SBP GROUP(01177): Cabometyx "CDK2/4/6 inhibitors" will be announced at the 2026 ASCO CDK4/6 inhibitor-treated population phase II clinical data.

SBP GROUP (01177) announced that its subsidiary, Zhengda Tianqing Pharmaceutical Group Co., Ltd. (Zhengda Tianqing), independently developed the national first-class innovative drug library mocetinib, a CDK2/4/6 inhibitor (development code: TQB3616, trade name: Saitanxin), which was presented at the 2026 American Society of Clinical Oncology (ASCO) meeting. The phase II clinical trial data in CDK4/6 inhibitor (CDK4/6i) treated population showed that the mocetinib combination regimen achieved the preset primary endpoint, demonstrating encouraging anti-tumor activity and manageable safety, offering a new option for targeted therapy in CDK4/6i resistant patients. The TQB3616-II-04 study is a prospective, multicenter, single-arm phase II clinical trial (NCT06702618) aiming to evaluate the efficacy and safety of mocetinib in combination with fulvestrant in hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer patients with disease progression after prior treatment with CDK4/6 inhibitors (CDK4/6i) combined with endocrine therapy (ET). The primary endpoint is the confirmed objective response rate (ORR) assessed by an independent review committee (IRC) or investigators, with secondary endpoints including progression-free survival (PFS), clinical benefit rate (CBR), disease control rate (DCR), and safety. As of April 15, 2026, a total of 35 patients were enrolled with a median follow-up time of 10.8 months. The overall population highly matched real-world characteristics of post-resistance patients: with a median age of 56 years, 71.4% had visceral metastases including 45.7% liver metastases, 45.7% lung metastases, and 5.7% brain metastases. All patients had previously received CDK4/6i + ET therapy (palbociclib 68.6%, ribociclib 28.6%, abemaciclib 8.6%, with 2 patients having received two different CDK4/6i treatments), with 37.1% of patients having received prior chemotherapy. Among 34 evaluable patients, the mocetinib combination regimen demonstrated strong tumor clearance capabilities: with a confirmed ORR of 32.4% (95% CI: 17.4-50.5, p <0.0001), achieving the primary research endpoint; a high DCR of 88.2% (95% CI: 72.6-96.7) and CBR of 82.4% (95% CI: 65.5-93.2); median time to response (TTR) was only 3.7 months. Of note, median PFS and duration of response had not yet been reached, with a 10-month PFS rate of 61.8% (95% CI: 42.3-76.4), indicating good potential for sustained disease control. This efficacy outcome is of significant clinical importance for patients who have failed CDK4/6i treatment in the past and have a high proportion of visceral metastases. The study suggests that mocetinib not only possesses clear anti-tumor activity but also maintains durable treatment benefits even in a resistant background. Regarding safety, the overall performance was consistent with previous studies, with no new safety signals identified. The incidence of grade 3 treatment-related adverse events (TRAE) was 40.0%. There were no instances of permanent discontinuation due to TRAE, and no treatment-related deaths. The incidence of grade 3 neutropenia, the most concerning adverse event with traditional CDK4/6 inhibitors, was only 5.7%, consistent with its lower CDK6 inhibitory activity. Overall, this regimen demonstrated good safety and tolerability.