Penitrium Targets Tumor 'Pseudo-Resistance' as First Prostate Cancer Patient Dosed and FDA Clears US Phase 2a
核心洞察
Hyundai Bioscience (搜索) has dosed the first prostate cancer (搜索) patient with Penitrium (搜索) in a Phase 1 trial testing whether the drug restores hormone therapy efficacy.
Penitrium (搜索) is an oral niclosamide formulation designed to dismantle physical defense barriers in the tumor microenvironment that reduce drug delivery to sub-lethal levels.
The FDA approved an investigational new drug application for a US Phase 2a trial combining Penitrium (搜索) with standard care in relapsed or refractory advanced solid tumors (搜索).
Hyundai Bioscience (搜索) has initiated first patient dosing in the low-dose cohort of its Phase 1 prostate cancer (搜索) trial for the anticancer drug candidate Penitrium (搜索), with the dose administered on September 12. The trial, led by Professor Chang Wook Jeong of the Department of Urology at Seoul National University Hospital, enrolled a prostate cancer patient whose prostate-specific antigen (PSA) levels have surged despite repeated administration of existing hormone therapy, indicating diminished drug efficacy.
The study is structured across three cohorts — low-dose, mid-dose and high-dose. Beginning with the low-dose cohort, each patient will receive Penitrium (搜索) in combination with existing hormone therapy for three months, with investigators tracking whether the efficacy of the existing hormone therapy is restored, along with safety outcomes.
A First Human Test of 'Pseudo-Resistance'
The company describes the dosing as the first clinical trial to directly validate in humans the "pseudo-resistance" challenge that has confounded oncology for 80 years, grounded in the classical oncology theory of "Seed & Soil." Historically, the medical community has focused on directly destroying cancer cells — the seed. While lethal doses capable of killing cancer cells are delivered during the initial phase of anticancer drug administration, repeated dosing leads to the formation of physical defense barriers in the tumor microenvironment, the soil. Those barriers cause the amount of drug reaching cancer cells to plummet to "sub-lethal doses," levels insufficient to kill the cells.
CnPharm (搜索), the parent company of Hyundai Bioscience (搜索), said it was the first to identify through in vivo experiments on naturally occurring cancer in companion dogs that pseudo-resistance is not a phenomenon where cancer cells acquire drug resistance on their own, but rather one where physical defense barriers reduce drug delivery to sub-lethal levels, rendering treatment ineffective.
Penitrium (搜索) functions by dismantling the physical defense barriers formed in the tumor microenvironment, restoring the delivery rate of existing anticancer drugs such as hormone therapy from sub-lethal levels back to lethal doses and thereby reactivating previously stalled anticancer efficacy. If the mechanism is validated in the current trial, it could delay or eliminate the need to transition patients to chemotherapy, which carries significant side effects. The company expects that, if realized, this could also substantially reduce the risk of triggering cancer metastasis.
Penitrium (搜索) is an oral formulation that improves the absorption in the body of niclosamide, an ingredient used in anti-parasitic medicines. The company expects the drug to break down physical and biological barriers around tumors and promote drug penetration.
Organoid Data in Ovarian Cancer
At the Penitrium (搜索) Global Clinical Development Symposium 2026, held in Seoul's Gangnam district, the company released findings from research on cancer organoids derived from lung and ovarian cancer (搜索) patients, conducted with MBD (搜索), a firm specializing in organoids.
According to the company, cancer cell viability in ovarian cancer (搜索) organoids stood at 50.5% when the targeted cancer drug daraxonrasib was given alone, and rose to 67.7% when the organoids were co-cultured with cancer-associated fibroblasts (搜索) (CAFs). Viability fell to 12.8% when Penitrium (搜索) was administered alongside the drug.
"What creates the ceiling in cancer treatment is pseudo-resistance in the tumor microenvironment, and we will open a new horizon for cancer treatment through trials in actual cancer patients," Cho Won-dong, chairman of Penitrium Bioscience (搜索), said at the symposium.
US Phase 2a Cleared by FDA
In the United States, the company plans to move soon into a Phase 2a trial to confirm the drug's efficacy. The step follows approval this month by the U.S. Food and Drug Administration (搜索) of an investigational new drug application for a trial combining Penitrium (搜索) with standard care in patients with relapsed or refractory advanced solid tumors (搜索). The trial is expected to conclude in September 2028. The company is also confirming Penitrium's safety through a Phase 1 trial in South Korea.
Lee Ji-eun, director of overseas clinical development at Penitrium (搜索), said the 12-week mark is the first readout point for both the domestic Phase 1 trial and the U.S. Phase 2a trial. "The trials do not end at 12 weeks, but because it is the point at which we can see what changed when Penitrium was added for patients on existing treatment, it will serve as a signal for setting clinical strategy for the next stage," she said. Cho said he could not comment at present on specific plans for raising the funding needed for the trials.
Patent Estate and Pancreatic Cancer Plans
Hyundai Bioscience (搜索) plans to initiate a pancreatic cancer (搜索) trial as soon as efficacy of the pseudo-resistance therapeutic, such as PSA level reduction, is confirmed during the interim stages of the ongoing prostate cancer (搜索) Phase 1 trial. Given that pancreatic cancer is an area of intense global interest, the company intends to proceed directly to a global Phase 2 trial.
In March 2023, CnPharm (搜索) launched a dedicated intellectual property team joined by an AI drug discovery research group and a major law firm, and has since completed patent applications and registrations in 23 countries worldwide, establishing significant barriers to entry.
On September 14, Penitrium Bio (搜索), the entity dedicated to the industrialization of the Penitrium (搜索) platform, will host an official event announcing entry into global Phase 2 trials. At the event, the "innovative mechanism of action in which a single drug simultaneously treats multiple intractable diseases" will be unveiled for the first time globally, along with the official announcement of the "Penitrium Global Phase 2 Comprehensive Plan (Master Roadmap)," encompassing both prostate cancer (搜索) and pancreatic cancer (搜索) Phase 2 trials.
Hyundai Bioscience (搜索), founded in May 2000, manufactures and sells bio-cosmetics, anti-hair loss cosmetics, Japanese quasi-drugs and hair dyes, and is developing the new drug Jefty (搜索), which is currently undergoing clinical trials in Vietnam as a treatment for dengue fever (搜索).