Dr Xie on the ARTEMIS-002 Study Investigating HS-20093 in Relapsed/Refractory Sarcomas

“After we finished [analyzing] cohorts 1 and 2, we noticed that osteosarcoma might be a good population subtype for this drug. For osteosarcoma, many adolescent and young adult [patients] need to get enrolled into a phase 3 [trial]. For cohort 3, we [enrolled] 10 more adolescent patients to check the immunogenicity and pharmacokinetics for these patients.”

Lu Xie, MD, a medical oncologist at Peking University People’s Hospital, discussed the design and objectives of the phase 2 ARTEMIS-002 trial (NCT05830123), which is evaluating the B7-H3–targeted antibody-drug conjugate (ADC) HS-20093 in patients with relapsed or refractory sarcomas. The trial is an open-label, multicohort study and represents the first clinical evaluation of HS-20093 in this patient population. The study builds upon findings from the prior phase 1 dose-escalation ARTEMIS-001 trial (NCT05276609), in which objective responses were observed with the agent across several sarcoma subtypes, including osteosarcoma, at doses of 8 mg/kg and 12 mg/kg, with acceptable tolerability.

Xie explained that cohort 1 of ARTEMIS-002 enrolled patients with relapsed or refractory osteosarcoma. This cohort was designed to determine the optimal dosing strategy by directly comparing efficacy and tolerability between 2 dose levels: 8 mg/kg and 12 mg/kg of HS-20093. Based on early observations from ARTEMIS-001, clinical activity appeared more pronounced at the higher 12-mg/kg dose, although the safety profiles were comparable between the dose levels. To confirm these preliminary findings, the trial was subsequently expanded by an additional 10 patients to comprise cohort 3 and further assess the efficacy, duration of response, and dose-related toxicities associated with the ADC.

Cohort 2 included adult patients with other relapsed or refractory sarcoma subtypes, excluding osteosarcoma. This cohort evaluated HS-20093 at the recommended phase 2 dose (RP2D) of 12 mg/kg. Overall, the primary objectives of the trial were to assess objective response rate and safety in a broader sarcoma population and to validate the RP2D established in earlier clinical work.

Following the evaluation of cohorts 1 and 2, the study design was further refined to include cohort 3, which enrolled adolescent and young adult patients with osteosarcoma. Xie noted that this group was incorporated to explore the immunogenicity and pharmacokinetic profile of HS-20093 in younger patients, as osteosarcoma predominantly affects this age group.

Xie emphasized that the trial is structured to define the efficacy, safety, and optimal dosing of HS-20093 across both adult and adolescent populations. The study is expected to inform future late-phase development and support the advancement of B7-H3–directed ADC therapy as a potential treatment strategy for patients with relapsed or refractory sarcomas.