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: Scheduled prospective tri-weekly modified FOLFOX6 maintenance chemotherapy in the treatment of metastatic colorectal cancer.  Oxaliplatin , which is effective for colorectal cancer ( CRC ) in combination with 5-fluorouracil ( 5-FU ) and leucovorin ( LV ) , is widely used for metastatic CRC . With the increasing use of oxaliplatin, however, serious adverse events have been experienced, including hematologic and neurologic toxicities. The aim of this study was to evaluate whether tri-weekly modified FOLFOX6 (mFOLFOX6) maintenance chemotherapy is associated with a low incidence of severe hematologic and neurologic toxicities in the treatment of patients with metastatic CRC. ### methodology We developed a new treatment regimen with mFOLFOX6 biweekly for 8-10 consecutive cycles (induction phase) followed by a 3-week rest period, after which treatment was resumed with cycles of tri-weekly mFOLFOX6 at standard doses (maintenance phase). Validity and complications were investigated retrospectively. ### results Twenty-nine patients were enrolled in this study. The median progression-free survival (PFS) and overall survival (OS) times were 9.4 months and 23 months, respectively. All patients had peripheral neuropathy during treatment, but grade 3 neurotoxicity was observed in only 2 patients (6.9%). ### conclusions mFOLFOX6 maintenance chemotherapy was associated with a very low incidence of grade 3 hematologic and neurologic toxicities. The toxicities associated with PFS and OS were comparable to those reported in the treatment of patients with metastatic CRC. A tri-weekly mFOLFOX maintenance strategy of alternative treatment with a less-toxic regimen may reduce toxicity and maintain efficacy.

sentence: Oxaliplatin , which is effective for colorectal cancer ( CRC ) in combination with 5-fluorouracil ( 5-FU ) and leucovorin ( LV ) , is widely used for metastatic CRC .
[["Oxaliplatin", "leucovorin", "5-fluorouracil", "POS"]]