SEATTLE--(BUSINESS WIRE)--ProfoundBio, a clinical-stage biotechnology company developing novel antibody-drug conjugate (ADC) therapeutics for cancer, today announced multiple data presentations at the Society for Immunotherapy of Cancer’s 38th Annual Meeting (SITC 2023). The company shared initial results from the dose escalation portion of an ongoing Phase 1/2 trial of its lead ADC candidate, rinatabart sesutecan (Rina-S; PRO1184), as well as preclinical data on its Protein Tyrosine Kinase 7 (PTK7)-directed ADC PRO1107 and its continued ADC platform innovations.
“We are thrilled to present proof-of-concept data from our novel sesutecan ADC platform with the initial clinical results for Rina-S,” said ProfoundBio Chief Medical Officer Naomi Hunder, M.D. “We believe Rina-S’s encouraging Phase 1 activity and safety data are differentiated within the landscape of emerging targeted therapies for ovarian and endometrial cancers, as Rina-S elicited robust responses at well-tolerated doses in heavily pretreated patients, including in tumors expressing low levels of FRα. These data validate our platform and approach to developing ADCs with the potential for meaningfully improved outcomes for patients.”
Abstract #708: A Phase 1/2 Study of Rinatabart Sesutecan (PRO1184), a Novel Folate Receptor Alpha-Directed Antibody-Drug Conjugate, in Patients with Locally Advanced and/or Metastatic Solid Tumors
Presented by Justin A. Call, M.D., of START Mountain Region, West Valley City, UT, on Saturday, November 4, 2023, Exhibit Halls A and B1, 9 a.m. to 8:30 p.m. PDT
Rina-S is an investigational folate receptor-alpha-(FRα)-directed ADC based on a novel topoisomerase-1 linker-drug currently in Phase 1/2 development for a number of solid tumors. Key findings from initial Phase 1 clinical results of the Rina-S trial include data from 36 patients treated at dose levels from 60 mg/m2 to 180 mg/m2 administered every 21 days.
Safety and activity highlights include:
Additional patients are being evaluated in Part A and Part B at multiple dose levels to further optimize the dose.
LD343 Platform and PRO1107 Preclinical Data Presentations, and PRO1160 Trial-In-Progress Presentation:
Abstract #1407: Expanding the Therapeutic Index of MMAE-Based Antibody-Drug Conjugates (ADCs) with a Novel Linker System (LD343)
Presented by Zhu Chen, Ph.D., ProfoundBio Chief Scientific Officer, on Friday, November 3, 2023, Exhibit Halls A and B1, 9 a.m. to 7:00 p.m. PDT
Data from ADCs incorporating ProfoundBio’s novel LD343 platform (a next-generation hydrophilic MMAE-based linker-drug) at a homogeneous drug-to-antibody ratio of 8 (DAR8) compared head-to-head with DAR4 vedotin ADCs highlights the potential to widen the therapeutic index of the clinically validated payload, MMAE.
Data highlights include:
Abstract #1406: A Novel PTK7-Directed Antibody-Drug Conjugate (ADC) PRO1107 Demonstrated Broad Antitumor Activity with a Promising Safety Profile in Preclinical Models
Presented by Zhu Chen, Ph.D., ProfoundBio Chief Scientific Officer, on Saturday, November 4, 2023, Exhibit Halls A and B1, 9 a.m. to 8:30 p.m. PDT
The poster presentation for the anti-PTK7 ADC, PRO1107, highlights preclinical data for this ADC which incorporates LD343 at DAR8.
Data highlights include:
Abstract #718: Phase 1/2 Study of PRO1160, a CD70-Directed Antibody-Drug Conjugate, in Patients with Advanced Solid Tumors and Hematologic Malignancies
Presented by Sharon Ma, MPH, ProfoundBio Director of Clinical Operations, on Saturday, November 4, 2023, Exhibit Halls A and B1, 9 a.m. to 8:30 p.m. PDT
The trial-in-progress poster presentation for the anti-CD70 sesutecan ADC, PRO1160, describes the currently recruiting PRO1160-001 Phase 1/2 study (NCT05721222) in patients with solid and liquid tumors.
About Rinatabart Sesutecan (Rina-S, PRO1184)
Rina-S is an ADC comprised of a folate receptor-alpha-directed antibody conjugated to sesutecan, ProfoundBio’s novel, proprietary hydrophilic exatecan-based linker-drug, LD038, at a homogeneous drug-to-antibody ratio (DAR) of 8. Exatecan is a highly potent, membrane permeable topoisomerase-1 inhibitor with strong bystander effect that has been extensively studied as a small molecule anticancer agent. Sesutecan is a highly hydrophilic stable, cleavable linker designed to mask the hydrophobicity of conjugated exatecan on the ADC, enabling high DAR and efficient delivery of the exatecan payload to tumors while maintaining favorable physicochemical and pharmacokinetic properties of the ADC.
About the PRO1184-001 trial (NCT05579366)
This is a Phase 1/2 study of PRO1184, a folate receptor-alpha-(FRα) targeted antibody-drug conjugate, to evaluate the safety, tolerability, PK, and antitumor activity of PRO1184 in patients with selected locally advanced and/or metastatic solid tumors, including epithelial ovarian cancer, endometrial cancer, breast cancer, non-small cell lung cancer, and mesothelioma. The study consists of two parts, Part A: Dose Escalation and Part B: Dose Expansion.
About PRO1107
PRO1107 is an ADC comprised of a Protein Tyrosine Kinase 7 (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 by multiple vedotin-based ADCs incorporating MMAE at a DAR of 4. LD343 is a highly hydrophilic stable, cleavable linker designed to mask the hydrophobicity of conjugated MMAE on the ADC, enabling high DAR and efficient delivery of the MMAE payload to tumors while maintaining favorable physicochemical and pharmacokinetic properties of the ADC. The investigational new drug (IND) application for PRO1107 has been cleared by FDA and its Phase 1/2 clinical trial is expected to begin enrollment in early 2024.
About ProfoundBio
ProfoundBio is a clinical-stage biotechnology company focused on the development of novel antibody-based therapeutics with curative potential for patients with cancer. Built on internally developed, innovative, and proprietary technology platforms, ProfoundBio has developed a pipeline consisting of multiple antibody-drug conjugate (ADC) drug candidates targeting solid tumors and hematological malignancies that are in discovery, preclinical, and clinical development stages. The company’s clinical stage programs are rinatabart sesutecan (Rina-S; PRO1184), an ADC targeting folate receptor-alpha, PRO1160, an ADC targeting CD70, and PRO1107, an ADC targeting PTK7. ProfoundBio is headquartered in Seattle, Washington.
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