– Part 2 of REFRαME-O1, the registration-directed study of luvelta for patients with platinum-resistant ovarian cancer (PROC), is open for enrollment –

–REFRαME-O1的第2部分是针对铂类耐药卵巢癌（PROC）患者的luvelta注册指导研究

– Planned 50 patients in Dose-Optimization (Part 1) of REFRαME-O1 have been enrolled and are in follow up –

-计划中的50名REFRαME-O1剂量优化（第1部分）患者已入选并正在随访中-

SOUTH SAN FRANCISCO, Calif., April 30, 2024 (GLOBE NEWSWIRE) -- Sutro Biopharma, Inc (Sutro or the Company) (NASDAQ: STRO), a clinical-stage oncology company pioneering site-specific and novel-format antibody drug conjugates (ADCs), today announced that the randomized portion (Part 2) of REFRαME-O1, the registration-directed trial of luveltamab tazevibulin (luvelta) in platinum-resistant ovarian cancer (PROC), is now open for enrollment, and the planned 50 patients in Part 1 of the trial have been enrolled.

加利福尼亚州南旧金山，2024年4月30日（环球通讯社）--Sutro Biopharma，Inc（Sutro或该公司）（纳斯达克：STRO），一家临床阶段肿瘤公司，开创了位点特异性和新型抗体-药物偶联物（ADC）的先河，今天宣布REFRαME-O1的随机部分（第2部分），即luveltamab tazevibulin（luvelta）在铂类耐药卵巢癌（PROC）中的注册指导试验，现已开放注册，该试验第1部分计划的50名患者已经入组。

Luvelta is a novel Folate Receptor-α (FRα) targeting ADC with the potential to benefit 8 out of 10 PROC patients, including addressing high unmet medical need in patients with low-medium FRα expression..

Luvelta是一种靶向ADC的新型叶酸受体-α（FRα），有可能使10名PROC患者中的8名受益，包括解决中低FRα表达患者的高未满足医疗需求。。

“We are pleased to announce the initiation of the Phase 3 portion of our global, registration-directed clinical trial of luvelta, in patients with platinum-resistant ovarian cancer,” said Anne Borgman, M.D., Sutro’s Chief Medical Officer. “The speed with which we were able to enroll Part 1 of the trial speaks to the continued demand for a targeted therapy for patients that are not well supported by the standard of care.

Sutro首席医疗官医学博士安妮·博格曼（AnneBorgman）表示：“我们很高兴宣布，针对铂类耐药卵巢癌患者的luvelta全球注册指导临床试验的第三阶段已经开始。”。“我们能够快速注册试验的第一部分，这表明对于没有得到标准护理支持的患者，仍然需要针对性治疗。

With evidence of clinical activity seen in all tumor types that have been tested with luvelta, we look forward to providing a promising treatment option to patients in need, including those with ovarian cancer and beyond.”.

有证据表明，已经用luvelta测试过的所有肿瘤类型都具有临床活性，我们期待着为有需要的患者（包括卵巢癌患者）提供有希望的治疗选择。”。

REFRaME-O1 is a global registration-directed study evaluating the efficacy and safety of luvelta versus chemotherapy in women with PROC with FRα expression ≥25% Tumor Proportion Score (TPS), defined as at least 25% or greater of tumor expressing FRα, at any intensity (1+,2+,3+). In Part 2, approximately 500 patients will be enrolled and randomized 1:1 to the selected luvelta dose or investigators’ choice of chemotherapy.

REFRaME-O1是一项全球注册指导的研究，评估了在任何强度（1+，2+，3+）下，FRα表达≥25%肿瘤比例评分（TPS）（定义为至少25%或更高的肿瘤表达FRα）的PROC女性中，luvelta与化疗的疗效和安全性。在第二部分中，将招募大约500名患者，并以1:1的比例随机分配到选定的luvelta剂量或研究者选择的化疗。

The trial includes a planned interim analysis to support a potential application for accelerated approval..

该试验包括计划的中期分析，以支持潜在的加速批准申请。。

About Luveltamab Tazevibulin

关于Luveltamab Tazevibulin

Luveltamab tazevibulin, abbreviated as “luvelta” and formerly known as STRO-002, is a FRα-targeting antibody-drug conjugate (ADC) designed to treat a broad range of patients with ovarian cancer, including those with lower FRα-expression who are not eligible for approved treatment options targeting FRα.

Luveltamab tazevibulin，缩写为“luvelta”，以前称为STRO-002，是一种FRα靶向抗体-药物偶联物（ADC），旨在治疗广泛的卵巢癌患者，包括FRα表达较低的患者，这些患者不符合批准的靶向FRα的治疗选择。

Developed and manufactured with Sutro’s cell-free XpressCF® platform, luvelta is a homogeneous ADC with four hemiasterlin cytotoxins per antibody, precisely positioned to efficiently deliver to the tumor while ensuring systemic stability after dosing. REFRαME-O1, a Phase 2/3 registration-directed study for patients with platinum-resistant ovarian cancer is ongoing.

luvelta是使用Sutro的无细胞XpressCF®平台开发和制造的均质ADC，每种抗体具有四种半星状细胞毒素，精确定位以有效递送至肿瘤，同时确保给药后的全身稳定性。REFRαME-O1是一项针对铂类耐药卵巢癌患者的2/3期注册指导研究。

The Company has additional ongoing trials in patients with endometrial cancer and in combination with bevacizumab in patients with ovarian cancer. The Company expects to file an Investigational New Drug (IND) Application for the initiation of a non-small cell lung cancer study in the first half of 2024 and expects to initiate REFRαME-P1, a Phase 2/3 registration-directed study for patients with CBF/GLIS2 acute myeloid leukemia, a rare subtype of pediatric cancer, in the second half of 2024.

该公司正在对子宫内膜癌患者进行额外的试验，并与贝伐单抗联合治疗卵巢癌患者。该公司预计在2024年上半年提交一份研究性新药（IND）申请，以启动非小细胞肺癌研究，并预计在2024年下半年启动REFRαME-P1，这是一项针对儿童癌症罕见亚型CBF/GLIS2急性髓细胞白血病患者的2/3期注册指导研究。

The U.S. Food and Drug Administration (FDA) has granted luvelta a Fast Track designation for Ovarian Cancer, as well as Orphan and Rare Pediatric Disease designations for CBF/GLIS2 Pediatric AML..

美国食品和药物管理局（FDA）已授予卢维塔卵巢癌快速通道指定，以及CBF/GLIS2儿科AML的孤儿和罕见儿科疾病指定。。

AboutSutroBiopharma

关于utroBiopharma

Sutro Biopharma, Inc., is a clinical-stage company relentlessly focused on the discovery and development of precisely designed cancer therapeutics, transforming what science can do for patients. Sutro’s fit-for-purpose technology, including cell-free XpressCF®, provides the opportunity for broader patient benefit and an improved patient experience.

Sutro Biopharma，Inc.是一家临床阶段公司，专注于发现和开发精确设计的癌症治疗药物，改变科学可以为患者做的事情。Sutro的fit-for-purpose技术，包括无细胞XpressCF®，为更广泛的患者利益和改善的患者体验提供了机会。

Sutro has multiple clinical stage candidates, including luveltamab tazevibulin, or luvelta, a registrational-stage folate receptor alpha (FolRα)-targeting ADC in clinical studies. A robust pipeline, coupled with high-value collaborations and industry partnerships, validates our continuous product innovation.

Sutro有多个临床阶段候选者，包括luveltamab tazevibulin或luvelta，这是临床研究中针对登记阶段叶酸受体α（FolRα）的ADC。强大的渠道，加上高价值的合作和行业伙伴关系，验证了我们持续的产品创新。

Sutro is headquartered in South San Francisco. For more information, follow Sutro on social media @Sutrobio, or visit www.sutrobio.com..

萨特罗总部位于旧金山南部。有关更多信息，请关注社交媒体上的Sutro @Sutrobio，或访问www.Sutrobio.com。。

Forward-LookingStatements

前瞻性陈述

This press release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, including, but not limited to, anticipated preclinical and clinical development activities, including enrollment and site activation; timing of announcements of clinical results, trial initiation, and regulatory filings; outcome of regulatory decisions; potential benefits of luvelta and the Company’s other product candidates and platform; potential expansion into other indications and combinations, including the timing and development activities related to such expansion; potential market opportunities for luvelta and the Company’s other product candidates; and the Company’s expected cash runway.

本新闻稿包含1995年《私人证券诉讼改革法案》中“安全港”条款含义内的前瞻性声明，包括但不限于预期的临床前和临床开发活动，包括注册和网站激活；宣布临床结果，试验开始和监管备案的时间；监管决定的结果；luvelta和公司其他候选产品和平台的潜在利益；可能扩展到其他适应症和组合，包括与此类扩展相关的时间安排和开发活动；luvelta和公司其他候选产品的潜在市场机会；以及该公司的预期现金跑道。

All statements other than statements of historical fact are statements that could be deemed forward-looking statements. Although the Company believes that the expectations reflected in such forward-looking statements are reasonable, the Company cannot guarantee future events, results, actions, levels of activity, performance or achievements, and the timing and results of biotechnology development and potential regulatory approval is inherently uncertain.

除历史事实陈述外的所有陈述均为可被视为前瞻性陈述的陈述。虽然公司认为这些前瞻性声明中反映的期望是合理的，但公司无法保证未来的事件、结果、行动、活动水平、绩效或成就，生物技术开发和潜在监管批准的时间和结果本身是不确定的。

Forward-looking statements are subject to risks and uncertainties that may cause the Company’s actual activities or results to differ significantly from those expressed in any forward-looking statement, including risks and uncertainties related to the Company’s ability to advance its product candidates, the receipt and timing of potential regulatory designations, approvals and commercialization of product candidates and the Company’s ability to successfully leverage Fast Track designation, the market size for the Company’s product candidates to be smaller than anticip.

前瞻性陈述具有可能导致公司的实际活动或结果与任何前瞻性陈述中所表达的显着不同的风险和不确定性，包括与公司推进其候选产品的能力，潜在监管指定的接收和时间，候选产品的批准和商业化以及公司成功利用快速通道指定的能力相关的风险和不确定性，公司候选产品的市场规模小于anticip。

Contact

联系人

Emily White

艾米丽·怀特

Sutro Biopharma

Sutro生物制药

(650) 823-7681

(650) 823-7681

ewhite@sutrobio.com

ewhite@sutrobio.com