Nonepithelioid malignant pleural mesotheliomas (MPMs), which comprise approximately a third of all mesotheliomas, often lack argininosuccinate synthetase 1 (ASS1) function (thus creating a metabolic dependence on exogenous arginine) and are therefore vulnerable to interventions that reduce arginine availability. Now, data from the phase II/III ATOMIC-Meso trial demonstrate the efficacy of pegargiminase (ADI-PEG20), a modified microbial enzyme, plus chemotherapy in this setting.

A total of 249 patients with any-stage histologically proven unresectable nonepithelioid MPM were randomly allocated (1:1) to receive intramuscular pegargiminase versus placebo, both in combination with pemetrexed plus either cisplatin or carboplatin. Patients were not selected for ASS1 deficiency, owing to concerns regarding the accuracy of the available anti-ASS1 antibodies. Overall survival (OS) was the primary end point.

非上皮样恶性胸膜间皮瘤 (MPM) 约占所有间皮瘤的三分之一，通常缺乏精氨酸琥珀酸合成酶 1 (ASS1) 功能（从而产生对外源性精氨酸的代谢依赖性），因此容易受到减少精氨酸可用性的干预措施的影响。现在，II/III 期 ATOMIC-Meso 试验的数据证明了聚乙二醇胺酶 (ADI-PEG20)（一种改良的微生物酶）在这种情况下加上化疗的功效。

总共 249 名经组织学证明处于任何阶段且不可切除的非上皮样 MPM 的患者被随机分配 (1:1) 接受肌内聚乙二醇化酶治疗与安慰剂治疗，均与培美曲塞加顺铂或卡铂联合治疗。由于担心现有抗 ASS1 抗体的准确性，没有选择患有 ASS1 缺陷的患者。总生存期（OS）是主要终点。