Patients with polycythemia vera were more likely to achieve durable long-term hematologic response with ropeginterferon alfa-2b than the standard cytoreductive therapy hydroxyurea, according to results from the phase III PROUD-PV trial and its extension study (CONTINUATION-PV). The results, which were published in Lancet Hematology, “suggest that ropeginterferon alfa-2b can be considered as firstline cytoreductive therapy instead of hydroxyurea,” according to lead author Heinz Gisslinger, MD, of the Medical University of Vienna in Austria, and colleagues.
PROUD-PV enrolled 306 adult patients with early-stage polycythemia vera, defined as no history of cytoreductive therapy use or less than 3 years of prior hydroxyurea use. After 1 year, patients could choose to enter the extension part of the trial, CONTINUATION-PV. 臨床三期試驗PROUD-PV招募了306名早期PV的病患,病患定義為無細胞減滅療法治療史或先前使用HU治療少於3年。在參與臨床試驗一年後,病患可以選擇進入延伸性試驗CONTINUATION-PV。
In PROUD-PV, the primary endpoint was noninferiority of ropeginterferon alfa-2b versus hydroxyurea in terms of achievement of complete hematologic response with normal spleen size (defined as a longitudinal diameter of ≤12 cm in women and ≤13 cm in men) assessed at 12 months. 在PROUD-PV臨床試驗,在主要臨床療效指標包括12個月的完全血液學反應與正常脾臟大小(定義為女性脾臟大小≤12cm,男性脾臟大小≤13cm)方面,藥華藥新一代干擾素P1101相較於HU呈現非劣性。
For CONTINUATION-PV, co-primary endpoints included achievement of complete hematologic response with spleen size normalization, as well as improved disease burden. The latter endpoint was assessed by clinical resolution or improvements in splenomegaly, microvascular disturbances, pruritus, and headache. 在延伸性試驗CONTI-PV部分,主要療效終點包括完全血液學反應和正常脾臟大小,以及改善疾病負擔部分。最後一項的評估包含脾腫大、微血管障礙、瘙癢和頭痛的改善。 A total of 257 patients (median age = 60 years; range = 21-85) in the PROUD-PV trial were randomized (1:1) to receive either:
在臨床三期試驗PROUD-PV試驗中,共有257名病患被隨機分配接受以下治療: • subcutaneous ropeginterferon alfa-2b at a starting dose of 100 μg, administered every 2 weeks (n=127) 127名病患被分配到使用藥華藥新一代干擾素P1101治療,起始劑量為100μg,每2週給藥一次。 • oral hydroxyurea 500 mg/day (n=127) 127名病患被分配到口服用藥HU每天500 mg A total of 171 patients chose to enter the CONTINUATION-PV extension trial. 共有171名病患持續進行CONTI-PV延伸性試驗 Overall, the median follow-up periods for each treatment were 182.1 weeks (interquartile range [IQR] = 166.3-201.7) in the ropeginterferon alfa-2b group and 164.5 weeks (IQR=144.4-169.3) in the hydroxyurea group. 整體而言,藥華藥新一代干擾素P1101組治療中位數為182.1週,HU組為164.5週 In PROUD-PV, after 1 year of treatment, approximately 21% of patients treated with ropeginterferon alfa-2b and 28% of patients treated with standard therapy met the primary endpoint of complete hematologic response with normal spleen size. The authors concluded that in the first year, ropeginterferon alfa-2b failed to show noninferiority to hydroxyurea. However, ropeginterferon alfa-2b was better with longer-term use. 在PROUD-PV經過1年的療程後,約有21%的接受過藥華藥新一代干擾素P1101治療的病患和28%的接受過標準療程的病患達到了完全血液學反應且脾臟正常的主要療效指標。作者得到的結論是,藥華藥新一代干擾素P1101第一年和HU呈現非劣性結果。然而,藥華藥新一代干擾素P1101長期治療療效更佳。 “Ropeginterferon alfa-2b was up-titrated cautiously in PROUD-PV,” the authors wrote. The mean efficacious dose in the PROUD-¬PV study was reached after 3.7 months in the experimental group and after 2.6 months in the standard-therapy group. The median doses at 36 months were 425 μg (IQR=250-500) per administration of ropeginterferon alfa-2b and 1,000 mg (IQR=750-1,375) per administration of hydroxyurea, which had remained stable since month 12. 作者提到:「藥華藥新一代干擾素P1101在臨床試驗PROUD-PV中謹慎調高劑量。”」P1101組的平均有效劑量是3.7個月,標準療法組中的平均有效劑量為2.6個月。36個月時的平均劑量為P1101組425μg,而HU組為1,000 mg,這劑量從第12個月之後一直保持穩定。
In CONTINUATION-PV trial, a significantly higher proportion of patients treated with ropeginterferon alfa-2b achieved complete hematologic response with improved disease burden at 36 months compared with patients treated with hydroxyurea (53% vs. 38%, respectively; rate ratio = 1.42; 95% CI 1.01-2.00; p=0.044). However, there was no significant difference between the treatment groups in terms of patients who achieved the composite primary endpoint at 12 months. 在CONTI-PV延伸性試驗中,36個月後的治療,使用P1101組治療的病患相較於HU組在完全的血液學反應,且改善了疾病負擔上有著更高的比例,分別為53%和38%,p值=0.044。然而,12個月時兩組之間在達到主要療效指標上沒有顯著差異。
The investigators observed that the proportion of patients with a response in the ropeginterferon alfa¬2b arm of the extension trial gradually increased up to 24 months and remained high at 36 months. In contrast, the proportion of responders in the hydroxyurea group was highest at 12 months but subsequently decreased. See the TABLE for a detailed report of the types of responses observed in the CONTINUATION-PV trial. 研究者觀察到延伸性試驗中,P1101組中完全血液學反應的病患比例逐漸增加到24個月,並持續到36個月。反之,HU組中完全血液學反應的病患比例在12個月時最高,但隨後下降。
Responses also appeared to be more durable in the ropeginterferon alfa-2b group: A significantly greater proportion of these patients maintained complete hematologic response (39% vs. 15%, respectively; p=0.0011) and complete response with improved disease burden (30% vs. 15%; p=0.025) over 36 months. 在P1101組中的完全血液學反應也顯示持續更長的時間:這些病患中有大比例的病患在36個月的療程持續完全血液學反應(分別為39%和15%; p = 0.0011)和疾病負擔得到改善的比例分別為(分別為30%和15%;p=0.025)。
When looking at molecular responses, the researchers noted that, from baseline to 12 months, the reductions in mean JAK2 V617F allele burden were not significantly different between the ropeginterferon alfa¬2b group (41.9% to 30.7%, respectively) and the hydroxyurea group (42.8% to 25.9%, respectively). However, at 24 months, these values were significantly lower in patients treated with ropeginterferon alfa¬2b versus hydroxyurea (20.9% vs. 32.1%, respectively; p<0.0001). Similar findings were observed at month 36 (19.7% for ropeginterferon alfa¬2b vs. 39.3% for hydroxyurea, respectively; p<0.0001). Post hoc analysis revealed that a lower JAK2 V617F allele burden correlated with complete hematologic response at 12, 24, and 36 months. 研究人員在觀察分子反應時注意到,P1101組和HU組在前12個月治療期間,平均JAK2 V617F等位基因負擔減少並無沒有顯著差異。但在24個月的治療時間,P1101組病患其數值顯著低於HU組(分別為20.9%和32.1%)。在第36個月的療程也觀察到了類似的發現(P1101組為19.7%,而HU組為39.3 %,P值<0.0001)。事後分析顯示,較低的JAK2V617F等位基因負擔和12個月、24個月和36個月時的完全血液學反應相關。
In the ropeginterferon alfa-2b group, the most frequently reported grade 3 and grade 4 treatment-related adverse events (AEs) included increased gamma-glutamyltransferase (6%) and increased alanine aminotransferase (3%). In patients treated with hydroxyurea, however, the most frequently reported grade 3 and grade 4 AEs were leukopenia (5%) and thrombocytopenia (4%). Overall, the investigators found that the proportion of grade ≥3 treatment-related AEs were similar in both treatment groups, at approximately 2% in the ropeginterferon alfa-2b group and 4% in the hydroxyurea group. 在P1101組中,最常被提及不良反應主要是3級和4級的GGT指數增加(6%)和增加的血清轉胺酶(ALT)(3%)。然而在接受HU治療的病患中,最常報告的3級和4級不良反應是白血球減少(5%)和血小板減少症(4%)。整體而言兩個治療組中,等級3級與治療相關的不良反應比例類似,P1101組約為2%,HU組約為4%。
Four deaths were recorded; only one death (in the hydroxyurea group, due to acute leukemia) was considered treatment related. 記錄中有4例死亡;僅1例死亡(在HU組中,由於急性白血病)被認定和治療有關。
While these findings appear to corroborate the disease-modifying potential of interferon alfa–based therapy that has been demonstrated in previous trials, the authors noted several potential limitations, including the low number of patients with baseline splenomegaly, the low number of patients who consented to bone marrow assessment for the evaluation of hematologic and clinical efficacy outcomes, the potential of confounding by some patients’ prior use of hydroxyurea for up to 3 years, and the possibility of selection bias in the extension study. 儘管這些發現似乎證實了先前試驗已證實的干擾素療法的疾病緩解潛力,但作者指出了一些潛在的局限性,包括原先脾腫大的病患比例少、接受骨髓檢查以評估血液學和臨床療效結果的病患人數很少、以及先前使用HU治療長達三年的病人可能會造成混淆,以及延伸性試驗的選擇性偏誤的可能。
另外,本次新冠肺炎疫情對本公司產品Besremi(P1101, Ropeginterferon)在歐洲之需求有正面影響,本公司已積極準備足量的P1101,以供給需求。本次正面影響顯然係因英國國民保健署(National Health Service , NHS)將血癌患者歸類於極易受到新冠病毒感染的族群。因骨髓增生性腫瘤 (Myeloproliferative Neoplasms, MPNs)為血癌,NHS與MPN專家針對包含PV在內的MPN患者提出一系列的呼籲[1]。因過去研究報告指出Ruxolitinib(Jakafi)會弱化患者之免疫系統,導致患者更容易遭受到他種病毒嚴重的感染,故MPN專家提醒服用Ruxolitinib的MPN患者更容易感染新冠肺炎,需要格外小心。但在同一份報告中表示,接受α干擾素治療的MPN患者則沒有這方面的疑慮。
藥華藥公告指出,百斯瑞明(R)針筒裝注射液劑500微克/毫升(Besremi(R) 500 mcg/mL solution for injection in prefilled syringe)於109年4月30日通過台灣衛福部新藥查驗登記審查,適應症為治療不具症狀性脾腫大之成人真性紅血球增多症病人(PV),5月5日獲衛福部之藥品查驗登記核准函,許可證字號為衛部菌疫製字第000143號。