Intra-Tumoral Mucolytic Therapy for Unresectable Pseudomyxoma Peritonei: Results of a Single-Center Expanded Access...

For patients with unresectable pseudomyxoma peritonei (PMP), intra-tumoral administration of a mucolytic drug combination comprising bromelain and acetylcysteine (BromAc) reduced mucinous tumor volume in phase 1/2 non-U.S.

This report describes the initial outcomes of an expanded access BromAc treatment program at a single U.S. center.

Eligible patients with progressive unresectable PMP underwent image-guided placement of percutaneous catheters in one or more mucinous tumors. BromAc was administered via the catheters, and after a 24 h dwell period, the dissolved mucus was aspirated. This treatment was repeated up to six times per tumor. Changes in tumor volume, post-treatment complications, and patient-reported quality-of-life (QOL) symptoms were recorded.

Ten appendiceal PMP patients with 23 individual tumors underwent 107 intra-tumoral BromAc treatments (median, 4 treatments; interquartile range [IQR], 4-6 treatments per tumor). The median pre-treatment tumor volume by imaging was 728 ml (IQR, 350-2104 ml). Among eight patients that completed post-treatment imaging, 14 (82.4 %) of 17 tumors exhibited a reduction in tumor volume (median tumor volume reduction, 48.6 %; IQR, 14.9-75.4 %). The median cumulative volume of dissolved mucus aspirated after treatment completion was 370 ml (IQR, 155-756 ml). There were 6 CTCAE grade 1, 20 grade 2, and 6 grade 3 adverse events. Two patients died within 40-days after protocol initiation from disease progression, clinical deterioration, or both. Seven patients completed post-treatment QOL surveys, with four patients (57.1 %) reporting improved symptoms.

Repeated intra-tumoral BromAc administration decreases mucinous tumor volume and may improve short-term QOL symptoms. Tumor characteristics influence treatment response, whereas patient factors impact safety and tolerability of therapy.