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 I/II study of gefitinib and capecitabine in patients with colorectal cancer . The objectives of this phase I/II study were to determine the maximum tolerated dose (MTD), characterise the principal toxicities in the phase I part and assess the efficacy in the phase II part of gefitinib, an oral selective inhibitor of the epidermal growth factor receptor, in combination with capecitabine in patients with advanced colorectal cancer (CRC). ### Methods And Patients Patients with advanced CRC were treated with gefitinib administered daily for 21 days and capecitabine administered twice daily for 14 days of a 21-day cycle. The dose levels of gefitinib (mg) and capecitabine (mg/m(2) bid) assessed were 250/1000 and 250/ 1250. An expanded cohort was enrolled at the MTD to better characterise toxicity and efficacy. A total of 32 previously treated patients were accrued. In the phase I part 10 subjects were treated, with one dose-limiting toxicity. Overall 26 patients were treated at the MTD of the combination, which was gefitinib 250 mg/day and capecitabine 1250 mg/m(2) twice daily. ### results The most frequent treatment-related adverse events included asthenia, diarrhoea, nausea, rash and anorexia. The incidence profile was very similar in phases I and II. No objective responses were documented but 53% of the patients achieved stable disease as best response to therapy. ### conclusions capecitabine 1250 mg/m(2) twice daily 14 of 21 days and gefitinib at 250 mg/day can be safely administered in combination. The combination is relatively well tolerated. There were no objective responses, although an interesting stabilisation rate was documented, in previously treated advanced CRC patients.

sentence: Phase I/II study of gefitinib and capecitabine in patients with colorectal cancer .
[["gefitinib", "capecitabine", "POS"]]