Early Clinical and Metabolic Response to Tazemetostat in Advanced Relapsed INI1 Negative Epithelioid Sarcoma

Abstract

Epithelioid sarcoma (ES) is a rare soft tissue sarcoma with an incidence of 0.05 per 100,000 population in the USA. It is characterized by multiple local recurrences and regional lymph nodes form the commonest site of metastases. The function of Integrase Inhibitor 1 (INI1) protein is lost in more than 90% of cases, which was the basis for the introduction of tazemetostat into the therapeutic armamentarium for management of advanced ES. The efficacy and manageable toxicity profile of tazemetostat have been demonstrated recently, leading to its accelerated approval for treatment of advanced ES. We report one of the first real-world cases of relapsed, metastatic ES treated with tazemetostat. The patient attained partial response with the therapy and is tolerating the drug well without serious toxicities.

Lay abstract

Epithelioid sarcoma (ES) is a rare soft tissue sarcoma found in 0.05 people per 100,000 in the USA. It can recur multiple times in the lymph nodes of the involved site. ES involves the loss of the INI1 protein and this pathway is targeted by a new drug, tazemetostat. Recent studies have found this drug to be safe and effective for advanced ES. We have utilized this drug for a patient with metastatic ES who had history of multiple relapses. The patient had an encouraging response with the therapy and did not experience any serious side effects with this new drug.

Keywords:

• epigenetics
• epithelioid sarcoma
• personalized medicine
• targeted therapy
• tazemetostat

Author contributions

G Tansir: conception and design, analysis and interpretation of the data and literature, drafting of the manuscript, final approval of the manuscript; S Rastogi: conception and design, analysis and interpretation of the data and literature, critical revision of the manuscript, final approval of the manuscript; SA Shamim: analysis and interpretation of the data, contribution of radiological images, final approval of the manuscript; A Barwad: analysis and interpretation of the data, contribution of histopathological images, final approval of the manuscript.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The case report was accepted by the Ethics Clearance Committee of the All India Institute of Medical Sciences, New Delhi, India. The authors state that they have obtained verbal and written informed consent from the patient/patients for the inclusion of their medical and treatment history within this case report.