You will be shown a paragraph from a biomedical research article. Your task is to extract all drug combinations appearing in a specific sentence within in the paragraph. Each drug combination should be assigned to one of the following three categories:

- POS: Indicates a positive interaction between the drugs in the combination; for instance, drugs that have an additive or synergistic effect.
- NEG: Indicates a negative interaction between the drugs in the combination; for instance, combining these drugs might result in adverse side effects, or might reduce their efficacy.
- COMB: Indicates that the drugs are given in combination, but the type of interaction between the drugs cannot be determined based on the provided context.

Please format your answer as a json array. Each entry in the array should itself be an array formatted as [<drug_1>, <drug_2>, ..., <drug_n>, <category>] where <category> is one of the three categories listed above and <drug_1>, ..., <drug_n> are drug names copied verbatim from the input sentence. Different combinations may involve different numbers of drugs; in other words, the `n` in <drug_n> may vary.

As an example, the following output describes two extracted drug combinations; one between two drugs, and one between three drugs:

[["artesunate", "artemether", "COMB"], ["Nifedipine", "Labetalol", "Prazosin", "POS"]]

The paragraph and specific sentence are below. You should only extract relationships expressed in the specific sentence; the paragraph is provided for context.

In your output, return only the json array and no other text. If no drug combinations appear, return an empty array `[]`.

paragraph: Combined 5-fluorouracil infusion with fractionated epirubicin and cyclophosphamide in advanced breast cancer. 5-fluorouracil (5-FU) given by continuous infusion (c.i.) allows higher dose delivery, causes less myelosuppression, and may interfere with repair of DNA damage caused by epirubicin and cyclophosphamide. With this rationale, we conducted a phase II study to test the activity and toxicity of 5-FU c.i., epirubicin, and cyclophosphamide in patients with metastatic breast cancer (MBC). Twenty-eight patients with MBC were entered in the trial. 5-FU (200 mg/m(2)) was administered by c.i. from day 1 to day 20. Epirubicin ( 35 mg/m(2 ) ) and cyclophosphamide ( 400 mg/m(2 ) ) were administered from day 2 to day 4 , every 4 weeks . All patients were evaluable for response and toxicity. A total of 125 courses of chemotherapy were administered, with a median of 4 per patient (range: 2--6). Toxicity, assessed using World Health Organization criteria, was as follows: nausea and vomiting grade III--IV occurred in 36%, alopecia (grade III) in 86%, neutropenia (grade III--IV) in 50%, and cardiac toxicity grade I--II in 11% of patients. Five patients (17.9%) had a complete response to therapy, and 16 (57.1%) had a partial response (response rate 75%, 95% CI 55--89%). Disease stability and progression occurred in 4 (14.3%) and 3 (10.7%) patients, respectively. Median time to progression was 13.1 months (range: 3.4--66.9+), and median survival time was 27.7 months (range: 5.4--67.1+). Outpatient treatment with combined 5-FU c.i., epirubicin, and cyclophosphamide shows high activity in advanced breast cancer and gives prolonged remission with acceptable toxicity.

sentence: Epirubicin ( 35 mg/m(2 ) ) and cyclophosphamide ( 400 mg/m(2 ) ) were administered from day 2 to day 4 , every 4 weeks .
[["Epirubicin", "cyclophosphamide", "POS"]]