Context Therapeutics has reported encouraging interim Phase 1 data for its bispecific antibody CTIM-76, with a 29% confirmed overall response rate in heavily pretreated patients with platinum-resistant ovarian cancer.

The clinical-stage biotechnology company said two of seven efficacy-evaluable patients achieved confirmed partial responses according to RECIST v1.1 criteria, while the disease control rate reached 57% in patients treated at active dose levels. Participants had received a median of seven previous lines of therapy before entering the study.

The findings come from the ongoing dose-escalation Phase 1 trial evaluating CTIM-76, a CLDN6 x CD3 T-cell engaging bispecific antibody being developed for advanced solid tumours.

Martin Lehr, chief executive officer of Context Therapeutics, said: “We are encouraged by the continued development of CTIM-76 as a potentially best-in-class CLDN6 T cell engager that may offer a much-needed new therapeutic approach for patients with platinum-resistant ovarian cancer.”

He added: “In our first clinical presentation of dose-escalation data, weekly administration of CTIM-76 produced compelling anti-tumor activity and a well-tolerated safety profile in heavily pretreated patients, many of whom had extensive prior exposure to antibody-drug conjugates.”

At the time of the data cut-off on 29 May 2026, 21 patients with platinum-resistant ovarian, testicular or endometrial cancer had received CTIM-76 across dose levels ranging from 22.5 µg to 560 µg administered weekly.

Among patients receiving active doses between 140 µg and 280 µg, seven with platinum-resistant ovarian cancer were evaluable for efficacy. Two achieved confirmed partial responses, while four experienced disease control through stable disease or partial response. In three early cohort patients with stable disease or partial response, benefit had been maintained for at least six months.

Safety findings also appeared favourable. Context reported that adverse events generally occurred during the first or second dose and were predominantly Grade 1 or Grade 2 in severity. Cytokine release syndrome was observed in one of nine platinum-resistant ovarian cancer patients treated at active dose levels and was limited to Grade 1.

The company said the pharmacokinetic profile supports evaluation of dosing every three weeks during the second half of 2026. CTIM-76 has also received FDA Fast Track designation for platinum-resistant ovarian cancer.

Lehr said: “Building on this encouraging data, we have advanced into the next phase of development, where we will evaluate CTIM-76 administered every three weeks (“Q3W”). These results are expected to inform subsequent Phase 1b dose expansion in 2027.”

CTIM-76 targets Claudin 6, a protein expressed across multiple solid tumour types including ovarian, endometrial, lung, gastric and testicular cancers. The therapy is designed to recruit T cells to attack CLDN6-expressing tumour cells through a bispecific mechanism.

Although the dataset remains small and the results are interim, the combination of objective responses, disease control and limited high-grade cytokine release syndrome supports continued clinical evaluation of CTIM-76 in patients with advanced platinum-resistant ovarian cancer, an area where treatment options remain limited after multiple prior therapies.