2018年6月3日，美国食品和药物管理局（FDA）加速批准pembrolizumab(商品名 Keytruda 默沙东药品)，用于化疗期间或化疗后病情进展且经FDA批准的一款检测试剂盒证实为肿瘤表达PD-L1（综合阳性评分[CPS]≥1）的复发性或转移性宫颈癌患者。基于肿瘤缓解率和缓解持续时间并通过FDA的加速审批程序批准，进一步的完全批准，将取决于确证性研究中临床受益的验证和描述。
此次批准，使Keytruda成为获批治疗晚期宫颈癌的首个PD-1免疫疗法，将为这类患者群体提供一种新的二线治疗选择。同时，此次批准也标志着Keytruda在妇科癌症领域的首个适应症。
此次晚期宫颈癌适应症的获批，是基于多中心、非随机、开放标签、多队列II期临床研究KEYNOTE-158队列E的数据。队列E入组了98例复发性或转移性宫颈癌患者，研究中，患者接受每3周一次200mg剂量Keytruda治疗，直至病情进展或不可接受的毒性，在病情无进展的患者中Keytruda治疗可至24个月。在治疗的前12个月，每9周对肿瘤状态进行一次评估。主要疗效指标是由盲法独立中心审查（BICR）根据RECIST1.1评估的客观缓解率（ORR）以及缓解持续时间（DOR）。
在队列E的98例患者中，77例（79%）患者肿瘤表达PD-L1（CPS≥1）并接受了至少一线化疗治疗转移性疾病。PD-L1状态采用PD-L1 IHC 22C3 PharmDx Kit进行测定。这77例患者的基线特征为：中位年龄45岁（范围：27-75岁）、白人81%、亚洲人14%、黑人3%；ECOG PS为0（32%）或1（68%）；92%为鳞状细胞癌，6%为腺癌，1%为腺鳞状组织学；95%为M1疾病，5%为复发性疾病；35%患者接受过1种、65%患者接受过2种或2种以上方案治疗复发性或转移性疾病。
中位随访11.7个月（范围：0.6个月-22.7个月）的数据显示，77例肿瘤表达PD-L1（CPS≥1%）的患者中，Keytruda治疗的ORR为14.3%（11例，95%CI:7.4-24.1），完全缓解率为2.6%，部分缓解率为11.7%。在这11例对治疗有应答的患者中，中位DOR尚未达到（范围：4.1个月至18.6+个月），DOR在6个月或以上的患者比例为91%。在另外21例肿瘤不表达PD-L1（CPS＜1）的患者中，未观察到治疗反应。
安全性方面，队列E的98例患者中，不良反应导致的Keytruda停药率为8%，39%的患者出现严重不良反应，最常见的严重不良反应（发生率≥20%）包括：贫血（7%），瘘管、出血和感染（尿路感染除外，均为4.1%）。最常见的不良反应（发生率≥20%）包括：疲劳（43%）、肌肉骨骼疼痛（27%）、腹泻（23%）、疼痛和腹痛（均为22%）和食欲下降（21%）。
Keytruda是一种人源化单克隆抗体，靶向阻断PD-1与其配体PD-L1和PD-L2之间的相互作用，从而激活可能影响肿瘤细胞和健康细胞的T淋巴细胞，增强免疫系统侦察和对抗肿瘤细胞的能力。目前，默沙东正在开发行业最大规模的免疫肿瘤学临床项目，涉及超过750个临床试验，治疗各种类型肿瘤。
宫颈癌推剂量为：每3周200mg
完整资料附件：
https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=9333c79b-d487-4538-a9f0-71b91a02b287
KEYTRUDA®(pembrolizumab)for injection, for intravenous use
KEYTRUDA®(pembrolizumab)injection, for intravenous use
General Information
Keytruda (pembrolizumab) is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response.
Keytruda is specifically indicated for the treatment of patients with unresectable or metastatic melanoma and disease progression following ipilimumab and, if BRAF V600 mutation positive, a BRAF inhibitor.
Keytruda is supplied as a solution for intravenous infusion. The recommended dose is 2 mg/kg administered as an intravenous infusion over 30 minutes every 3 weeks until disease progression or unacceptable toxicity.
Clinical Results
FDA Approval
Keytruda for the treatment of patients with unresectable or metastatic melanoma and disease progression following ipilimumab and, if BRAF V600 mutation positive, a BRAF inhibitor was approved under accelerated approval based on tumor response rate and durability of response. An improvement in survival or disease-related symptoms has not yet been established. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials.
The efficacy was Keytruda was eva luated in an open label, randomized, comparative dose trial in subjects with unresectable or metastatic melanoma with progression of disease; refractory to two or more doses of ipilimumab (3 mg/kg or higher) and, if BRAF V600 mutation-positive, a BRAF or MEK inhibitor; and disease progression within 24 weeks following the last dose of ipilimumab. The subjects were randomized to receive 2 mg/kg (n=89) or 10 mg/kg (n=84) of Keytruda every 3 weeks until unacceptable toxicity or disease progression that was symptomatic, was rapidly progressive, required urgent intervention, occurred with a decline in performance status, or was confirmed at 4 to 6 weeks with repeat imaging. Assessment of tumor status was performed every 12 weeks. The major efficacy outcome measures were confirmed overall response rate (ORR) according to Response eva luation Criteria in Solid Tumors (RECIST 1.1) as assessed by blinded independent central review and duration of response. The ORR was 24% (95% confidence interval: 15, 34) in the 2 mg/kg arm, consisting of 1 complete response and 20 partial responses. Among the 21 subjects with an objective response, 3 (14%) had progression of disease 2.8, 2.9, and 8.2 months after initial response. The remaining 18 subjects (86%) had ongoing responses with durations ranging from 1.4+ to 8.5+ months, which included 8 subjects with ongoing responses of 6 months or longer. One additional subject developed two new asymptomatic lesions at the first tumor assessment concurrent with a 75% decrease in overall tumor burden; Keytruda was continued and this reduction in tumor burden was durable for 5+ months. There were objective responses in subjects with and without BRAF V600 mutation-positive melanoma. Similar ORR results were observed in the 10 mg/kg arm.
Mechanism of Action
Keytruda (pembrolizumab) is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2. Binding of the PD-1 ligands, PD-L1 and PD-L2, to the PD-1 receptor found on T cells, inhibits T cell proliferation and cytokine production. Upregulation of PD-1 ligands occurs in some tumors and signaling through this pathway can contribute to inhibition of active T-cell immune surveillance of tumors. Pembrolizumab is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response. |
