ASCO 2021: Combination of HDAC Inhibitor and Pembrolizumab in Advanced Skin Cancer
Posted: Wednesday, June 23, 2021
During the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting, Jessica Cecile Hassel, MD, of the National Center for Tumor Diseases, Heidelberg University Hospital, Germany, and colleagues presented results from the phase Ib SENSITIZE trial. This study focused on combining the anti–PD-1 inhibitor pembrolizumab with the histone deacetylase inhibitor (HDAC) domatinostat in patients with advanced melanoma (Abstract 9545). This treatment not only demonstrated similar safety profiles to those of pembrolizumab and domatinostat alone but may even influence further research of checkpoint inhibitors in combination with domatinostat in skin cancer.
The investigators focused on 40 patients with advanced, unresectable or metastatic skin cancer who had primary refractory disease or did not respond to previous checkpoint inhibitor therapy. Participants were administered pembrolizumab at 2 mg/kg every 3 weeks, along with domatinostat at five different dose levels. Every 12 weeks, tumor assessments were performed.
The median number of previous therapies at stage 4 was three; 65% of patients had stage 1 clinical metastasis, and 35% had elevated lactate dehydrogenase levels. Grade 1 to 2 treatment-related adverse events associated with domatinostat affected at least 10% of participants, with the most common being diarrhea (23%), fatigue (20%), nausea (20%), and rash (15%). Although eight individuals experienced grade 3 or greater adverse events, no deaths related to treatment were reported. Four patients discontinued therapy due to grade 3 adverse events. The maximum tolerated dose was not reached.
Complete response, confirmed partial response, and stable disease were achieved in one, two, and nine patients, respectively. In highly pretreated individuals, the disease control rate was 30% among all dose levels.
“Notably, three out of seven patients achieved disease control in the third dose level and were on treatment at least 1.5 years, indicating a trend of dose-dependent clinical activity,” the investigators concluded.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.