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: Phase IV study of bevacizumab in combination with infusional fluorouracil , leucovorin and irinotecan ( FOLFIRI ) in first-line metastatic colorectal cancer . bevacizumab (Avastin) significantly improves overall survival (OS) and progression-free survival (PFS) when combined with first-line irinotecan (IFL) plus bolus 5-fluorouracil (5-FU) and leucovorin (LV) in patients with metastatic colorectal cancer (CRC). This open-label, phase IV trial evaluated the efficacy and safety of first-line bevacizumab in combination with IFL and infusional 5-FU/LV (FOLFIRI). ### methods Two-hundred and nine treatment-naïve metastatic CRC patients were enrolled and received bevacizumab and FOLFIRI every 2 weeks. Treatment was continued until disease progression. The primary objective was PFS, with additional determinations of OS, response and toxicity. ### results Median PFS was 11.1 months and is comparable to that observed in published phase III and community-based trials using first-line bevacizumab plus FOLFIRI, and to phase III trials using bevacizumab in combination with bolus 5-FU/LV plus IFL. Median OS was 22.2 months. Overall response rate was 53.1% and the disease control rate 85.6%. Most adverse events were grade 1/2 and were manageable. The most common grade 3/4 adverse events (> or =10%) were neutropenia, venous thromboembolic events, diarrhea, and fatigue. ### conclusion bevacizumab combined with first-line FOLFIRI is an effective and well-tolerated therapy option for patients with metastatic CRC.

sentence: Phase IV study of bevacizumab in combination with infusional fluorouracil , leucovorin and irinotecan ( FOLFIRI ) in first-line metastatic colorectal cancer .
[["bevacizumab", "fluorouracil", "leucovorin", "irinotecan", "POS"]]