On June 18, 2025 Merck reported the first patient has been dosed in the IDeate-Prostate01 phase 3 trial evaluating the efficacy and safety of investigational ifinatamab deruxtecan (I-DXd) versus docetaxel in patients with metastatic castration-resistant prostate cancer (mCRPC) with disease progression during or after treatment with an androgen receptor pathway inhibitor (Press release, Merck & Co, JUN 18, 2025, View Source [SID1234653976]).
Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:
Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing
Schedule Your 30 min Free Demo!
Ifinatamab deruxtecan is a specifically engineered, potential first-in-class B7-H3 directed DXd antibody drug conjugate (ADC) discovered by Daiichi Sankyo (TSE: 4568) and being jointly developed by Daiichi Sankyo and Merck (NYSE: MRK), known as MSD outside of the United States and Canada.
While localized prostate cancer has a five-year survival rate of more than 90%, survival decreases to 31% in the advanced or metastatic stage.1 Current standard of care for patients with mCRPC includes treatment with androgen receptor pathway inhibitors followed by taxane-based chemotherapy.2-5 However, due to poor prognosis associated with previously treated mCRPC, many patients do not receive subsequent therapy, reinforcing the need for new approaches to improve outcomes.6
"Despite the emergence of new therapies, the current treatment landscape for patients with metastatic castration-resistant prostate cancer is challenging, and there is a need for new treatments," said Mark Rutstein, MD, Head, Therapeutic Area Oncology Development, Daiichi Sankyo. "Following the promising results seen in our earlier phase trial, IDeate-Prostate01 has been initiated to evaluate whether ifinatamab deruxtecan may replace standard taxane-based chemotherapy as a potential treatment strategy in patients with metastatic castration-resistant prostate cancer with disease progression during or after treatment with androgen receptor pathway inhibitors."
"IDeate-Prostate01 marks the initiation of the third pivotal trial in the ifinatamab deruxtecan development program and reinforces our commitment to addressing critical unmet needs for patients," said Marjorie Green, MD, Senior Vice President and Head of Oncology, Global Clinical Development, Merck Research Laboratories. "Our continued progress in the exploration of this potential first-in-class B7-H3 antibody drug conjugate in collaboration with Daiichi Sankyo, speaks to our pursuit of novel science in the hopes of making a difference for patients in need of new options."
The initiation of IDeate-Prostate01 is based on results from the IDeate-PanTumor01 phase 1/2 trial previously presented at the 2022 and 2023 European Society of Medical Oncology (ESMO) (Free ESMO Whitepaper) Congresses where ifinatamab deruxtecan showed promising responses in heavily pretreated patients with mCRPC.
About the IDeate-Prostate01 Trial
IDeate-Prostate01 is a multicenter, open-label, randomized phase 3 trial evaluating the safety and efficacy of ifinatamab deruxtecan (12 mg/kg) versus docetaxel (75 mg/m2) plus corticosteroid in patients with mCRPC. Eligible patients must have received prior treatment with one or two androgen receptor pathway inhibitors and experienced disease progression during or after at least eight weeks of treatment.
The dual primary endpoints of IDeate-Prostate01 are overall survival and radiographic progression-free survival. Secondary endpoints include objective response rate, time to first subsequent therapy, duration of response, time to pain progression, time to prostate-specific antigen (PSA) progression, PSA response, time to first symptomatic skeletal-related event and safety.
IDeate-Prostate01 will enroll approximately 1,440 patients across Asia, Europe, North America and Oceania. For more information, please visit ClinicalTrials.gov.
About Metastatic Castration-Resistant Prostate Cancer
Prostate cancer is the second most common cancer in men, and the fifth leading cause of cancer death in men worldwide.7 Nearly 1.5 million prostate cancer cases were diagnosed in 2022, with approximately 400,000 deaths globally.7
While localized prostate cancer has a five-year survival rate of more than 90%, survival decreases to 31% in advanced or metastatic stage.1 Approximately 10% to 20% of early-stage prostate cancer cases progress to metastatic disease within five years of treatment on hormonal therapies such as androgen deprivation therapy.8,9 Current standard of care for patients with mCRPC includes treatment with androgen receptor pathway inhibitors followed by taxane-based chemotherapy. However, due to poor prognosis associated with previously treated mCRPC, many patients do not receive subsequent therapy, reinforcing the need for new approaches to improve outcomes.6
About B7-H3
B7-H3 is a transmembrane protein that belongs to the B7 family of proteins, which bind to the CD28 family of receptors that includes PD-1.10,11 B7-H3 is overexpressed in a wide range of cancer types, including mCRPC and its overexpression has been shown to correlate with poor prognosis, making B7-H3 a promising therapeutic target.12-15 There are currently no B7-H3 directed medicines approved for the treatment of any cancer.
About Ifinatamab Deruxtecan
Ifinatamab deruxtecan (I-DXd) is an investigational potential first-in-class B7-H3 directed ADC. Designed using Daiichi Sankyo’s proprietary DXd ADC Technology, ifinatamab deruxtecan is comprised of a humanized anti-B7-H3 IgG1 monoclonal antibody attached to a number of topoisomerase I inhibitor payloads (an exatecan derivative, DXd) via tetrapeptide-based cleavable linkers.
Ifinatamab deruxtecan has been granted orphan drug designation by the U.S. Food and Drug Administration, European Commission, Japan Ministry of Health, Labour and Welfare and Taiwan Food and Drug Administration for the treatment of small cell lung cancer.
About the Ifinatamab Deruxtecan Clinical Development Program
A comprehensive global clinical development program is underway evaluating the efficacy and safety of ifinatamab deruxtecan across multiple B7-H3 targetable cancers. Trials in combination with other anticancer treatments also are underway.