(1) who have a documented history of severe active psoriatic arthritis with a record of rheumatoid factor negative status; and

(2) whose most recent course of PBS-subsidised treatment with a biological agent for this condition in the current Treatment Cycle was with infliximab; and

(3) who, at the time of application, demonstrate an adequate response to treatment with infliximab; and

where biological agent means adalimumab or etanercept or infliximab; and

where a Biological Treatment Cycle is a period of treatment with successive biological agents which commences when an eligible patient (one who has not received PBS-subsidised treatment with a biological agent for psoriatic arthritis in at least the previous 5 years) receives an initial course of PBS-subsidised therapy with 1 biological agent, and which continues until the patient has tried, and either failed or ceased to respond to, PBS-subsidised treatment with 3 biological agents, at which point the patient is no longer eligible for treatment and the period of treatment ceases; and

where the following conditions apply:

an adequate response to treatment with infliximab is defined as an erythrocyte sedimentation rate no greater than 25 mm per hour or a C-reactive protein level no greater than 15 mg per L or either marker reduced by at least 20% from baseline, and either a reduction in the total active (swollen and tender) joint count by at least 50% from baseline, where baseline is at least 20 active joints, or a reduction in the number of the following major joints which are active, from at least 4, by at least 50%:

- elbow, wrist, knee or ankle (assessed as active if swollen and tender); or

- shoulder or hip (assessed as active if there is pain in passive movement and restriction of passive movement, and where pain and limitation of movement are due to active disease and not irreversible damage such as joint destruction or bony overgrowth);

the same indices of disease severity used to establish baseline at the commencement of treatment are used to determine response;

the authority application is made in writing and includes a completed copy of the appropriate Psoriatic Arthritis PBS Authority Application - Supporting Information Form, and a measurement of response to the most recent prior course of therapy with infliximab, where response is assessed, and this assessment is provided to the Medicare Australia CEO, no later than 4 weeks from the cessation of that treatment course;

if the most recent course of infliximab therapy was a 22 week initial treatment course, the application for continuing treatment is accompanied by an assessment of response to a minimum of 12 weeks of treatment with that course;

a course of continuing treatment within an ongoing Treatment Cycle is limited to a maximum of 24 weeks of treatment;