PRO-1107

SEATTLE, April 4, 2024 /PRNewswire/ --ProfoundBio, a clinical-stage biotechnology company dedicated to developing novel antibody-drug conjugate (ADC) therapies for patients with cancer, today announced its participation at the upcoming American Association for Cancer Research (AACR) Annual Meeting 2024, taking place from April 5-10 in San Diego, California. ProfoundBio will showcase its innovative ADC programs through an oral presentation on its EGFR- and cMET-dual targeting ADC PRO1286, a poster presentation detailing preclinical data of a SLITRK6-directed ADC PRO1106, and a late-breaking poster presentation on a CD98-directed ADC developed in partnership with Huahui Health, a clinical-stage biotechnology company. "We are pleased to share our latest research at the AACR Meeting this year," stated Zhu Chen, Ph.D., Chief Scientific Officer of ProfoundBio. "These presentations underscore our commitment to leveraging our proprietary ADC platforms to target some of the most challenging cancers. With PRO1286, PRO1106, and our CD98-directed ADC, we are aiming to provide patients with more effective and tolerable treatment options, and look forward to sharing the latest findings with the scientific community." Key Presentations at AACR 2024 About ProfoundBio's ADC Programs FRα-Targeted ADC: Rinatabart sesutecan (Rina-S, PRO1184) Rina-S is a FRα-targeted ADC being developed as a novel treatment option for patients with ovarian and endometrial cancer, and other FRα-expressing cancers. Rina-S is comprised of a FRα-directed antibody conjugated to sesutecan, ProfoundBio's novel, proprietary hydrophilic exatecan-based linker-drug, at a homogeneous drug-to-antibody ratio (DAR) of 8. Exatecan is a potent, membrane permeable topoisomerase-1 inhibitor with strong bystander effect. The linker component of sesutecan is a highly hydrophilic, stable, cleavable linker designed to mask the hydrophobicity of exatecan, enabling high DAR and efficient delivery of the exatecan payload to tumors while maintaining favorable physicochemical and pharmacokinetic properties of the ADC. Rina-S is currently being evaluated in a Phase 1/2 clinical trial (NCT05579366) and has been granted Fast Track Designation by the U.S. Food and Drug Administration (FDA) for the treatment of patients with FRα-expressing high-grade serous or endometrioid platinum-resistant ovarian cancer. CD70-Targeted ADC: PRO1160 PRO1160 is an ADC consisting of a CD70-targeted antibody conjugated to ProfoundBio's novel, proprietary hydrophilic exatecan-based linker-drug, sesutecan. CD70 is a protein expressed on both solid tumors and hematological malignancies including renal cell carcinoma, nasopharyngeal carcinoma, and non-Hodgkin lymphoma, yet is largely absent in normal tissues. With preclinical results showcasing encouraging pharmacokinetics, efficacy, and tolerability, PRO1160 is emerging as a potential advancement in the treatment of these cancers and is currently being evaluated in a Phase 1/2 clinical trial (NCT05721222). PTK7-Targeted ADC: PRO1107 PRO1107 is an ADC consisting of a PTK7-targeted antibody conjugated to ProfoundBio's novel, proprietary hydrophilic MMAE-based linker-drug, LD343, at a homogeneous DAR of 8. MMAE is a potent, membrane-permeable microtubule inhibitor that has been clinically validated as an ADC payload with multiple marketed vedotin ADCs at a DAR of 4. The linker component of LD343 is a highly hydrophilic, stable, cleavable linker designed to mask the hydrophobicity of MMAE, enabling high DAR and efficient delivery of the MMAE payload to tumors while maintaining favorable physicochemical and pharmacokinetic properties of the ADC. PRO1107 is currently being evaluated in a Phase 1/2 clinical trial (NCT06171789). Bispecific ADC: PRO1286 PRO1286 is a novel EGFR- and cMET-dual targeting ADC that has the potential to treat a broad range of tumors. PRO1286 is built on the clinically validated sesutecan platform and is anticipated to enter the clinic in 2024. About ProfoundBio ProfoundBio is a clinical-stage biotechnology company focused on the development of novel antibody-based therapeutics for patients with cancer. Built on internally developed, innovative, and proprietary technology platforms, ProfoundBio has developed a pipeline consisting of multiple ADC drug candidates targeting solid tumors and hematological malignancies. The company's disclosed development pipeline consists of rinatabart sesutecan (Rina-S; PRO1184), an ADC targeting FRα; PRO1160, an ADC targeting CD70; PRO1107, an ADC targeting PTK7; and PRO1286, a bispecific ADC targeting EGFR and cMET. ProfoundBio is headquartered in Seattle, Washington with an R&D center of innovation in Suzhou, China. For more information, please visit and follow us on LinkedIn. Investor Contact: ir@profoundbio.com Media Contact: Priyanka Shah 908-447-6134 pshah@elephantheadcommunicationsllc.com

Genmab continued to expand its presence in the antibody-drug conjugate (ADC) field with a deal to buy ProfoundBio for $1.8 billion in cash. The transaction will give Genmab three clinical programmes, including the FRα-targeted, Topo1 ADC rinatabart sesutecan (Rina-S).The therapy, also known as PRO1184, is currently in Phase II development for the treatment of ovarian cancer and other FRα-expressing solid tumours. ProfoundBio’s pipeline also includes the CD70-targeted ADC PRO1160 and another dubbed PRO1107 that targets PTK7.Jan van de Winkel, CEO of Genmab, noted that the purchase “firmly aligns with our long-term strategy,” adding that “ProfoundBio’s ADC candidates, proprietary technology platforms and talented team will be a great addition.” The transaction is expected to close this quarter.Genmab already has an ADC partnership with Seagen, which produced the drug Tivdak (tisotumab vedotin-tftv) approved by the FDA in 2021 as a treatment for cervical cancer. The company also has a collaboration with ADC Therapeutics and another agreement with Synaffix for its ADC technologies.