Complete response of metastatic pleomorphic dermal sarcoma to anti‐PD‐1 therapy

Abstract

DEAR EDITOR, An 87-year-old gentleman presented with a scalp nodule. A subsequent biopsy (a) demonstrated pleomorphic dermal sarcoma (PDS). The patient underwent an excision and received adjuvant radiotherapy. He presented 4 months later with two new scalp lesions and an enlarged left parotid gland. A biopsy confirmed metastatic PDS that was heavily infiltrated by T lymphocytes (b). A staging positron emission tomography (PET) scan demonstrated two lung metastases. The patient commenced treatment with the anti-PD-1 antibody pembrolizumab, leading to a rapid clinical response. Treatment had to be discontinued after two doses owing to a flare of pre-existing polymyalgia rheumatica. A PET scan 3 months after commencement of therapy demonstrated a complete response with regression of all sites of metastatic disease (c, d), which is ongoing.

Immune checkpoint inhibitors for unresectable or metastatic pleomorphic dermal sarcomas

“…pembrolizumab, nivolumab) or the anti–CTLA-4 antibody (ipilimumab), or a combination of these agents was presumed in reference to other highly mutated and immunogenic tumors including other skin tumors such as malignant melanoma and cSCC ( 18 , 32 , 33 ). In the meantime, the exceptionally high efficacy of the anti-PD-1 inhibitor pembrolizumab has been described in case reports or small case series (see Table 1 ) ( 2 , 15 – 17 ). Until now, there are no case reports describing the use of other CPI in PDS patients.…”

“…In the last years, it could be shown that PDS are inflammatory and immunogenic tumors with a very high mutational burden. Experimental data and clinical reports indicate that PD-1/PD-L1-blocking antibodies are highly effective in patients with unresectable or metastatic PDS and suggest its use as first line treatment in these advanced tumor stages ( 2 , 15 – 17 ).…”

S1‐guideline atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS)

“…In cases with high numbers of TIL and expression of PD-L1 or other checkpoint molecules, off-label treatment with a checkpoint inhibitor such as an anti-PD-1 antibody may be considered, provided that the reimbursement situation has been clarified. There are some case reports that PD-1/PD-L1 inhibiting antibodies may be effective [18,43,44,58].…”

S1‐Leitlinie Atypisches Fibroxanthom (AFX) und pleomorphes dermales Sarkom (PDS)

“…Im Falle einer hohen Zahl an TIL als auch Expression von PD-L1 oder weiterer Checkpoint-Moleküle, kann eine Off-Label-Therapie mit einem Checkpoint-Inhibitor wie einem Anti-PD-1-Antikörper nach entsprechender Klärung der Kostenübernahme erwogen werden, zumal in Fallberichten eine Wirksamkeit von PD-1/PD-L1-blockierenden Antikörpern beschrieben wurde [18,43,44,58].…”