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Purpose: In the randomized phase II LOTUS trial, combining ipatasertib with first-line paclitaxel for triple-negative breast cancer (TNBC) improved progression-free survival (PFS), particularly in patients with PIK3CA/AKT1/PTEN-altered tumors. We aimed to validate these findings in a biomarker-selected TNBC population., Patients and Methods: In Cohort A of the randomized double-blind placebo-controlled phase III IPATunity130 trial, taxane-eligible patients with PIK3CA/AKT1/PTEN-altered measurable advanced TNBC and no prior chemotherapy for advanced disease were randomized 2:1 to ipatasertib (400 mg, days 1-21) or placebo, both plus paclitaxel (80 mg/m2, days 1, 8, and 15), every 28 days until disease progression or unacceptable toxicity. The primary endpoint was investigator-assessed PFS., Results: Between February 2018 and April 2020, 255 patients were randomized (168 to ipatasertib, 87 to placebo). At the primary analysis, there was no significant difference between treatment arms in PFS [hazard ratio 1.02, 95% confidence interval (CI), 0.71-1.45; median 7.4 months with ipatasertib vs. 6.1 months with placebo]. The final analysis showed no difference in overall survival between treatment arms (hazard ratio 1.08, 95% CI, 0.73-1.58; median 24.4 vs. 24.9 months, respectively). Ipatasertib was associated with more grade ≥3 diarrhea (9% vs. 2%) and adverse events leading to dose reduction (39% vs. 14%) but similar incidences of grade ≥3 adverse events (51% vs. 46%). Exploratory subgroup analyses by PAM50 and Burstein gene expression showed inconsistent results., Conclusions: Adding ipatasertib to paclitaxel did not improve efficacy in PIK3CA/AKT1/PTEN-altered advanced TNBC. Biomarkers for benefit from PI3K/AKT pathway inhibition in TNBC remain poorly understood., (©2024 The Authors; Published by the American Association for Cancer Research.)

Background: KEYNOTE-522 demonstrated statistically significant improvements in pathological complete response (pCR) with neoadjuvant pembrolizumab plus chemotherapy and event-free survival (EFS) with neoadjuvant pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab in patients with high-risk, early-stage triple-negative breast cancer (TNBC). Prior studies have shown the prognostic value of the residual cancer burden (RCB) index to quantify the extent of residual disease after neoadjuvant chemotherapy. In this preplanned exploratory analysis, we assessed RCB distribution and EFS within RCB categories by treatment group., Patients and Methods: A total of 1174 patients with stage T1c/N1-2 or T2-4/N0-2 TNBC were randomized 2 : 1 to pembrolizumab 200 mg or placebo every 3 weeks given with four cycles of paclitaxel + carboplatin, followed by four cycles of doxorubicin or epirubicin + cyclophosphamide. After surgery, patients received pembrolizumab or placebo for nine cycles or until recurrence or unacceptable toxicity. Primary endpoints are pCR and EFS. RCB is a prespecified exploratory endpoint. The association between EFS and RCB was assessed using a Cox regression model., Results: Pembrolizumab shifted patients into lower RCB categories across the entire spectrum compared with placebo. There were more patients in the pembrolizumab group with RCB-0 (pCR), and fewer patients in the pembrolizumab group with RCB-1, RCB-2, and RCB-3. The corresponding hazard ratios (95% confidence intervals) for EFS were 0.70 (0.38-1.31), 0.92 (0.39-2.20), 0.52 (0.32-0.82), and 1.24 (0.69-2.23). The most common first EFS events were distant recurrences, with fewer in the pembrolizumab group across all RCB categories. Among patients with RCB-0/1, more than half [21/38 (55.3%)] of all events were central nervous system recurrences, with 13/22 (59.1%) in the pembrolizumab group and 8/16 (50.0%) in the placebo group., Conclusions: Addition of pembrolizumab to chemotherapy resulted in fewer EFS events in the RCB-0, RCB-1, and RCB-2 categories, with the greatest benefit in RCB-2. These findings demonstrate that pembrolizumab not only increased pCR rates, but also improved EFS among most patients who do not have a pCR., Competing Interests: Disclosure All authors’ institutions received research funding from Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA, for the conduct of this study. YZ, WP, and KT are full-time employees of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA and hold stock and/or restricted stock units in Merck & Co., Inc., Rahway, NJ, USA., (Copyright © 2024 European Society for Medical Oncology. All rights reserved.)

Purpose: PI3K/AKT pathway alterations are frequent in hormone receptor-positive (HR+) breast cancers. IPATunity130 Cohort B investigated ipatasertib-paclitaxel in PI3K pathway-mutant HR+ unresectable locally advanced/metastatic breast cancer (aBC)., Methods: Cohort B of the randomized, double-blind, placebo-controlled, phase 3 IPATunity130 trial enrolled patients with HR+ HER2-negative PIK3CA/AKT1/PTEN-altered measurable aBC who were considered inappropriate for endocrine-based therapy (demonstrated insensitivity to endocrine therapy or visceral crisis) and were candidates for taxane monotherapy. Patients with prior chemotherapy for aBC or relapse < 1 year since (neo)adjuvant chemotherapy were ineligible. Patients were randomized 2:1 to ipatasertib (400 mg, days 1-21) or placebo, plus paclitaxel (80 mg/m 2 , days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity. The primary endpoint was investigator-assessed progression-free survival (PFS)., Results: Overall, 146 patients were randomized to ipatasertib-paclitaxel and 76 to placebo-paclitaxel. In both arms, median investigator-assessed PFS was 9.3 months (hazard ratio, 1.00, 95% CI 0.71-1.40) and the objective response rate was 47%. Median paclitaxel duration was 6.9 versus 8.8 months in the ipatasertib-paclitaxel versus placebo-paclitaxel arms, respectively; median ipatasertib/placebo duration was 8.0 versus 9.1 months, respectively. The most common grade ≥ 3 adverse events were diarrhea (12% with ipatasertib-paclitaxel vs 1% with placebo-paclitaxel), neutrophil count decreased (9% vs 7%), neutropenia (8% vs 9%), peripheral neuropathy (7% vs 3%), peripheral sensory neuropathy (3% vs 5%) and hypertension (1% vs 5%)., Conclusion: Adding ipatasertib to paclitaxel did not improve efficacy in PIK3CA/AKT1/PTEN-altered HR+ HER2-negative aBC. The ipatasertib-paclitaxel safety profile was consistent with each agent's known adverse effects. Trial registration NCT03337724., (© 2021. The Author(s).)

Importance: Elevated expression of AURKA adversely affects prognosis in estrogen receptor (ER)-positive and ERBB2 (formerly HER2)-negative and triple-negative breast cancer and is associated with resistance to taxanes., Objective: To compare paclitaxel alone vs paclitaxel plus alisertib in patients with ER-positive and ERBB2-negative or triple-negative metastatic breast cancer (MBC)., Design, Setting, and Participants: In this randomized clinical trial conducted with the US Oncology Network, participants were randomized to intravenous (IV) paclitaxel 90 mg/m2 on days 1, 8, and 15 on a 28-day cycle or IV paclitaxel 60 mg/m2 on days 1, 8, and 15 plus oral alisertib 40 mg twice daily on days 1 to 3, 8 to 10, and 15 to 17 on a 28-day cycle. Stratification was by prior neo or adjuvant taxane and by line of metastatic therapy. Eligible patients were those who had undergone endocrine therapy, 0 or 1 prior chemotherapy regimens for MBC, more than 12 months treatment-free interval from neo or adjuvant taxane therapy, and with measurable or evaluable lytic bone-disease. Data were analyzed from March 2019 through May 2019., Main Outcomes and Measures: The main outcome was progression-free survival (PFS) with secondary end points of overall survival (OS), overall response rate, clinical benefit rate, safety, and analysis of archival breast cancer tissues for molecular markers associated with benefit from alisertib., Results: A total of 174 patients were randomized, including with 86 randomized to paclitaxel and 88 patients randomized to paclitaxel plus alisertib, and 169 patients received study treatment. The final cohort included 139 patients with a median (interquartile range [IQR]) age of 62 (27-84) years with ER-positive and ERBB2-negative MBC, with 70 randomized to paclitaxel and 69 randomized to paclitaxel plus alisertib. The TNBC cohort closed with only 35 patients enrolled due to slow accrual and were not included in efficacy analyses. The median (IQR) follow-up was 22 (10.6-25.1) months, and median (IQR) PFS was 10.2 (3.8-15.7) months with paclitaxel plus alisertib vs 7.1 (3.8-10.6) months with paclitaxel alone (HR, 0.56; 95% CI, 0.37-0.84; P = .005). Median (IQR) OS was 26.3 (12.4-37.2) months for patients who received paclitaxel plus alisertib vs 25.1 (11.0-31.4) months for paclitaxel alone (HR, 0.89; 95% CI, 0.58-1.38; P = .61). Grade 3 or 4 adverse events occurred in 56 patients (84.8%) receiving paclitaxel plus alisertib vs 34 patients (48.6%) receiving paclitaxel alone. The main grade 3 or 4 adverse events with paclitaxel plus alisertib vs paclitaxel alone were neutropenia (50 patients [59.5%] vs 14 patients [16.4%]), anemia (8 patients [9.5%] vs 1 patient [1.2%]), diarrhea (9 patients [10.7%] vs 0 patients), and stomatitis or oral mucositis (13 patients [15.5%] vs 0 patients). One patient receiving paclitaxel plus alisertib died of sepsis., Conclusions and Relevance: This randomized clinical trial found that the addition of oral alisertib to a reduced dose of weekly paclitaxel significantly improved PFS compared with paclitaxel alone, and toxic effects with paclitaxel plus alisertib were manageable with alisertib dose reduction. These data support further evaluation of alisertib in patients with ER-positive, ERBB2-negative MBC., Trial Registration: ClinicalTrials.gov Identifier: NCT02187991.

Purpose: Vantictumab is a monoclonal antibody that binds to frizzled (FZD) receptors and inhibits canonical WNT signaling. This phase Ib dose escalation study enrolled patients with locally recurrent or metastatic HER2-negative breast cancer who were treated with weekly paclitaxel in combination with escalating doses of vantictumab., Methods: Patients were enrolled in dose escalation cohorts treated with weekly paclitaxel 90 mg/m 2 on days 1, 8 and 15 in combination with vantictumab 3.5-14 mg/kg days 1 and 15 or 3-8 mg/kg day 1 of every 28-day cycle. Primary endpoints were safety, dose-limiting toxicities (DLTs). Secondary endpoints included pharmacokinetics, efficacy and an exploratory biomarker analysis., Results: Forty-eight female patients with a mean age of 54 were enrolled. The majority (66.6%) received prior chemotherapy for recurrent or metastatic disease; 45.8% were hormone receptor (HR)-positive, HER2-negative and 54.2% triple-negative. The most frequent adverse events related to any study treatment were nausea (54.2%), alopecia (52.1%), fatigue (47.9%), and peripheral neuropathy (43.8%). No DLTs occurred; however, 6 patients experienced fractures outside of the DLT window. The overall response rate was 31.3% and the clinical benefit rate was 68.8%. A 6-gene WNT pathway signature showed significant association with progression-free survival (PFS) and overall survival (OS) for the biomarker high versus biomarker low groups (PFS: p = 0.029 and OS: p = 0.00045, respectively)., Conclusions: The combination of vantictumab and weekly paclitaxel was generally well tolerated with promising efficacy; however, the incidence of fractures limits future clinical development of this particular WNT inhibitor in metastatic breast cancer., Clinical Trial Registration: ClinicalTrials.gov registration: NCT01973309.

Background: Triple-negative breast cancer is an aggressive disease with unmet clinical needs. In a phase III study of patients with metastatic triple-negative breast cancer, first-line gemcitabine/carboplatin resulted in a median progression-free survival of 4.6 months. nab-paclitaxel-based regimens (with gemcitabine or carboplatin±bevacizumab) also demonstrated efficacy and safety in first-line phase II trials of human epidermal growth factor receptor 2-negative metastatic breast cancer., Trial Design: In this international, multicenter, open-label, randomized phase II/III trial, the efficacy and safety of first-line nab-paclitaxel with gemcitabine or with carboplatin will be compared with gemcitabine/carboplatin (control arm) for metastatic triple-negative breast cancer., Methods: In the phase II portion, 240 patients with measurable metastatic triple-negative breast cancer and treatment-naive for metastatic disease will be randomized 1:1:1 (stratified by disease-free interval: ≤1 versus>1 year) to nab-paclitaxel 125 mg/m2 plus gemcitabine 1000 mg/m2, nab-paclitaxel 125 mg/m2 plus carboplatin area under the curve 2 mg×min/mL, or gemcitabine 1000 mg/m2 plus carboplatin area under the curve 2 mg×min/mL, all given on days 1 and 8 of a 21-day cycle. Investigator-assessed progression-free survival (primary endpoint), overall response rate, overall survival, and safety will be assessed. A ranking algorithm of five efficacy and safety parameters will be used to pick the "winner" of the nab-paclitaxel regimens. In the phase III portion, 550 patients will be randomized 1:1 (stratified by disease-free interval: ≤1 versus >1 year, and prior adjuvant/neoadjuvant taxane use) to the nab-paclitaxel combination arm selected from the phase II portion or to the control arm. Patients in phase II will not be part of the phase III population. The phase III primary endpoint is blinded, independently-assessed progression-free survival; secondary endpoints include blinded, independently-assessed overall response rate, overall survival, disease control rate, duration of response, and safety. Biomarker and circulating tumor-cell exploratory analyses and quality-of-life assessments will also be performed. A list of approving ethical bodies was provided in Additional file 1., Discussion: The tnAcity trial aims to identify a new standard cytotoxic chemotherapy regimen for first-line treatment of metastatic triple-negative breast cancer., Trial Registration: ClinicalTrials.gov: NCT01881230 . Date of registration: 17 June 2013.

Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) has demonstrated clinical benefit in metastatic breast cancer (MBC) in a randomized phase III trial versus paclitaxel (CA012; N = 454) and in a randomized phase II trial versus docetaxel (CA024; N = 300). This retrospective analysis examines whether patients with poor prognostic factors demonstrate similar outcomes to the intent-to-treat (ITT) populations in these trials. This retrospective analysis evaluated the efficacy and safety of previously untreated patients with MBC with the following poor prognostic factors: visceral dominant metastases and short disease-free interval (DFI; ≤2 years). In CA012 (n = 186 first-line patients), nab-paclitaxel demonstrated a significantly higher overall response rate (ORR) versus paclitaxel in patients with visceral dominant metastases (42 vs. 23 %; P = 0.022), whereas the higher ORR for nab-paclitaxel in patients with a short DFI (43 vs. 33 %; P = NS) was not statistically significant. In CA024, a significantly higher ORR for nab-paclitaxel 150 mg/m(2) versus docetaxel was observed in patients with visceral dominant metastases (76 vs. 37 %; P < 0.001). No significant differences in ORR were observed in patients with a short DFI. Although progression-free survival (PFS) and overall survival showed trends similar to ORR, statistical significance was only achieved for comparisons of PFS in patients with visceral dominant metastases in CA024 (13.1 months for nab-paclitaxel 150 mg/m(2) vs. 7.8 months for docetaxel [P = 0.019] and 7.5 months for nab-paclitaxel 100 mg/m(2) [P = 0.010]). Safety results were similar to previous reports of the ITT populations. nab-Paclitaxel demonstrated similar efficacy in patients with poor prognostic factors as in the ITT populations of these two trials. In each trial, ORR was significantly higher for nab-paclitaxel versus the comparator taxane among patients with visceral dominant metastases.

Purpose: This manuscript presents health-related quality of life (HRQL) results from a phase III trial of gemcitabine-paclitaxel (GT) versus paclitaxel (T) in metastatic breast cancer patients., Methods: Patients completed the Rotterdam Symptom Checklist (RSCL) and Brief Pain Inventory (BPI) at baseline and at the end of each cycle. Sensitivity analyses for six longitudinal pattern mixture models (PMMs) assessed potential bias due to informative dropout. Cumulative probability plots with 50% confidence intervals indicated the proportion of patients whose HRQL was likely to improve, decline, or stay the same., Results: Sensitivity analyses addressing nonignorable missing RSCL data included 351 patients. The mean RSCL global HRQL score for GT was significantly and consistently better than that for T (all PMMs P < 0.040). The slope estimate of 1.5 points (100-point scale) per cycle from one PMM translated to a clinically significant 9-point improvement over six cycles with GT versus T. For GT, ~25% of patients were more likely than not to have improved HRQL, whereas that proportion for T was ~5%. PMMs showed no consistent treatment arm differences for BPI or other RSCL outcomes., Conclusions: Adding gemcitabine to paclitaxel for the treatment of metastatic breast cancer is more likely to improve global HRQL over time compared to monotherapy treatment.

Purpose: The objective of this phase III global study was to compare the efficacy of gemcitabine plus paclitaxel (GT) versus paclitaxel in patients with advanced breast cancer. It was designed as a pivotal study for the approval of G for a breast cancer treatment indication., Patients and Methods: Patients who relapsed after adjuvant anthracyclines were randomly assigned to gemcitabine,1,250 mg/m(2) days 1 and 8 plus paclitaxel, 175 mg/m(2) on day 1; or, to paclitaxel at same dose on day 1 (both arms administered every 21 days, unblinded). The primary end point was overall survival (OS) and secondary end points were time to progression (TTP), response rate (RR), progression-free survival, response duration, and toxicity. This final OS analysis was planned at 380 deaths., Results: A total of 266 patients were randomly assigned to GT and 263 to paclitaxel. Median survival on GT was 18.6 months versus 15.8 months on paclitaxel (log-rank P = . 0489), with an adjusted Cox hazard ratio of 0.78 (95% CI, 0.64 to 0.96; P = .0187). The TTP was longer (6.14 v 3.98 months; log-rank P = .0002) and the RR was better (41.4% v 26.2%; P = .0002) on GT. There was more grade 3 to 4 neutropenia on GT and grade 2 to 4 fatigue and neuropathy were slightly more prevalent on GT., Conclusion: This phase III study documents a role for gemcitabine in advanced breast cancer after anthracycline-based adjuvant therapy. The results establish GT as a reasonable choice for women who require cytoreduction with manageable toxicities and validate ongoing testing of GT in the adjuvant setting.

Purpose: ABI-007, the first biologically interactive albumin-bound paclitaxel in a nanameter particle, free of solvents, was compared with polyethylated castor oil-based standard paclitaxel in patients with metastatic breast cancer (MBC). This phase III study was performed to confirm preclinical studies demonstrating superior efficacy and reduced toxicity of ABI-007 compared with standard paclitaxel., Patients and Methods: Patients were randomly assigned to 3-week cycles of either ABI-007 260 mg/m(2) intravenously without premedication (n = 229) or standard paclitaxel 175 mg/m(2) intravenously with premedication (n = 225)., Results: ABI-007 demonstrated significantly higher response rates compared with standard paclitaxel (33% v 19%, respectively; P = .001) and significantly longer time to tumor progression (23.0 v 16.9 weeks, respectively; hazard ratio = 0.75; P = .006). The incidence of grade 4 neutropenia was significantly lower for ABI-007 compared with standard paclitaxel (9% v 22%, respectively; P < .001) despite a 49% higher paclitaxel dose. Febrile neutropenia was uncommon (< 2%), and the incidence did not differ between the two study arms. Grade 3 sensory neuropathy was more common in the ABI-007 arm than in the standard paclitaxel arm (10% v 2%, respectively; P < .001) but was easily managed and improved rapidly (median, 22 days). No hypersensitivity reactions occurred with ABI-007 despite the absence of premedication and shorter administration time., Conclusion: ABI-007 demonstrated greater efficacy and a favorable safety profile compared with standard paclitaxel in this patient population. The improved therapeutic index and elimination of corticosteroid premedication required for solvent-based taxanes make the novel albumin-bound paclitaxel ABI-007 an important advance in the treatment of MBC.

A recent phase III trial demonstrated that the combination of capecitabine (Xeloda) and docetaxel (Taxotere) significantly improved objective tumor response rate, time to disease progression, and overall survival compared with single-agent docetaxel in anthracycline-pretreated patients with advanced breast cancer. Early separation of survival curves suggests that combined treatment prevented early mortality seen with single-agent docetaxel and, thus, that the capecitabine/docetaxel combination may be more beneficial than sequential treatment in some patients in this setting. Dose reduction of the combination (eg, to capecitabine at 950 mg/m2) did not reduce effectiveness of treatment and was associated with reduced toxicity; study of the combination in the adjuvant setting has been initiated with a lower capecitabine starting dose. Poststudy treatment with capecitabine in patients in the docetaxel-alone group was associated with significantly improved survival compared with poststudy treatment with all other cytotoxic agents, suggesting that some patients may benefit from sequential therapy with docetaxel and capecitabine. No difference in reduction of riskfor death was seen according to whether combined treatment was given as first-, second-, or third-line therapy. The capecitabine/docetaxel combination appears to influence the natural history of metastatic breast cancer in a significant manner; it remains to be determined whether the benefits of the combination reflect additive or synergistic effects and whether greater benefit may be derived from sequential or combined treatment in overall populations or patient subgroups.

Purpose: Docetaxel and capecitabine, a tumor-activated oral fluoropyrimidine, show high single-agent efficacy in metastatic breast cancer (MBC) and synergy in preclinical studies. This international phase III trial compared efficacy and tolerability of capecitabine/docetaxel therapy with single-agent docetaxel in anthracycline-pretreated patients with MBC., Patients and Methods: Patients were randomized to 21-day cycles of oral capecitabine 1,250 mg/m(2) twice daily on days 1 to 14 plus docetaxel 75 mg/m(2) on day 1 (n = 255) or to docetaxel 100 mg/m(2) on day 1 (n = 256)., Results: Capecitabine/docetaxel resulted in significantly superior efficacy in time to disease progression (TTP) (hazard ratio, 0.652; 95% confidence interval [CI], 0.545 to 0.780; P =.0001; median, 6.1 v 4.2 months), overall survival (hazard ratio, 0.775; 95% CI, 0.634 to 0.947; P =.0126; median, 14.5 v 11.5 months), and objective tumor response rate (42% v 30%, P =.006) compared with docetaxel. Gastrointestinal side effects and hand-foot syndrome were more common with combination therapy, whereas myalgia, arthralgia, and neutropenic fever/sepsis were more common with single-agent docetaxel. More grade 3 adverse events occurred with combination therapy (71% v 49%, respectively), whereas grade 4 events were slightly more common with docetaxel (31% v 25% with combination)., Conclusion: The significantly superior TTP and survival achieved with the addition of capecitabine to docetaxel 75 mg/m(2), with the manageable toxicity profile, indicate that this combination provides clear benefits over single-agent docetaxel 100 mg/m(2). Docetaxel/capecitabine therapy is an important treatment option for women with anthracycline-pretreated MBC.

Background: Neutropenia is common in patients receiving myelotoxic chemotherapy. Pegfilgrastim, a sustained-duration filgrastim is a once-per-cycle therapy for prophylactic neutrophil support., Patients and Methods: Women, treated with four cycles of doxorubicin/docetaxel chemotherapy every 21 days, received pegfilgrastim or filgrastim 24 h after chemotherapy as a single subcutaneous injection per chemotherapy cycle (pegfilgrastim 30, 60 or 100 microg/kg) or daily subcutaneous injections (filgrastim 5 microg/kg/day). Safety, efficacy and pharmacokinetics were analyzed., Results: The incidence of grade 4 neutropenia in cycle 1 was 95, 90 and 74%, in patients who received pegfilgrastim 30, 60 and 100 microg/kg, respectively, and 76% in patients who received filgrastim. Mean duration of grade 4 neutropenia in cycle 1 was 2.7,2 and 1.3 days for doses of pegfilgrastim, and 1.6 days for filgrastim. The pharmacokinetics of pegfilgrastim were non-linear and dependent on both dose and neutrophil count. Pegfilgrastim serum concentration was sustained until the neutrophil nadir occurred then declined rapidly as neutrophils started to recover, consistent with a self-regulating neutrophil-mediated clearance mechanism. The safety profiles of pegfilgrastim and filgrastim were similar., Conclusions: A single subcutaneous injection of pegfilgrastim 100 microg/kg provided neutrophil support and a safety profile comparable to daily subcutaneous injections of filgrastim during multiple chemotherapy cycles.

Purpose: This multicenter, randomized, double-blind, active-control study was designed to determine whether a single subcutaneous injection of pegfilgrastim (SD/01, sustained-duration filgrastim; 100 microg/kg) is as safe and effective as daily filgrastim (5 microg/kg/d) for reducing neutropenia in patients who received four cycles of myelosuppressive chemotherapy., Patients and Methods: Sixty-two centers enrolled 310 patients who received chemotherapy with docetaxel 75 mg/m(2) and doxorubicin 60 mg/m(2) on day 1 of each cycle for a maximum of four cycles. Patients were randomized to receive on day 2 either a single subcutaneous injection of pegfilgrastim 100 microg/kg per chemotherapy cycle (154 patients) or daily subcutaneous injections of filgrastim 5 microg/kg/d (156 patients). Absolute neutrophil count (ANC), duration of grade 4 neutropenia, and safety parameters were monitored., Results: One dose of pegfilgrastim per chemotherapy cycle was comparable to daily subcutaneous injections of filgrastim with regard to all efficacy end points, including the duration of severe neutropenia and the depth of ANC nadir in all cycles. Febrile neutropenia across all cycles occurred less often in patients who received pegfilgrastim. The difference in the mean duration of severe neutropenia between the pegfilgrastim and filgrastim treatment groups was less than 1 day. Pegfilgrastim was safe and well tolerated, and it was similar to filgrastim. Adverse event profiles in the pegfilgrastim and filgrastim groups were similar., Conclusion: A single injection of pegfilgrastim 100 microg/kg per cycle was as safe and effective as daily injections of filgrastim 5 microg/kg/d in reducing neutropenia and its complications in patients who received four cycles of doxorubicin 60 mg/m(2) and docetaxel 75 mg/m(2).

As a result of increasing anthracycline use earlier in the course of breast cancer, oncologists are frequently faced with the challenge of treating patients whose disease has progressed during or following anthracycline therapy or who are ineligible for further anthracycline therapy. Many of these women remain candidates for cytotoxic chemotherapy, and several treatment options exist. Until recently, the taxanes, docetaxel in particular, were widely regarded as the most effective therapy for these patients, based on a survival advantage observed with docetaxel. However, a recent phase III study demonstrated that the addition of capecitabine to docetaxel results in superior overall survival (with a 3-month improvement in median survival), superior time to disease progression, and a superior response rate, with a manageable safety profile. Capecitabine/docetaxel is the first cytotoxic combination to improve survival over standard monotherapy in patients with anthracycline-pretreated metastatic breast cancer. Moreover, the survival benefit can be attributed to the addition of capecitabine, as it was achieved despite the lower dose of docetaxel administered in the combination arm. Quality of life was maintained with capecitabine/docetaxel combination therapy, which further supports the use of this regimen in patients with anthracycline-pretreated metastatic breast cancer. Pharmacoeconomic modeling using the data from the phase III trial has shown that the capecitabine/docetaxel combination therapy is highly cost effective when compared with other cancer treatments that improve survival. This review describes several treatment options for patients with anthracycline-pretreated breast cancer, including the phase III data (efficacy, tolerability, quality of life, and pharmacoeconomics) for capecitabine plus docetaxel in this setting.

The MDR1 multidrug resistance gene confers resistance to natural-product anticancer drugs including paclitaxel. We conducted a clinical gene therapy study to determine whether retroviral-mediated transfer of MDR1 in human hematopoietic cells would result in stable engraftment, and possibly expansion, of cells containing this gene after treatment with myelosuppressive doses of paclitaxel. Patients with metastatic breast cancer who achieved a complete or partial remission after standard chemotherapy were eligible for the study. Hematopoietic stem cells (HSCs) were collected by both peripheral blood apheresis and bone marrow harvest after mobilization with a single dose of cyclophosphamide (4 g/m2) and daily filgrastim therapy (10 microg/kg/day). After enrichment for CD34+ cells, one-third of each collection was incubated ex vivo for 72 h with a replication-incompetent retrovirus containing the MDR1 gene (G1MD) in the presence of stem-cell factor, interleukin 3, and interleukin 6. The remaining CD34+ cells were stored without further manipulation. All of the CD34+ cells were reinfused for hematopoietic rescue after conditioning chemotherapy with ifosfamide, carboplatin, and etoposide regimen. After hematopoietic recovery, patients received six cycles of paclitaxel (175 mg/m2 every 3 weeks). Bone marrow and serial peripheral blood samples were obtained and tested for the presence of the MDR1 transgene using a PCR assay. Six patients were enrolled in the study and four patients received infusion of genetically altered cells. The ex vivo transduction efficiency, estimated by the PCR assay, ranged from 0.1 to 0.5%. Three of the four patients demonstrated engraftment of cells containing the MDR1 transgene. The estimated percentage of granulocytes containing the MDR1 transgene ranged from a maximum of 9% of circulating nucleated cells down to the limit of detection of 0.01%. One patient remained positive for the MDR1 transgene throughout all six cycles of paclitaxel therapy, whereas the other 2 patients showed a decrease in the number of cells containing the transgene to undetectable levels. Despite the low level of engraftment of MDR1-marked cells, a correlation was observed between the relative number of granulocytes containing the MDR1 transgene and the granulocyte nadir after paclitaxel therapy. No adverse reactions to the genetic manipulation procedures were detected. Therefore, engraftment of human HSCs transduced with the MDR1 gene can be achieved. However, the overall transduction efficiency and stable engraftment of gene-modified HSCs must be improved before MDR1 gene therapy and in vivo selection with anticancer drugs can be reliably used to protect cancer patients from drug-related myelosuppression.

Purpose: We conducted a phase I crossover study of escalating doses of both paclitaxel (Taxol; Bristol-Myers, Squibb, Princeton, NJ) and r-verapamil, the less cardiotoxic stereoisomer, in heavily pretreated patients with metastatic breast cancer., Patients and Methods: Twenty-nine patients refractory to paclitaxel by 3-hour infusion were treated orally with r-verapamil every 4 hours starting 24 hours before the same-dose 3-hour paclitaxel infusion and continuing for a total of 12 doses. Once the maximum-tolerated dose (MTD) of the combination was determined, seven additional patients who had not been treated with either drug were evaluated to determine whether the addition of r-verapamil altered the pharmacokinetics of paclitaxel. Consenting patients had tumor biopsies for P-glycoprotein (Pgp) expression before receiving paclitaxel and after becoming refractory to paclitaxel therapy., Results: The MTD of the combination was 225 mg/m2 of r-verapamil every 4 hours with paclitaxel 200 mg/m2 by 3-hour infusion. Dose-limiting hypotension and bradycardia were observed in three of five patients treated at 250 mg/m2 r-verapamil. Fourteen patients received 32 cycles of r-verapamil at the MTD as outpatient therapy without developing cardiac toxicity. The median peak and trough serum verapamil concentrations at the MTD were 5.1 micromol/L (range, 1.9 to 6.3), respectively, which are within the range necessary for in vitro modulation of Pgp-mediated multidrug resistance (MDR). Increased serum verapamil concentrations and cardiac toxicity were observed more frequently in patients with elevated hepatic transaminases and bilirubin levels. Hematologic toxicity from combined paclitaxel and r-verapamil was significantly worse compared with the previous cycle of paclitxel without r-verapamil. In the pharmacokinetic analysis, r-verapamil delayed mean paclitaxel clearance and increased mean peak paclitaxel concentrations., Conclusion: r-Verapamil at 225 mg/m2 orally every 4 hours can be given safely with paclitaxel 200 mg/m2 by 3-hour infusion as outpatient therapy and is associated with serum levels considered active for Pgp inhibition. The addition of r-verapamil significantly alters the toxicity and pharmacokinetics of paclitaxel.

Purpose: In vitro data suggest that prolonged exposure to paclitaxel enhances breast cancer cytotoxicity. Our objective in this phase I study was to determine the tolerability of paclitaxel administered by 72-hour continuous intravenous (i.v.) infusion (CIVI) in combination with high-dose cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) in the ambulatory setting to metastatic breast cancer patients., Patients and Methods: Paclitaxel was administered over 72 hours by CIVI and cyclophosphamide was given daily by i.v. bolus on days 1, 2, and 3, followed by G-CSF every 21 days. The availability of ambulatory infusion pumps and paclitaxel-compatible tubing permitted outpatient administration., Results: Fifty-five patients with metastatic breast cancer who had been previously treated with a median of two prior chemotherapy regimens were entered onto the study. Dose-limiting toxicity of grade 4 neutropenia for longer than 5 days and grade 4 thrombocytopenia occurred in three of five patients treated with paclitaxel 160 mg/m2 CIVI and cyclophosphamide 3,300 mg/m2 followed by G-CSF. The maximum-tolerated dose (MTD) was paclitaxel 160 mg/m2 CIVI and cyclophosphamide 2,700 mg/m2 in divided doses with G-CSF. Nonhematologic toxicities were moderate and included diarrhea, mucositis, and arthalgias. Although hemorrhagic cystitis developed in six patients, recurrence was prevented with i.v. and oral mesna, which permitted continued outpatient delivery. One hundred seventy-four cycles were safely administered in the ambulatory setting using infusional pumps and tubing. Objective responses occurred in 23 (one complete and 22 partial) of 42 patients with bidimensionally measurable disease (55%; 95% confidence interval, 38% to 70%), with a response rate of 73% (11 of 15) seen at the highest dose levels., Conclusion: Paclitaxel by 72-hour CIVI with daily cyclophosphamide followed by G-CSF can be administered safely in the ambulatory setting, has acceptable toxicity, and is an active regimen in the treatment of metastatic breast cancer.

Purpose: To study the effect of the multidrug-resistance reversal agent R-verapamil on the pharmacokinetic behavior of paclitaxel., Methods: Six women with breast cancer who received paclitaxel as a 3-hour infusion with and without R-verapamil were monitored with frequent plasma sampling up to 24 hours postinfusion. Paclitaxel concentrations were measured using a reverse-phase high-pressure liquid chromatography assay., Results: Concomitant administration of R-verapamil resulted in a decrease in mean (+/- SD) paclitaxel clearance from 179 +/- 67 mL/min/m2 to 90 +/- 34 mL/min/m2 (P < .03) and in a twofold increase in paclitaxel exposure (area under the curve [AUC]). The mean end-infusion paclitaxel concentration was also twofold higher: 5.1 +/- 1.8 mumol/L versus 11.3 +/- 4.1 mumol/L (P < .03)., Conclusion: The alteration in paclitaxel pharmacokinetics when paclitaxel and R-verapamil are coadministered complicates the interpretation of response and toxicity data from clinical trials of this drug combination.

Paclitaxel is a highly active single agent as therapy for previously untreated as well as doxorubicin-refractory metastatic breast cancer, with associated response rates of 62% and 20-48%, respectively. Complete responses with paclitaxel occur chiefly in breast cancer patients whose metastatic disease has not been previously treated with chemotherapy. Early data suggest a possible dose-response relationship for paclitaxel in metastatic breast cancer, but the optimal dose has not yet been defined. The optimal duration of infusional paclitaxel treatment is also not yet known. A study of 96-hour infusional paclitaxel in the treatment of doxorubicin- or mitoxantrone-refractory metastatic breast cancer patients has demonstrated a 48% response rate suggesting that prolonged exposures to paclitaxel may offer a therapeutic advantage. Randomized trials of 3- vs 96-hour paclitaxel are ongoing or planned. The relative efficacy of paclitaxel versus standard chemotherapy as front-line or salvage therapy for metastatic breast cancer is currently under study. In addition, two randomized trials are under way in node positive breast cancer patients to study whether treatment with paclitaxel following standard or high dose doxorubicin and cyclophosphamide adjuvant therapy results in improved patient benefit. Combining paclitaxel with other active agents in the treatment of metastatic breast cancer is an area of active investigation. Combined paclitaxel and doxorubicin, administered concurrently or sequentially, is associated with modest complete response rates in metastatic breast cancer patients. Sequential paclitaxel-->doxorubicin administration is associated with more mucositis than is doxorubicin-->paclitaxel when paclitaxel is administered over 24 hours. High doses of cyclophosphamide can be combined with 24- or 72-hour infusional paclitaxel, and phase II studies of this combination are warranted. Early data suggest that administering biweekly paclitaxel and cisplatin to previously untreated metastatic breast cancer patients is associated with high response rates, and confirmatory studies of this combination and schedule are planned. Preclinical data suggest that cell cycle considerations may be important in combining doxorubicin and possibly other agents with paclitaxel. Paclitaxel is an excellent substrate for P-glycoprotein, the protein product of the multidrug resistance-1 (mdr-1) gene, and phase I trials are under way combining paclitaxel with several known blockers of Pgp function. Finally, pilot studies are under way to determine whether the radiation sensitizing effects of paclitaxel can be exploited as part of radiation therapy for patients with locally advanced breast cancer.

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) is a very active agent for the treatment of breast cancer, with associated complete response rates of 12% in patients with minimally pretreated metastatic disease. Simultaneous paclitaxel and doxorubicin administration by 72-hour continuous infusion in patients with previously untreated metastatic breast cancer has yielded an overall response rate of 72% with 8% complete responses. No alterations in paclitaxel or doxorubicin pharmacokinetics were observed when the drugs were administered alone versus in combination. Two phase I studies from the M.D. Anderson Cancer Center (Houston, TX) and the University of Indiana (Indianapolis, IN) have shown that administration of a 24-hour paclitaxel infusion prior to doxorubicin results in a significantly higher incidence of mucositis than the reverse sequence. Preliminary pharmacokinetic studies from M.D. Anderson suggest that peak plasma concentration and clearance of doxorubicin are altered by pretreatment with 24-hour paclitaxel. In contrast, in an ongoing phase I study at the Istituto Nazionale Tumori in Milan, Italy, no differences in toxicities have been observed with the combination of intravenous bolus doxorubicin and 3-hour infusional paclitaxel administered by either sequence. Preclinical in vitro and in vivo studies suggest that the combination of paclitaxel and doxorubicin is associated with no or minimal additive antitumor effects. The modest complete response rates that have been observed in patients with metastatic breast cancer to date are in agreement with these observations. A randomized study of paclitaxel versus doxorubicin versus intravenous bolus doxorubicin followed by 24-hour paclitaxel is now being conducted by the Eastern Cooperative Oncology Group.

Purpose: A phase I study of paclitaxel infused over 96-hours was performed to determine toxicity, maximum-tolerated dose (MTD), and pharmacokinetics in patients with incurable lymphomas and solid tumors. A phase II study was performed at the MTD of paclitaxel in patients with doxorubicin/mitoxantrone-refractory metastatic breast cancer., Patients and Methods: In the phase I study, paclitaxel dose levels ranged from 120 to 160 mg/m2, administered on a 21-day cycle. Patients with metastatic breast cancer who had either no response or a partial response (PR) to doxorubicin or mitoxantrone and had measurable disease were eligible for the phase I and II studies. Expression of the multidrug resistance (mdr-1) gene was determined in tumor biopsies by mRNA quantitative polymerase chain reaction., Results: Twelve patients received a total of 73 cycles of paclitaxel on the phase I study. Dose-limiting mucositis and/or grade IV granulocytopenia was reached at 160 mg/m2, and 140 mg/m2 was selected as the phase II dose. Thirty-six consecutive patients with metastatic breast cancer were treated, of whom three were not assessable. The median age was 49 years, with disease in the liver and/or lung in 76%. Patients received a median of two prior regimens for metastatic disease, and 73% had no response to prior doxorubicin or mitoxantrone. Of 33 patients treated with paclitaxel, 16 patients (48%) achieved a PR and five (15%) achieved a minor response (MR). With a median potential follow-up duration of 60 weeks, the median progression-free and overall survival durations were 27 and 43 weeks, respectively. No correlation was found between extent of prior treatment or prior response to doxorubicin/mitoxantrone, and response to paclitaxel. Paclitaxel pharmacokinetics showed a correlation between both granulocyte and mucosal toxicity, and serum steady-state concentrations (Css) more than 0.07 mumol/L. Patients with liver metastases had significantly decreased paclitaxel clearance and higher paclitaxel Css. Levels of mdr-1 were uniformly low in all tumor biopsies studied., Conclusion: The recommended phase II dose of paclitaxel is 140 mg/m2 in patients without liver metastases and 105 mg/m2 in patients with liver metastases. Ninety-six-hour infusions of paclitaxel were effective and well tolerated in patients with doxorubicin/mitoxantrone-refractory breast cancer. Prolonged infusion schedules may be more effective than shorter schedules and deserve further study.

Background: Typhlitis is being recognized with increasing frequency as a serious complication of aggressive chemotherapy for hematologic and solid malignancies., Methods: In this report the authors describe two cases of typhlitis in patients with metastatic breast cancer treated with taxol and doxorubicin., Results: Both cases occurred during the first cycle of treatment with taxol (180 mg/m2) and doxorubicin (75 mg/m2), being given simultaneously as 72-hour continuous intravenous infusions., Conclusion: Two cases of typhlitis have occurred after combined treatment with taxol and doxorubicin, while typhlitis has not been described after treatment with either drug alone.

The objective of this phase I trial was to determine the maximal tolerated dose (MTD) of Taxol and doxorubicin administered as a simultaneous intravenous infusion over 72 hours every 21 days. Granulocyte-colony stimulating factor (G-CSF) 10 micrograms/kg, was administered on days 4-18 of each cycle. The treated population consisted of metastatic breast cancer patients previously untreated with chemotherapy for metastatic disease, who had not received doxorubicin in the adjuvant setting and who had bidimensionally measurable disease. The MTD was determined to be 75 mg/m2 of doxorubicin and 160 mg/m2 of Taxol. The dose-limiting toxicity of the combination was clinical typhlitis in three of three patients. Other significant toxicities included grade 3 diarrhea at the higher dose levels and grade 4 neutropenia in all patients. Eighteen patients were treated on this initial phase I study. The overall response rate was 62%, with 6% complete responses and 56% partial responses. The combination of doxorubicin and Taxol by 72-hour continuous infusion with G-CSF is an active regimen in patients with metastatic breast cancer.

Results from two phase II studies in metastatic breast cancer have shown that the novel, tumour-selective fluoropyrimidine capecitabine provides an effective and well tolerated therapy in patients with metastatic breast cancer failing or resistant to anthracycline and taxane therapy. Response rates of between 20 and 25% have been observed, with median survival of 12.2–12.6 months. In addition, there was an acceptable incidence of adverse events including diarrhoea and hand–foot syndrome, which can be controlled with a dose reduction. Promising results from two further randomised, phase II studies have indicated that capecitabine may also play a role in first- and second-line treatment of metastatic breast cancer. Capecitabine compared favourably with paclitaxel in anthracycline-resistant patients and with intravenous (i.v.) CMF (cyclophosphamide/methotrexate/5-fluorouracil (5-FU)) in post-menopausal women who had received no prior chemotherapy for metastatic disease, with high efficacy and good tolerability. The results of these four phase II studies demonstrate that capecitabine is active and well tolerated in a range of settings for metastatic breast cancer. [Copyright &y& Elsevier]

In the phase III IMpassion130 trial, combining atezolizumab with first-line nanoparticle albumin-bound-paclitaxel for advanced triple-negative breast cancer (aTNBC) showed a statistically significant progression-free survival (PFS) benefit in the intention-to-treat (ITT) and programmed death-ligand 1 (PD-L1)-positive populations, and a clinically meaningful overall survival (OS) effect in PD-L1-positive aTNBC. The phase III KEYNOTE-355 trial adding pembrolizumab to chemotherapy for aTNBC showed similar PFS effects. IMpassion131 evaluated first-line atezolizumab–paclitaxel in aTNBC. Eligible patients [no prior systemic therapy or ≥12 months since (neo)adjuvant chemotherapy] were randomised 2:1 to atezolizumab 840 mg or placebo (days 1, 15), both with paclitaxel 90 mg/m2 (days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity. Stratification factors were tumour PD-L1 status, prior taxane, liver metastases and geographical region. The primary endpoint was investigator-assessed PFS, tested hierarchically first in the PD-L1-positive [immune cell expression ≥1%, VENTANA PD-L1 (SP142) assay] population, and then in the ITT population. OS was a secondary endpoint. Of 651 randomised patients, 45% had PD-L1-positive aTNBC. At the primary PFS analysis, adding atezolizumab to paclitaxel did not improve investigator-assessed PFS in the PD-L1-positive population [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.60-1.12; P = 0.20; median PFS 6.0 months with atezolizumab–paclitaxel versus 5.7 months with placebo–paclitaxel]. In the PD-L1-positive population, atezolizumab–paclitaxel was associated with more favourable unconfirmed best overall response rate (63% versus 55% with placebo–paclitaxel) and median duration of response (7.2 versus 5.5 months, respectively). Final OS results showed no difference between arms (HR 1.11, 95% CI 0.76-1.64; median 22.1 months with atezolizumab–paclitaxel versus 28.3 months with placebo–paclitaxel in the PD-L1-positive population). Results in the ITT population were consistent with the PD-L1-positive population. The safety profile was consistent with known effects of each study drug. Combining atezolizumab with paclitaxel did not improve PFS or OS versus paclitaxel alone. NCT03125902. • The phase III IMpassion131 trial evaluated atezolizumab combined with paclitaxel as first-line therapy for aTNBC. • The primary endpoint was investigator-assessed PFS, tested hierarchically in the PD-L1+ and then ITT populations. • Neither PFS nor OS was improved with the combination of atezolizumab plus paclitaxel in either population. • These findings may result from imbalances in prognostic features or chance findings in a relatively small trial. • IMpassion131 results highlight the need for further research into immunotherapy for TNBC. [ABSTRACT FROM AUTHOR]

Background: Phosphatidylinositol 3-kinase (PI3K) pathway activation in preclinical models of breast cancer is associated with tumor growth and resistance to anticancer therapies, including paclitaxel. Effects of the pan-Class I PI3K inhibitor buparlisib (BKM120) appear synergistic with paclitaxel in preclinical and clinical models. Patients and methods: BELLE-4 was a 1:1 randomized, double-blind, placebo-controlled, adaptive phase II/III study investigating the combination of buparlisib or placebo with paclitaxel in women with human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer with no prior chemotherapy for advanced disease. Patients were stratified by PI3K pathway activation and hormone receptor status. The primary endpoint was progression-free survival (PFS) in the full and PI3K pathway-activated populations. An adaptive interim analysis was planned following the phase II part of the study, after ≥125 PFS events had occurred in the full population, to decide whether the study would enter phase III (in the full or PI3K pathway-activated population) or be stopped for futility. Results: As of August 2014, 416 patients were randomized to receive buparlisib (207) or placebo (209) with paclitaxel. At adaptive interim analysis, there was no improvement in PFS with buparlisib versus placebo in the full (median PFS 8.0 versus 9.2 months, hazard ratio [HR] 1.18), or PI3K pathway-activated population (median PFS 9.1 versus 9.2 months, HR 1.17). The study met protocol-specified criteria for futility in both populations, and phase III was not initiated. Median duration of study treatment exposure was 3.5 months in the buparlisib arm versus 4.6 months in the placebo arm. The most frequent adverse events with buparlisib plus paclitaxel (≥40% of patients) were diarrhea, alopecia, rash, nausea, and hyperglycemia. Conclusions: Addition of buparlisib to paclitaxel did not improve PFS in the full or PI3K pathway-activated study population. Consequently, the trial was stopped for futility at the end of phase II. [ABSTRACT FROM AUTHOR]