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: Outcomes of patients with chronic lymphocytic leukemia treated with first-line idelalisib plus rituximab after cessation of treatment for toxicity.  More active therapies are needed for older and unfit patients with chronic lymphocytic leukemia ( CLL ) who are not eligible for chemoimmunotherapy with fludarabine , cyclophosphamide , and rituximab . The phosphyotidylinositol-3-kinase δ inhibitor idelalisib is effective in patients with treatment-naive and relapsed/refractory CLL as monotherapy and in combination with rituximab, but it can be associated with treatment-limiting adverse events, particularly diarrhea/colitis. The outcomes for patients who cease treatment for adverse events have not been previously described. ### methods The authors analyzed long-term follow-up data from 40 treatment-naïve patients aged ≥65 years who received treatment at The University of Texas MD Anderson Cancer Center on a phase 2 study of idelalisib plus rituximab for CLL. ### results In patients who permanently ceased treatment because of toxicity, the time to subsequent disease progression was analyzed according to baseline characteristics. Fifteen patients permanently ceased therapy (PCT) because of toxicity (PCTTOX ), most commonly diarrhea/colitis (n = 7), at a median of 11 months after commencing treatment. PCTTOX was associated with a higher risk of subsequent disease progression (hazard ratio, 6.61; 95% confidence interval, 1.77-16.15) relative to that observed in patients who remained on therapy. Ten patients subsequently progressed, and 7 required salvage therapy; 5 patients remained progression-free at a median of 23.3 months (range, 8.5-28.6 months). Patients who were positive for ζ-associated protein-70 had more rapid disease progression after treatment cessation (P = .048). There were no CLL-related deaths. ### conclusions PCTTOX is the major determinant of PFS in patients who receive first-line idelalisib-based treatment. However, a subgroup of patients with favorable biologic characteristics has prolonged PFS, even after PCTTOX . The absence of CLL-related deaths indicates that salvage treatment is generally successful after PCTTOX . Cancer 2016;122:2505-11. © 2016 American Cancer Society.

sentence: More active therapies are needed for older and unfit patients with chronic lymphocytic leukemia ( CLL ) who are not eligible for chemoimmunotherapy with fludarabine , cyclophosphamide , and rituximab .
[]