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: Rationale for examining the combination of paclitaxel and ifosfamide in the treatment of advanced ovarian cancer.  Both paclitaxel ( Taxol ; Bristol-Myers Squibb Company , Princeton , NJ ) and ifosfamide have been demonstrated to be active agents in patients with clinically defined platinum-refractory ovarian cancer . While there might be interest in combining these two drugs as salvage therapy for this disease, the recent inclusion of paclitaxel as initial therapy for advanced ovarian cancer, along with a platinum agent (cisplatin or carboplatin), makes it unlikely that paclitaxel and ifosfamide will be used clinically in this malignancy. However, if alkylating agents are not to be used as part of the initial chemotherapy strategy for women with advanced ovarian cancer, it will be important to evaluate the activity of ifosfamide as salvage therapy in individuals treated only with, and demonstrated to be refractory to, a platinum agent and paclitaxel. If significant activity for ifosfamide is observed in this clinical setting, evaluation of the potential utility of a three-drug combination regimen comprising ifosfamide, paclitaxel, and cisplatin or carboplatin may be quite relevant.

sentence: Both paclitaxel ( Taxol ; Bristol-Myers Squibb Company , Princeton , NJ ) and ifosfamide have been demonstrated to be active agents in patients with clinically defined platinum-refractory ovarian cancer .
[]