Adjuvant Abemaciclib Combined with Endocrine Therapy for High Risk Early Breast Cancer: Safety and Patient-Reported Outcomes From the monarchE Study

BACKGROUND

In monarchE, abemaciclib plus endocrine therapy (ET) as adjuvant treatment of hormone receptor-positive, human epidermal growth factor 2-negative, high risk, early breast cancer demonstrated a clinically meaningful improvement in invasive disease-free survival versus ET alone. Detailed safety analyses conducted at a median follow-up of 27 months and key patient-reported outcomes (PRO) are presented.

PATIENTS AND METHODS

The safety population included all patients who received at least one dose of study treatment (n=5591). Safety analyses included incidence, management, and outcomes of common and clinically relevant adverse events (AEs). Patient-reported health-related quality-of-life, ET symptoms, fatigue, and side effect burden were assessed.

RESULTS

The addition of abemaciclib to ET resulted in higher incidence of Grade≥3 AEs (49.7% vs 16.3% with ET alone), predominantly laboratory cytopenias (e.g., neutropenia [19.6%]) without clinical complications. Abemaciclib-treated patients experienced more serious adverse events (SAEs; 13.3% vs 7.8%). Discontinuation of abemaciclib and/or ET due to AEs occurred in 18.5% of patients, mainly due to Grade1/2 AEs (66.8%). AEs were managed with comedications (e.g., antidiarrheals), abemaciclib dose holds (61.7%), and/or dose reductions (43.4%). Diarrhea was generally low grade (Grade1/2: 77%); Grade2/3 events were highest in the first month (20.5%), most short-lived (≤7 days) and did not recur. Venous thromboembolic events (VTE) were higher with abemaciclib+ET (2.5%) vs ET (0.6%); in the abemaciclib arm, increased VTE risk was observed with tamoxifen vs AIs (4.3% vs 1.8%). PROs were similar between arms, including being 'bothered by side effects of treatment', except for diarrhea. At ≥3 months, most patients reporting diarrhea reported "a little bit" or "somewhat".

CONCLUSION

In patients with high risk EBC, adjuvant abemaciclib+ET has an acceptable safety profile and tolerability is supported by PRO findings. Most AEs were reversible and manageable with comedications and/or dose modifications, consistent with the known abemaciclib toxicity profile.

Adjuvant abemaciclib combined with endocrine therapy for high-risk early breast cancer: updated efficacy and Ki-67 analysis from the monarchE study

BACKGROUND

Adjuvant abemaciclib combined with endocrine therapy (ET) previously demonstrated clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer at the second interim analysis, however follow-up was limited. Here, we present results of the prespecified primary outcome analysis and an additional follow-up analysis.

PATIENTS AND METHODS

This global, phase III, open-label trial randomized (1 : 1) 5637 patients to adjuvant ET for ≥5 years ± abemaciclib for 2 years. Cohort 1 enrolled patients with ≥4 positive axillary lymph nodes (ALNs), or 1-3 positive ALNs and either grade 3 disease or tumor ≥5 cm. Cohort 2 enrolled patients with 1-3 positive ALNs and centrally determined high Ki-67 index (≥20%). The primary endpoint was IDFS in the intent-to-treat population (cohorts 1 and 2). Secondary endpoints were IDFS in patients with high Ki-67, DRFS, overall survival, and safety.

RESULTS

At the primary outcome analysis, with 19 months median follow-up time, abemaciclib + ET resulted in a 29% reduction in the risk of developing an IDFS event [hazard ratio (HR) = 0.71, 95% confidence interval (CI) 0.58-0.87; nominal P = 0.0009]. At the additional follow-up analysis, with 27 months median follow-up and 90% of patients off treatment, IDFS (HR = 0.70, 95% CI 0.59-0.82; nominal P < 0.0001) and DRFS (HR = 0.69, 95% CI 0.57-0.83; nominal P < 0.0001) benefit was maintained. The absolute improvements in 3-year IDFS and DRFS rates were 5.4% and 4.2%, respectively. Whereas Ki-67 index was prognostic, abemaciclib benefit was consistent regardless of Ki-67 index. Safety data were consistent with the known abemaciclib risk profile.

CONCLUSION

Abemaciclib + ET significantly improved IDFS in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer, with an acceptable safety profile. Ki-67 index was prognostic, but abemaciclib benefit was observed regardless of Ki-67 index. Overall, the robust treatment benefit of abemaciclib extended beyond the 2-year treatment period.

Efficacy and safety of maintenance pemetrexed in patients with advanced nonsquamous non-small cell lung cancer following pemetrexed plus cisplatin induction treatment: A cross-trial comparison of two phase III trials

OBJECTIVES

Two phase III trials of advanced NSCLC patients were compared to examine relative efficacy and safety of differing treatment regimens. The JMDB trial investigated first-line pemetrexed-cisplatin (pemetrexed 500mg/m(2) plus cisplatin 75mg/m(2) every 21 days; maximum: 6 cycles). The PARAMOUNT phase III trial compared maintenance pemetrexed versus placebo after patients with nonsquamous NSCLC completed 4 cycles of first-line pemetrexed-cisplatin without disease progression.

METHODS

Overall survival (OS) and progression-free survival (PFS), analyzed by Kaplan-Meier and Cox methods, and toxicity rates were compared between the PARAMOUNT arms and a selected homogeneous population from JMDB: 346 patients with disease and prior treatment characteristics matching the PARAMOUNT population.

RESULTS

Outcomes for the PARAMOUNT placebo arm were similar to the JMDB homogeneous group (median PFS: 5.6 versus 6.2 months, p=0.117, HR=1.16; median OS: 14.0 versus 14.2 months, p=0.979, HR=1.00). The PARAMOUNT maintenance pemetrexed group had statistically superior efficacy compared with the JMDB homogeneous group (median PFS: 7.5 versus 6.2 months, p<0.00001, HR=0.66; median OS: 16.9 versus 14.2 months, p=0.003, HR=0.75). Patients who received pemetrexed maintenance (median 4 cycles, range 1-44) following 4 cycles of pemetrexed-cisplatin exhibited a higher incidence of drug-related serious adverse events compared with JMDB patients (median 6 cycles of pemetrexed-cisplatin) (10.6% versus 2.9%); grade 3/4 fatigue and renal toxicity were also higher in the pemetrexed arm of PARAMOUNT.

CONCLUSIONS

The across-trial comparison of a relevant JMDB study population with the two arms of the PARAMOUNT study supported the efficacy of the pemetrexed continuation maintenance strategy and suggested the results are not influenced by limiting the pemetrexed-cisplatin induction treatment to four cycles. Although longer exposure to pemetrexed-cisplatin or maintenance pemetrexed increased some toxicities, the overall incidence remained low, underscoring the relative safety of these treatment regimens.

Biweekly docetaxel and gemcitabine as neoadjuvant chemotherapy followed by adjuvant doxorubicin and cyclophosphamide therapy in stage II and III breast cancer patients: results of a phase II study

INTRODUCTION

The purpose of this phase II study was to evaluate the efficacy and safety of neoadjuvant docetaxel/gemcitabine treatment in a biweekly regimen.

MATERIALS AND METHODS

Patients with stage II/III breast cancer were treated with docetaxel (65 mg/m(2)) followed by gemcitabine (2500 mg/m(2)) every 2 weeks for 6 cycles. Patients with a clinical response or stable disease underwent mastectomy or breast-conserving surgery plus axillary dissection. After surgery, patients received 4 cycles of standard doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2) every 21 days.

RESULTS

Thirty-five patients were included in the trial. The overall response rate was 71.4% (95% CI: 53.7-85.4), with 8 complete and 17 partial responses. Breast conservation was possible in 59% of the patients. Toxicity was manageable.

CONCLUSIONS

We consider biweekly docetaxel and gemcitabine could be an active and tolerable regimen option in the neoadjuvant setting sequentially with standard adjuvant doxorubicin-cyclophosphamide in patients with stage II or III breast cancer.

Phase I study of bi-weekly pemetrexed (P) plus cisplatin (C) in patients with advanced cancer

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Background: Cisplatin and pemetrexed have demonstrated clinical activity in several malignant tumors including mesothelioma and non small cell lung cancer. There is preclinical evidence of synergism between both agents as well as clinical non-overlapping toxicities, thus providing the rationale for their evaluation in combination. Our aim was to develop a well-tolerated combination of bi-weekly CP able to deliver higher dose intensity than the every 3-week standard. Methods: Escalating doses of P from a starting dose level of 300 mg/m2, with a fixed-dose of C 50 mg/m2, both biweekly on 28-day cycles, were administered to patients with refractory advanced solid malignancies and calculated creatinine clearance = 45 mL/min. Results: Twenty one patients (5 female/16 male); median age 61 (39–76); ECOG 0 (16), 1 (5); lung cancer (9); soft-tissue sarcoma (3); unknown primary, bladder, breast, rectum, esophagus, melanoma, mesothelioma, prostate, and tonsil (1, each) have received a total of 48 courses (median 2, range 0–5), at P dose levels of 300 mg/m2 [8 pts, Dose level 1 (DL1)], 400 mg/m2 (7 pts, DL2), and 500 mg/m2 (6 pts, DL3), with full doses of C. Four patients were non-evaluable (2 at DL1, 1 at DL2 and 1 at DL3) because of early PD (2) and non-drug related serious adverse event (2 pt). Dose Limiting Toxicities (DLT) were G4 neutropenia (1 pt) at 300 mg/m2; and prolonged G 1/2 thrombocytopenia (1 pt) at 500 mg/m2. There were also 2 pts with non-DLT G4 neutropenia at DL3. The rest of toxicities were mild to moderate being the most frequent asthenia, nausea, anorexia, stomatatis, and sensory neuropathy. DL3 was considered the Maximum Tolerated Dose (MTD) and the previous level with P at 400 mg/m2 was declared the recommended phase II dose. Three additional patients were treated at DL2 for dose confirmation. A PR has been observed in 2 pts with NSCLC, 1 pt with breast, and 1 with esophagus cancer. Conclusions: Biweekly administration of pemetrexed (400 mg/m2) plus cisplatin (50 mg/m2) is clinically well tolerated and can be used safely. The regimen delivers higher dose intensity of P and equal of C as the standard. This regimen is currently being studied in a phase 2 trial in patients with locally advanced, non resectable or metastatic urothelial cancer.

No significant financial relationships to disclose.