A 47-year-old woman presents with a 6-month history of symmetrical pain and stiffness in the small joints of her hands and feet, worst in the morning and improving with activity. Examination shows swelling of the metacarpophalangeal and proximal interphalangeal joints bilaterally. Rheumatoid factor and anti-CCP are positive. According to Australian rheumatology practice, what is the most appropriate initial disease-modifying therapy?