ARTEMIS-011 (NCT06935409) is a phase 3 trial in China testing risvutatug rezetecan (Ris-Rez), Hansoh’s B7-H3 antibody-drug conjugate (investigational; not FDA, EMA or NMPA approved), against gemcitabine plus docetaxel in relapsed or refractory osteosarcoma after at least two prior lines. At ESMO 2026 (LBA9) and in Annals of Oncology, median PFS was 5.5 vs 1.4 months (HR 0.33); OS is immature.
ESMO 2026 · LBA9 · Presidential Symposium · Annals of OncologyPhase III · NCT06935409Relapsed/refractory osteosarcoma · ≥2 prior lines · age ≥12Ris-Rez (B7-H3 ADC) vs gemcitabine + docetaxelPrimary analysis · median follow-up 7.1 mo · ChinaInvestigational · not FDA/EMA/NMPA approved
Primary endpoint met: progression-free survival by BICR
At the prespecified primary analysis (data cutoff June 17, 2026; median follow-up 7.1 months), median PFS by blinded independent central review was 5.5 months (95% CI 4.1–7.4) with risvutatug rezetecan vs 1.4 months (0.8–2.7) with gemcitabine plus docetaxel (41 of 80 vs 31 of 42 patients had progressed or died): HR 0.33 (95% CI 0.20–0.55), P < 0.0001. The 4-month PFS rate was 65% vs 33%. Investigator-assessed PFS was consistent: 5.6 vs 1.0 months, HR 0.30 (0.19–0.50) (LBA9 slide; Annals of Oncology).
OS is a secondary endpoint. At the data cutoff there had been 10 deaths in each arm (13% of the Ris-Rez arm and 24% of the gemcitabine plus docetaxel arm); median OS was not reached in either arm, HR 0.51 (95% CI 0.21–1.23). The estimated 6-month OS rate was 93% vs 82% (Annals of Oncology). Seventeen patients in the chemotherapy arm crossed over to Ris-Rez after progression. The presenter described a numerical trend; an OS benefit has not been established.
By BICR, ORR was 15% (12 partial responses) vs 2% (1 partial response), odds ratio 7.1 (95% CI 0.9–56.1); no patient had a complete response. Disease control was 76% vs 33%, odds ratio 6.2 (2.8–14.0). Median duration of response was 7.6 months with Ris-Rez and was not reached with gemcitabine plus docetaxel, where only one patient responded (LBA9 slide). ORR, DCR and DOR are secondary endpoints.
Safety: more toxicity, mostly hematologic, with longer treatment
Treatment-related AEs, n (%)
Ris-Rez (n=80)
Gemcitabine + docetaxel (n=42)
Median treatment duration, months
4.5
1.5 (gemcitabine), 1.4 (docetaxel)
Grade ≥3
74 (93)
35 (83)
Serious
51 (64)
12 (29)
Leading to dose reduction
57 (71)
11 (26)
Leading to dose delay or interruption
38 (48)
17 (40)
Leading to permanent discontinuation
3 (3.8)
1 (2.4)
Leading to death
0
0
Grade ≥3 hematologic TRAEs were common with Ris-Rez: white blood cell count decreased 80% vs 40%, neutrophil count decreased 79% vs 43%, platelet count decreased 71% vs 60% and anemia 63% vs 29% (LBA9 safety profile slide). Grade ≥3 febrile neutropenia occurred in 11% vs 2% of patients (treatment-emergent; Annals of Oncology). One treatment-related interstitial lung disease (grade 2, resolved) was reported with Ris-Rez; the paper lists two ILD/pneumonitis events in that arm in total (grade 2 and grade 3), only one considered treatment related. The abstract reports grade ≥3 treatment-emergent AEs of 92.5% vs 83.3% (74 vs 35 patients, the same counts as grade ≥3 TRAEs in the Annals paper) and treatment-related serious AEs of 63.8% vs 28.6% (51 vs 12 patients).
⚠ Investigational. Risvutatug rezetecan is not approved by the FDA, the European Medicines Agency or China’s NMPA for any indication (FDA label database and EMA medicines list checked October 26, 2026). The FDA granted Breakthrough Therapy Designation in January 2025 for adults with relapsed or refractory osteosarcoma after at least two prior lines, based on the phase 2 ARTEMIS-002 study; the NMPA granted Breakthrough Therapy Designation for the same setting in February 2025. After the topline result, Hansoh said in July 2026 that it would begin talks with the regulator to prepare a biologics license application in China, and GSK said on October 26 that the results will support a regulatory submission by Hansoh in China. GSK is running a global phase Ib/II trial in previously treated unresectable advanced or metastatic sarcomas, including osteosarcoma (EMBOLD Sarcoma-202). Hansoh sponsors the trial; GSK holds rights to the drug (GSK’227) outside mainland China, Hong Kong, Macau and Taiwan. Gemcitabine plus docetaxel, the control arm, is a guideline-listed, widely used regimen in this setting rather than an approved osteosarcoma indication. The presenter’s conclusion slide calls Ris-Rez “a promising treatment option for patients with previously-treated R/R osteosarcoma”; that is not a regulatory decision. All patients were enrolled in China.
Sources: ESMO 2026 abstract LBA9 and presentation (Lu Xie, MD, Presidential Symposium III, October 26, 2026) and invited discussion (Nathalie Gaspar, MD, PhD); Annals of Oncology (Xie L, et al., published October 26, 2026, doi 10.1016/j.annonc.2026.10.1284); Hansoh and GSK releases (including GSK, October 26, 2026); ClinicalTrials.gov NCT06935409. All efficacy and safety figures are from the primary analysis (data cutoff June 17, 2026). Slides were shared on X by the physicians credited in Key Slides.
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Top KOLs Discussing ARTEMIS-011
The physicians whose ARTEMIS-011 posts drew the most views. The presenter, Lu Xie, MD (Musculoskeletal Tumor Center, Peking University People’s Hospital), has no X profile we could verify; the presentation slides are in Key Slides. The invited discussant was Nathalie Gaspar, MD, PhD (Villejuif, France).
The LBA9 presentation (presenter: Lu Xie, MD) and the discussion by Nathalie Gaspar, MD, PhD, as photographed and shared on X by physicians on October 26, plus the abstract. Survival curves, response and safety data are summarized in number tables under the slide groups. Click any image to view it full size, and open the transcribed text under each group. All ESMO 2026 ARTEMIS-011 slides in the KOL Pulse slide library →
Slide text (transcribed from the slide images)
[LBA9 title slide] Risvutatug Rezetecan Versus Gemcitabine and Docetaxel in Heavily Pretreated Patients With Relapsed or Refractory Osteosarcoma: Primary Results From the Phase 3 ARTEMIS-011 Study
L. Xie; W. Yao; Y. Hua; W. Luo; C. Tu; J. Wang; J. Chen; B. Li; D. Zhu; X. Li; Y. Xiao; J. Ma; H. Hu; M. Fang; H. Wang; Q. Liu; Y. Jin; X. Zhang; X. Niu; X. Tang
Presented by: Lu Xie, MD, Musculoskeletal Tumor Center, Peking University People's Hospital (PKUPH), Beijing, China. Madrid, Spain; October 26, 2026
[Conclusions]
• Ris-Rez demonstrated a statistically significant and clinically meaningful improvement in BICR-assessed PFS, with a 67% reduction in the risk of disease progression or death in patients with R/R osteosarcoma
• Immature OS data showed a numerical trend toward benefit with Ris-Rez
• Despite higher AE rates, Ris-Rez was associated with longer treatment duration (4.5 vs 1.5 months) and a manageable safety profile. The most common AEs of any Grade and of Grade ≥3 in both arms were haematological; No Grade 5 event occurred
• ARTEMIS-011 findings suggest that Ris-Rez represents a promising treatment option for patients with previously-treated R/R osteosarcoma
[ARTEMIS-011: A Multi-Centre, Open-Label, Randomised, Controlled Phase 3 Study]
Key eligibility criteria: Age ≥12 years; Pathologically confirmed diagnosis of osteosarcoma; Progression or intolerance to at least two previous lines of therapy; ≥1 measurable target lesion per RECIST v1.1; ECOG PS 0–1
Study treatment (R 2:1; treatment until PD, toxicity, or withdrawal of consent): Ris-Rez 12.0 mg/kg IV on Day 1, Q3W (n = 80) | Gemcitabine 1000 mg/m2 IV on Day 1 and 8 + Docetaxel 75 mg/m2 IV on Day 8, Q3W (n = 42). Crossover allowed*
Primary endpoint: PFS by BICR per RECIST v1.1. Secondary endpoints: OS; PFS by investigator per RECIST v1.1; ORR, DCR, DOR by BICR/investigator per RECIST v1.1; Safety
Stratification: Age (12 to <18 years or ≥18 years); Lung metastases (Yes or No)
* Crossover to Ris-Rez following objective PD in patients meeting the crossover criteria
[Primary Endpoint: BICR-assessed PFS with Ris-Rez vs Gemcitabine + Docetaxel]
• At data cutoff date, there were 41 PFS events per BICR (41/80; 51%) in the Ris-Rez arm and 31 (31/42; 74%) in the Gemcitabine + Docetaxel arm
• Ris-Rez demonstrated a statistically significant and clinically meaningful improvement in BICR-PFS vs Gemcitabine + Docetaxel
Ris-Rez (n = 80) | Gemcitabine + Docetaxel (n = 42): Median, mo (95% CI) 5.5 (4.1–7.4) | 1.4 (0.8–2.7); HR (95% CI) 0.33 (0.20–0.55); P-value <0.0001. 4-month rate (marked on curve): 65% vs 33%
Number at risk, months 0/1/2/3/4/5/6/9/12: Ris-Rez 80 65 59 43 37 26 13 1 0; Gemcitabine + Docetaxel 42 24 17 12 9 7 0 0 0
DCO: 17 June 2026.
(Kaplan-Meier curve: values are in the number table above.)
Slide text (transcribed from the slide images)
[ARTEMIS-011: A Multi-Centre, Open-Label, Randomised, Controlled Phase 3 Study]
Key eligibility criteria: Age ≥12 years; Pathologically confirmed diagnosis of osteosarcoma; Progression or intolerance to at least two previous lines of therapy; ≥1 measurable target lesion per RECIST v1.1; ECOG PS 0–1
Study treatment (R 2:1; treatment until PD, toxicity, or withdrawal of consent): Ris-Rez 12.0 mg/kg IV on Day 1, Q3W (n = 80) | Gemcitabine 1000 mg/m2 IV on Day 1 and 8 + Docetaxel 75 mg/m2 IV on Day 8, Q3W (n = 42). Crossover allowed*
Primary endpoint: PFS by BICR per RECIST v1.1. Secondary endpoints: OS; PFS by investigator per RECIST v1.1; ORR, DCR, DOR by BICR/investigator per RECIST v1.1; Safety
Stratification: Age (12 to <18 years or ≥18 years); Lung metastases (Yes or No)
* Crossover to Ris-Rez following objective PD in patients meeting the crossover criteria
[Primary Endpoint: BICR-assessed PFS with Ris-Rez vs Gemcitabine + Docetaxel]
• At data cutoff date, there were 41 PFS events per BICR (41/80; 51%) in the Ris-Rez arm and 31 (31/42; 74%) in the Gemcitabine + Docetaxel arm
• Ris-Rez demonstrated a statistically significant and clinically meaningful improvement in BICR-PFS vs Gemcitabine + Docetaxel
Ris-Rez (n = 80) | Gemcitabine + Docetaxel (n = 42): Median, mo (95% CI) 5.5 (4.1–7.4) | 1.4 (0.8–2.7); HR (95% CI) 0.33 (0.20–0.55); P-value <0.0001. 4-month rate (marked on curve): 65% vs 33%
Number at risk, months 0/1/2/3/4/5/6/9/12: Ris-Rez 80 65 59 43 37 26 13 1 0; Gemcitabine + Docetaxel 42 24 17 12 9 7 0 0 0
DCO: 17 June 2026.
(Kaplan-Meier curve: values are in the number table above.)
[Tumour Response Assessed by BICR]
• BICR-assessed ORR and DCR were markedly higher with Ris-Rez vs Gemcitabine + Docetaxel
• Median DOR by BICR was 7.6 months with Ris-Rez and was not reached in the Gemcitabine + Docetaxel arm (only one patient achieved PR)
BICR-assessed ORR: Ris-Rez (n = 80) 15% (PR) | Gemcitabine + Docetaxel (n = 42) 2% (PR); Odds Ratio (95% CI): 7.1 (0.9–56.1)
BICR-assessed DCR: Ris-Rez 76% (PR + SD) | Gemcitabine + Docetaxel 33% (PR + SD); Odds Ratio (95% CI): 6.2 (2.8–14.0)
DCO: 17 June 2026. No patient had a CR.
[OS in R/R Osteosarcoma with Ris-Rez vs Gemcitabine + Docetaxel]
• OS data were immature but suggested a numerical trend toward benefit with Ris-Rez
• 10 events had occurred in each arm: 13% with Ris-Rez and 24% with Gemcitabine + Docetaxel
• 17 patients* in the Gemcitabine + Docetaxel arm crossed over to Ris-Rez following PD
Ris-Rez (n = 80) | Gemcitabine + Docetaxel (n = 42): Median, mo Not reached | Not reached; HR (95% CI) 0.51 (0.21–1.23)
Number at risk, months 0/3/4/6/9/12/15: Ris-Rez 80 78 72 45 16 1 0; Gemcitabine + Docetaxel 42 37 32 26 10 2 0
DCO: 17 June 2026. Symbols show censoring. *Crossover criteria were met.
(Kaplan-Meier curve: values are in the number table above.)
Slide text (transcribed from the slide images)
[Background slide, partly visible] Ris-Rez is a B7-H3-directed ADC: human anti-B7-H3 IgG1 monoclonal Ab; cysteine conjugation site; cleavable linker; TOP1 inhibitor payload (rezetecan); DAR ≈ 4.
Here we report the primary results of the Phase 3 ARTEMIS-011 study (NCT06935409) of Ris-Rez vs Gemcitabine + Docetaxel in R/R osteosarcoma after failure of ≥2L therapy.
Background: Patients with R/R osteosarcoma have limited treatment options, especially after failure of 2L therapy. Current treatments can impact cognition, quality-of-life, and possibility of secondary malignancies. B7-H3 is an immunosuppressive checkpoint protein that is highly expressed in many tumours, including sarcoma, whereas its expression in normal tissue is limited. Risvutatug rezetecan (Ris-Rez, previously known as HS-20093 or GSK5764227) is a B7-H3-directed ADC with a TOP1 inhibitor payload. Ris-Rez showed promising antitumour activity in patients with heavily pretreated R/R sarcomas (ARTEMIS-002).
[Primary Endpoint: BICR-assessed PFS with Ris-Rez vs Gemcitabine + Docetaxel]
• At data cutoff date, there were 41 PFS events per BICR (41/80; 51%) in the Ris-Rez arm and 31 (31/42; 74%) in the Gemcitabine + Docetaxel arm
• Ris-Rez demonstrated a statistically significant and clinically meaningful improvement in BICR-PFS vs Gemcitabine + Docetaxel
Ris-Rez (n = 80) | Gemcitabine + Docetaxel (n = 42): Median, mo (95% CI) 5.5 (4.1–7.4) | 1.4 (0.8–2.7); HR (95% CI) 0.33 (0.20–0.55); P-value <0.0001. 4-month rate (marked on curve): 65% vs 33%
Number at risk, months 0/1/2/3/4/5/6/9/12: Ris-Rez 80 65 59 43 37 26 13 1 0; Gemcitabine + Docetaxel 42 24 17 12 9 7 0 0 0
DCO: 17 June 2026.
(Kaplan-Meier curve: values are in the number table above.)
[Tumour Response Assessed by BICR]
• BICR-assessed ORR and DCR were markedly higher with Ris-Rez vs Gemcitabine + Docetaxel
• Median DOR by BICR was 7.6 months with Ris-Rez and was not reached in the Gemcitabine + Docetaxel arm (only one patient achieved PR)
BICR-assessed ORR: Ris-Rez (n = 80) 15% (PR) | Gemcitabine + Docetaxel (n = 42) 2% (PR); Odds Ratio (95% CI): 7.1 (0.9–56.1)
BICR-assessed DCR: Ris-Rez 76% (PR + SD) | Gemcitabine + Docetaxel 33% (PR + SD); Odds Ratio (95% CI): 6.2 (2.8–14.0)
DCO: 17 June 2026. No patient had a CR.
Slide text (transcribed from the slide images)
[LBA9 title slide] Risvutatug Rezetecan Versus Gemcitabine and Docetaxel in Heavily Pretreated Patients With Relapsed or Refractory Osteosarcoma: Primary Results From the Phase 3 ARTEMIS-011 Study
L. Xie; W. Yao; Y. Hua; W. Luo; C. Tu; J. Wang; J. Chen; B. Li; D. Zhu; X. Li; Y. Xiao; J. Ma; H. Hu; M. Fang; H. Wang; Q. Liu; Y. Jin; X. Zhang; X. Niu; X. Tang
Presented by: Lu Xie, MD, Musculoskeletal Tumor Center, Peking University People's Hospital (PKUPH), Beijing, China. Madrid, Spain; October 26, 2026
[Primary Endpoint: BICR-assessed PFS with Ris-Rez vs Gemcitabine + Docetaxel]
• At data cutoff date, there were 41 PFS events per BICR (41/80; 51%) in the Ris-Rez arm and 31 (31/42; 74%) in the Gemcitabine + Docetaxel arm
• Ris-Rez demonstrated a statistically significant and clinically meaningful improvement in BICR-PFS vs Gemcitabine + Docetaxel
Ris-Rez (n = 80) | Gemcitabine + Docetaxel (n = 42): Median, mo (95% CI) 5.5 (4.1–7.4) | 1.4 (0.8–2.7); HR (95% CI) 0.33 (0.20–0.55); P-value <0.0001. 4-month rate (marked on curve): 65% vs 33%
Number at risk, months 0/1/2/3/4/5/6/9/12: Ris-Rez 80 65 59 43 37 26 13 1 0; Gemcitabine + Docetaxel 42 24 17 12 9 7 0 0 0
DCO: 17 June 2026.
(Kaplan-Meier curve: values are in the number table above.)
[Tumour Response Assessed by BICR]
• BICR-assessed ORR and DCR were markedly higher with Ris-Rez vs Gemcitabine + Docetaxel
• Median DOR by BICR was 7.6 months with Ris-Rez and was not reached in the Gemcitabine + Docetaxel arm (only one patient achieved PR)
BICR-assessed ORR: Ris-Rez (n = 80) 15% (PR) | Gemcitabine + Docetaxel (n = 42) 2% (PR); Odds Ratio (95% CI): 7.1 (0.9–56.1)
BICR-assessed DCR: Ris-Rez 76% (PR + SD) | Gemcitabine + Docetaxel 33% (PR + SD); Odds Ratio (95% CI): 6.2 (2.8–14.0)
DCO: 17 June 2026. No patient had a CR.
[Invited discussant slide, Dr Nathalie Gaspar, MD, PhD: ADCs: what is the optimal construct?] (Not exhaustive)
ADC | NCT number | Age at inclusion | Target | Payload | DAR | Phase | ORR (%) | DCR (%) | Median PFS | Reference
HS-20093 (ARTEMIS-002) | NCT05830123 | ≥18 y | B7-H3 | topoisomerase I inhibitor | 4 | II | ~20 | ~87 | 8.4 | ESMO 2025
HS-20093 (ARTEMIS-011) | NCT06935409 | ≥12 y | B7-H3 | Rezetecan topoisomerase I inhibitor | 4 | III | 15 | 76 | 5.5 | ESMO 2026
Ifinatamab deruxtecan (DS-7300a) | NCT04145622 | ≥12 y | B7-H3 | DXd topoisomerase I inhibitor | 4 | I/II | NR | NR | NR | ASCO 2023 / ESMO 2023
Trastuzumab deruxtecan (T-DXd) PEPN1924 | NCT04616560 | 12-39 y | HER2 | DXd topoisomerase I inhibitor | 8 | II | 0 | NR | NR | Reed et al. JCO OA 2025
Glembatumumab vedotin | NCT02487979 | 12-50 y | GPNMB | MMAE microtubule inhibitor | 4-4.5 | II | 1/19 | 3/19 | NR | Kopp et al. EJC 2019
Samrotamab vedotin (ABBV-085) | NCT02565758 | ≥18 y | LRRC15 | MMAE microtubule inhibitor | 2 | I | 20 | NR | 3.1 mo | Demetri et al. 2021
SOT106 | NCT07801222 (not yet recruiting) | ≥12-18 y | LRRC15 | MMAE microtubule inhibitor | 4 | I/II | NR | NR | NR | Preclinical data ESMO 2025
SIM0613 | NCT07618260 (just recruiting) | ≥18 y | LRRC15 | topoisomerase I inhibitor | 4 | I | NA | NA | NA |
Importance of each component for ADC efficacy: targeting antibody (selectivity), linker (balance between efficacy and safety), cytotoxic payload (potency, depth and durability of response); all three components are essential and must be optimized together.
(Cross-trial table as printed by the discussant; trials differ in population, phase and line of therapy.)
Investigator-assessed efficacy (secondary endpoints), as printed on the LBA9 slide
Ris-Rez (n=80)
Gemcitabine + docetaxel (n=42)
HR or odds ratio (95% CI)
Median PFS, months (95% CI)
5.6 (4.2–7.4)
1.0 (0.7–2.3)
HR 0.30 (0.19–0.50)
ORR (all partial responses)
15%
2%
OR 7.1 (0.9–56.4)
DCR
83%
31%
OR 10.4 (4.3–24.8)
Slide text (transcribed from the slide images)
[Efficacy Assessed by Investigator] • Investigator-assessed PFS, ORR, and DCR were consistent with BICR-assessed results
Investigator-assessed PFS, Ris-Rez (n = 80) | Gemcitabine + Docetaxel (n = 42): Median (95% CI) 5.6 mo (4.2–7.4) | 1.0 mo (0.7–2.3); HR (95% CI) 0.30 (0.19–0.50)
Number at risk, months 0/1/2/3/4/5/6/9/12: Ris-Rez 80 68 64 52 44 29 14 1 0; Gemcitabine + Docetaxel 42 19 13 9 8 7 0 0 0
Investigator-assessed ORR: 15% (PR) | 2% (PR); Odds Ratio (95% CI): 7.1 (0.9–56.4)
Investigator-assessed DCR: 83% (PR + SD) | 31% (PR + SD); Odds Ratio (95% CI): 10.4 (4.3–24.8)
DCO: 17 June 2026. Symbols show censoring. No patient had a complete response.
(Kaplan-Meier curve: values are in the number table above.)
[LBA9 title slide] Risvutatug Rezetecan Versus Gemcitabine and Docetaxel in Heavily Pretreated Patients With Relapsed or Refractory Osteosarcoma: Primary Results From the Phase 3 ARTEMIS-011 Study
L. Xie; W. Yao; Y. Hua; W. Luo; C. Tu; J. Wang; J. Chen; B. Li; D. Zhu; X. Li; Y. Xiao; J. Ma; H. Hu; M. Fang; H. Wang; Q. Liu; Y. Jin; X. Zhang; X. Niu; X. Tang
Presented by: Lu Xie, MD, Musculoskeletal Tumor Center, Peking University People's Hospital (PKUPH), Beijing, China. Madrid, Spain; October 26, 2026
[Primary Endpoint: BICR-assessed PFS with Ris-Rez vs Gemcitabine + Docetaxel]
• At data cutoff date, there were 41 PFS events per BICR (41/80; 51%) in the Ris-Rez arm and 31 (31/42; 74%) in the Gemcitabine + Docetaxel arm
• Ris-Rez demonstrated a statistically significant and clinically meaningful improvement in BICR-PFS vs Gemcitabine + Docetaxel
Ris-Rez (n = 80) | Gemcitabine + Docetaxel (n = 42): Median, mo (95% CI) 5.5 (4.1–7.4) | 1.4 (0.8–2.7); HR (95% CI) 0.33 (0.20–0.55); P-value <0.0001. 4-month rate (marked on curve): 65% vs 33%
Number at risk, months 0/1/2/3/4/5/6/9/12: Ris-Rez 80 65 59 43 37 26 13 1 0; Gemcitabine + Docetaxel 42 24 17 12 9 7 0 0 0
DCO: 17 June 2026.
(Kaplan-Meier curve: values are in the number table above.)
Slide text (transcribed from the slide images)
LBA9 - Risvutatug rezetecan (Ris-Rez) versus gemcitabine and docetaxel (GD) in heavily pretreated patients (pts) with relapsed or refractory (R/R) osteosarcoma: Primary results from the phase 3 ARTEMIS-011 study
Speakers: Lu Xie (Beijing, China)
Authors: Lu Xie (Beijing, China) Weitao Yao (Zhengzhou, China) Yingqi Hua (Shanghai, China) Wei Luo (Changsha, China) Chongqi Tu (Chengdu, China) Jin Wang (Guangzhou, China) Jing Chen (Wuhan, China) Binghao Li (Hangzhou, China) Dongyuan Zhu (Jinan, China) Xianan Li (Changsha, China) Yanbin Xiao (Kunming, China) Jie Ma (Nanning, China) Haiyan Hu (Shanghai, China) Meiyu Fang (Hangzhou, China) Haiyan Wang (Shanghai, China) Qingyuan Liu (Shanghai, China) Yizhou Jin (Shanghai, China) Xiaoqing Zhang (Shanghai, China) Xiaohui Niu (Beijing, China) Xiaodong Tang (Beijing, China)
Background
Ris-Rez (HS-20093/GSK5764227), a B7-H3-directed antibody-drug conjugate (ADC), previously showed promising antitumor activity with manageable toxicity in heavily pretreated pts with R/R sarcomas. Here, we report the primary results from a phase 3 ARTEMIS-011 study (NCT06935409) comparing Ris-Rez with GD in Chinese pts with R/R osteosarcoma.
Methods
ARTEMIS-011 was a multi-center, open-label, randomized phase 3 trial. Eligible pts should have progressed or relapsed after ≥2 prior lines of systemic therapy. Pts (≥12 years) were randomized (2:1) to receive either Ris-Rez 12.0 mg/kg every 3 weeks (Q3W) or GD Q3W. The primary endpoint was progression-free survival (PFS) assessed by Blinded Independent Central Review (BICR).
Results
As of data cutoff (June 17, 2026), a total of 122 pts were randomized to receive Ris-Rez (n=80) or GD (n=42), the median (m) follow-up time was 7.1 months (mo). The median age was 21.0 years, 31 pts (25.4%) were adolescents (12-18 years). Ris-Rez demonstrated a statistically significant and clinically meaningful improvement in BICR-assessed PFS compared with GD (mPFS, 5.5 vs. 1.4 mo; HR, 0.33; p<0.0001), consistent with Investigator-assessed mPFS (5.6 vs. 1.0 mo). OS data were immature, but a favorable trend was observed toward Ris-Rez (HR, 0.51). Ris-Rez showed a manageable safety profile. Grade ≥3 TEAEs were reported in 92.5% with Ris-Rez vs. 83.3% with GD. Incidence of treatment-related SAE was numerically higher with Ris-Rez than with GD (63.8% vs. 28.6%), mainly driven by hematologic toxicities. Treatment discontinuation due to TRAE was similar between the groups (3.8% vs. 2.4%). One treatment-related interstitial lung disease was reported (CTCAE grade 2, resolved) in Ris-Rez group. No treatment-related deaths or new safety signals were observed.
Conclusions
In the ARTEMIS-011 study, Ris-Rez demonstrated a statistically significant and clinically meaningful improvement in BICR-assessed PFS, accompanied by a favorable trend in OS and a manageable safety profile, highlighting its potential as a new treatment standard for patients with R/R osteosarcoma.
KOL-Made Infographics
Summary graphics designed by physicians from the LBA9 abstract (not conference slides). Values are as the authors drew them. Click to enlarge.
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Debate · ESMO 2026
Dose and toxicity: the ARTEMIS-011 debate
Physicians welcomed the PFS result but questioned the toxicity at the 12.0 mg/kg dose. Their posts are shown verbatim; other physicians also flagged the modest response rate and immature OS (see Physician Reactions).
What the data show: treatment-related AEs led to dose reduction in 71% of Ris-Rez patients vs 26% with gemcitabine plus docetaxel, and to dose delay or interruption in 48% vs 40%; permanent discontinuation was 3.8% vs 2.4%, and there were no treatment-related deaths (LBA9 safety slide; Annals of Oncology). Serious TRAEs were 64% vs 29%, mostly hematologic. As rationale, GSK’s October 26 release says the higher 12 mg/kg dose was chosen “to account for potential difficulty in penetrating bone tissue,” compared with 8 mg/kg in the ARTEMIS-008 small cell lung cancer trial, and that ARTEMIS-011 will help inform dose selection in GSK’s global EMBOLD Sarcoma-202 trial. The Annals paper notes that the 12.0 mg/kg every-3-weeks dose is higher than doses tested in some other indications, and that median treatment duration was about three times longer with Ris-Rez (4.5 vs 1.5 months). Patient-reported outcomes were not collected.
Physician Reactions · ESMO 2026
Physician reactions to ARTEMIS-011
Full, verbatim posts, newest first, linked to the originals; the dose and toxicity posts are in the debate above. In all, 13 posts from 13 physicians, including posts based on the abstract before the presentation.
ARTEMIS-011 asked whether risvutatug rezetecan, an antibody-drug conjugate that delivers a topoisomerase I inhibitor payload to B7-H3-expressing cells, improves outcomes over gemcitabine plus docetaxel in heavily pretreated relapsed or refractory osteosarcoma, a setting with no clear standard of care after two lines of therapy. The trial is sponsored and funded by Shanghai Hansoh BioMedical. Results were presented by Lu Xie, MD, in Presidential Symposium III at ESMO 2026 (LBA9, October 26, 2026), with Nathalie Gaspar, MD, PhD, as invited discussant, and published in Annals of Oncology the same day.
Study Design
Randomized 2:1, open-label, multicenter phase 3 at 24 sites in China (NCT06935409); 80 vs 42 patients. Stratified by age (12 to <18 vs ≥18 years); lung metastasis was planned as a second factor but was dropped after blinded data review because only three patients lacked lung metastases.
Population
Age ≥12 years; osteosarcoma progressing after (or intolerant of) ≥2 lines of systemic therapy; ≥1 measurable lesion; ECOG PS 0–1; no prior B7-H3 therapy, topoisomerase I inhibitor, gemcitabine or docetaxel. Median age 21; 25% aged 12 to <18; all metastatic; lung metastases 99% vs 95%.
Interventions
Ris-Rez 12.0 mg/kg IV day 1 Q3W vs gemcitabine 1000 mg/m² IV days 1 and 8 plus docetaxel 75 mg/m² IV day 8, Q3W. Crossover to Ris-Rez allowed after progression.
Endpoints
Primary: PFS by BICR (RECIST 1.1). Secondary: OS, investigator-assessed PFS, ORR, DCR and DOR by BICR and investigator, safety. Exploratory: PFS2.
Presenter & Discussant
Presenter: Lu Xie, MD (Peking University People’s Hospital, Beijing). Invited discussant: Nathalie Gaspar, MD, PhD (Villejuif, France).
Data Cut
Prespecified primary analysis; data cutoff June 17, 2026; median follow-up 7.1 months. OS immature.
ARTEMIS-011 (NCT06935409) is a randomized, open-label, multicenter phase 3 trial run at 24 sites in China and sponsored by Hansoh. It compared risvutatug rezetecan (Ris-Rez, HS-20093, GSK5764227), a B7-H3-directed antibody-drug conjugate, with gemcitabine plus docetaxel in 122 patients aged 12 years or older with relapsed or refractory osteosarcoma after at least two prior lines of systemic therapy (randomized 2:1, 80 vs 42).
What did ARTEMIS-011 show at ESMO 2026?
At the primary analysis (data cutoff June 17, 2026; median follow-up 7.1 months), the primary endpoint was met: median PFS by blinded independent central review was 5.5 vs 1.4 months, HR 0.33 (95% CI 0.20–0.55), P < 0.0001. ORR by BICR was 15% vs 2% (all partial responses) and disease control 76% vs 33%. Results were presented by Lu Xie, MD, in the Presidential Symposium (LBA9) and published the same day in Annals of Oncology.
Did Ris-Rez improve overall survival?
Not yet shown. Overall survival is a secondary endpoint and the data are immature: 10 deaths in each arm (13% vs 24%), medians not reached, HR 0.51 (95% CI 0.21–1.23). Seventeen patients in the chemotherapy arm crossed over to Ris-Rez after progression, which will complicate later OS analyses.
How toxic was Ris-Rez at 12.0 mg/kg?
Grade ≥3 treatment-related AEs occurred in 93% vs 83% of patients and serious TRAEs in 64% vs 29%, mostly hematologic. TRAEs led to dose reduction in 71% vs 26% and to permanent discontinuation in 3.8% vs 2.4%; there were no treatment-related deaths. One treatment-related ILD (grade 2) occurred with Ris-Rez. Median treatment duration was 4.5 vs 1.5 months.
Is risvutatug rezetecan FDA approved?
No. Ris-Rez is not approved by the FDA, the European Medicines Agency or China’s NMPA for any indication; it is investigational. The FDA (January 2025, adults) and the NMPA (February 2025) granted Breakthrough Therapy Designation for relapsed or refractory osteosarcoma after at least two prior lines. Hansoh said in July 2026 it would prepare a biologics license application in China. GSK holds rights outside mainland China, Hong Kong, Macau and Taiwan.
Who was in the trial?
All patients were enrolled in China and had metastatic disease; nearly all had lung metastases. Median age was 21 years and 25% were adolescents aged 12 to under 18. Patients had a median of 2.5 vs 3 prior lines of systemic therapy. The authors note that the China-only, open-label design limits generalization, and B7-H3 expression data are not yet available.
Physician Opinions
Key KOL Sentiments - ARTEMIS-011
6 positive, 7 neutral and 0 negative posts from physicians, each shown verbatim.
Posted on October 23, before the presentation, during a separate ESMO 2026 talk on ADCs in sarcoma; the slides in that post show phase 2 ARTEMIS-002 data, not ARTEMIS-011.
Compiled and reviewed by the KOL Pulse research team, led by Brian Shields, Founder, KOL Pulse. Last updated October 26, 2026. Every quote verbatim; every number checked against the ESMO 2026 LBA9 abstract and presentation slides, the Annals of Oncology publication, the Hansoh and GSK releases or ClinicalTrials.gov, with the source labelled.
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