Abstract Body (Do not enter title and authors here): Background: Recurrent pericarditis results from inflammasome activation and is associated with significant morbidity. Cannabidiol has been shown to block numerous inflammasome signaling pathways, including reducing transcription of pro-IL-1β and NLRP3, and inhibiting secretion of IL-1β and IL-6.

Aim: To assess the impact of oral pharmaceutically manufactured (P-)cannabidiol in recurrent pericarditis patients (pts).

Methods: Adult pts (≥18 years) with symptomatic, recurrent pericarditis (≥2 recurrences) were eligible for this open-label, multicenter study. Eligible pts had pericarditis chest pain with a numerical rating scale (NRS) pain score ≥4 within 7 days prior to enrollment, together with either elevated (≥1.0 mg/dL) C-reactive protein (CRP) within the prior 7 days or prior pericardial late gadolinium enhancement (LGE) on cardiac imaging. Pts had to be on chronic treatment with NSAIDs, colchicine or corticosteroids (any combination) with stable baseline (BL) doses. Oral P-cannabidiol was uptitrated to 10 mg/kg twice daily (BID), or maximum tolerated dose. The primary efficacy endpoint was improvement in NRS pain score at week 8 (WK8). A secondary efficacy endpoint among pts with elevated BL CRP was the percentage of pts with CRP normalization (≤0.5 mg/dL) at WK8.

Results: 27 pts, mean age of 53 years (range 24-77), 18 of female sex, with a median of 3 prior pericarditis episodes were enrolled. CRP was ≥1.0 mg/dL in 10 pts (37%) at BL. Prior evidence of LGE was present in 21 pts (78%). At BL, 41% of pts were receiving corticosteroid therapy. The highest tolerated study medication dose was BID 10 mg/kg in 20 pts (74.1%), 7.5 mg/kg in 4 pts (14.8%), and 5 mg/kg in 3 pts (11.1%). All 27 pts (100%) completed the WK8 visit. Mean NRS score decreased by 3.7, from 5.8 at BL to 2.1 at WK8. In those with CRP elevation at BL, CRP normalized in 8 pts (80%) by WK8, with mean CRP decreasing from 5.71 to 0.31 mg/dL. Study medication was discontinued due to AEs in 2 pts (7.4%). 24 pts (89%) tolerated P-cannabidiol with a treatment response and proceeded into the 18-week extension period (EP) where background therapy is weaned.

Conclusions: Among pts with symptomatic pericarditis recurrence, oral administration of P-cannabidiol led to a clinically relevant reduction in pericarditis chest pain (measured by NRS score) and in CRP. P-cannabidiol was shown to be safe and generally well tolerated, with the majority of pts reaching the target dose and continuing into the study EP.