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: Combination chemotherapy for advanced breast cancer: response and effect on survival.  Forty patients with metastatic breast cancer who had received no previous cytotoxic therapy were treated with a combination chemotherapy program CMF ( P ) , which included methotrexate , 60 mg/m2 , and 5-fluorouracil , 700 mg/m2 intravenously on the first and eighth days , in addition to cyclophosphamide , 100 mg/m2 , and prednisone , 40 mg/m2 , by mouth daily from the first to the fourteenth day of a 28-day cycle . Only 2 of 25 patients responded to hormonal therapy or endocrine ablation. Twenty-seven of the 40 patients (68%) had a complete response (8 patients) or partial response (19 patients). Lung, soft tissue, and nodal metastases were the most responsive sites. The median survival of 18 months for the responding group. The nonresponders had a median survival of 4 months. The toxicity was primarily hematologic and was especially severe in patients with functional liver impairment due to metastatic disease.

sentence: Forty patients with metastatic breast cancer who had received no previous cytotoxic therapy were treated with a combination chemotherapy program CMF ( P ) , which included methotrexate , 60 mg/m2 , and 5-fluorouracil , 700 mg/m2 intravenously on the first and eighth days , in addition to cyclophosphamide , 100 mg/m2 , and prednisone , 40 mg/m2 , by mouth daily from the first to the fourteenth day of a 28-day cycle .
[["methotrexate", "cyclophosphamide", "prednisone", "5-fluorouracil", "POS"]]