Severe and delayed-onset acneiform eruptions as an adverse reaction to regorafenib

Area of Science:

• Oncology
• Dermatology
• Pharmacology

Background:

• Regorafenib is an oral multikinase inhibitor used for metastatic gastrointestinal stromal tumor (GIST).
• Common adverse reactions include fatigue and palmar-plantar erythrodysesthesia, while acneiform eruptions are less frequently reported with regorafenib compared to other BRAF/EGFR inhibitors.
• The association between acneiform eruptions and EGFR inhibitor efficacy suggests potential anticancer activity.

Purpose of the Study:

• To report the first documented case of a severe, delayed-onset acneiform eruption in a patient treated with regorafenib for GIST.
• To highlight the potential for late-emerging skin toxicities associated with regorafenib therapy.

Main Methods:

• A case report of a 61-year-old woman with metastatic GIST treated with regorafenib.
• Clinical observation of a severe acneiform eruption developing 24 months after initiating regorafenib.
• Histopathologic analysis of a skin biopsy revealing neutrophilic suppurative folliculitis.
• Management involved temporary discontinuation of regorafenib and topical clindamycin treatment.

Main Results:

• The patient developed a severe acneiform eruption on her back 24 months into regorafenib treatment.
• Histopathology confirmed neutrophilic suppurative folliculitis.
• Treatment with topical clindamycin and a brief interruption of regorafenib led to effective resolution of the skin eruption.
• Regorafenib demonstrated good anticancer activity in this patient.

Conclusions:

• Acneiform eruptions can manifest as a delayed-onset adverse reaction to regorafenib, occurring up to 24 months after treatment initiation.
• This case underscores the importance of monitoring for late-emerging skin toxicities in patients receiving regorafenib.
• Effective management strategies, including topical treatments, can address these delayed reactions without necessarily compromising anticancer therapy.