Racial Disparities in Neutrophil Counts Among Patients with Metastatic Breast Cancer during Treatment with CDK4/6 Inhibitors

Abstract Purpose: The three CDK4/6 inhibitors (CDK4/6i) approved for use in HR-positive/HER2-negative metastatic breast cancer (MBC), palbociclib, ribociclib, and abemaciclib, are generally well tolerated but their most common toxicity is neutropenia. Within the general population, neutropenia has been shown to be more common in individuals of African descent. The landmark CDK4/6i trials in MBC lacked racial diversity in their patient populations. We aimed to assess the toxicity profiles of CDK4/6i in a racially diverse population.Methods: We conducted a retrospective study at Montefiore Medical Center in patients with HR-positive/HER2-negative MBC prescribed CDK4/6i as first or subsequent lines of therapy between January 2015 and April 2020. Baseline characteristics and laboratory data at various treatment timepoints were collected. Results: A total of 182 patients were included in the final analysis. Baseline absolute neutrophil count (ANC) was lower in the Black vs. Non-Black cohort (p=0.001) but the change in ANC from baseline (Delta-ANC) was smaller in the Black vs. Non-Black cohort and the ANC at different treatment timepoints was similar between groups. There was no difference in the rate of infection or number of dose delays or reductions between Black and Non-Black cohorts. Conclusion: We analyzed toxicity profiles of 182 patients with HR-positive/HER2-negative MBC treated with CDK4/6i. Our population included 46% Black patients, who were found to have a lower baseline ANC but no increase in complications. Despite the lower baseline ANC seen in our Black cohort prior to starting CDK4/6i, treatment toxicities were similar between racial groups.

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Trastuzumab emtansine (T-DM1) in patients with HER2-positive metastatic breast cancer and brain metastases: exploratory final analysis of cohort 1 from KAMILLA, a single-arm phase IIIb clinical trial☆

Annals of Oncology ◽

10.1016/j.annonc.2020.06.020 ◽

2020 ◽

Vol 31 (10) ◽

pp. 1350-1358 ◽

Cited By ~ 9

Author(s):

F. Montemurro ◽

S. Delaloge ◽

C.H. Barrios ◽

R. Wuerstlein ◽

A. Anton ◽

...

Keyword(s):

Breast Cancer ◽

Clinical Trial ◽

Metastatic Breast Cancer ◽

Brain Metastases ◽

Metastatic Breast ◽

Final Analysis ◽

Trastuzumab Emtansine ◽

Her2 Positive ◽

Phase Iiib

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The combination of capecitabine and cyclophosphamide for metastatic breast cancer patients

Journal of Clinical Oncology ◽

10.1200/jco.2009.27.15_suppl.e12025 ◽

2009 ◽

Vol 27 (15_suppl) ◽

pp. e12025-e12025

Author(s):

M. Suzuki ◽

I. Kimijima ◽

M. Ishii

Keyword(s):

Breast Cancer ◽

Metastatic Breast Cancer ◽

Cancer Patients ◽

Medical Center ◽

Objective Response ◽

Metastatic Breast ◽

Complete Response ◽

Preclinical Study ◽

Synergistic Activity ◽

Breast Cancer Patients

e12025 Background: Capecitabine (X) is converted into 5-FU by thymidine phospholylase (TP). Cyclophosphamide (C) has been shown to make TP higher in the preclinical study. Therefore, the combination of capecitabine and cyclophosphamide (XC) is thought to have a synergistic activity. We explored the efficacy of XC for metastatic breast cancer patients. Methods: 50 metastatic breast cancer patients were treated with XC in our medical center between April 2004 and December 2008. Median patient age was 58 years old (range: 34–79 years old). 36 patients were postmenopausal. X was 1675mg/m2 days 1–21 and C was 67mg/m2 days 1–14 on a 28-day cycle in all-oral combination. This therapy was continued until progression of disease or unacceptable toxicities occurring. Results: Median time to treatment failure was 28 weeks (range: 2–158 weeks). 9 patients were not evaluable for tumor response. Among 41 evaluable patients, complete response (CR) was observed in 2.4% (1 patient) and partial response (PR) was 29.2% (12 patients). Stable disease (SD) was 41.4% (17 patients) and progression of the disease (PD) was 26.8% (11 patients). The objective response rate (CR+PR) was 31.7% and the overall clinical benefit (CR+PR+SDÅÜ24 weeks) was 53.6%. Significant toxicities were uncommon: grade 3 toxicities were encountered for neutropenia in 1 patient, anorexia in 1 patient and hand-foot syndrome in 2 patients. Conclusions: XC is an effective regimen in metastatic breast cancer, and this therapy is of an easy administration and very well tolerated. No significant financial relationships to disclose.

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Final analysis of phase II study of EZN-2208 (PEG-SN38) in metastatic breast cancer (MBC).

Journal of Clinical Oncology ◽

10.1200/jco.2012.30.15_suppl.1017 ◽

2012 ◽

Vol 30 (15_suppl) ◽

pp. 1017-1017 ◽

Cited By ~ 1

Author(s):

Cynthia R. C. Osborne ◽

Joyce O'Shaughnessy ◽

Frankie Ann Holmes ◽

Hyun Sue Kim ◽

Darren M. Kocs ◽

...

Keyword(s):

Breast Cancer ◽

Metastatic Breast Cancer ◽

Clinical Benefit ◽

Response Rate ◽

Objective Response ◽

Metastatic Breast ◽

Final Analysis ◽

Water Soluble ◽

Prolonged Release ◽

Previously Treated

1017 Background: EZN-2208 is a water-soluble PEGylated conjugate of SN38. EZN-2208 results in prolonged exposure of tumors to SN38 via preferential accumulation of EZN-2208 in the tumor and prolonged release of SN38. These data represent the final analysis of our study evaluating EZN-2208 in MBC. Methods: EZN-2208 9 mg/m2 (SN38 equivalents) was delivered as a 60-minute IV infusion, weekly for 3 wks in 4‑wk cycles. The primary objective was to determine the overall response rate (RR) in female patients with metastatic breast cancer (MBC) who had received prior adjuvant or metastatic therapy with either 1) anthracycline and taxane (AT) or 2) anthracycline, taxane, and capecitabine (ATX). Secondary objectives included evaluation of RR based on tumor receptor status, duration of response, progression-free survival (PFS), overall survival (OS), and safety. Results: Patients with MBC (n=164) were treated with a median (range) of 3.3 (0.3-22) cycles of EZN-2208. The objective response rate (RR) was 20% for AT and 9% for ATX. The clinical benefit rate (CBR=%CR + %PR + %SD ≥6 months) was 41% and 27% in patients in the AT and ATX cohorts, respectively. The RR and CBR among ER+ patients were 11% (10/91 pts) and 41.8% (38/91 pts). In patients who progressed during or within 30 days of prior platinum-containing regimens (Platinum Progressors), the CBR was 20% (8/40 pts). Among triple negative breast cancer (TNBC) patients, the RR and CBR were 22.5% (11/49 pts) and 36.7% (18/49 pts). For TNBC, Platinum Progressors, the CBR was 26.1% (6/23 pts). Overall, most common reported drug-related adverse events were diarrhea, nausea and neutropenia. Conclusions: EZN-2208 has notable activity in patients with previously treated MBC and appears to be an active agent for treatment of TNBC. Patients with TNBC, who had been previously treated with a platinum-based regimen, also derive clinical benefit from EZN-2208. The safety profile of EZN-2208 is acceptable with good tolerability in most patients. Further evaluation of EZN-2208 in MBC in general and TNBC in particular is warranted.

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