Dose-Reduced Docetaxel With Cyclophosphamide for the Treatment of Vulnerable Older Women With Stage I-III HER2 Negative Breast Cancer, the DOROTHY Trial

Overview

This phase II trial tests how well dose-reduced docetaxel combined with cyclophosphamide works in treating older women with early stage (stage I-III) HER2 negative breast cancer vulnerable to toxicity. Chemotherapy drugs, such as docetaxel and cyclophosphamide, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Docetaxel and cyclophosphamide are commonly used, but is not well tolerated at the standard dose and can affect the way older patients feel physically and emotionally. Giving dose-reduced docetaxel combined with cyclophosphamide may be an effective treatment option and improve quality of life in vulnerable older women with stage I-III HER2 negative breast cancer.

Full Title of Study: “Dose Reduction of Docetaxel-Based Chemotherapy in Vulnerable Older Women With Early-Stage Breast Cancer (DOROTHY)”

Study Type

• Study Type: Interventional
• Study Design
  • Allocation: Randomized
  • Intervention Model: Parallel Assignment
  • Primary Purpose: Treatment
  • Masking: Single (Investigator)
• Study Primary Completion Date: August 6, 2026

Detailed Description

PRIMARY OBJECTIVE: I. Compare the relative dose intensity (RDI) of reduced- versus (vs.) standard-dose docetaxel dosing strategies. SECONDARY OBJECTIVE: I. Compare treatment tolerability of reduced- vs. standard-dose docetaxel dosing strategies. OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: Patients receive dose-reduced docetaxel intravenously (IV) over 60 minutes and cyclophosphamide IV over 30 minutes on day 1 of each cycle. Treatment repeats every 21 days for 4 cycles in the absence of disease progression or unacceptable toxicity. ARM II: Patients receive standard dose docetaxel IV over 60 minutes and cyclophosphamide IV over 30 minutes on day 1 of each cycle. Treatment repeats every 21 days for 4 cycles in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days then at least twice yearly for 2 years.

Interventions

• Drug: Cyclophosphamide
  • Given IV
• Drug: Docetaxel
  • Given IV
• Other: Medical Chart Review
  • Ancillary studies
• Other: Questionnaire Administration
  • Ancillary studies

Arms, Groups and Cohorts

• Experimental: Arm I: (Dose-reduced docetaxel, cyclophosphamide)
  • Patients receive dose-reduced docetaxel IV over 60 minutes and cyclophosphamide IV over 30 minutes on day 1 of each cycle. Treatment repeats every 21 days for 4 cycles in the absence of disease progression or unacceptable toxicity.
• Active Comparator: Arm II: (Standard dose docetaxel, cyclophosphamide)
  • Patients receive standard dose docetaxel IV over 60 minutes and cyclophosphamide IV over 30 minutes on day 1 of each cycle. Treatment repeats every 21 days for 4 cycles in the absence of disease progression or unacceptable toxicity.

Clinical Trial Outcome Measures

Primary Measures

• Relative dose intensity (RDI)
  • Time Frame: At completion of 4 cycles, up to 12 weeks (each cycle is every three weeks)
  • RDI is defined as the ratio of actual dose intensity received to the standard dose intensity, ranging from 0 to 100%. The RDI between the two arms will be compared using T-test, RDI difference and 90% confidence interval. A one-sided p-value < 0.05 will be considered statistically significant.

Secondary Measures

• Treatment success
  • Time Frame: At completion of 4 cycles, up to 12 weeks (Each cycle is three weeks)
  • Treatment success is defined as the proportion of patients who receive all 4 planned cycles of chemotherapy without unacceptable toxicity (grade 3-4), hospitalization/death at the end of treatment, and without decline in physical function status. Proportion of treatment success between the 2 arms will be compared using Chi-square test. A one-sided p-value of < 0.05 will be considered statistically significant.
• Patient-reported symptomatic toxicities
  • Time Frame: At each chemotherapy cycle for 4 cycles, end of treatment and at 3, 6, 12 and 24 months after treatment ends)(Each cycle is three weeks).
  • Toxicities will be described using the National Cancer Institute (NCI) Patient Reported Outcomes Common Terminology Criteria for Adverse Events (PRO-CTCAE). Patient reported outcomes will evaluate how well symptoms reported correlate/agree with clinician reported adverse events.
• Differences in PRO-CTCAE and clinician-reported toxicities
  • Time Frame: At each chemotherapy cycle for 4 cycles and at 3, 6, 12, and 24 months after treatment ends (Each cycle is three weeks).
  • Treatment related toxicities grade 3 or higher experienced by patients between the 2 arms will be described using NCI-CTCAE version (v) 5.0. Chi-square or Fisher exact test will be used to explore the difference in terms of rate of PRO-CTCAE and clinician reported CTCAE between the 2 arms at the end of chemotherapy. Agreement proportions between PRO-CTCAE and clinician reported CTCAE will be explored and calculated for the 2 arms combined.
• Patient satisfaction
  • Time Frame: Up to 3 months after treatment ends
  • Patient-reported satisfaction will be measured using the Was It Worth It questionnaire. Data will be scored and summarized according to their scoring manual. Chi-square or Fisher exact test will be used to compare the proportion of patients who consider it worthwhile to undergo treatment, the proportion of patients who would undergo the treatment again, and the proportionof patients who would recommend the treatment to others between the 2 arms.
• Changes in function and health status
  • Time Frame: At baseline and at 3, 6, 12 and 24 months after treatment ends
  • Elements of the Geriatric Assessment (GA) will be used to calculate the deficit accumulation index for each patient on each study arm over time. Trajectories of change in function will be examined. Data will be scored and summarized according to the GA scoring manual.
• Incidence of adverse events
  • Time Frame: At every 3 weeks up to completion of study treatment
  • Toxicity experienced by patients for each arm at each cycle will be described using NCI CTCAE v 5.0. Hematologic and non-hematologic toxicities will be examined by grade, type and offending agent.
• Invasive disease-free survival
  • Time Frame: Up to 2 years
  • Defined as an occurrence of ipsilateral invasive breast cancer recurrence, regional invasive breast cancer recurrence, distant recurrence, death attributable to any cause, contralateral invasive breast cancer and second non-breast invasive cancer.
• Local recurrences
  • Time Frame: Up to 3 years
  • Local recurrence will be defined as the number of in-breast, chest wall after mastectomy and axillary recurrences.
• Distant recurrences
  • Time Frame: Up to 2 years
  • Distant recurrence will be defined as the number of recurrences occurring with or without localized recurrence that have occurred distant to the breast.
• Overall survival
  • Time Frame: From registration to death due to any cause up to 24 months
  • Breast cancer-specific survival and cause of death will also be examined.
• Progression-free survival
  • Time Frame: From registration to the earliest of progression or death due to any cause up to 24 months
  • The length of time during and after the treatment of a disease, such as cancer, that a patient lives with the disease but it does not get worse. In a clinical trial, measuring the progression-free survival is one way to see how well a new treatment works.

Participating in This Clinical Trial

Inclusion Criteria

• Ability to provided informed consent or a legally authorized representative is able to consent on behalf of the patient – Willing to answer questionnaires as part of their participation – Age: >= 65 years by the time of study registration – Cancer and Aging Research Group- Breast Cancer (CARG-BC) score >= 6 – Histologically or cytologically confirmed breast cancer(s) that is human epidermal growth factor receptor 2 negative (HER2-negative) per the most recent 2018 American Society of Clinical Oncology College of American Pathologists (ASCO CAP) guidelines relapsed/ refractory disease – Estrogen receptor and progesterone receptor immunohistochemistry (IHC) status must be known; any estrogen receptor (ER)/progesterone receptor (PR) status is eligible – Non-metastatic, invasive breast cancer (scans are not required to document non-metastatic disease- any staging work-up is up to the treating providers' discretion) – Recommended to have either standard dose neoadjuvant docetaxel, cyclophosphamide (TC) chemotherapy or adjuvant TC chemotherapy per their treating provider. Participant may be on immunotherapy concurrently with the protocol regimen at the discretion of the treating physician – Any surgery, nodal assessment, radiation, hormonal therapy is left up to the treating provider but should not occur concurrently with study therapy – Any patient who received pre-operative hormonal therapy and who is then recommended for neo/adjuvant chemotherapy is eligible, though hormonal therapy should be held during study treatment administration – For patients with bilateral or multifocal/multicentric breast cancers, the following criteria must be met to enroll: (1) both cancer are HER2 negative, AND (2) the provider feels the patient will benefit from TC for at least one of the cancers – Patients who do not speak or read English are eligible as long as adequate interpreter services are available or the surveys are available in the preferred language (i.e. the Geriatric Assessment [GA] and Patient Reported Outcomes [PRO] surveys are available in many languages) Exclusion Criteria:

• Participants who have already received any chemotherapy for their current breast cancer – Patients with recurrent and/or metastatic disease will be excluded. Prior diagnoses of breast cancers (including ductal carcinoma in situ [DCIS]) are allowed, provided that the treating provider feels that the current cancer most likely represents a new primary breast cancer and not recurrent disease – History of allergic reactions attributed to compounds of similar chemical or biologic composition to cyclophosphamide and/or docetaxel – Past treatment with the regimen TC for prior breast cancer

Gender Eligibility: All

Minimum Age: 65 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

• Lead Sponsor
  • City of Hope Medical Center
• Collaborator
  • National Cancer Institute (NCI)
• Provider of Information About this Clinical Study
  • Sponsor
• Overall Official(s)
  • Joanne E Mortimer, Principal Investigator, City of Hope Medical Center