Long-Term Follow-Up of the Anthracyclines in Early Breast Cancer Trials (USOR 06-090, NSABP B-46-I/USOR 07132, and NSABP B-49 [NRG Oncology]).

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The primary joint efficacy analysis of the Anthracyclines in Early Breast Cancer (ABC) trials reported in 2017 failed to demonstrate nonanthracycline adjuvant therapy was noninferior to anthracycline-based regimens in high-risk, early breast cancer. Full analyses of the studies had proceeded when the prespecified futility boundary was crossed at a planned futility analysis for the ability to demonstrate noninferiority of a nonanthracycline regimen with continued follow-up. These results were presented with 3.3 years of median follow-up. This manuscript reports results of the final analyses of the study efficacy end points conducted with 6.9 years of median follow-up. Long-term analysis of invasive disease-free survival (IDFS), the primary end point of the ABC trials, remains consistent with the original results, as noninferiority of the nonanthracycline regimens could not be declared on the basis of the original criteria. The secondary end point of recurrence-free interval, which excluded deaths not due to breast cancer as events, favored anthracycline-based regimens, and tests for heterogeneity were significant for hormone receptor status (P = .02) favoring anthracycline regimens for the hormone receptor-negative cohorts. There was no difference in overall survival, and review of the type of IDFS events in the groups suggested reductions in cancer recurrences achieved with anthracycline regimens were offset by late leukemias and deaths unrelated to breast cancer.

Measures of functional status in older patients treated with palbociclib for advanced breast cancer.

INTRODUCTION: Limited data are available on the effects of treatment for advanced breast cancer (ABC) in older patients because this population has limited enrollment in clinical trials. Data generated from the prospective, noninterventional POLARIS study of patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative ABC may help bridge the gap in our understanding of the tolerability and outcomes in this vulnerable population. MATERIALS AND METHODS: We evaluated measures of geriatric impairments and activities of daily living in patients with ABC aged ≥70 years in POLARIS to evaluate the change within six months of palbociclib initiation. Geriatric impairments and activities of daily living (functional) status were assessed using the Geriatric 8 (G8) and Activities of Daily Living (ADL) screening tools. The G8, ADL, and Eastern Cooperative Oncology Group performance status (ECOG PS) scores were assessed at baseline and month six through end of treatment with palbociclib. ECOG PS scores were also stratified by G8 and ADL score severity subgroups (G8: ≤14 = impaired subgroup; >14 = not at all impaired subgroup; ADL: <18 = dependent subgroup, 18 = independent subgroup). RESULTS: At data cutoff in November 2020, of 1282 POLARIS patients of all ages, 287 (22.4%) were ≥ 70 years old and completed ≥6 months of palbociclib therapy. At baseline, 117 (45%; n = 260) of these patients had an ECOG PS score of 0, 143 (55%; n = 260) had ECOG PS score > 0, 248 (86%) had G8 scores (mean [SD] 13.6 [2.14]), and 256 (89%) had ADL scores (17.7 [1.03]) among the available 287 patients. At six months, 102 (40%; n = 255) had an ECOG PS score of 0, 153 (60%; n = 255) had ECOG PS score > 0, 198 (69%) had G8 scores (13.6 [1.99]), and 211 (74%) had ADL scores (17.6 [1.22]) among the 287 available patients. There was no mean change (standard deviation) from baseline to 6 months in mean ECOG PS scores (0.0 [0.61], P = 0.24), G8 scores (0.0 [2.17], P = 0.89), or ADL scores (0.0 [1.00], P = 0.62). DISCUSSION: In this subgroup analysis of older patients with ABC from POLARIS, functional status and impairment outcomes were preserved in older patients receiving palbociclib. G8, ADL, and ECOG PS scores were generally maintained during the first six months of palbociclib therapy. CLINICALTRIALS: govidentification number. NCT03280303.

Outcomes of male patients with HR+/HER2- advanced breast cancer receiving palbociclib in the real-world POLARIS study.

PURPOSE: Data on treatments for male breast cancer patients are limited owing to rarity and underrepresentation in clinical trials. The real-world POLARIS study gathers data on palbociclib use for the treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC) in female and male patients. This sub-analysis describes real-world palbociclib treatment patterns, clinical outcomes, and quality of life (QoL) in male patients. METHODS: POLARIS is a prospective, noninterventional, multicenter, real-world study of patients with HR+/HER2- ABC receiving palbociclib. Assessments included medical record reviews, patient QoL questionnaires (European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire-Core 30), site characteristics questionnaires, and physician treatment selection surveys. Variables included demographics, disease history, global health status/QoL, clinical assessments and adverse events. Analyses were descriptive in nature. For clinical outcomes, real-world tumor responses and progression were determined by physician assessment in routine clinical practice. Real-world progression-free survival (rwPFS) was described using the Kaplan-Meier method. RESULTS: At data cutoff, 15 male patients were enrolled (median age, 66 years). Nine patients received palbociclib as a first-line treatment and 6 as a second-line or later treatment. Patients received a median of 20 cycles of palbociclib. Neutropenia was experienced by 2 patients and grade ≥ 3 adverse events were reported in 11 patients. Global health status/QoL scores remained generally consistent during the study. One patient (6.7%) achieved a complete tumor response, 4 (26.7%) a partial response, and 8 (53.3%) stable disease. Median rwPFS was 19.8 months (95% CI, 7.4-38.0). Median follow-up duration was 24.7 months (95% CI, 20.0-35.7). CONCLUSION: This real-world analysis showed that palbociclib was well tolerated and provides preliminary data on treatment patterns and outcomes with palbociclib in male patients with HR+/HER2- ABC, helping inform the use of palbociclib in this patient subgroup. TRIAL IDENTIFIER: NCT03280303.

Neoadjuvant Talazoparib in Patients With Germline BRCA1/2 Mutation-Positive, Early-Stage Triple-Negative Breast Cancer: Results of a Phase II Study.

BACKGROUND: The undetermined efficacy of the current standard-of-care neoadjuvant treatment, anthracycline/platinum-based chemotherapy, in patients with early-stage triple-negative breast cancer (TNBC) and germline BRCA mutations emphasizes the need for biomarker-targeted treatment, such as poly(ADP-ribose) polymerase inhibitors, in this setting. This phase II, single-arm, open-label study evaluated the efficacy and safety of neoadjuvant talazoparib in patients with germline BRCA1/2-mutated early-stage TNBC. PATIENTS AND METHODS: Patients with germline BRCA1/2-mutated early-stage TNBC received talazoparib 1 mg once daily for 24 weeks (0.75 mg for moderate renal impairment) followed by surgery. The primary endpoint was pathologic complete response (pCR) by independent central review (ICR). Secondary endpoints included residual cancer burden (RCB) by ICR. Safety and tolerability of talazoparib and patient-reported outcomes were assessed. RESULTS: Of 61 patients, 48 received ≥80% talazoparib doses, underwent surgery, and were assessed for pCR or progressed before pCR assessment and considered nonresponders. pCR rate was 45.8% (95% confidence interval [CI], 32.0%-60.6%) and 49.2% (95% CI, 36.7%-61.6%) in the evaluable and intent-to-treat (ITT) population, respectively. RCB 0/I rate was 45.8% (95% CI, 29.4%-63.2%) and 50.8% (95% CI, 35.5%-66.0%) in the evaluable and ITT population, respectively. Treatment-related adverse events (TRAE) were reported in 58 (95.1%) patients. Most common grade 3 and 4 TRAEs were anemia (39.3%) and neutropenia (9.8%). There was no clinically meaningful detriment in quality of life. No deaths occurred during the reporting period; 2 deaths due to progressive disease occurred during long-term follow-up (>400 days after first dose). CONCLUSIONS: Neoadjuvant talazoparib monotherapy was active despite pCR rates not meeting the prespecified threshold; these rates were comparable to those observed with combination anthracycline- and taxane-based chemotherapy regimens. Talazoparib was generally well tolerated. CLINICALTRIALS.GOV IDENTIFIER: NCT03499353.

Determinants of Response to Talazoparib in Patients with HER2-Negative, Germline BRCA1/2-Mutated Breast Cancer.

PURPOSE: PARP inhibitors (PARPi) have demonstrated efficacy in tumors with germline breast cancer susceptibility genes (gBRCA) 1 and 2 mutations, but further factors influencing response to PARPi are poorly understood. EXPERIMENTAL DESIGN: Breast cancer tumor tissue from patients with gBRCA1/2 mutations from the phase III EMBRACA trial of the PARPi talazoparib versus chemotherapy was sequenced using FoundationOne CDx. RESULTS: In the evaluable intent-to-treat population, 96.1% (296/308) had ≥1 tumor BRCA (tBRCA) mutation and there was strong concordance (95.3%) between tBRCA and gBRCA mutational status. Genetic/genomic characteristics including BRCA loss of heterozygosity (LOH; identified in 82.6% of evaluable patients), DNA damage response (DDR) gene mutational burden, and tumor homologous recombination deficiency [assessed by genomic LOH (gLOH)] demonstrated no association with talazoparib efficacy. CONCLUSIONS: Overall, BRCA LOH status, DDR gene mutational burden, and gLOH were not associated with talazoparib efficacy; however, these conclusions are qualified by population heterogeneity and low patient numbers in some subgroups. Further investigation in larger patient populations is warranted.

POLARIS: a prospective, multicenter, noninterventional study assessing palbociclib in hormone receptor-positive advanced breast cancer.

This report describes the rationale, purpose and design of the POLARIS study. POLARIS is an ongoing noninterventional, prospective, multicenter study. Female and male patients in the USA and Canada diagnosed with hormone receptor-positive/HER2-negative metastatic breast cancer were enrolled in the study and treated with the cyclin-dependent kinase 4/6 inhibitor palbociclib when hormone receptor-positive/HER2-negative metastatic breast cancer was deemed to be indicated by their physician. The study will provide real-world data on palbociclib prescribing and treatment patterns in routine clinical practice, associated clinical outcomes, treatment sequencing in the advanced/metastatic setting, patient quality of life and geriatric-specific assessments. The tumor genomic landscape in relation to clinical outcomes will be explored. POLARIS will identify benefits and side effects of palbociclib across multiple lines of therapy and in discrete subsets of patients. Clinical Trial Registration: NCT03280303 (ClinicalTrials.gov).

Outcomes in Clinically Relevant Patient Subgroups From the EMBRACA Study: Talazoparib vs Physician's Choice Standard-of-Care Chemotherapy.

BACKGROUND: Talazoparib is a poly(adenosine diphosphate-ribose) polymerase inhibitor that causes death in cells with breast cancer susceptibility gene 1 or 2 (BRCA1/2) mutations. METHODS: EMBRACA (NCT01945775) was a randomized phase III study comparing efficacy, safety, and patient-reported outcomes (PROs) of talazoparib (1 mg) with physician's choice of chemotherapy (PCT: capecitabine, eribulin, gemcitabine, vinorelbine) in locally advanced or metastatic breast cancer with a germline BRCA1/2 (gBRCA1/2) mutation. Prespecified patient subgroups were analyzed for progression-free survival, objective response, clinical benefit, duration of response, and safety. PROs were evaluated in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) or triple-negative breast cancer (TNBC) subgroups. RESULTS: Of 431 patients, 287 were randomly assigned to talazoparib and 144 to PCT. Prespecified subgroup analyses showed prolonged progression-free survival with talazoparib (HR+/HER2-: hazard ratio = 0.47, 95% confidence interval = 0.32 to 0.71; TNBC: hazard ratio = 0.60, 95% confidence interval = 0.41 to 0.87) and greater objective response rate (odds ratio = 1.97 to 11.89), clinical benefit rate (odds ratio = 2.05 to 7.77), and duration of response with talazoparib in all subgroups. PROs in HR+/HER2- and TNBC subgroups showed consistent overall improvement and delay in time to definitive clinically meaningful deterioration with talazoparib vs PCT. Across subgroups, common adverse events included anemia, fatigue, and nausea with talazoparib and neutropenia, fatigue, and nausea with PCT. Seven patients (2.4%) receiving talazoparib had grade II alopecia and 22.7% had grade I alopecia. CONCLUSIONS: Across all patient subgroups with gBRCA-mutated advanced breast cancer, talazoparib demonstrated clinically significant superiority in outcomes compared with PCT.

Talazoparib in Patients with a Germline BRCA-Mutated Advanced Breast Cancer: Detailed Safety Analyses from the Phase III EMBRACA Trial.

BACKGROUND: In the EMBRACA phase III study (NCT01945775), talazoparib was associated with a significantly prolonged progression-free survival (PFS) compared with physician's choice of chemotherapy (PCT) in germline BRCA1/2-mutated HER2-negative advanced breast cancer (ABC). Herein, the safety profile of talazoparib is explored in detail. MATERIALS AND METHODS: Overall, 412 patients received ≥1 dose of talazoparib (n = 286) or PCT (n = 126). Adverse events (AEs) were evaluated, including timing, duration, and potential overlap of selected AEs. The relationship between talazoparib plasma exposure and grade ≥3 anemia was analyzed. Time-varying Cox proportional hazard models assessed the impact of dose reductions on PFS. Patient-reported outcomes (PROs) in patients with common AEs and health resource utilization (HRU) were assessed in both treatment arms. RESULTS: The most common AEs with talazoparib were hematologic (195 [68.2%] patients) and typically occurred within the first 3-4 months of receiving talazoparib. Grade 3-4 anemia lasted approximately 7 days for both arms. Overlapping grade 3-4 hematologic AEs were infrequent with talazoparib. Higher talazoparib exposure was associated with grade ≥3 anemia. Permanent discontinuation of talazoparib due to hematologic AEs was low (<2%). A total of 150 (52.4%) patients receiving talazoparib had AEs associated with dose reduction. Hematologic toxicities were managed by supportive care medication (including transfusion) and dose modifications. Among patients with anemia or nausea and/or vomiting AEs, PROs favored talazoparib. After accounting for the treatment-emergent period, talazoparib was generally associated with a lower rate of hospitalization and supportive care medication use compared with chemotherapy. CONCLUSION: Talazoparib was associated with superior efficacy, favorable PROs, and lower HRU rate versus chemotherapy in gBRCA-mutated ABC. Toxicities were manageable with talazoparib dose modification and supportive care. IMPLICATIONS FOR PRACTICE: Talazoparib was generally well tolerated in patients with germline BRCA-mutated HER2-negative advanced breast cancer in the EMBRACA trial. Common toxicities with talazoparib were primarily hematologic and infrequently resulted in permanent drug discontinuation (<2% of patients discontinued talazoparib due to hematologic toxicity). Hematologic toxicities typically occurred during the first 3-4 months of treatment and were managed by dose modifications and supportive care measures. A significant efficacy benefit, improved patient-reported outcomes, lower rate of health resource utilization and a tolerable safety profile support incorporating talazoparib into routine management of germline BRCA-mutated locally advanced/metastatic breast cancer.

Randomized phase-II evaluation of letrozole plus dasatinib in hormone receptor positive metastatic breast cancer patients.

The non-receptor tyrosine kinase Src activation plays a role in the malignant progression of breast cancer, including development of endocrine therapy resistance and survival of bone metastases. This study investigated whether adding Src kinase inhibitor dasatinib to aromatase inhibitor (AI) therapy improved outcomes in estrogen receptor (ER)-positive, HER2-negative metastatic breast cancer (MBC). Postmenopausal patients with ER-positive, HER2-negative MBC (0-1 prior chemotherapies and no prior AI for MBC) were eligible for this non-comparative, parallel group, phase-II study. Patients were randomized to letrozole (2.5 mg/day PO) alone or with dasatinib (100 mg/day PO). Patients with disease progression on letrozole alone could crossover to dasatinib plus continued letrozole. The primary endpoint was clinical-benefit-rate (CBR; complete response + partial response + stable disease ≥6 months). A total of 120 patients were randomized. The CBR of 71% (95% CI 58-83%) was observed with letrozole + dasatinib versus the projected CBR of the combination of 56%. The CBR of 66% (95% CI 52-77%) with letrozole alone also exceeded the projected CBR of 39% with letrozole alone. The CBR was 23% in the crossover arm of letrozole plus dasatinib in patients progressing on letrozole alone. Median progression-free survival with the combination was 20.1 months and 9.9 months with letrozole alone. Letrozole plus dasatinib was well tolerated, although 26% of patients required dasatinib dose reductions. In this non-comparative phase-II trial, the CBR of 71% and the median PFS of 20.1 months with letrozole + dasatinib are encouraging and suggest that dasatinib may inhibit the emergence of acquired resistance to AI therapy.

Perturbed myoepithelial cell differentiation in BRCA mutation carriers and in ductal carcinoma in situ.

Myoepithelial cells play key roles in normal mammary gland development and in limiting pre-invasive to invasive breast tumor progression, yet their differentiation and perturbation in ductal carcinoma in situ (DCIS) are poorly understood. Here, we investigated myoepithelial cells in normal breast tissues of BRCA1 and BRCA2 germline mutation carriers and in non-carrier controls, and in sporadic DCIS. We found that in the normal breast of non-carriers, myoepithelial cells frequently co-express the p63 and TCF7 transcription factors and that p63 and TCF7 show overlapping chromatin peaks associated with differentiated myoepithelium-specific genes. In contrast, in normal breast tissues of BRCA1 mutation carriers the frequency of p63+TCF7+ myoepithelial cells is significantly decreased and p63 and TCF7 chromatin peaks do not overlap. These myoepithelial perturbations in normal breast tissues of BRCA1 germline mutation carriers may play a role in their higher risk of breast cancer. The fraction of p63+TCF7+ myoepithelial cells is also significantly decreased in DCIS, which may be associated with invasive progression.

Barriers to the utilization of genetic testing and genetic counseling in patients with suspected hereditary breast and ovarian cancers.

A heritable condition is the identified cause of cancer in 5% to 10% of women with breast cancer and in 25% of women with ovarian cancer. It is critical to identify patients at risk for inherited genetic mutations to implement risk-reducing screening and interventions; however, reports in the medical literature indicate that an alarming number of patients with inherited genetic mutations do not receive recommended genetic counseling, testing, or interventions. In order to improve outcomes for these high-risk patients, barriers to genetic testing and counseling must be identified. We analyzed approximately 200 patients seen at our institution with breast or ovarian cancer who met criteria of the National Comprehensive Cancer Network for genetic counseling and testing. Of these patients, almost 70% had appropriate genetic testing and counseling. Review of the remaining 30% revealed that the largest obstacle to receiving genetic testing and/or counseling was lack of referral from the treating oncologist. Of the patients diagnosed with a pathogenic heritable mutation, most underwent appropriate risk-reducing procedures and surveillance. Thus, the initial referral to genetic counseling is the most significant barrier for at-risk patients at our institution and likely in this population at large. Additional study is needed to identify ways to improve appropriate use of genetic testing and counseling.

Talazoparib in Patients with Advanced Breast Cancer and a Germline BRCA Mutation.

BACKGROUND: The poly(adenosine diphosphate-ribose) inhibitor talazoparib has shown antitumor activity in patients with advanced breast cancer and germline mutations in BRCA1 and BRCA2 ( BRCA1/2). METHODS: We conducted a randomized, open-label, phase 3 trial in which patients with advanced breast cancer and a germline BRCA1/2 mutation were assigned, in a 2:1 ratio, to receive talazoparib (1 mg once daily) or standard single-agent therapy of the physician's choice (capecitabine, eribulin, gemcitabine, or vinorelbine in continuous 21-day cycles). The primary end point was progression-free survival, which was assessed by blinded independent central review. RESULTS: Of the 431 patients who underwent randomization, 287 were assigned to receive talazoparib and 144 were assigned to receive standard therapy. Median progression-free survival was significantly longer in the talazoparib group than in the standard-therapy group (8.6 months vs. 5.6 months; hazard ratio for disease progression or death, 0.54; 95% confidence interval [CI], 0.41 to 0.71; P<0.001). The interim median hazard ratio for death was 0.76 (95% CI, 0.55 to 1.06; P=0.11 [57% of projected events]). The objective response rate was higher in the talazoparib group than in the standard-therapy group (62.6% vs. 27.2%; odds ratio, 5.0; 95% CI, 2.9 to 8.8; P<0.001). Hematologic grade 3-4 adverse events (primarily anemia) occurred in 55% of the patients who received talazoparib and in 38% of the patients who received standard therapy; nonhematologic grade 3 adverse events occurred in 32% and 38% of the patients, respectively. Patient-reported outcomes favored talazoparib; significant overall improvements and significant delays in the time to clinically meaningful deterioration according to both the global health status-quality-of-life and breast symptoms scales were observed. CONCLUSIONS: Among patients with advanced breast cancer and a germline BRCA1/2 mutation, single-agent talazoparib provided a significant benefit over standard chemotherapy with respect to progression-free survival. Patient-reported outcomes were superior with talazoparib. (Funded by Medivation [Pfizer]; EMBRACA ClinicalTrials.gov number, NCT01945775 .).

Five-year results of a phase II trial of preoperative 5-fluorouracil, epirubicin, cyclophosphamide followed by docetaxel with capecitabine (wTX) (with trastuzumab in HER2-positive patients) for patients with stage II or III breast cancer.

We aimed to increase pathologic complete response (pCR) in patients with invasive breast cancer by adding preoperative capecitabine to docetaxel following 5-fluorouracil, epirubicin, cyclophosphamide (FEC) (with trastuzumab for patients with HER2-positive disease) and to evaluate 5-year disease-free survival (DFS) associated with this preoperative regimen. Chemotherapy included four cycles of FEC100 (5-fluorouracil 500 mg/m2 , epirubicin 100 mg/m2 , cyclophosphamide 500 mg/m2 IV on Day 1 every 21 days) followed by 4 21-day cycles of docetaxel (35 mg/m2  days 1 and 8) concurrently with capecitabine (825 mg/m2 orally twice daily for 14 days followed by 7 days off) (wTX). For HER2-positive patients, treatment was modified by decreasing epirubicin to 75 mg/m2 and adding trastuzumab (H) in standard doses (FEC75-H →wTX-H). The study objective was to achieve a pCR rate in the breast and axillary lymph nodes of 37% in patients with HER2-negative breast cancer and of 67% in patients with HER2-positive breast cancer treated with preoperative trastuzumab. A total of 186 patients were enrolled on study. In an intent-to-treat analysis, the pCR rate was 31% (37/118, 95% CI: 24-40%) in the HER2-negative patients, 24% (15/62, 95% CI: 14-37%) in ER-positive/HER2-negative patients, 39% (22/56, 95% CI: 27-53%) in the ER-negative/HER2-negative patients, and 46% (29/63, 95% CI: 34-48%) in the HER2-positive patients. The pCR rate in the 40 trastuzumab-treated patients was 53% (21/40, 95% CI: 38-67%). Grade 3 and 4 adverse events included neutropenia, leukopenia, diarrhea, and hand-foot skin reactions. One trastuzumab-treated patient developed grade 3 cardiotoxicity, and 4 others experienced grade 1-2 decrements in left ventricular function; all five patients' cardiac function returned to their baseline upon completion of trastuzumab. At 5 years, disease-free survival was 70% in the HER2-negative population (78% in ER-positive/HER2-negative and 62% in the ER-negative/HER2-negative patients) and 80% in the HER2-positive patients (87% in the trastuzumab-treated HER2-positive patients). At 5 years, overall survival was 80% in the HER2-negative population (88% in ER-positive/HER2-negative and 71% in the ER-negative/HER2-negative patients) and 86% in the HER2-positive patients (94.5% in the trastuzumab-treated HER2-positive patients). FEC100 (FEC75 with trastuzumab) followed by weekly docetaxel plus capecitabine, with or without trastuzumab is a safe, effective preoperative cytotoxic regimen. However, the addition of capecitabine to docetaxel following FEC, with or without trastuzumab, did not increase pCR rates nor 5-year DFS over the rates that have been reported with standard preoperative doxorubicin/cyclophosphamide (AC) followed by paclitaxel, with or without trastuzumab. Therefore, the use of capecitabine as part of preoperative chemotherapy is not recommended.

A randomized phase II trial of ridaforolimus, dalotuzumab, and exemestane compared with ridaforolimus and exemestane in patients with advanced breast cancer.

PURPOSE: To evaluate whether adding humanized monoclonal insulin growth factor-1 receptor (IGF-1R) antibody (dalotuzumab) to mammalian target of rapamycin (mTOR) inhibitor (ridaforolimus) plus aromatase inhibitor (exemestane) improves outcomes in patients with estrogen receptor (ER)-positive advanced/metastatic breast cancer. METHODS: This randomized, open-label, phase II trial enrolled 80 postmenopausal women with high-proliferation (Ki67 index staining ≥15%), ER-positive breast cancer that progressed after a non-steroidal aromatase inhibitor (NCT01605396). Randomly assigned patients were given oral ridaforolimus 10 mg QD 5 ×/week, intravenous dalotuzumab 10 mg/kg/week, and oral exemestane 25 mg/day (R/D/E, n = 40), or ridaforolimus 30 mg QD 5 ×/week and exemestane 25 mg/day (R/E; n = 40). Primary end point was progression-free survival (PFS). RESULTS: Median PFS was 23.3 weeks for R/D/E versus 31.9 weeks for R/E (hazard ratio 1.18; 80% CI 0.81-1.72; P = 0.565). Grade 3-5 adverse events were reported in 67.5% of patients in the R/E arm and 59.0% in the R/D/E arm. Stomatitis (95.0 vs. 76.9%; P = 0.021) and pneumonitis (22.5 vs. 5.1%; P = 0.027) occurred more frequently in the R/E than the R/D/E arm; hyperglycemia (27.5 vs. 28.2%) occurred at a similar rate. CONCLUSIONS: R/D/E did not improve PFS compared with R/E. Because the PFS reported for R/E was similar to that reported for everolimus plus exemestane in patients with advanced breast cancer, it is possible that lower-dose ridaforolimus in the R/D/E arm (from overlapping toxicities with IGF1R inhibitor) contributed to lack of improved PFS.

Higher antitumor activity of trabectedin in germline BRCA2 carriers with advanced breast cancer as compared to BRCA1 carriers: A subset analysis of a dedicated phase II trial.

Specific alkylators may allow synthetic lethality among patients with germline BRCA1/2-mutations related cancers. The tetrahydroisoquinolone trabectedin administered at 1.3 mg/m2 as a 3-h intravenous infusion every 3 weeks showed activity in patients with pretreated metastatic breast cancer (MBC) and BRCA germline mutations, but mainly in BRCA2 carriers. Data from a phase II study were retrospectively analyzed to compare the efficacy and safety of this trabectedin dose and schedule in pretreated MBC patients bearing germline BRCA1/2 mutations. The primary efficacy endpoint was the objective response rate (ORR) as per Response Evaluation Criteria In Solid Tumors (RECIST) by independent expert review. Duration of response (DR) and progression-free survival (PFS) were secondary efficacy endpoints. Safety was evaluated using the National Cancer Institute Common Toxicity Criteria (NCI-CTC). Data from 26 BRCA1-mutated and 13 BRCA2-mutated patients were analyzed. 69% of BRCA1-mutated cancers were triple-negative vs. 31% of BRCA2-mutated ones. 77% of BRCA1 and 31% of BRCA2 carriers were platinum-pretreated. The ORR in BRCA2-mutated patients was higher than in BRCA1-mutated patients (33.3% vs. 9.1%). DR ranged for 1.4-6.8 months in BRCA2-mutated patients and for 1.5-1.7 months in BRCA1-mutated patients. More BRCA2-mutated patients had disease stabilization for ≥4 months (25.0% vs. 9.1%) and their median PFS was longer (4.7 vs. 2.5 months). Trabectedin was well tolerated in both patient subtypes. In conclusion, trabectedin showed higher antitumor activity in relapsed MBC patients with germline BRCA2 mutations than in those with BRCA1 mutations.

Anthracyclines in Early Breast Cancer: The ABC Trials-USOR 06-090, NSABP B-46-I/USOR 07132, and NSABP B-49 (NRG Oncology).

Purpose Docetaxel and cyclophosphamide (TC) was superior to doxorubicin and cyclophosphamide (AC) in a trial in early breast cancer. However, activity of TC relative to AC regimens with a taxane (TaxAC) is unknown. Methods In a series of three adjuvant trials, women were randomly assigned to TC for six cycles (TC6) or to a standard TaxAC regimen. US Oncology Research (USOR) 06-090 compared TC6 with docetaxel, doxorubicin, and cyclophosphamide (TAC6). National Surgical Adjuvant Breast and Bowel Project (NSABP) B-46-I/USOR 07132 compared TC6, TAC6, or TC6 plus bevacizumab. NSABP B-49 compared TC6 with several standard AC and taxane combination regimens. Before any analysis of individual trials, a joint efficacy analysis of TC versus the TaxAC regimens was planned, with invasive disease-free survival (IDFS) as the primary end point. Patients who received TC6 plus bevacizumab on NSABP B-46-I/USOR 07132 were not included. A hazard ratio (HR) from a stratified Cox model that exceeded 1.18 for TC6 versus TaxAC was predefined as inferiority for TC6. The prespecified interim monitoring plan was to report for futility if the HR was > 1.18 when 334 IDFS events were observed (50% of 668 events required for definitive analysis). Results A total of 2,125 patients were randomly assigned to receive TC6 regimens and 2,117 patients were randomly assigned to receive TaxAC regimens. The median follow-up time was 3.3 years. There were 334 IDFS events, and the HR for TC6 versus TaxAC was 1.202 (95% CI, 0.97 to 1.49), which triggered early reporting for futility. The 4-year IDFS was 88.2% for TC6 and was 90.7% for TaxAC ( P = .04). Tests for treatment interaction by protocol, hormone receptor status, and nodal status were negative. Conclusion The TaxAC regimens improved IDFS in patients with high-risk human epidermal growth factor receptor 2-negative breast cancer compared with the TC6 regimen.

A phase II study of combined ridaforolimus and dalotuzumab compared with exemestane in patients with estrogen receptor-positive breast cancer.

PURPOSE: Combining the mTOR inhibitor ridaforolimus and the anti-IGFR antibody dalotuzumab demonstrated antitumor activity, including partial responses, in estrogen receptor (ER)-positive advanced breast cancer, especially in high proliferation tumors (Ki67 > 15%). METHODS: This randomized, multicenter, international, phase II study enrolled postmenopausal women with advanced ER-positive breast cancer previously treated with a nonsteroidal aromatase inhibitor (NCT01234857). Patients were randomized to either oral ridaforolimus 30 mg daily for 5 of 7 days (once daily [qd] × 5 days/week) plus intravenous dalotuzumab 10 mg/kg/week or oral exemestane 25 mg/day, and stratified by Ki67 status. Due to a high incidence of stomatitis in the ridaforolimus-dalotuzumab group, two sequential, nonrandomized, reduced-dose cohorts were explored with ridaforolimus 20 and 10 mg qd × 5 days/week. The primary endpoint was progression-free survival (PFS). RESULTS: Median PFS was 21.4 weeks for ridaforolimus 30 mg qd × 5 days/week plus dalotuzumab 10 mg/kg (n = 29) and 24.3 weeks for exemestane (n = 33; hazard ratio = 1.00; P = 0.5). Overall survival and objective response rates were similar between treatment arms. The incidence of drug-related, nonserious, and serious adverse events was higher with ridaforolimus/dalotuzumab (any ridaforolimus dose) than with exemestane. Lowering the ridaforolimus dose reduced the incidence of grade 3 stomatitis, but overall toxicity remained higher than acceptable at all doses without improved efficacy. CONCLUSIONS: The combination of ridaforolimus plus dalotuzumab was no more effective than exemestane in patients with advanced ER-positive breast cancer, and the incidence of adverse events was higher. Therefore, the combination is not being further pursued.

The incidence of cardiomyopathy in BRCA1 and BRCA2 mutation carriers after anthracycline-based adjuvant chemotherapy.

PURPOSE: Breast cancer remains the fourth-leading cause of death in the United States. Nearly 10% of breast cancers are hereditary, with deleterious mutations in BRCA1 and BRCA2 genes being the leading cause. Anthracycline chemotherapy, used commonly for breast cancer, carries cardiotoxicity risk. Recent studies demonstrated anthracycline-induced cardiac failure in homozygous BRCA2-deficient mice and increased rates of heart failure in homozygous BRCA1-deficient mice following ischemic insult. Therefore, we conducted a retrospective matched cohort study to determine the rates of anthracycline-induced cardiomyopathy in breast cancer patients with germline mutation in BRCA1 or BRCA2 genes compared to age-matched patients without a BRCA1 or BRCA2 gene mutation. METHODS: The primary endpoint was to determine the rate of cardiomyopathy defined as either congestive heart failure or asymptomatic decline in ejection fraction to <50%. A total of 102 breast cancer patients who were BRCA gene mutation carriers (55 BRCA1, 45 BRCA2, and two with both), who received anthracycline-based chemotherapy were compared to a matched cohort of breast cancer patients with wild-type BRCA gene status. RESULTS: We found a 4.9% rate of cardiomyopathy in the BRCA mutation carriers and 5.2% in the matched controls (p = 0.99). Cox proportional hazards model showed that only trastuzumab and hypertension were significantly associated with the development of cardiomyopathy in both groups (p < 0.05). CONCLUSIONS: Given the limitations of a retrospective study, we saw no increased risk of cardiotoxicity among breast cancer patients with BRCA1 and/or BRCA2 gene mutations treated with standard doses of anthracycline compared to the general population.