IMPACT THERAP-B (07630) announced that the latest clinical data for its pipeline drugs Senaparib (IMP4297), IMP1734 (also known as EIK1003), and IMP1707 (also known as EIK1004) were presented in poster sessions at the 2026 European Society for Medical Oncology (ESMO) Congress, held from October 23 to 27, 2026, in Madrid, Spain.
Latest Clinical Data for Senaparib: At a median follow-up of 48.5 months, the overall population continued to demonstrate a stable and statistically significant progression-free survival (PFS) benefit, with a median PFS of 38.7 months by blinded independent central review (BICR) versus 13.6 months for placebo (HR=0.47; 95% CI: 0.36, 0.62; p<0.0001). Importantly, the PFS benefit was consistent across both BRCAm and BRCAwt patient subgroups, with median PFS of 49.8 months versus 15.6 months for Senaparib and placebo in BRCAm patients (HR=0.41; 95% CI: 0.25, 0.70), and 33.3 months versus 12.9 months in BRCAwt patients (HR=0.49; 95% CI: 0.36, 0.68), further demonstrating that Senaparib provides clear clinical benefit regardless of BRCA mutation status.
Latest Clinical Data for IMP1734 Cohort 1B (Combination with Abiraterone): IMP1734 combined with abiraterone demonstrated tolerable safety and encouraging antitumor activity across all dose levels in patients with metastatic prostate cancer (mPC) after multiple lines of prior therapy. Among all Grade ≥3 TEAEs, anemia (15%) was the only hematologic adverse event observed with an incidence ≥10%, indicating a favorable hematologic safety profile for this combination regimen, consistent with the mechanism of highly selective PARP1 inhibition. Furthermore, responses were observed in the HRR-mutant population regardless of BRCA mutation or non-BRCA (including ATM) mutation status, suggesting potential activity across a broader HRR-mutant population. Among 24 efficacy-evaluable participants, the ORR was 19.0% (4/21) for mCRPC and 33.3% (1/3) for mCSPC. Among 39 PSA-evaluable participants, the PSA response rate (PSA50) was 26.5% (9/34) for mCRPC and 60.0% (3/5) for mCSPC. These data support the feasibility of combining selective PARP1 inhibitors with androgen receptor pathway inhibitors.
Latest Clinical Data for IMP1734 Cohorts 1A and 1C (Monotherapy and Combination with Paclitaxel): Extended follow-up data from Cohort 1A reaffirmed that IMP1734 monotherapy has a favorable safety profile and durable responses in the heavily pretreated HRR-mutant population. The incidence of Grade ≥3 anemia and neutropenia was low at 9.2% and 7.7%, respectively. The ORR in this heavily pretreated population was 14.3%, with one responder still on treatment for more than 21 months. In Cohort 1C, IMP1734 combined with weekly paclitaxel demonstrated manageable safety in participants with advanced ovarian cancer and breast cancer without biomarker selection. The hematologic toxicity profile was similar to that previously observed in weekly paclitaxel monotherapy studies, with 49.2% and 18.0% of participants reporting Grade ≥3 neutropenia and anemia, respectively, indicating no visible additive hematologic toxicity from the combination. Encouraging antitumor activity was also observed in this population with extensive prior taxane and PARP inhibitor (PARPi) treatment. The ORR was 29.6% (8/27) in ovarian cancer participants and 23.1% (6/26) in breast cancer participants. Among the 14 responders, 12 had prior taxane therapy and 9 had prior PARPi therapy. Notably, among ovarian cancer participants with prior PARPi treatment, the ORR was 38.1% (8/21), indicating that this combination can still achieve clinical benefit in participants who have failed prior PARPi therapy. These data also provide the first clinical confirmation that selective PARP1 inhibitors can be safely combined with cytotoxic chemotherapy and maintain antitumor activity in patients with prior taxane and PARPi treatment, thereby addressing the needs of populations with high unmet medical need.
Latest Clinical Data for IMP1707: IMP1707 demonstrated a favorable safety profile consistent with its selective PARP1 mechanism of action. Hematologic toxicity was minimal, with Grade ≥3 anemia and neutropenia each occurring at only 1.5%, and no Grade ≥3 thrombocytopenia events were observed. Early antitumor activity was observed across multiple tumor types, including ovarian cancer, prostate cancer, and breast cancer, with tumor shrinkage observed in heavily pretreated patients, including those with prior PARPi treatment. Among 4 efficacy-evaluable prostate cancer patients, 2 achieved partial response (PR) per RECIST 1.1 criteria. Notably, IMP1707 showed clinical benefit even at lower dose levels: one breast cancer patient achieved a confirmed complete response (CR) at the 20mg dose level and has continued treatment for more than 10 months.
Dr. Cai Suixiong, Chief Executive Officer of the company, stated: We are pleased that the latest clinical data for Senaparib and the two novel selective PARP1 inhibitors IMP1734 and IMP1707 were presented at the 2026 ESMO Congress. These data further demonstrate the steady progress of our synthetic lethality pipeline. The updated PFS data from the Phase 3 FLAMES study of Senaparib provide more mature evidence for Senaparib as first-line maintenance therapy in the overall population of advanced ovarian cancer, with patients benefiting from Senaparib treatment regardless of BRCA mutation status. Updated data from the IMP1734 monotherapy cohort and its combination cohorts with paclitaxel and abiraterone show that selective PARP1 inhibitors can be combined with chemotherapy and endocrine therapy with favorable efficacy and manageable safety profiles; while first-in-human data for the brain-penetrant IMP1707 in patients with HRR-mutant advanced solid tumors demonstrated good tolerability and preliminary efficacy, providing initial clinical validation for the molecule's design. Looking ahead, we will continue to advance differentiated precision anticancer therapies, accelerate global clinical development of our products, and deepen our collaboration with Eikon Therapeutics, striving to bring tangible clinical benefits to cancer patients worldwide.
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