在过去十年中,前列腺癌的治疗格局发生了巨大变化,其中放射性配体疗法(RLT)的兴起尤为瞩目。从最初针对终末期患者的挽救性治疗,到如今向早期阶段迈进,RLT展现出巨大的临床应用潜力。在近期举行的上海泌尿肿瘤学术大会上,肿瘤瞭望-泌尿时讯特邀澳大利亚彼得麦卡勒姆癌症中心Renu Eapen教授分享Lu-PSMA系列研究及其在转移性激素敏感性前列腺癌(mHSPC)领域最新进展的深刻见解。
编者按:在过去十年中,前列腺癌的治疗格局发生了巨大变化,其中放射性配体疗法(RLT)的兴起尤为瞩目。从最初针对终末期患者的挽救性治疗,到如今向早期阶段迈进,RLT展现出巨大的临床应用潜力。在近期举行的上海泌尿肿瘤学术大会上,肿瘤瞭望-泌尿时讯特邀澳大利亚彼得麦卡勒姆癌症中心Renu Eapen教授分享Lu-PSMA系列研究及其在转移性激素敏感性前列腺癌(mHSPC)领域最新进展的深刻见解。
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《肿瘤瞭望-泌尿时讯》:近年来,前列腺癌放射性配体疗法(RLT)领域取得了哪些重要研究进展?特别是近期报道的PSMAddition研究可能会对临床实践产生怎样的影响?
Renu Eapen教授:过去十年,前列腺癌RLT领域发生了显著变化。首个前瞻性研究是由我中心Michael Hoffman教授牵头的LuPSMA试验。该研究是一项前瞻性、单臂II期临床研究,旨在评估177-Lu-PSMA-617治疗多线疗法失败(中位既往接受过4线方案)的mCRPC患者。该研究的核心亮点是采用PSMA/FDG双PET/CT进行精准筛选,剔除PSMA低表达或FDG阳性/PSMA阴性的异质性病灶。结果显示:64%的患者PSA下降≥50%,中位OS达13.3个月,且显著缓解骨痛并改善生活质量。安全性方面,仅见轻度口干及可控的血液毒性。这项研究推动了后续TheraP与VISION研究的开展。这些临床试验,共同证实了Lu-177-PSMA对于晚期终末期患者能带来良好的临床疗效和生活质量改善。
改善晚期患者生存
VISION研究是一项具有里程碑意义的随机开放标签III期临床试验。研究对比了在最佳标准治疗(BSoC)基础上,加用177-Lu-PSMA-617对既往接受过至少一种AR抑制剂和紫杉烷类化疗的PSMA阳性mCRPC患者的疗效。研究结果显示:与单用BSoC相比,联合组的中位OS显著延长(15.3 vs 11.3个月),rPFS也得到明显改善(8.7 vs 3.4个月)。该研究证实了RLT能显著降低死亡风险,直接推动了FDA批准上市,确立了核素治疗在晚期前列腺癌中的标准方案地位。
TheraP研究是全球首个将放射性配体疗法与标准化疗进行头对头比较的随机、多中心II期临床试验。该研究为177-Lu-PSMA-617在mCRPC治疗中的二线地位提供了强有力的证据。研究入组了200名在多西他赛化疗后出现进展的mCRPC患者。试验组接受177-Lu-PSMA-617治疗,对照组接受二线化疗药物卡巴他赛。与VISION研究不同,TheraP采用了更严格的PSMA/FDG双PET筛选方案,要求患者病灶的SUV≥20,且剔除了FDG阳性但PSMA阴性的“不匹配”病灶(这部分患者约占10%)。研究结果显示,在PSA反应率方面,Lu-PSMA组显著优于化疗组(66%vs 37%)。PFS方面,在12个月随访中,Lu-PSMA组的PFS比例明显更高(19%vs 3%),显著降低了疾病进展风险。此外Lu-PSMA组的3-4级不良事件发生率远低于化疗组(33%vs 53%),且在疼痛、体力等生活质量指标上表现更佳。对于经过PET精准筛选的患者,177-Lu-PSMA-617较传统二线化疗具有更高的活性、更低的毒性和更好的患者依从性。
RLT应用正逐步前移
ENZA-P研究是一项前瞻性随机对照的II期临床试验,旨在探讨将RLT与新型内分泌药物恩扎卢胺联合使用的增效作用。研究纳入尚未接受过新型内分泌治疗(如阿比特龙、恩扎卢胺)的mCRPC患者。试验组采用恩扎卢胺联合177-Lu-PSMA-617(根据PET表现给予2-4次治疗),对照组仅单用恩扎卢胺。研究结果显示:联合组PSA-PFS显著优于单药组(13.0 vs 7.8个月),降低了57%的进展风险。联合组PSA 50反应率可达到93%,而单药组为68%。研究结果显示在恩扎卢胺基础上加入Lu-PSMA具有显著的协同效应,能更早、更强力地控制疾病进展。
PSMAfore研究是一项具有深远影响的随机对照III期临床试验,其核心贡献是将RLT的应用时机从“化疗后”正式推向了“化疗前”。研究入组了既往仅接受过一种ARPI治疗(如阿比特龙或恩扎卢胺)出现进展、且从未接受过多西他赛化疗的PSMA阳性mCRPC患者。实验组接受177-Lu-PSMA-617,对照组则接受ARPI方案转换(即换用另一种内分泌药物)。研究结果显示:Lu-PSMA组rPFS显著优于对照组,中位rPFS达12.0个月,而对照组仅为5.6个月(HR=0.41),疾病进展风险降低了59%。OS方面实验组也显示出明显的获益趋势。在生活质量方面:Lu-PSMA组在维持生活质量和缓解疼痛方面展现出明显优势。该研究证明了对于内分泌治疗耐药后的mCRPC患者,直接使用RLT比更换另一种内分泌药物更有效,确立了其在二线(化疗前)治疗中的地位。
mHSPC阶段,RLT目前亦有尝试
UpFrontPSMA是一项具有开创性的随机、多中心II期临床研究,旨在评估177-Lu-PSMA-617联合多西他赛在初诊高负荷mHSPC患者中的疗效。患者随机接受2周期Lu-PSMA序贯6周期多西他赛(试验组)或单用多西他赛化疗(对照组),两组均维持基础ADT治疗。研究结果显示,48周时,试验组达到PSA不可测(≤0.2ng/ml)的比例显著更高(41%vs 16%,P=0.002)。此外,试验组的中位PSA-PFS显著延长(31 vs 20个月),且两组3-4级不良事件发生率相当(29%vs 27%),安全性良好。该研究是全球首个在mHSPC阶段证实RLT获益的随机对照研究,有力支持了前列腺癌核素治疗的早期应用。
PSMAddition研究是一项关键的国际多中心III期临床试验,代表了RLT向mHSPC阶段迈进的最前沿探索。研究纳入了PSMA PET阳性的初治或仅接受过短期基础治疗的mHSPC患者。试验组在现有标准治疗(SOC:ADT联合新型ARPI,即“双重疗法”的基础上,加用177-Lu-PSMA-617);对照组则仅接受标准疗法。研究主要终点为rPFS,次要终点包括OS和PSA进展时间。该研究旨在验证“三联疗法”在疾病极早期介入的价值。在患者尚处于激素敏感阶段时,利用核素精准打击微小转移灶,能更有效地减少肿瘤负荷,从而显著延缓患者进入CRPC阶段的时间。
这些研究表明,Lu-PSMA耐受性良好,在疾病各阶段(包括mHSPC)都显示出治疗活性。未来的重点将是精准筛选患者,并考虑在mHSPC阶段早期序贯应用最佳疗法,以尽可能延缓疾病进展至mCRPC。
The RLT landscape has evolved significantly over the last ten years5.The first prospective study was the LuPSMA trial,led by Professor Michael Hofman at our center.This single-arm Phase II study evaluated 177-Lu-PSMA-617 in patients with metastatic castration-resistant prostate cancer(mCRPC)who had failed multiple lines of therapy(median of 4 prior regimens).A core highlight was the use of PSMA/FDG dual PET/CT for precision screening to exclude patients with low PSMA expression or discordant lesions(FDG-positive/PSMA-negative).The results were impressive:64%of patients achieved a PSA decline of≥50%,the median overall survival(OS)reached 13.3 months,and patients experienced significant relief from bone pain and improved quality of life.This foundational work directly paved the way for the TheraP and VISION trials,confirming that 177-Lu-PSMA-617 provides excellent biochemical responses and improved quality of life even in late-stage,terminal patients.
The VISION study was a landmark randomized,open-label Phase III trial.It compared 177-Lu-PSMA-617 plus Best Standard of Care(BSoC)against BSoC alone in PSMA-positive mCRPC patients who had previously received at least one AR pathway inhibitor(ARPI)and taxane-based chemotherapy.The results showed that the combination significantly extended median OS(15.3 vs.11.3 months)and markedly improved radiographic progression-free survival(rPFS)(8.7 vs.3.4 months).This study confirmed that RLT significantly reduces the risk of death,leading to the FDA approval of Pluvicto and establishing RLT as a standard of care for advanced prostate cancer.
The TheraP study(ANZUP 1603)was the world’s first randomized,multicenter Phase II trial to conduct a head-to-head comparison between RLT and standard chemotherapy.It provided strong evidence for the second-line status of177-Lu-PSMA-617 in mCRPC.The trial enrolled 200 patients whose disease progressed after docetaxel.The experimental group received 177-Lu-PSMA-617,while the control group received cabazitaxel.Unlike VISION,TheraP utilized stricter PSMA/FDG dual PET screening(requiring SUVmax≥20).Results showed a significantly higher PSA response rate for the Lu-PSMA group(66%vs.37%)and a higher proportion of progression-free survival at 12 months(19%vs.3%).Furthermore,Grade 3-4 adverse events were much lower in the Lu-PSMA group(33%vs.53%),with superior quality-of-life indicators.
Currently,the application of RLT is moving earlier in the treatment continuum.
●ENZA-P Study:This Phase II trial explored the synergy of RLT with the novel endocrine drug enzalutamide in ARPI-naive mCRPC patients.The combination reduced the risk of progression by 57%,with a PSA 50 response rate of 93%compared to 68%for enzalutamide alone.
●PSMAfore Study:This Phase III trial moved RLT into the pre-chemotherapy(taxane-naive)setting.Compared to switching to a different ARPI,177-Lu-PSMA-617 significantly improved rPFS(12.0 vs.5.6 months)and reduced the risk of disease progression by 59%.
●UpFrontPSMA Study:A pioneering Phase II study in high-volume mHSPC.It showed that two cycles of Lu-PSMA followed by six cycles of docetaxel resulted in a significantly higher proportion of patients achieving undetectable PSA(≤0.2 ng/ml)at 48 weeks(41%vs.16%)and extended PSA-PFS(31 vs.20 months).
●PSMAddition Study:This ongoing international Phase III trial represents the frontier of RLT in the mHSPC stage.It evaluates a"triplet therapy"(ADT+novel ARPI+177-Lu-PSMA-617)versus standard doublet therapy.The goal is to use radioligands to precisely target micrometastases early on,reducing tumor burden and delaying the transition to the CRPC stage.
In summary,Lu-PSMA is well-tolerated and demonstrates activity across various stages of the disease.Future focus will remain on precision patient selection and the optimal sequencing of therapies in the mHSPC stage to delay progression as much as possible.
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《肿瘤瞭望-泌尿时讯》:近年来,抗体药物偶联物(ADC)等在实体瘤治疗中展现出巨大潜力。您如何看待这类新型药物在前列腺癌领域的应用前景?
Renu Eapen教授:针对前列腺癌不同靶点的抗体偶联药物(ADC)和放射性配体药物是一个极具吸引力的研究方向。据悉,中国目前也有多项针对不同靶点的ADC药物正处于I-II期临床试验阶段,前景十分可观。然而,面临的挑战在于如何精准筛选出能从中获益的人群。与PSMA靶向疗法相比,ADC的患者筛选或许更具挑战性。目前已有成熟的PSMA PET-CT成像技术来筛选PSMA高表达的患者。但对于不同靶点的ADC,我们仍需要研发相应的生物标志物以指导治疗。此外,开展涉及这些ADC药物的新辅助治疗研究至关重要,这有助于我们深入了解其作用机制和疾病生物学特性,为未来的临床应用奠定基础。
ADCs and radioligand therapies targeting different antigens in prostate cancer represent a highly attractive research direction.Several ADC candidates targeting various antigens are currently in Phase I-II clinical trials in China,showing promising prospects.However,the challenge lies in precision screening of the population most likely to benefit.Compared to PSMA-targeted therapies,where PSMA PET-CT imaging is a mature screening tool,ADCs require the development of corresponding biomarkers to guide treatment.Furthermore,conducting neoadjuvant studies with these ADCs is essential.Such research will help us better understand their mechanisms of action and the underlying biology of the disease,building a solid foundation for future clinical applications.
Renu Eapen教授
澳大利亚彼得麦卡勒姆癌症中心
Eapen教授目前受聘于墨尔本皇家医院Peter MacCallum肿瘤中心泌尿外科。她是澳大利亚和新西兰泌尿学会(USANZ)、美国泌尿学会(AUA)、泌尿肿瘤学会(SUO)和泌尿动力学、女性盆腔医学和泌尿生殖重建学会(SUFU)的成员,目前主持LuTectomy临床试验,曾获2022年前列腺癌基金(PCF)青年研究者奖,目前在European Urology等国际期刊发表论文40余篇,是GUCast全球泌尿肿瘤自媒体共同主理人。