Summary of Radiopharm Theranostics (RADX) Update / Briefing August 26, 2025 Company and Industry Overview - **Company**: Radiopharm Theranostics (RADX) - **Industry**: Oncology, specifically focusing on prostate cancer treatment and radiopharmaceutical therapies Key Points and Arguments 1. **Prostate Cancer Treatment Landscape**: The treatment of prostate cancer has evolved significantly, moving from traditional methods like surgery and chemotherapy to incorporating genetics, molecular imaging, and targeted therapies, including immunotherapy and radiopharmaceuticals [11][12][30] 2. **B7-H3 as a Target**: B7-H3 is highlighted as a promising new target for prostate cancer treatment, being highly expressed in various tumors, including 93% of castrate-resistant prostate cancer cases. This makes it a viable alternative to PSMA-targeted therapies, especially in cases where PSMA expression is low [39][41][43] 3. **Need for New Therapies**: There is a critical need for more effective therapies for metastatic castration-resistant prostate cancer, as current treatments often provide limited survival benefits [18][30] 4. **NCCN Guidelines**: The National Comprehensive Cancer Network (NCCN) guidelines are discussed, emphasizing the importance of treatment sequencing and the variety of options available based on prior therapies [19][20] 5. **Theranostics Concept**: The concept of theranostics is introduced, where ligands are designed to bind to specific cancer cell targets, allowing for both diagnosis and treatment using radiopharmaceuticals [24][25] 6. **Clinical Trials and FDA Approvals**: The presentation mentions several clinical trials demonstrating survival benefits from new therapies, including the FDA approval of Plavicto (lutetium-177) for prostate cancer treatment [27][28][51] 7. **BetaBART Development**: The development of BetaBART, a humanized monoclonal antibody targeting the four Ig isoform of B7-H3, is presented as a novel approach in radioimmunotherapy, with plans for a Phase 1 trial in 2025 [51][66] 8. **Competitive Landscape**: The competitive landscape for B7-H3 targeting is discussed, noting that while there are other modalities like ADCs and CAR T-cell therapies, the unique properties of BetaBART provide a competitive advantage [75][78][87] 9. **Immunological Memory**: Evidence of secondary immune memory from prior treatments suggests that BetaBART may not only target tumors but also enhance the immune response against them [64][66] 10. **Market Potential**: The potential market for B7-H3 targeting therapies is significant, with opportunities extending beyond prostate cancer to other solid tumors [46][51] Other Important but Overlooked Content 1. **Challenges with Current Therapies**: The limitations of existing therapies, including the need for better options post-Plavicto treatment, are emphasized, highlighting the urgency for innovation in this space [30][102] 2. **Mechanism of Action**: The mechanism of action for BetaBART is discussed, focusing on its ability to selectively target the four Ig isoform of B7-H3 while minimizing off-target effects and toxicity [49][66] 3. **Future Directions**: The discussion includes the need for randomized control groups in future trials to better assess the efficacy of new treatments [31] This summary encapsulates the critical insights from the briefing, focusing on the advancements in prostate cancer treatment, the significance of B7-H3 as a target, and the innovative approaches being developed by Radiopharm Theranostics.

Core Insights - Y-mAbs Therapeutics, Inc. is focused on developing and commercializing novel radioimmunotherapy and antibody-based therapeutic products for cancer treatment [1][4] - The company presented data on GD2-SADA in a trial for recurrent or refractory metastatic solid tumors expressing GD2 at the Advances in Neuroblastoma Research Meeting [1][2] Company Overview - Y-mAbs is a commercial-stage biopharmaceutical company with a focus on radioimmunotherapy and antibody-based cancer therapies [4] - The company’s product pipeline includes DANYELZA® (naxitamab-gqgk), the first FDA-approved treatment for relapsed or refractory high-risk neuroblastoma [4] Trial Information - The ongoing Phase 1 trial (Trial 1001, NCT05130255) evaluates the safety and tolerability of GD2-SADA Pretargeted Radioimmunotherapy (GD2-SADA PRIT) with Lutetium 177 DOTA (177Lu-DOTA) in patients with GD2-expressing solid tumors [2][5] - Part A of the trial focuses on dose escalation to determine the optimal safe dose of GD2-SADA and the administration interval between GD2-SADA and 177Lu-DOTA [2] Presentation Details - The trial data was presented in a poster format at the Advances in Neuroblastoma Research Meeting on May 26, 2025 [3] - The initial data readout from Trial 1001 is expected to be provided during a virtual Radiopharmaceutical R&D update on May 28, 2025 [3] Technology Overview - GD2-SADA is a bispecific fusion protein designed to bind to GD2 and Lutetium 177 DOTA, facilitating targeted radiotherapy [5] - The pre-targeted radiotherapy process involves an initial infusion of non-radiolabeled GD2-SADA followed by a second infusion delivering the radioactive payload for localized irradiation [5] Research Collaboration - The SADA technology for radioimmunotherapy was developed by researchers at Memorial Sloan Kettering Cancer Center and is exclusively licensed to Y-mAbs [6]

Core Viewpoint - Y-mAbs Therapeutics, Inc. is set to hold a virtual Radiopharmaceutical R&D update on May 28, 2025, focusing on its ongoing clinical trials and pipeline strategy for cancer treatment [1][2]. Group 1: Upcoming Event Details - The virtual update will cover Part A clinical data from the ongoing Phase 1 GD2-SADA clinical trial, including pharmacokinetic and dosimetry data [2]. - The update will also include information on nonclinical optimization studies for the GD2-SADA asset and plans for clinical implementation [2]. - The duration of the update is expected to be 90 minutes, with a live audio webcast available on the company's Investor Relations website [3]. Group 2: Company Overview - Y-mAbs is a commercial-stage biopharmaceutical company focused on developing novel radioimmunotherapy and antibody-based therapeutic products for cancer treatment [4]. - The company utilizes technologies such as the Self-Assembly DisAssembly (SADA) Pretargeted Radioimmunotherapy Platform (PRIT) and bispecific antibodies generated using the Y-BiClone platform [4]. - The product pipeline includes DANYELZA® (naxitamab-gqgk), the first FDA-approved treatment for relapsed or refractory high-risk neuroblastoma in specific patient populations [4].

Core Viewpoint - Y-mAbs Therapeutics reported solid financial results for Q1 2025, highlighting growth in DANYELZA net product revenue and advancements in its SADA PRIT platform, while also managing operational costs prudently [2][4][20]. Financial Results - Total net product revenues for Q1 2025 were $20.9 million, an 8% increase from $19.4 million in Q1 2024 [4][7]. - U.S. DANYELZA net product revenues decreased by 28% to $13.4 million, while Ex-U.S. revenues increased by $6.7 million to $7.5 million [8][9]. - Gross profit remained stable at $17.9 million, with gross margins of 86% in Q1 2025 compared to 89% in Q1 2024 [14]. - Operating costs included $11.4 million in R&D expenses, down from $13.3 million in the previous year, and $13.1 million in SG&A expenses, up from $11.4 million [15][16]. - The net loss for Q1 2025 was $5.2 million, or ($0.12) per share, an improvement from a net loss of $6.6 million, or ($0.15) per share, in Q1 2024 [18]. Corporate Developments - The National Comprehensive Cancer Network updated its guidelines to include DANYELZA as a Category 2A treatment option for high-risk neuroblastoma [5]. - The first patient was dosed in the Phase 1 clinical trial (Trial 1201) for CD38-SADA pretargeted radioimmunotherapy in relapsed/refractory non-Hodgkin Lymphoma [5][6]. - The company plans to host a virtual R&D update on May 28, 2025, to discuss clinical data and future strategies [4][12]. Cash Position and Guidance - As of March 31, 2025, Y-mAbs had cash and cash equivalents of $60.3 million, expected to support operations into 2027 [19][25]. - The company reiterated its full-year 2025 revenue guidance of $75 million to $90 million and projected Q2 2025 revenues between $17 million and $19 million [20][21].

Core Viewpoint - Y-mAbs Therapeutics, Inc. announced that naxitamab-gqgk (DANYELZA®) has been recommended as a Category 2A treatment option for high-risk neuroblastoma by the National Comprehensive Cancer Network (NCCN) [1][2] Company Overview - Y-mAbs is a commercial-stage biopharmaceutical company focused on developing and commercializing novel radioimmunotherapy and antibody-based therapeutic products for cancer treatment [8] - The company’s product pipeline includes DANYELZA (naxitamab-gqgk), which is the first FDA-approved treatment for relapsed or refractory high-risk neuroblastoma in patients who have shown a partial response, minor response, or stable disease to prior therapy [8] Product Information - Naxitamab-gqgk (DANYELZA) was granted accelerated approval by the FDA on November 25, 2020, for pediatric patients aged one year and older and adult patients with relapsed or refractory high-risk neuroblastoma [3] - The approval was based on efficacy results from two single-arm, open-label trials [3] - DANYELZA is indicated for use in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF) [6] - The product includes a Boxed Warning for serious infusion-related reactions and neurotoxicity [6] NCCN Guidelines - The NCCN is a not-for-profit alliance of 33 leading cancer centers focused on advancing quality cancer care [4] - The inclusion of DANYELZA in the NCCN Guidelines reinforces its position as a leading anti-GD2 therapy for high-risk neuroblastoma [2]

Core Insights - Y-mAbs Therapeutics, Inc. is set to report its first quarter 2025 results on May 13, 2025, before market opening [1] - A conference call and webcast will be held on the same day at 8:00 a.m. ET to discuss the results, with a live audio webcast available on the company's Investor Relations website [2] Company Overview - Y-mAbs is a commercial-stage biopharmaceutical company focused on developing and commercializing novel radioimmunotherapy and antibody-based therapeutic products for cancer treatment [3] - The company utilizes advanced technologies such as the Self-Assembly DisAssembly (SADA) Pretargeted Radioimmunotherapy Platform (PRIT) and bispecific antibodies from the Y-BiClone platform [3] - Y-mAbs has a broad product pipeline, including DANYELZA® (naxitamab-gqgk), which is the first FDA-approved treatment for relapsed or refractory high-risk neuroblastoma in specific patient conditions [3]

Core Insights - Y-mAbs Therapeutics, Inc. presented preclinical and translational pharmacokinetics (PK) data of CD38-SADA at the 2025 AACR Annual Meeting, focusing on its potential for cancer treatment [1][2] Group 1: Presentation Details - The poster titled "Preclinical and translational pharmacokinetic (PK) modeling of the self-assembling and disassembling (SADA) bispecific fusion protein CD38-SADA for first-in-human (FIH) pretargeted radioimmunotherapy (PRIT)" was presented, detailing plasma concentrations of CD38-SADA in animal models [2][5] - The presentation took place on April 27, 2025, from 2:00 p.m. to 5:00 p.m. CT at Poster Section 25 [5] Group 2: Research Findings - The study characterized the concentration- and time-dependent equilibrium between CD38-SADA tetramers and monomers, with the model showing that low molecular weight CD38-SADA monomers cleared from plasma 20 times faster than the tetramers [3] - The preclinical PK model provided insights into the circulating levels of CD38-SADA protein in vivo, which informed the design and initial dosing regimen of the first-in-human Phase 1 Trial 1201 [4] Group 3: Company Overview - Y-mAbs is a commercial-stage biopharmaceutical company focused on developing novel radioimmunotherapy and antibody-based therapeutic products for cancer treatment [6] - The company's product pipeline includes DANYELZA®, the first FDA-approved treatment for relapsed or refractory high-risk neuroblastoma [6] Group 4: CD38-SADA PRIT Technology - CD38-SADA is a bispecific fusion protein that binds to CD38 and Lu-DOTA, facilitating a two-step pre-targeted radioimmunotherapy process [7][8] - The technology has shown robust anti-tumor efficacy in preclinical studies and is currently being investigated in adults with relapsed, progressive, or refractory non-Hodgkin lymphoma [8]

Core Insights - Y-mAbs Therapeutics has initiated its Phase 1 clinical trial (Trial 1201) for the CD38-SADA Pre-targeted Radioimmunotherapy (PRIT) platform aimed at treating relapsed or refractory non-Hodgkin Lymphoma (r/r NHL) [1][3] - The trial focuses on the safety and tolerability of the CD38-SADA: Lu-DOTA Drug Complex, with the first patient successfully administered both the protein and imaging doses [1][2] - The SADA PRIT platform is designed to enhance targeted delivery of therapeutic agents while minimizing radiation exposure to normal tissues [2][6] Company Overview - Y-mAbs is a commercial-stage biopharmaceutical company specializing in novel radioimmunotherapy and antibody-based therapeutic products for cancer treatment [5] - The company’s product pipeline includes DANYELZA® (naxitamab-gqgk), the first FDA-approved treatment for relapsed or refractory high-risk neuroblastoma [5] Technology and Innovation - The CD38-SADA is a bispecific fusion protein that binds to CD38-expressing lymphoma cells and delivers a radioactive payload for localized irradiation [6] - The SADA technology was developed by researchers at MSK and is exclusively licensed to Y-mAbs, indicating a strong collaboration between the two entities [4]