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: Efficacy of telaprevir-based therapy for difficult-to-treat patients with genotype 2 chronic hepatitis C in Japan.  This study assessed the efficacy and safety of telaprevir in combination with peginterferon-α-2b ( PEG IFN ) and ribavirin ( RBV ) , for Japanese difficult-to-treat patients with hepatitis C virus ( HCV ) genotype 2 who had not achieved sustained virological response ( SVR ) during prior treatment . ### methods In total, 108 relapsed (median age, 59.0 years) and 10 non-responding (median age, 59.0 years) patients with genotype 2 HCV participated. Patients received telaprevir (750 mg, every 8 h) for 12 weeks and PEG IFN/RBV for 24 weeks. ### results The SVR rates for relapsers and non-responders were 88.0% (95/108) and 50.0% (5/10), respectively. The SVR rates did not differ significantly between patients with rs8099917 TT and non-TT. The SVR rates for relapsers and non-responders with extended rapid viral response (eRVR) were 97.6% (82/84) and 100% (5/5), respectively. On the other hand, the SVR rates for relapsers and non-responders completing the treatment protocol were 98.4% (61/62) and 100% (5/5), respectively. The overall safety profiles of telaprevir-based regimens were similar for Japanese patients with genotype 1 and 2 HCV infection who experienced treatment failure. ### conclusion telaprevir, in combination with PEG IFN/RBV, provided a high SVR rate for genotype 2 HCV, difficult-to-treat patients who had not achieved SVR during prior IFN-based treatment. The eRVR had a strong influence on the cure rate of telaprevir-based therapy. In addition, the continuation of telaprevir-based treatment for up to 24 weeks was a significant predictor of SVR.

sentence: This study assessed the efficacy and safety of telaprevir in combination with peginterferon-α-2b ( PEG IFN ) and ribavirin ( RBV ) , for Japanese difficult-to-treat patients with hepatitis C virus ( HCV ) genotype 2 who had not achieved sustained virological response ( SVR ) during prior treatment .
[["telaprevir", "peginterferon-\u03b1-2b", "POS"], ["telaprevir", "ribavirin", "POS"]]