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: A prospective, non-randomised phase 1-2 trial of VACOP-B with filgrastim support for HIV-related non-Hodgkin's lymphoma. Non-Hodgkin's lymphoma (NHL) remains an important complication of associated HIV infection despite advances in antiretroviral therapy (ART), and the optimum chemotherapy regimen for this disease remains to be defined. A dose-escalation trial was performed to determine the maximum tolerated doses of etoposide and doxorubicin as part of the 12-week VACOP-B regimen, supported by filgrastim (r-metHuG-CSF). Patients with aggressive histology HIV-related NHL who were previously untreated with chemotherapy, and who had no active opportunistic infection were eligible for the study. Chemotherapy consisted of cyclophosphamide 350 mg/m2, vincristine 2 mg, bleomycin 10 U/m2; and prednisone 100 mg q2 days x 12 weeks, with increasing doses of doxorubicin 25-50 mg/m2 and etoposide 25-50 mg/m2 intravenously and 50-100 mg/m2 orally. Central nervous system prophylaxis (intrathecal cytarabine 50 mg x 4 doses), antifungal, and Pneumocystis carinii prophylaxis were used, and filgrastim was administered to prevent neutropenic complications. One dose level was expanded to permit the concomitant use of ART. Endpoints were determination of maximum tolerated dose of doxorubicin and etoposide , treatment tolerability , and survival . Forty-seven patients were enrolled, most with diffuse large-cell or immunoblastic NHL. Protocol-defined maximum tolerated dose was not reached and the limits of dose-limiting toxicity were not exceeded, even in patients receiving ART. Thirty-two cycles (4.9%) were delayed >6 days because of toxicity; 30 patients (64%) completed all 12 weeks of treatment. After completion of therapy, 14 patients had a complete response (30%), and 4 had a partial response (8%). Median time to progression was 9 months. At 42 months, progression-free survival was 25% and overall survival was 28%.

sentence: Endpoints were determination of maximum tolerated dose of doxorubicin and etoposide , treatment tolerability , and survival .
[["doxorubicin", "etoposide", "POS"]]