Trilaciclib plus chemotherapy versus chemotherapy alone in patients with metastatic triple-negative breast cancer: a multicentre, randomised, open-label, phase 2 trial.

BACKGROUND: Trilaciclib is an intravenous cell-cycle inhibitor that transiently maintains immune cells and haemopoietic stem and progenitor cells in G1 arrest. By protecting the immune cells and bone marrow from chemotherapy-induced damage, trilaciclib has the potential to optimise antitumour activity while minimising myelotoxicity. We report safety and activity data for trilaciclib plus gemcitabine and carboplatin chemotherapy in patients with metastatic triple-negative breast cancer. METHODS: In this randomised, open-label, multicentre, phase 2 study, adult patients (aged ≥18 years) with evaluable, biopsy-confirmed, locally recurrent or metastatic triple-negative breast cancer who had no more than two previous lines of chemotherapy were recruited from 26 sites in the USA, three in Serbia, two in North Macedonia, one in Croatia, and one in Bulgaria; sites were academic and community hospitals. Availability of diagnostic samples of tumour tissue confirming triple-negative breast cancer was a prerequisite for enrolment. Eligible patients were randomly assigned (1:1:1) by an interactive web-response system, stratified by number of previous lines of systemic therapy and the presence of liver metastases, to receive intravenous gemcitabine 1000 mg/m2 and intravenous carboplatin (area under the concentration-time curve 2 µg × h/mL) on days 1 and 8 (group 1), gemcitabine and carboplatin plus intravenous trilaciclib 240 mg/m2 on days 1 and 8 (group 2), or gemcitabine and carboplatin on days 2 and 9 plus trilaciclib on days 1, 2, 8, and 9 (group 3) of 21-day cycles. Patients continued treatment until disease progression, unacceptable toxicity, withdrawal of consent, or discontinuation by the investigator. The primary objective was to assess the safety and tolerability of combining trilaciclib with gemcitabine and carboplatin chemotherapy. The primary endpoints were duration of severe neutropenia during cycle 1 and the occurrence of severe neutropenia during the treatment period. Overall survival was included as a key secondary endpoint. Analyses were in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of study treatment. This study is registered with EudraCT, 2016-004466-26, and ClinicalTrials.gov, NCT02978716, and is ongoing but closed to accrual. FINDINGS: Between Feb 7, 2017, and May 15, 2018, 142 patients were assessed for eligibility and 102 were randomly assigned to group 1 (n=34), group 2 (n=33), or group 3 (n=35). Of all patients, 38 (37%) had received one or two lines of previous chemotherapy in the metastatic setting. Median follow-up was 8·4 months (IQR 3·8-13·6) for group 1, 12·7 months (5·5-17·4) for group 2, and 12·9 months (6·7-16·8) for group 3. Data cutoff for myelosuppression endpoints was July 30, 2018, and for antitumour activity endpoints was May 17, 2019. During cycle 1, mean duration of severe neutropenia was 0·8 day (SD 2·4) in group 1, 1·5 days (3·5) in group 2, and 1·0 day (2·6) in group 3 (group 3 vs group 1 one-sided adjusted p=0·70). Severe neutropenia occurred in nine (26%) of 34 patients in group 1, 12 (36%) of 33 patients in group 2, and eight (23%) of 35 patients in group 3 (p=0·70). Overall survival was 12·6 months (IQR 5·8-15·6) in group 1, 20·1 months (9·4-not reached) in group 2, and 17·8 months (8·8-not reached) in group 3 (group 3 vs group 1 two-sided p=0·0023). The most common treatment-emergent adverse events were anaemia (22 [73%] of 34), neutropenia (21 [70%]), and thrombocytopenia (18 [60%]) in group 1; neutropenia (27 [82%] of 33), thrombocytopenia (18 [55%]) and anaemia (17 [52%]) in group 2; and neutropenia (23 [66%] of 35), thrombocytopenia (22 [63%]), and nausea (17 [49%]) in group 3. There were no treatment-related deaths. INTERPRETATION: No significant differences were observed in myelosuppression endpoints with trilaciclib plus gemcitabine and carboplatin in patients with metastatic triple-negative breast cancer; however, the regimen was generally well tolerated and overall survival results were encouraging. Further studies of trilaciclib in this setting are warranted. FUNDING: G1 Therapeutics.

The prevalence and pattern of chemotherapy-induced peripheral neuropathy among women with breast cancer receiving care in a large community oncology practice.

PURPOSE: To describe the prevalence, severity, and risk factors of chemotherapy-induced peripheral neuropathy (CIPN) and its impact on function and quality of life (QOL) among women treated for breast cancer in a large U.S. Community Oncology practice. METHODS: Women previously treated with taxane-based chemotherapy for early-stage breast cancer completed the EORTC QLQ-C30, QLQ-BR23, and QLQ-CIPN20. Subscales are scored 0-100; higher scores indicate greater symptom severity. Pre-specified hypotheses were tested. RESULTS: 126 women with mean age 56.7 years (SD 11.8) were stage I-II (79.4%) or stage III (20.6%) at the time of the survey; 65.1% were White and 27.8% were Black or African American. The mean time since last taxane chemotherapy cycle was 144.9 weeks (SD 112.9). 73.0% reported having CIPN. QLQ-CIPN20 mean scores for the sensory, motor, and autonomic subscales were 18.9 (SD 23.1), 18.6 (SD 18.7), and 17.1 (SD 21.8), respectively. CIPN symptom severity was negatively correlated with global health status/QOL and physical and role functioning (range of r = -0.46 to -0.72). It was not associated with age, body mass index, diabetes, or cumulative taxane dosage, but was greater for Black or African American women (e.g., sensory, p < 0.002). CIPN sensory impairment was marginally greater for patients treated with paclitaxel compared to docetaxel (p < 0.064). CONCLUSIONS: CIPN was prevalent in this community oncology practice and significantly impacts function and QOL. These data highlight the importance of developing methods to mitigate CIPN, and for screening for CIPN particularly among Black or African American women.

Systemic Treatment of Patients With Metastatic Breast Cancer: ASCO Resource-Stratified Guideline.

PURPOSE: To guide clinicians and policymakers in three global resource-constrained settings on treating patients with metastatic breast cancer (MBC) when Maximal setting-guideline recommended treatment is unavailable. METHODS: A multidisciplinary, multinational panel reviewed existing ASCO guidelines and conducted modified ADAPTE and formal consensus processes. RESULTS: Four published resource-agnostic guidelines were adapted for resource-constrained settings; informing two rounds of formal consensus; recommendations received ≥75% agreement. RECOMMENDATIONS: Clinicians should recommend treatment according to menopausal status, pathological and biomarker features when quality results are available. In first-line, for hormone receptor (HR)-positive MBC, when a non-steroidal aromatase inhibitor and CDK 4/6 inhibitor combination is unavailable, use hormonal therapy alone. For life-threatening disease, use single-agent chemotherapy or surgery for local control. For premenopausal patients, use ovarian suppression or ablation plus hormone therapy in Basic settings. For human epidermal growth factor receptor 2 (HER2)-positive MBC, if trastuzumab, pertuzumab, and chemotherapy are unavailable, use trastuzumab and chemotherapy; if unavailable, use chemotherapy. For HER2-positive, HR-positive MBC, use standard first-line therapy, or endocrine therapy if contraindications. For triple-negative MBC with unknown PD-L1 status, or if PD-L1-positive and immunotherapy unavailable, use single-agent chemotherapy. For germline BRCA1/2 mutation-positive MBC, if poly(ADP-ribose) polymerase inhibitor is unavailable, use hormonal therapy (HR-positive MBC) and chemotherapy (HR-negative MBC). In second-line, for HR-positive MBC, Enhanced setting recommendations depend on prior treatment; for Limited, use tamoxifen or chemotherapy. For HER2-positive MBC, if trastuzumab deruxtecan is unavailable, use trastuzumab emtansine; if unavailable, capecitabine and lapatinib; if unavailable, trastuzumab and/or chemotherapy (hormonal therapy alone for HR-positive MBC).Additional information is available at www.asco.org/resource-stratified-guidelines. It is ASCO's view that healthcare providers and system decision-makers should be guided by the recommendations for the highest stratum of resources available. The guideline is intended to complement but not replace local guidelines.

Trilaciclib Prior to Chemotherapy in Patients with Metastatic Triple-Negative Breast Cancer: Final Efficacy and Subgroup Analysis from a Randomized Phase II Study.

PURPOSE: We report final antitumor efficacy results from a phase II study of trilaciclib, an intravenous cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, administered prior to gemcitabine plus carboplatin (GCb) in patients with metastatic triple-negative breast cancer (NCT02978716). PATIENTS AND METHODS: Patients were randomized (1:1:1) to group 1 [GCb (days 1, 8); n = 34], group 2 [trilaciclib prior to GCb (days 1, 8); n = 33], or group 3 [trilaciclib (days 1, 8) and trilaciclib prior to GCb (days 2, 9); n = 35]. Subgroup analyses were performed according to CDK4/6 dependence, level of programmed death-ligand 1 (PD-L1) expression, and RNA-based immune signatures using proportional hazards regression. T-cell receptor (TCR) ß CDR3 regions were amplified and sequenced to identify, quantify, and compare the abundance of each unique TCRß CDR3 at baseline and on treatment. RESULTS: Median overall survival (OS) was 12.6 months in group 1, not reached in group 2 (HR = 0.31; P = 0.0016), 17.8 months in group 3 (HR = 0.40; P = 0.0004), and 19.8 months in groups 2 and 3 combined (HR = 0.37; P < 0.0001). Efficacy outcomes were comparable regardless of cancer CDK4/6 dependence status and immune signatures. Administering trilaciclib prior to GCb prolonged OS irrespective of PD-L1 status but had greater benefit in the PD-L1-positive population. T-cell activation was enhanced in patients receiving trilaciclib. CONCLUSIONS: Administering trilaciclib prior to GCb enhanced antitumor efficacy, with significant improvements in OS. Efficacy outcomes in immunologic subgroups and enhancements in T-cell activation suggest these improvements may be mediated via immunologic mechanisms.

Cisplatin +/- rucaparib after preoperative chemotherapy in patients with triple-negative or BRCA mutated breast cancer.

Patients with triple-negative breast cancer (TNBC) who have residual disease after neoadjuvant therapy have a high risk of recurrence. We tested the impact of DNA-damaging chemotherapy alone or with PARP inhibition in this high-risk population. Patients with TNBC or deleterious BRCA mutation (TNBC/BRCAmut) who had >2 cm of invasive disease in the breast or persistent lymph node (LN) involvement after neoadjuvant therapy were assigned 1:1 to cisplatin alone or with rucaparib. Germline mutations were identified with BROCA analysis. The primary endpoint was 2-year disease-free survival (DFS) with 80% power to detect an HR 0.5. From Feb 2010 to May 2013, 128 patients were enrolled. Median tumor size at surgery was 1.9 cm (0-11.5 cm) with 1 (0-38) involved LN; median Residual Cancer Burden (RCB) score was 2.6. Six patients had known deleterious BRCA1 or BRCA2 mutations at study entry, but BROCA identified deleterious mutations in 22% of patients with available samples. Toxicity was similar in both arms. Despite frequent dose reductions (21% of patients) and delays (43.8% of patients), 73% of patients completed planned cisplatin. Rucaparib exposure was limited with median concentration 275 (82-4694) ng/mL post-infusion on day 3. The addition of rucaparib to cisplatin did not increase 2-year DFS (54.2% cisplatin vs. 64.1% cisplatin + rucaparib; P = 0.29). In the high-risk post preoperative TNBC/BRCAmut setting, the addition of low-dose rucaparib did not improve 2-year DFS or increase the toxicity of cisplatin. Genetic testing was underutilized in this high-risk population.

Chemotherapy and Targeted Therapy for Patients With Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer That is Either Endocrine-Pretreated or Hormone Receptor-Negative: ASCO Guideline Update.

PURPOSE: This guideline updates recommendations of the ASCO guideline on chemotherapy and targeted therapy for patients with human epidermal growth factor receptor 2-negative metastatic breast cancer (MBC) that is either endocrine-pretreated or hormone receptor (HR)-negative. METHODS: An Expert Panel conducted a targeted systematic literature review guided by a signals approach to identify new, potentially practice-changing data that might translate into revised guideline recommendations. RESULTS: The Expert Panel reviewed abstracts from the literature review and retained 14 articles. RECOMMENDATIONS: Patients with triple-negative, programmed cell death ligand-1-positive MBC may be offered the addition of immune checkpoint inhibitor to chemotherapy as first-line therapy. Patients with triple-negative, programmed cell death ligand-1-negative MBC should be offered single-agent chemotherapy rather than combination chemotherapy as first-line treatment, although combination regimens may be offered for life-threatening disease. Patients with triple-negative MBC who have received at least two prior therapies for MBC should be offered treatment with sacituzumab govitecan. Patients with triple-negative MBC with germline BRCA mutations previously treated with chemotherapy may be offered a poly (ADP-ribose) polymerase inhibitor rather than chemotherapy. Patients with HR-positive human epidermal growth factor receptor 2-negative MBC for whom chemotherapy is being considered should be offered single-agent chemotherapy rather than combination chemotherapy, although combination regimens may be offered for highly symptomatic or life-threatening disease. Patients with HR-positive MBC with disease progression on an endocrine agent may be offered treatment with either endocrine therapy with or without targeted therapy or single-agent chemotherapy. Patients with HR-positive MBC with germline BRCA mutations no longer benefiting from endocrine therapy may be offered a poly (ADP-ribose) polymerase inhibitor rather than chemotherapy. No recommendation regarding when a patient's care should be transitioned to hospice or best supportive care alone is possible.Additional information is available at www.asco.org/breast-cancer-guidelines.

Antiemetics: ASCO Guideline Update.

PURPOSE: To update the guideline to include new anticancer agents, antiemetics, and antiemetic regimens and to provide recommendations on the use of dexamethasone as a prophylactic antiemetic in patients receiving checkpoint inhibitors (CPIs). METHODS: ASCO convened an Expert Panel and updated the systematic review to include randomized controlled trials (RCTs) and meta-analyses of RCTs published between June 1, 2016, and January 24, 2020. To address the dexamethasone and CPI question, we conducted a systematic review of RCTs that evaluated the addition of a CPI to chemotherapy. RESULTS: The systematic reviews included 3 publications from the updated search and 10 publications on CPIs. Two phase III trials in adult patients with non-small-cell lung cancers evaluating a platinum-based doublet with or without the programmed death 1 (PD-1) inhibitor pembrolizumab recommended that all patients receive dexamethasone as a component of the prophylactic antiemetic regimen. In both studies, superior outcomes were noted in the PD-1 inhibitor-containing arms. Other important findings address olanzapine in adults and fosaprepitant in pediatric patients. RECOMMENDATIONS: Recommendations for adults are unchanged with the exception of the option of adding olanzapine in the setting of hematopoietic stem cell transplantation. Dosing information now includes the option of a 5-mg dose of olanzapine in adults and intravenous formulations of aprepitant and netupitant-palonosetron. The option of fosaprepitant is added to pediatric recommendations. There is no clinical evidence to warrant omission of dexamethasone from guideline-compliant prophylactic antiemetic regimens when CPIs are administered to adults in combination with chemotherapy. CPIs administered alone or in combination with another CPI do not require the routine use of a prophylactic antiemetic.Additional information is available at www.asco.org/supportive-care-guidelines.

Antiemetics: American Society of Clinical Oncology Clinical Practice Guideline Update.

Purpose To update the ASCO guideline for antiemetics in oncology. Methods ASCO convened an Expert Panel and conducted a systematic review of the medical literature for the period of November 2009 to June 2016. Results Forty-one publications were included in this systematic review. A phase III randomized controlled trial demonstrated that adding olanzapine to antiemetic prophylaxis reduces the likelihood of nausea among adult patients who are treated with high emetic risk antineoplastic agents. Randomized controlled trials also support an expanded role for neurokinin 1 receptor antagonists in patients who are treated with chemotherapy. Recommendation Key updates include the addition of olanzapine to antiemetic regimens for adults who receive high-emetic-risk antineoplastic agents or who experience breakthrough nausea and vomiting; a recommendation to administer dexamethasone on day 1 only for adults who receive anthracycline and cyclophosphamide chemotherapy; and the addition of a neurokinin 1 receptor antagonist for adults who receive carboplatin area under the curve ≥ 4 mg/mL per minute or high-dose chemotherapy, and for pediatric patients who receive high-emetic-risk antineoplastic agents. For radiation-induced nausea and vomiting, adjustments were made to anatomic regions, risk levels, and antiemetic administration schedules. Rescue therapy alone is now recommended for low-emetic-risk radiation therapy. The Expert Panel reiterated the importance of using the most effective antiemetic regimens that are appropriate for antineoplastic agents or radiotherapy being administered. Such regimens should be used with initial treatment, rather than first assessing the patient's emetic response with less-effective treatment. Additional information is available at www.asco.org/supportive-care-guidelines and www.asco.org/guidelineswiki .

Antiemetics: American Society of Clinical Oncology Focused Guideline Update.

PURPOSE: To update a key recommendation of the American Society of Clinical Oncology antiemetic guideline. This update addresses the use of the oral combination of netupitant (a neurokinin 1 [NK1] receptor antagonist) and palonosetron (a 5-hydroxytryptamine-3 [5-HT3] receptor antagonist) for the prevention of acute and delayed nausea and vomiting in patients receiving chemotherapy. METHODS: An update committee conducted a targeted systematic literature review and identified two phase III clinical trials and a randomized phase II dose-ranging study. RESULTS: In one phase III trial, the oral combination of netupitant and palonosetron was associated with higher complete response rates (no emesis and no rescue medications) compared with palonosetron alone in patients treated with anthracycline plus cyclophosphamide chemotherapy (74% v 67% overall; P = .001). In another phase III trial, the oral combination of netupitant and palonosetron was safe and effective across multiple cycles of moderately or highly emetogenic chemotherapies. In the phase II dose-ranging study, each dose of netupitant (coadministered with palonosetron 0.50 mg) produced higher complete response rates than palonosetron alone among patients receiving cisplatin-based chemotherapy. The highest dose of netupitant (ie, 300 mg) was most effective. RECOMMENDATIONS: All patients who receive highly emetogenic chemotherapy regimens (including anthracycline plus cyclophosphamide) should be offered a three-drug combination of an NK1 receptor antagonist, a 5-HT3 receptor antagonist, and dexamethasone. The oral combination of netupitant and palonosetron plus dexamethasone is an additional treatment option in this setting. The remaining recommendations from the 2011 ASCO guideline are unchanged pending a full update. Additional information is available at www.asco.org/guidelines/antiemetics and www.asco.org/guidelineswiki.

Phase III study of iniparib plus gemcitabine and carboplatin versus gemcitabine and carboplatin in patients with metastatic triple-negative breast cancer.

PURPOSE: There is a lack of treatments providing survival benefit for patients with metastatic triple-negative breast cancer (mTNBC), with no standard of care. A randomized phase II trial showed significant benefit for gemcitabine, carboplatin, and iniparib (GCI) over gemcitabine and carboplatin (GC) in clinical benefit rate, response rate, progression-free survival (PFS), and overall survival (OS). Here, we formally compare the efficacy of these regimens in a phase III trial. PATIENTS AND METHODS: Patients with stage IV/locally recurrent TNBC who had received no more than two previous chemotherapy regimens for mTNBC were randomly allocated to gemcitabine 1,000 mg/m(2) and carboplatin area under the curve 2 (days 1 and 8) alone or GC plus iniparib 5.6 mg/kg (days 1, 4, 8, and 11) every 3 weeks. Random assignment was stratified by the number of prior chemotherapies. The coprimary end points were OS and PFS. Patients receiving GC could cross over to iniparib on progression. RESULTS: Five hundred nineteen patients were randomly assigned (261 GCI; 258 GC). In the primary analysis, no statistically significant difference was observed for OS (hazard ratio [HR] = 0.88; 95% CI, 0.69 to 1.12; P = .28) nor PFS (HR = 0.79; 95% CI, 0.65 to 0.98; P = .027). An exploratory analysis showed that patients in the second-/third-line had improved OS (HR = 0.65; 95% CI, 0.46 to 0.91) and PFS (HR = 0.68; 95% CI, 0.50 to 0.92) with GCI. The safety profile for GCI was similar to GC. CONCLUSION: The trial did not meet the prespecified criteria for the coprimary end points of PFS and OS in the ITT population. The potential benefit with iniparib observed in second-/third-line subgroup warrants further evaluation.

Chemotherapy and targeted therapy for women with human epidermal growth factor receptor 2-negative (or unknown) advanced breast cancer: American Society of Clinical Oncology Clinical Practice Guideline.

PURPOSE: To identify optimal chemo- and targeted therapy for women with human epidermal growth factor 2 (HER2)- negative (or unknown) advanced breast cancer. METHODS: A systematic review of randomized evidence (including systematic reviews and meta-analyses) from 1993 through to current was completed. Outcomes of interest included survival, progression-free survival, response, quality of life, and adverse effects. Guideline recommendations were evidence based and were agreed on by the Expert Panel via consensus. RESULTS: Seventy-nine studies met the inclusion criteria, comprising 20 systematic reviews and/or meta-analyses, 30 trials on first-line treatment, and 29 trials on second-line and subsequent treatment. These trials form the evidence base for the guideline recommendations. RECOMMENDATIONS: Endocrine therapy is preferable to chemotherapy as first-line treatment for patients with estrogen receptor-positive metastatic breast cancer unless improvement is medically necessary (eg, immediately life-threatening disease). Single agent is preferable to combination chemotherapy, and longer planned duration improves outcome but must be balanced against toxicity. There is no single optimal first-line or subsequent line chemotherapy, and choice of treatment will be determined by multiple factors including prior therapy, toxicity, performance status, comorbid conditions, and patient preference. The role of bevacizumab remains controversial. Other targeted therapies have not so far been shown to enhance chemotherapy outcome in HER2-negative breast cancer.