ASCO 2025: Breakthrough Clinical Data of Domestic New Drugs - Kelun Biotech, Mabwell, Zelgen, Hengrui

Kelun Biotech

Sichuan Kelun Biotech will disclose six clinical study results at this conference for its TROP2 ADC Sacituzumab Govitecan (sac-TMT), anti-PD-L1 monoclonal antibody Tagoritumab (A167), and RET inhibitor KL590586 (A400/EP0031):

In the Phase III OptiTROP-Lung03 study, 137 patients with advanced non-small cell lung cancer (NSCLC) harboring EGFR mutations who progressed after EGFR-TKI and platinum-based chemotherapy were enrolled. At a median follow-up of 12.2 months, the sacituzumab govitecan group showed an objective response rate (ORR) assessed by the independent imaging review committee (BIRC) of 45.1%, significantly better than the control docetaxel group (15.6%, one-sided p=0.0004); median progression-free survival (PFS) was 6.9 months vs. 2.8 months, hazard ratio (HR)=0.30 (one-sided p<0.0001); investigator-assessed PFS was 7.9 months vs. 2.8 months, HR=0.23. Although 36.4% of patients in the docetaxel group crossed over to sacituzumab govitecan after disease progression, median overall survival (OS) was not reached in either group. After adjustment by the rank-preserving structural failure time (RPSFT) model, median OS remained unreached in the sacituzumab govitecan group versus 9.3 months in the control group, HR=0.36, suggesting potential survival benefit.

In the Phase II OptiTROP-Breast05 study, 41 previously untreated patients with unresectable locally advanced or metastatic triple-negative breast cancer (a/m TNBC) were enrolled. Of these, 43.9% had ECOG PS of 1, and 78.0% had PD-L1 CPS scores <10. At a median follow-up of 18.6 months, results showed an ORR of 70.7%, disease control rate (DCR) of 92.7%, median duration of response (DoR) of 12.2 months, and median PFS of 13.4 months. In 32 patients with PD-L1 CPS <10, ORR was 71.9%, DCR 93.8%, and median PFS 13.1 months, indicating efficacy was not strongly correlated with PD-L1 expression level.

Mabwell | 9MW2821

At the 2025 ASCO Annual Meeting, Mabwell presented multiple clinical study results, including the first oral presentation of its Nectin-4 ADC 9MW2821 combined with PD-1 antibody Toripalimab in a Phase Ib/II trial.

9MW2821, independently developed by Mabwell, showed strong efficacy in advanced or metastatic urothelial carcinoma (la/mUC). The study enrolled 40 previously untreated la/mUC patients who received 9MW2821 (1.25 mg/kg) combined with Toripalimab (240 mg). As of December 19, 2024, data showed an ORR of 87.5%, confirmed ORR of 80%, and DCR of 92.5%. Median PFS and DoR have not yet been reached, indicating durable treatment potential. Notably, no new safety signals related to 9MW2821 or Toripalimab were observed, suggesting a good balance between efficacy and tolerability.

Zelgen Bio | ZG006

In this Phase II study, ZG006 monotherapy (10 mg or 30 mg every two weeks) was used for patients with small cell lung cancer (SCLC) who had received at least two prior lines of standard systemic therapy, showing promising preliminary efficacy.

As of December 31, 2024, 40 patients were enrolled, with 27 evaluable for efficacy. Results showed 18 patients achieved partial response (PR), 5 confirmed, others pending confirmation, with preliminary ORR of 66.7% and DCR of 92.6%. Dose groups showed ORRs of 53.8% (7/13) and 78.6% (11/14) for 10 mg and 30 mg groups, respectively; DCR was 84.6% and 100%. Duration of response (DoR) and PFS are immature and require further follow-up. In 21 patients with low (17) or moderate (4) DLL3 expression, ZG006 still demonstrated good anti-tumor activity with 15 PRs and ORR of 71.4%, suggesting potential efficacy regardless of DLL3 expression level.

Safety-wise, treatment-related adverse events (TRAEs) occurred in 87.5% (35/40), with Grade 3 or higher TRAEs in 12.5% (5/40) and serious adverse events (SAEs) also 12.5%, with no treatment discontinuation or death related to TRAEs, indicating manageable safety profile. These results lay the foundation for further development of ZG006 in SCLC later-line treatment.

Hengrui Pharma | SHR-1501

In a Phase I/II clinical study targeting high-risk non-muscle invasive bladder cancer (NMIBC) patients, researchers evaluated the safety, tolerability, and preliminary efficacy of SHR-1501 monotherapy or combined with Bacillus Calmette-Guérin (BCG).

The Phase I study included Ia dose-escalation of SHR-1501 monotherapy (n=8) and Ib SHR-1501 plus BCG treatment (n=6), with no dose-limiting toxicities (DLTs) or maximum tolerated dose (MTD) reached, establishing safety for subsequent trials.

In Phase II, SHR-1501 (600μg) combined with BCG was evaluated in three patient cohorts: Cohort A with NMIBC patients receiving initial BCG treatment (n=29), Cohort B with carcinoma in situ (CIS) patients unresponsive to BCG (n=17), and Cohort C with high-grade Ta/T1 NMIBC patients unresponsive to BCG without CIS (n=24).

In Cohort B, efficacy evaluation showed complete response (CR) rates of up to 90.9% (10/11) at 3 or 6 months in evaluable patients. 12-month disease-free survival (DFS) data for Cohorts A and C are immature, but interim analyses showed 9-month DFS rates of 94.4% and 53.9%, respectively, indicating positive clinical trends.

Regarding safety, treatment-related adverse events (TRAEs) occurred in 50.0% (4/8) of the SHR-1501 monotherapy group and 69.7% (53/76) in the combination group. Grade 3 or higher TRAEs were 12.5% (1/8) and 9.2% (7/76) respectively. No Grade 4-5 TRAEs or serious adverse events (SAEs) were reported, showing overall good treatment tolerability.