A 52-year-old woman presents with a 6-month history of bilateral hand pain and stiffness, worse in the mornings lasting for over an hour. She describes swelling in her MCP and PIP joints. On examination, there is symmetrical synovitis of the MCP and PIP joints of both hands, and bilateral wrist swelling and tenderness. Rheumatoid factor is positive and anti-CCP antibodies are strongly positive. According to NICE guidelines, what is the most appropriate initial disease-modifying anti-rheumatic drug (DMARD) therapy?