvant breast cancer trials

BACKGROUND

Young women receiving chemotherapy for early breast cancer (EBC) have a high probability for ovarian failure, defined by chemotherapy-induced amenorrhea (CIA) as a surrogate. CIA is insufficiently reliable and reproducible. We analysed chemotherapy-induced ovarian failure (CIOF) by assessing hormone parameters, CIA, and antral follicle count (AFC).

METHODS

Blood samples of women aged ≤45 years treated with anthracycline/taxane-based chemotherapy for EBC from four neoadjuvant/adjuvant trials were collected at baseline, at the end of treatment (EOT), and at 6, 12, 18, and 24 months after EOT. Centrally assessed oestradiol (cutoff <52.2 ng/L) and follicle-stimulating hormone (cutoff >12.4IU/L) were used to define CIOF for patients with baseline premenopausal hormone levels, anti-Müllerian hormone (AMH), and AFC to assess ovarian reserve. Further analyses included CIA, regain of premenopausal hormone levels, and disease-free survival (DFS) also in subgroups.

RESULTS

Six hundred ninety-six patients aged ≤45 years had premenopausal hormone levels at baseline. Overall, 85.1% (592/696) experienced CIOF at EOT, and 147 of 592 had further hormone measurements after EOT. Of those, 32.7% (48/147) regained premenopausal hormone levels after 6 months, 57.9% (66/114) regained premenopausal hormone levels after 12 months, 83.0% (73/88) regained premenopausal hormone levels after 18 months, and 89.2% (74/83) regained premenopausal hormone levels after 24 months. After 24 months, 72.4% (21/29) of patients without CIOF and 100% (14/14) with CIOF had low AMH levels. Four-year DFS without CIOF versus CIOF was 65.9% versus 84.6% (hazard ratio [HR] = 2.09, 95% confidence interval [CI]: 1.37-3.19; P < 0.001); in hormone receptor positive 61.8% versus 87.5% (HR = 2.69, 95% CI: 1.57-4.60; P < 0.001); in <30 years 68.3% versus 92.6% (HR = 4.87, 95% CI: 1.05-22.63; P = 0.026).

CONCLUSION

Most premenopausal women experienced CIOF after chemotherapy for EBC. After 2 years, nearly all regain premenopausal hormone levels. CIOF was associated with better DFS, especially in patients with hormone receptor-positive EBC or aged <30 years.

Comparison between nab-paclitaxel and solvent-based taxanes as neoadjuvant therapy in breast cancer: a systematic review and meta-analysis

Background

To compare the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) and solvent-based taxanes (sb-taxanes) as neoadjuvant therapy in the treatment of breast cancer.

Methods

We systematically searched the PubMed, Embase, and Cochrane Central Register databases. Randomized controlled trials (RCTs) and cohort studies, published in English, about the comparison between nab-paclitaxel and sb-taxanes as neoadjuvant therapy in patients with breast cancer were searched up to September 2019.

Results

The primary outcome was the proportion of patients with pathological complete response (pCR, defined as ypT0 ypN0 or ypT0/is ypN0). Other main outcomes included long-term survival and adverse events (AEs). Seven studies (five RCTs and two cohorts) and 2949 patients were included. Neoadjuvant nab-paclitaxel improved pCR compared with sb-taxanes (ypT0 ypN0: OR = 1.52, 95%CI: 1.27–1.83, P < 0.001; ypT0/is ypN0: OR = 1.40, 95%CI: 1.17–1.68, P < 0.001). The benefits of nab-paclitaxel on pCR were persistent in HER2-negative, hormone receptor (HR)-positive breast cancer (OR = 1.53, 95%CI: 1.07–2.19, P = 0.020), triple-negative breast cancer (weekly/every 2 weeks regimen; OR = 2.95, 95%CI: 1.54–5.67, P < 0.001), and tumors with Ki-67 > 20% (OR = 1.63, 95%CI: 1.26–2.12, P < 0.001). Patients treated with nab-paclitaxel had better event-free survival (EFS; HR = 0.69, 95%CI: 0.57–0.85, P < 0.001) than with sb-taxanes. There were no differences in most of grade > 3 AEs between nab-paclitaxel and sb-taxanes (all P > 0.05), besides of any grade hypersensitivity (OR = 0.29, 95%CI: 0.11–0.72, P = 0.008), any grade (OR = 2.10, 95%CI: 1.37–3.23, P = 0.001) and grade > 3 (OR = 4.01, 95%CI: 2.51–6.41, P < 0.001) neuropathy.

Conclusion

Nab-paclitaxel is effective for the treatment of non-metastatic breast cancer in the neoadjuvant setting. Nab-paclitaxel could improve pCR rate and EFS compared with sb-taxanes and with reasonable toxicities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07831-7.