Objective response rate of 45.5% and disease control rate of 72.7% observed in 11 heavily pretreated patients with recurrent germ cell tumors

Responses observed in three of six patients with disease progression after high-dose chemotherapy and autologous stem cell transplantation, a population in which long-term survival is achieved in fewer than 10% of patients

LOS ANGELES, Oct. 23, 2026 /PRNewswire/ — TORL BioTherapeutics LLC (“TORL” or the “Company”), a clinical-stage oncology company, today announced preliminary safety and efficacy data for ixotatug vedotin (Ixo-V or TORL-1-23) monotherapy in patients with recurrent germ cell tumors (GCT) from the ongoing Phase 1 CATALINA-1 study in an oral presentation at the European Society for Medical Oncology (ESMO) Congress 2026 in Madrid, Spain. Ixo-V is a first- and potentially best-in-class antibody-drug conjugate (ADC) targeting Claudin 6 (CLDN6), which is widely expressed across GCTs. Ixo-V monotherapy showed meaningful clinical activity and a manageable safety profile in heavily pretreated patients with recurrent GCT, including those with disease progression following high-dose chemotherapy with autologous stem cell transplantation (HDCT/ASCT).

“The high prevalence of CLDN6 in germ cell tumors, coupled with its often strong and widespread expression on tumor cell membranes, makes this a particularly compelling setting for Ixo-V,” said Eric Sievers, M.D., Chief Medical Officer of TORL BioTherapeutics. “While most patients with germ cell tumors are cured, those whose disease progresses despite platinum-based chemotherapy and for whom no appropriate curative treatment options remain face an exceptionally poor prognosis. The responses observed with Ixo-V, including in patients whose disease progressed following high-dose chemotherapy and stem cell transplantation, are especially encouraging and suggest the potential to meaningfully improve outcomes for patients with this difficult-to-treat disease.”

CATALINA-1 (NCT05103683) is a first-in-human, dose-escalation and expansion study evaluating the safety and antitumor activity of Ixo-V in patients with advanced solid tumors. The GCT cohort included 11 patients with previously treated advanced or metastatic disease (nine testicular, one ovarian, and one extragonadal). Patients received Ixo-V monotherapy at doses ranging from 0.4 to 3.4 mg/kg every three weeks. Tumors from all 10 patients with available tissue for testing expressed CLDN6 by immunohistochemistry.

Patients had received a median of three prior lines of therapy (range: 1–5). All had received platinum-based chemotherapy, and six of 11 had undergone HDCT/ASCT. The objective response rate (ORR) was 45.5% (5 of 11 patients, all partial responses) by RECIST v1.1, including confirmed responses in three of six patients previously treated with HDCT/ASCT.

Key study findings as of the March 16, 2026 data cutoff, with a median follow-up of 13.8 months, include the following:

• Ixo-V showed a manageable safety profile, with primarily low-grade treatment-emergent adverse events (TEAEs), consistent with experience in other solid tumors.
• The objective response rate (ORR) across all 11 patients was 45.5% (five partial responses), with responses observed at dose levels ranging from 1 mg/kg to 3.4 mg/kg.
• The disease control rate (DCR) across all patients was 72.7%.
• Three of six patients who had received prior HDCT/ASCT achieved a confirmed response.
• Median progression-free survival (mPFS) was 5.8 months.
• Responses showed preliminary durability, including one patient maintaining a response for 47.4 months.

Presentation Details

Title: Safety and Efficacy of Ixotatug Vedotin (TORL-1-23), a Claudin 6-Targeted ADC, as Monotherapy in Germ Cell Tumors (GCT)
Speaker: Darren R. Feldman, M.D., Memorial Sloan Kettering Cancer Center, New York
Presentation Number: 1210RO
Presentation Session: Rapid oral: Genitourinary tumours, prostate, penile and testis
Presentation Session Date and Time: Friday, October 23, 2026; 13:30 – 15:00 CEST

About Germ Cell Tumors (GCTs)

Germ cell tumors are a group of malignancies that most commonly arise in the testes or ovaries but can also develop outside these organs. Testicular GCTs are the most common solid cancers in adolescent and young adult men. Although most patients with GCTs can be cured with surgery and platinum-based chemotherapy, a subset develops relapsed or refractory disease requiring additional treatment, including salvage chemotherapy or high-dose chemotherapy with autologous stem cell transplantation. Patients whose disease progresses despite these treatments, or for whom no appropriate curative treatment options remain, face a poor prognosis and have a substantial unmet medical need for new therapies.

About Claudin 6

Claudin 6 is an oncofetal cell-surface protein involved in maintaining tight junctions between cells. Normally expressed during embryonic and fetal development, CLDN6 has little to no detectable expression in normal adult tissues but is aberrantly expressed in several malignancies, including ovarian, non-small cell lung, endometrial, germ cell, and desmoplastic small round cell tumors. This tumor-associated expression and limited presence in normal tissues make CLDN6 an attractive target for ADC therapies. Elevated CLDN6 expression has also been associated with poorer survival outcomes in patients with ovarian cancer.

About Ixotatug Vedotin (Ixo-V; TORL-1-23)

Ixo-V is a first-in-class ADC that selectively targets CLDN6 and incorporates a clinically validated MMAE linker-payload technology. Ixo-V is being evaluated as monotherapy and in combination regimens across multiple malignancies, including germ cell tumors, ovarian cancer, and non-small cell lung cancer. Ongoing studies include CATALINA-2, a global, randomized, open-label Phase 2 study in patients with CLDN6-positive platinum-resistant ovarian cancer, and CATALINA-4, a Phase 1b/2 study evaluating Ixo-V in combination with neoadjuvant chemotherapy in patients with CLDN6-positive advanced ovarian cancer. Ixo-V has received FDA Fast Track designation for the treatment of CLDN6-positive platinum-resistant ovarian cancer.

About TORL BioTherapeutics LLC

TORL BioTherapeutics is a clinical-stage oncology company developing antibody-based therapeutics against first-in-world targets for solid tumors and hematologic cancers. Lead asset ixotatug vedotin (Ixo-V; TORL-1-23) is the first and only ADC that selectively targets Claudin 6 (CLDN6) with a proven monomethyl auristatin E (MMAE) linker-payload construct. Ixo-V is being evaluated in platinum-resistant ovarian cancer and other CLDN6-expressing cancers such as germ cell tumors and in various combinations. Ixo-V has been granted FDA Fast Track designation. The early pipeline includes the Phase 1 hematology asset TORL-5-700 and other undisclosed programs. TORL’s unique discovery engine is enabled by a strategic partnership with the Slamon Research Lab at the University of California, Los Angeles (UCLA), which provides preferential access to novel cancer targets for therapeutic development. To date, TORL has raised more than $450 million from leading global biotechnology investors.

View original content to download multimedia:https://www.prnewswire.com/news-releases/torl-biotherapeutics-presents-preliminary-safety-and-efficacy-data-of-ixotatug-vedotin-monotherapy-in-treatment-refractory-germ-cell-tumors-at-the-esmo-congress-2026-302917597.html

SOURCE TORL Biotherapeutics LLC