The goal of this clinical trial is to learn if Naderin works to prevent low white blood cell counts in people with breast cancer receiving first-line chemotherapy. The main questions it aims to answer are:

1. Does taking Naderin lower the number of people who get low white blood cell counts during chemotherapy?
2. Does taking Naderin help people finish all of their chemotherapy treatments without interruptions? Researchers will compare people who receive chemotherapy with Naderin to people who receive chemotherapy alone to see if Naderin helps prevent low white blood cell counts.

Participants will:

Receive standard AC chemotherapy for breast cancer Either receive Naderin along with chemotherapy or receive chemotherapy alone Have regular blood tests to check white blood cell counts Complete all 4 chemotherapy cycles

Key finding: The study found that 14 out of 100 people who received Naderin developed low white blood cell counts, compared to 39 out of 100 people who did not receive Naderin.

Study Rationale Myelosuppression and related immunologic complications are common dose-limiting toxicities of cytotoxic chemotherapy and can lead to treatment delays, dose reductions, or discontinuation. This study assessed prophylactic administration of Naderin (sodium deoxyribonucleate; immunomodulatory agent) as supportive care during first-line AC chemotherapy, with the intent to mitigate hematologic toxicity and preserve chemotherapy delivery.

Study Design and Setting This was a prospective, open-label, two-group interventional study conducted at the Kazakh Scientific Research Institute of Oncology and Radiology (Almaty, Kazakhstan) in collaboration with KazNMU and the Almaty Oncology Center. Treatment allocation was non-randomized and based on consecutive enrollment, treatment availability, and participant consent.

Study Groups and Interventions Control group: standard institutional AC chemotherapy (doxorubicin + cyclophosphamide), intravenous administration, 4 planned cycles.

Intervention group: the same AC chemotherapy regimen plus Naderin administered as a prophylactic adjunct with each chemotherapy cycle (route and dosing per local institutional protocol).

Concomitant medications and supportive care (including any antiemetics, antimicrobials, or use of colony-stimulating factors) were permitted according to institutional practice and recorded.

Assessments and Follow-up

Participants underwent:

Baseline evaluation prior to chemotherapy initiation, including clinical assessment and laboratory testing.

On-treatment monitoring during each AC cycle with serial complete blood counts and structured adverse-event assessment.

End-of-treatment evaluation after completion of planned chemotherapy cycles (or earlier discontinuation), including laboratory reassessment and documentation of chemotherapy delivery (cycle completion, delays, interruptions).

Outcomes (high-level; details recorded elsewhere) The study evaluated hematologic toxicity during chemotherapy and chemotherapy delivery feasibility (ability to complete planned cycles without interruption), along with safety/tolerability of adjunctive Naderin.

Statistical Approach (high-level) The primary between-group comparison for hematologic toxicity incidence was planned using categorical testing (chi-square) with a two-sided alpha threshold of 0.05, with descriptive summaries of chemotherapy delivery metrics and adverse events.

Ethical and Oversight Considerations The study was approved by the Local Ethics Committee of KazNMU (Approval No. 15677). Written informed consent was obtained from all participants prior to enrollment. No independent data monitoring committee was used.

Inclusion Criteria:

• Confirmed histological diagnosis of breast cancer
• Receiving first-line AC chemotherapy (doxorubicin + cyclophosphamide)
• Age 18 years or older
• Female sex
• Eastern Cooperative Oncology Group (ECOG) performance status 0-2
• Adequate bone marrow function (absolute neutrophil count ≥ 1.5 × 10⁹/L, platelet count ≥ 100 × 10⁹/L)
• Adequate hepatic function (transaminases ≤ 2.5 × upper limit of normal)
• Adequate renal function (creatinine ≤ 1.5 × upper limit of normal)
• Normal cardiac function (left ventricular ejection fraction ≥ 50%)
• Willing and able to provide written informed consent

Exclusion Criteria:

• Previous chemotherapy or radiotherapy for breast cancer
• History of other malignant neoplasms (except non-melanoma skin cancer or carcinoma in situ of the cervix)
• Severe organ dysfunction (cardiac, hepatic, renal, pulmonary)
• Active infection requiring systemic therapy
• Known hypersensitivity to Naderin or any of its components
• Known hypersensitivity to doxorubicin, cyclophosphamide, or any excipients
• Pregnancy or breastfeeding
• Psychiatric or cognitive impairment that would interfere with study participation
• Participation in another interventional clinical trial within 30 days prior to enrollment
• Any condition that, in the investigator's opinion, would compromise participant safety or interfere with study objectives

Participants and care providers were aware of the treatment assignments. However, the outcomes assessor performing the final analysis of leukopenia incidence was blinded to the allocation.