Your goal is to extract structured information from the user's input that matches the form described below. When extracting information please make sure it matches the type information exactly. Do not add any attributes that do not appear in the schema shown below.

```TypeScript

 { // Information on the clinical trial characteristics from the abstract
 conditions: string // The condition or disease being treated in the clinical trial
 drug_or_intervention: string // The drug or intervention used in the clinical trial
}
```


Please output the extracted information in JSON format. Do not output anything except for the extracted information. Do not add any clarifying information. Do not add any fields that are not in the schema. If the text contains attributes that do not appear in the schema, please ignore them. All output must be in JSON format and follow the schema specified above. Wrap the JSON in <json> tags.



Input:Efficacy and safety of CH-1504, a metabolically stable antifolate, in patients with active rheumatoid arthritis: results of a phase II multicenter randomized study.  To investigate the potential efficacy, safety, and tolerability of daily use of CH-1504 in patients with active rheumatoid arthritis (RA). US National Institutes of Health database no. NCT00658047. In our phase II randomized double-blind double-dummy study, patients naive to methotrexate (MTX; n = 201) and having moderate to severe RA received either CH-1504 (0.25 mg, 0.5 mg, or 1.0 mg once-daily oral doses) or MTX (titrated to 20.0 mg once-weekly oral doses). All received weekly 10-mg folate supplementation. Efficacy and safety were assessed at 2, 4, 8, and 12 weeks, with a treatment-free followup at 16 weeks. Safety and tolerability were assessed. Primary efficacy endpoint was proportion of patients achieving ACR20 response at Week 12. Secondary endpoints included difference from baseline in the 28-joint Disease Activity Score (DAS28) and individual components of the American College of Rheumatology (ACR) composite index. Demographic characteristics were similar in all treatment groups: mean age 54.3 ± 11.4 years, female sex 87%, mean baseline DAS28 6.6 ± 0.9. At Week 12, CH-1504 demonstrated comparable efficacy compared to MTX as measured by ACR20, DAS28, and ACR composite core-set measures, including tender and swollen joints. No dose-response relationship was observed. Adverse events across treatment groups were mild. Liver enzyme levels increased from baseline to Week 16 in the MTX group, with qualitatively lesser increases in the CH-1504 groups. Two patients in the MTX group withdrew because of gastrointestinal-related adverse events. CH-1504 appeared safe and well tolerated at all dose levels. CH-1504 has comparable efficacy to MTX and is safe and well tolerated. Metabolically stable antifolates are a promising therapeutic option that warrants further study. Output:
{'conditions': 'Arthritis, Rheumatoid', 'interventions': 'Drug: CH-1504|Drug: Methotrexate'}