This will be a single-blind, placebo-controlled phase 2 trial to compare prednisolone effects with and without SPI-62 in participants with PMR.

This will be a single-blind, placebo-controlled phase 2 trial to compare prednisolone effects with and without SPI-62 in participants with PMR. Up to 6 cohorts of 12 participants could be recruited (12 to 72 participants). Each participant who provides consent and meets all inclusion and exclusion criteria will participate in 3 periods: a screening period up to 28 days (Day -28 to Day-1), a 4-week treatment period (Day 1 to Day 28) and a follow up Period (Day 29 to Day 56). During the 4-week treatment period for the first cohort, all participants will receive prednisolone 10mg per day for 4-weeks plus SPI-62 for 2-weeks and matching placebo for 2-weeks. For cohorts 2 through 6, the dose of prednisolone co-administered with SPI-62 could be adjusted. For cohorts 5 and 6, the dose of SPI-62 could be adjusted.

Inclusion Criteria:

• Written informed consent
• Diagnosis of PMR according to EULAR/ACR classification criteria
• Absence of PMR relapse based on symptoms and acute phase markers
• Daily oral prednisolone 10mg dose that will have been stable for at least 1-week at the Baseline visit and is expected to remain stable during the treatment period

Exclusion Criteria:

• Any contraindication for prednisolone administration.
• A diagnosis or any clinical features of giant cell arteritis.
• Any autoimmune disease (e.g., late-onset rheumatoid arthritis) other than PMR.
• Use of medications for treatment of PMR within specified intervals prior to the Baseline Visit other than oral prednisolone.
• Use of other medications likely to interfere with trial assessments.
• History or diagnosis of endogenous hypercortisolism.
• Any current or prior medical condition, medical or surgical therapies, or clinical trial participation expected to interfere with the conduct of the trial or the evaluation of its results.

Drug and Placebo are masked and assigned via Interactive Response Technology (IRT)