ASTRIDE (NCT05468489) is a randomized US bridging trial comparing serplulimab, Henlius’s anti-PD-1 antibody (not FDA approved; EU-authorized as HETRONIFLY), with atezolizumab (TECENTRIQ), each plus carboplatin-etoposide, for first-line extensive-stage SCLC (one prior chemotherapy cycle allowed). At ESMO 2026 (3809O), median OS was 12.4 vs 10.2 months (HR 0.82, 95% CI 0.56–1.20) in a descriptive analysis (bridging study; no P values reported).
ESMO 2026 · 3809O · Proffered paperNCT05468489 · US bridging study1L extensive-stage SCLCSerplulimab vs atezolizumab, each + carboplatin-etoposideDescriptive analysis · median follow-up 14.1 moSerplulimab not FDA approved · EU-authorized for 1L ES-SCLC
Primary endpoint, overall survival: numerically longer with serplulimab, descriptive only
ASTRIDE is a bridging study, and its statistical design was descriptive only; no P values were reported. At the February 18, 2026 data cutoff (median follow-up 14.1 months), median OS in the ITT population was 12.4 months (95% CI 9.0–17.9) with serplulimab plus carboplatin-etoposide vs 10.2 months (8.4–13.2) with atezolizumab plus carboplatin-etoposide (50 vs 58 deaths): HR 0.82 (95% CI 0.56–1.20). The confidence interval includes 1, so the difference is not statistically established. The 1-year OS rate was 52.4% vs 41.4% and the 2-year rate 32.2% vs 17.6%; only 6 and 4 patients were still at risk at 24 months, and the 2-year confidence intervals are wide (20.1–44.9% vs 8.1–30.0%). The presenter described the result as “numerically longer median OS.”
Secondary endpoints: similar PFS, response and duration of response
By blinded independent central review in treated patients (99 vs 100), median PFS was 5.4 vs 4.9 months (HR 0.95, 95% CI 0.67–1.35), ORR 65.7% vs 67.0% and median duration of response 4.2 vs 4.0 months (HR 0.95, 0.62–1.47) (3809O slide). The abstract reports ORR in the ITT denominator, 64.4% vs 67.0% (IRRC-assessed).
The protocol let patients enroll after one cycle of chemotherapy for newly diagnosed ES-SCLC (18.8% vs 24.0% did). In patients without that prior cycle, median OS was 13.4 vs 10.8 months, HR 0.77 (0.50–1.17) (slide and abstract); in those with it, HR 1.16 (0.49–2.75). More serplulimab patients had liver metastases (49.5% vs 40.0%); OS HRs were 0.85 (0.51–1.42) with and 0.60 (0.33–1.09) without liver metastases. In the age subgroups, HRs were 1.03 (<65) and 0.70 (≥65). Subsequent cancer therapy was given to 37.6% vs 45.0%, including tarlatamab in 12.9% vs 15.0% and lurbinectedin in 21.8% vs 16.0%. All subgroup results are exploratory, with small numbers and confidence intervals that include 1.
TEAEs related to serplulimab or atezolizumab, grade ≥3
20 (20.2)
25 (25.0)
Related TEAEs leading to death
2 (2.0)
2 (2.0)
Immune-related adverse events
21 (21.2)
23 (23.0)
Infusion-related reactions
4 (4.0)
3 (3.0)
The related deaths were respiratory failure with septic shock and respiratory failure (serplulimab), and colitis with septic shock and myocarditis (atezolizumab). The most common TEAEs in either arm included anemia, nausea, fatigue, neutrophil count decreased and alopecia (3809O slide). The abstract reports no new safety signals.
⚠ Not FDA approved. Serplulimab has no FDA approval; the FDA granted it orphan drug designation for small cell lung cancer in March 2022. According to the abstract, ASTRIDE evaluated serplulimab in US patients “per FDA request,” and Henlius said in October 2025 that completing enrollment “paves the way” for a Biologics License Application. ✓ In the European Union, serplulimab (HETRONIFLY; marketing authorization holder Accord Healthcare) was authorized in February 2025 with carboplatin and etoposide for first-line ES-SCLC, based on ASTRUM-005; it is also approved in China and other countries. ✓ The comparator, atezolizumab (TECENTRIQ) plus carboplatin and etoposide, is an FDA-approved first-line regimen for ES-SCLC. ASTRUM-005, the trial behind the ex-US approvals, compared serplulimab 4.5 mg/kg with placebo (median OS 15.4 vs 10.9 months, HR 0.63, 95% CI 0.49–0.82; interim analysis, JAMA 2022); ASTRIDE used a 300 mg flat dose against an active comparator. The presenter concluded that serplulimab-chemotherapy “compared favorably” with atezolizumab-chemotherapy; that is not a regulatory decision.
Sources: ESMO 2026 abstract 3809O and presentation (David R. Gandara, MD, October 26, 2026); ClinicalTrials.gov NCT05468489; Henlius releases (October 22, 2025; September 28 and October 19, 2026); EMA EPAR for HETRONIFLY; TECENTRIQ US prescribing information; ASTRUM-005 (Cheng Y, et al. JAMA 2022;328:1223-1232). All ASTRIDE figures are from the February 18, 2026 data cutoff. FDA status checked against the FDA label and Drugs@FDA databases on October 26, 2026. Slides were shared on X by the physicians credited in Key Slides.
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Influence Leaders
Top KOLs Discussing ASTRIDE
The presenter, David R. Gandara, MD (UC Davis Comprehensive Cancer Center), leads the grid, followed by the physicians whose ASTRIDE posts drew the most views.
The 3809O presentation by David R. Gandara, MD, as photographed and shared on X by physicians on October 26, plus the abstract. Survival, subgroup and response 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 trials →
Slide text (transcribed from the slide images)
[ASTRIDE study design] Between 2022 and 2025, a total of 201 patients were enrolled at 70 study sites across the United States.
Key eligibility criteria: Age >=18 years; Performance status 0/1; Histologically or cytologically confirmed ES-SCLC; No prior systemic therapy for ES-SCLC (Patients who have received one cycle of chemotherapy for newly diagnosed ES-SCLC are eligible); Measurable disease as assessed by BICR per RECIST v1.1.
N = 201, R 1:1
IV, Q3W, up to 4 cycles: Serplulimab (300 mg, D1) + carboplatin (AUC 5, D1)a + etoposide (100 mg/m2, D1-3) -> IV, Q3W(b): Serplulimab (300 mg, D1)
Atezolizumab (1200 mg, D1) + carboplatin (AUC 5, D1)a + etoposide (100 mg/m2, D1-3) -> Atezolizumab (1200 mg, D1)
Descriptive Statistical Analysis: Primary endpoint: Overall survival
Secondary endpoints: PFS, ORR, DOR, safety, pharmacokinetics, immunogenicity, quality of life, exploratory biomarker analysis.
a Up to 750 mg. b Until disease progression, intolerable toxicity, discontinuation decided by the participant or the investigator, death, withdrawal of informed consent, pregnancy, noncompliance with protocol or procedure requirements, administrative reasons, or other protocol-specified reasons, whichever occurred first.
[Efficacy: OS and subgroup analysis]
Median OS (95% CI), months; Events, n (%): Serplulimab group 12.4 (9.0-17.9); 50 (49.5). Atezolizumab group 10.2 (8.4-13.2); 58 (58.0). Hazard ratio (95% CI), 0.82 (0.56-1.20)
1-year OS rate (95% CI): 52.4% (40.8%-62.7%) vs 41.4% (30.2%-52.3%)
2-year OS rate (95% CI): 32.2% (20.1%-44.9%) vs 17.6% (8.1%-30.0%)
No. at risk (No. censored), months 0/3/6/9/12/15/18/21/24/27/30/33: Serplulimab 101 (0), 90 (5), 66 (14), 41 (25), 28 (33), 19 (37), 13 (40), 10 (42), 6 (46), 4 (47), 1 (50), 0 (51); Atezolizumab 100 (0), 89 (3), 67 (12), 39 (21), 24 (28), 18 (30), 15 (32), 9 (36), 4 (38), 0 (42), 0 (42), 0 (42)
Subgroup: Serplulimab events/patients | Atezolizumab events/patients | HR for death (95% CI)
Age <65 years 18/39 | 19/37 | 1.03 (0.54-1.97); >=65 years 32/62 | 39/63 | 0.70 (0.44-1.13)
Sex Female 26/55 | 26/47 | 0.79 (0.46-1.36); Male 24/46 | 32/53 | 0.87 (0.51-1.49)
Performance status 0: 12/30 | 8/23 | 0.92 (0.37-2.29); 1: 38/70 | 49/76 | 0.89 (0.58-1.36); >=2: 0/1 | 1/1 | NE
Race American Indian or Alaska native 3/3 | 0/0 | NE; Asian American 1/2 | 1/4 | NE; Black or African American 0/2 | 4/8 | NE; White 46/94 | 53/88 | 0.78 (0.52-1.16)
Smoking history Current 20/35 | 17/28 | 0.78 (0.41-1.51); Former 28/62 | 41/69 | 0.71 (0.44-1.16); Never 2/4 | 0/3 | NE
Liver metastasis Yes 33/50 | 27/40 | 0.85 (0.51-1.42); No 17/51 | 31/60 | 0.60 (0.33-1.09)
Brain metastasis Yes 4/15 | 7/14 | 0.67 (0.20-2.31); No 46/86 | 51/86 | 0.83 (0.55-1.24)
1st cycle chemotherapy Yes 9/19 | 12/24 | 1.16 (0.49-2.75); No 41/82 | 46/76 | 0.77 (0.50-1.17)
[Efficacy: Secondary endpoints assessed by BICR] Serplulimab (n = 99)a | Atezolizumab (n = 100)
PFS(b), median (95% CI), months: 5.4 (4.5-5.8) | 4.9 (4.2-5.6); HR (95% CI) 0.95 (0.67-1.35)
Best overall response(c), n (%): Complete response 1 (1.0) | 1 (1.0); Partial response 64 (64.6) | 66 (66.0); Stable disease 25 (25.3) | 21 (21.0); Progressive disease 3 (3.0) | 6 (6.0); Not evaluable(d) 6 (6.1) | 6 (6.0)
ORR(c) (95% CI), %: 65.7 (55.4-74.9) | 67.0 (56.9-76.1)
DOR(c), median (95% CI), months: 4.2 (4.1-5.6) | 4.0 (3.1-4.5); HR (95% CI) 0.95 (0.62-1.47)
a Patients who did not receive study treatment were excluded from the secondary endpoint analyses. b According to BICR assessments per RECIST v1.1. c Based on confirmed tumor responses according to BICR assessments per RECIST v1.1. d These patients did not have post-treatment tumor assessment, except for one patient in the atezolizumab group with a non-evaluable target lesion at post-treatment tumor assessment.
[Safety and tolerability] Serplulimab (n = 99) | Atezolizumab (n = 100)
TEAE 97 (98.0) | 99 (99.0); Grade >=3 73 (73.7) | 73 (73.0); Serious 44 (44.4) | 46 (46.0); Leading to Tx interruption 54 (54.5) | 51 (51.0); Leading to Tx discontinuation 16 (16.2) | 12 (12.0); Leading to death 9 (9.1) | 8 (8.0)
TEAEs related to serplulimab or atezolizumab 63 (63.6) | 68 (68.0); Grade >=3 20 (20.2) | 25 (25.0); Serious 9 (9.1) | 7 (7.0); Leading to Tx interruption 22 (22.2) | 22 (22.0); Leading to Tx discontinuation 5 (5.1) | 4 (4.0); Leading to death(a) 2 (2.0) | 2 (2.0)
Adverse event of special interest 23 (23.2) | 23 (23.0); Infusion-related reaction 4 (4.0) | 3 (3.0); Immune-related adverse event 21 (21.2) | 23 (23.0)
Most common TEAEs (incidence >=15% in either group), bar chart by grade 1-2 and 3-4 (bar values not transcribed): anemia, nausea, fatigue, neutrophil count decreased, alopecia, diarrhea, vomiting, constipation, hypokalemia, platelet count decreased, arthralgia, dyspnea, decreased appetite, headache.
a One patient in the serplulimab group had respiratory failure and septic shock, and the other one had respiratory failure. One patient in the atezolizumab group had colitis and septic shock, and the other one had myocarditis.
Selected baseline characteristics (ITT), as printed on the 3809O slide
Serplulimab + chemo (n=101)
Atezolizumab + chemo (n=100)
Median age, years (range)
68 (35–91)
67 (40–82)
Female
54.5%
47.0%
ECOG PS 1
69.3%
76.0%
White / Black or African American
93.1% / 2.0%
88.0% / 8.0%
Liver metastasis
49.5%
40.0%
Brain metastasis
14.9%
14.0%
Received 1 cycle of chemotherapy before randomization
18.8%
24.0%
Any subsequent cancer therapy
37.6%
45.0%
Subsequent lurbinectedin / tarlatamab
21.8% / 12.9%
16.0% / 15.0%
Slide text (transcribed from the slide images)
[ASTRIDE study design] Between 2022 and 2025, a total of 201 patients were enrolled at 70 study sites across the United States.
Key eligibility criteria: Age >=18 years; Performance status 0/1; Histologically or cytologically confirmed ES-SCLC; No prior systemic therapy for ES-SCLC (Patients who have received one cycle of chemotherapy for newly diagnosed ES-SCLC are eligible); Measurable disease as assessed by BICR per RECIST v1.1.
N = 201, R 1:1
IV, Q3W, up to 4 cycles: Serplulimab (300 mg, D1) + carboplatin (AUC 5, D1)a + etoposide (100 mg/m2, D1-3) -> IV, Q3W(b): Serplulimab (300 mg, D1)
Atezolizumab (1200 mg, D1) + carboplatin (AUC 5, D1)a + etoposide (100 mg/m2, D1-3) -> Atezolizumab (1200 mg, D1)
Descriptive Statistical Analysis: Primary endpoint: Overall survival
Secondary endpoints: PFS, ORR, DOR, safety, pharmacokinetics, immunogenicity, quality of life, exploratory biomarker analysis.
a Up to 750 mg. b Until disease progression, intolerable toxicity, discontinuation decided by the participant or the investigator, death, withdrawal of informed consent, pregnancy, noncompliance with protocol or procedure requirements, administrative reasons, or other protocol-specified reasons, whichever occurred first.
[Baseline characteristics and subsequent cancer therapy] Data cutoff date: February 18, 2026; Median follow-up duration: 14.1 months. ITT population: 201 patients; Safety set: 199 patients
Serplulimab (n = 101) | Atezolizumab (n = 100)
Age, median (range), years: 68 (35-91) | 67 (40-82); <65 years, n (%): 39 (38.6) | 37 (37.0); >=65 years: 62 (61.4) | 63 (63.0)
Sex: Female 55 (54.5) | 47 (47.0); Male 46 (45.5) | 53 (53.0)
Performance status: 0: 30 (29.7) | 23 (23.0); 1: 70 (69.3) | 76 (76.0); >=2(a): 1 (1.0) | 1 (1.0)
Race: American Indian or Alaska native 3 (3.0) | 0; Asian 2 (2.0) | 4 (4.0); Black or African American 2 (2.0) | 8 (8.0); White 94 (93.1) | 88 (88.0)
Sum of longest diameter of target lesions, median (range), mm: 109.0 (12.0-262.0) | 108.0 (17.0-273.0)
Smoking history: Current 35 (34.7) | 28 (28.0); Former 62 (61.4) | 69 (69.0); Never 4 (4.0) | 3 (3.0)
Metastatic disease: 98 (97.0) | 98 (98.0); Liver metastasis 50 (49.5) | 40 (40.0); Bone metastasis 25 (24.8) | 28 (28.0); Brain metastasis 15 (14.9) | 14 (14.0)
Had 1st cycle of chemotherapy: 19 (18.8) | 24 (24.0)
Subsequent cancer therapy: 38 (37.6) | 45 (45.0); Chemotherapy 27 (26.7) | 24 (24.0); Lurbinectedin 22 (21.8) | 16 (16.0); Immunotherapy 16 (15.8) | 20 (20.0); Tarlatamab 13 (12.9) | 15 (15.0); Radiotherapy 21 (20.8) | 21 (21.0); Targeted therapy 1 (1.0) | 1 (1.0)
a The most recent performance status evaluations prior to the first dose of study treatment are presented. One patient in each group had performance status 1 at screening and 2 before the first dose of study treatment.
[Efficacy: OS and subgroup analysis]
Median OS (95% CI), months; Events, n (%): Serplulimab group 12.4 (9.0-17.9); 50 (49.5). Atezolizumab group 10.2 (8.4-13.2); 58 (58.0). Hazard ratio (95% CI), 0.82 (0.56-1.20)
1-year OS rate (95% CI): 52.4% (40.8%-62.7%) vs 41.4% (30.2%-52.3%)
2-year OS rate (95% CI): 32.2% (20.1%-44.9%) vs 17.6% (8.1%-30.0%)
No. at risk (No. censored), months 0/3/6/9/12/15/18/21/24/27/30/33: Serplulimab 101 (0), 90 (5), 66 (14), 41 (25), 28 (33), 19 (37), 13 (40), 10 (42), 6 (46), 4 (47), 1 (50), 0 (51); Atezolizumab 100 (0), 89 (3), 67 (12), 39 (21), 24 (28), 18 (30), 15 (32), 9 (36), 4 (38), 0 (42), 0 (42), 0 (42)
Subgroup: Serplulimab events/patients | Atezolizumab events/patients | HR for death (95% CI)
Age <65 years 18/39 | 19/37 | 1.03 (0.54-1.97); >=65 years 32/62 | 39/63 | 0.70 (0.44-1.13)
Sex Female 26/55 | 26/47 | 0.79 (0.46-1.36); Male 24/46 | 32/53 | 0.87 (0.51-1.49)
Performance status 0: 12/30 | 8/23 | 0.92 (0.37-2.29); 1: 38/70 | 49/76 | 0.89 (0.58-1.36); >=2: 0/1 | 1/1 | NE
Race American Indian or Alaska native 3/3 | 0/0 | NE; Asian American 1/2 | 1/4 | NE; Black or African American 0/2 | 4/8 | NE; White 46/94 | 53/88 | 0.78 (0.52-1.16)
Smoking history Current 20/35 | 17/28 | 0.78 (0.41-1.51); Former 28/62 | 41/69 | 0.71 (0.44-1.16); Never 2/4 | 0/3 | NE
Liver metastasis Yes 33/50 | 27/40 | 0.85 (0.51-1.42); No 17/51 | 31/60 | 0.60 (0.33-1.09)
Brain metastasis Yes 4/15 | 7/14 | 0.67 (0.20-2.31); No 46/86 | 51/86 | 0.83 (0.55-1.24)
1st cycle chemotherapy Yes 9/19 | 12/24 | 1.16 (0.49-2.75); No 41/82 | 46/76 | 0.77 (0.50-1.17)
[Efficacy: Secondary endpoints assessed by BICR] Serplulimab (n = 99)a | Atezolizumab (n = 100)
PFS(b), median (95% CI), months: 5.4 (4.5-5.8) | 4.9 (4.2-5.6); HR (95% CI) 0.95 (0.67-1.35)
Best overall response(c), n (%): Complete response 1 (1.0) | 1 (1.0); Partial response 64 (64.6) | 66 (66.0); Stable disease 25 (25.3) | 21 (21.0); Progressive disease 3 (3.0) | 6 (6.0); Not evaluable(d) 6 (6.1) | 6 (6.0)
ORR(c) (95% CI), %: 65.7 (55.4-74.9) | 67.0 (56.9-76.1)
DOR(c), median (95% CI), months: 4.2 (4.1-5.6) | 4.0 (3.1-4.5); HR (95% CI) 0.95 (0.62-1.47)
a Patients who did not receive study treatment were excluded from the secondary endpoint analyses. b According to BICR assessments per RECIST v1.1. c Based on confirmed tumor responses according to BICR assessments per RECIST v1.1. d These patients did not have post-treatment tumor assessment, except for one patient in the atezolizumab group with a non-evaluable target lesion at post-treatment tumor assessment.
Slide text (transcribed from the slide images)
[Title slide] Randomized trial of serplulimab or atezolizumab plus chemotherapy in USA patients with extensive-stage small cell lung cancer (ASTRIDE)
David R. Gandara, Evan Wu, Eric Schaefer, Rama Balaraman, Faris Badin, Murtaza Bhuriwala, Vu Phan, Mitchell Haut, Nagaprasad Nagajothi, Sumit Sawhney, Omar Abughanimeh, Shakar Dakhil, Santosh Nair, Roger S. Keresztes, Nikki James, Hongyan Ni, Qingyu Wang, Afshin Dowlati
Presented by Dr. David R. Gandara, Hematology and Oncology, University of California Davis Comprehensive Cancer Center, Sacramento, USA. 26 October 2026
[ASTRIDE study design] Between 2022 and 2025, a total of 201 patients were enrolled at 70 study sites across the United States.
Key eligibility criteria: Age >=18 years; Performance status 0/1; Histologically or cytologically confirmed ES-SCLC; No prior systemic therapy for ES-SCLC (Patients who have received one cycle of chemotherapy for newly diagnosed ES-SCLC are eligible); Measurable disease as assessed by BICR per RECIST v1.1.
N = 201, R 1:1
IV, Q3W, up to 4 cycles: Serplulimab (300 mg, D1) + carboplatin (AUC 5, D1)a + etoposide (100 mg/m2, D1-3) -> IV, Q3W(b): Serplulimab (300 mg, D1)
Atezolizumab (1200 mg, D1) + carboplatin (AUC 5, D1)a + etoposide (100 mg/m2, D1-3) -> Atezolizumab (1200 mg, D1)
Descriptive Statistical Analysis: Primary endpoint: Overall survival
Secondary endpoints: PFS, ORR, DOR, safety, pharmacokinetics, immunogenicity, quality of life, exploratory biomarker analysis.
a Up to 750 mg. b Until disease progression, intolerable toxicity, discontinuation decided by the participant or the investigator, death, withdrawal of informed consent, pregnancy, noncompliance with protocol or procedure requirements, administrative reasons, or other protocol-specified reasons, whichever occurred first.
[Conclusions] In the ASTRIDE trial, compared with atezolizumab, serplulimab was associated with
> numerically longer median OS
- ITT population: 12.4 versus 10.2 months, HR 0.82; 95% CI, 0.56-1.20
- No 1st cycle chemotherapy: 13.4 versus 10.8 months, HR 0.77; 95% CI, 0.50-1.17
> similar PFS, ORR, DOR outcomes
> similar safety profiles
Serplulimab-chemotherapy compared favorably with atezolizumab-chemotherapy, supporting the benefit of serplulimab and applicability of the ASTRUM-005 findings to the USA patients with treatment-naive ES-SCLC.
Abstract 3809O table (released before the presentation; same data cutoff): ITT vs patients without a prior cycle of chemotherapy (exploratory). ORR and DOR are IRRC-assessed in the ITT denominator (ORR 64.4% vs the slide’s 65.7% in treated patients)
ITT: serplulimab (n=101)
ITT: atezolizumab (n=100)
No prior cycle: serplulimab (n=82)
No prior cycle: atezolizumab (n=76)
Median OS, months
12.4
10.2
13.4
10.8
OS HR (95% CI)
0.82 (0.56–1.20)
0.77 (0.50–1.17)
24-month OS rate
32.2%
17.6%
34.8%
17.2%
Median PFS, months (HR, 95% CI)
5.4
4.9 (0.95, 0.67–1.35)
5.5
5.2 (0.97, 0.65–1.45)
ORR / median DOR (months)
64.4% / 4.2
67.0% / 4.0
68.3% / 4.4
64.5% / 4.1
Slide text (transcribed from the slide images)
3809O - Randomized trial of serplulimab or atezolizumab plus chemotherapy in USA patients with extensive-stage small cell lung cancer (ASTRIDE). Speakers: David R. Gandara (Sacramento, United States of America). Lecture Time 14:55 - 15:05
Background: Serplulimab (serplu), a programmed death 1 inhibitor, demonstrated significant survival benefits in the international, randomized phase 3 ASTRUM-005 study. ASTRIDE aims to evaluate the efficacy and safety of serplu vs atezolizumab (atezo), in USA patients (pts) with extensive-stage small cell lung cancer (ES-SCLC), per FDA request.
Methods: Pts with histologically or cytologically confirmed ES-SCLC and <=1 prior cycle of chemotherapy (chemo) for ES-SCLC were randomized 1:1 to receive up to 4 cycles of serplu (300 mg) or atezo, each in combination with carboplatin and etoposide, followed by maintenance serplu or atezo, respectively. Allowing 1 prior cycle of chemo reflected real-world practice. Treatments were administered intravenously every 3 weeks. The primary endpoint was overall survival (OS). As a bridging study, the statistical design was descriptive only.
Results: From July 2022 to October 2025, 201 USA pts were enrolled at 63 centers and randomized to the serplu (n=101) or atezo (n=100) group. As of February 18, 2026, median follow-up was 14.1 months (mo, 95% CI, 11.4-18.5). The proportion of pts with liver metastasis was higher in the serplu group (49.5% vs 40.0%). Other baseline characteristics were balanced. In the ITT, median OS was 12.4 mo with serplu and 10.2 mo with atezo; 24-mo OS rates were 32.2% and 17.6%, respectively. Detailed efficacy results are shown below (Table). Outcomes also appeared more favorable with serplu in pts without prior 1-cycle chemo (Table). The incidence and severity of adverse events were comparable between groups, with no new safety signals identified.
Table 3809O, Summary of efficacy. ITT: Serplulimab (n=101) | Atezolizumab (n=100); Without 1-cycle chemo: Serplulimab (n=82) | Atezolizumab (n=76)
IRRC assessed ORR, %: 64.4 | 67.0 | 68.3 | 64.5
IRRC assessed DOR, months: 4.2 | 4.0 | 4.4 | 4.1
IRRC assessed median PFS, months: 5.4 | 4.9 | 5.5 | 5.2; HR (95% CI): 0.95 (0.67, 1.35) | 0.97 (0.65, 1.45)
Median OS, months: 12.4 | 10.2 | 13.4 | 10.8; HR (95% CI): 0.82 (0.56, 1.20) | 0.77 (0.50, 1.17)
OS rate at 24 months, %: 32.2 | 17.6 | 34.8 | 17.2
Median OS in pts without liver metastasis, months: 18.9 | 13.2 | 18.9 | 13.2; HR (95% CI): 0.60 (0.33, 1.09) | 0.63 (0.33, 1.19)
Median OS in pts with liver metastasis, months: 8.6 | 8.2 | 9.0 | 8.4; HR (95% CI): 0.85 (0.51, 1.42) | 0.77 (0.43, 1.37)
Conclusions: Serplu plus chemo compared favorably with the comparator in this bridging trial, showing numerically longer OS and higher 24-mo OS rates vs atezo plus chemo in USA pts with ES-SCLC. These results support the benefit of serplu and the applicability of ASTRUM-005 findings to the USA population.
Physician Reactions · ESMO 2026
Physician reactions to ASTRIDE
Full, verbatim posts, newest first, linked to the originals. In all, 5 posts from 5 physicians, including the presenter’s post before the session.
ASTRIDE tested serplulimab, an anti-PD-1 antibody developed by Shanghai Henlius Biotech, against atezolizumab, an anti-PD-L1 antibody, each with carboplatin and etoposide, as first-line treatment in US patients with extensive-stage small cell lung cancer. Atezolizumab plus carboplatin-etoposide is a US standard first-line regimen. The trial bridges the international ASTRUM-005 results to a US population and is sponsored by Henlius. Results were presented by David R. Gandara, MD, at ESMO 2026 (abstract 3809O, Proffered paper, October 26, 2026).
Study Design
Randomized 1:1, open-label bridging study (NCT05468489; registered as phase 3). 201 patients (101 vs 100) enrolled 2022–2025 at 70 US sites per the slide (63 centers per the abstract). Statistical design descriptive only.
Population
Adults with histologically or cytologically confirmed ES-SCLC, ECOG PS 0–1, measurable disease by BICR, no prior systemic therapy for ES-SCLC except one allowed cycle of chemotherapy. Median age 68 vs 67; 93.1% vs 88.0% White; liver metastasis 49.5% vs 40.0%.
Interventions
Serplulimab 300 mg or atezolizumab 1200 mg IV day 1, plus carboplatin AUC 5 (up to 750 mg) day 1 and etoposide 100 mg/m² days 1–3, every 3 weeks for up to 4 cycles, then maintenance serplulimab or atezolizumab every 3 weeks.
Endpoints
Primary: overall survival (descriptive). Secondary: PFS, ORR and DOR by BICR (RECIST v1.1), safety, pharmacokinetics, immunogenicity, quality of life, exploratory biomarkers.
Presenter
David R. Gandara, MD, UC Davis Comprehensive Cancer Center, Sacramento; principal investigator. The ITT population was 201 patients and the safety set 199.
Data Cut
Data cutoff February 18, 2026; median follow-up 14.1 months (95% CI 11.4–18.5).
ASTRIDE (NCT05468489; HLX10-005-SCLC301-E) is a randomized, open-label US bridging trial sponsored by Shanghai Henlius Biotech. It compared serplulimab, an anti-PD-1 antibody, with atezolizumab, each combined with carboplatin and etoposide and followed by maintenance with the same antibody, as first-line treatment in 201 US patients with extensive-stage small cell lung cancer (ES-SCLC). The abstract says the trial was run at FDA request to evaluate serplulimab in US patients after the international ASTRUM-005 trial.
What did ASTRIDE show at ESMO 2026?
At the February 18, 2026 data cutoff (median follow-up 14.1 months), median overall survival was 12.4 months with serplulimab vs 10.2 months with atezolizumab (HR 0.82, 95% CI 0.56–1.20), and the 2-year OS rate was 32.2% vs 17.6%. PFS (5.4 vs 4.9 months), response rate and duration of response by BICR were similar. The results were presented by David R. Gandara, MD, at ESMO 2026 (abstract 3809O).
Did serplulimab beat atezolizumab?
The trial was not designed to show that. As a bridging study, its statistical design was descriptive only, no P values were reported, and the 95% confidence interval for the OS hazard ratio (0.56–1.20) includes 1. The presenter’s conclusion was that serplulimab was associated with numerically longer median OS and similar PFS, response and safety. Only 6 and 4 patients were still at risk at 24 months, so the 2-year rates carry wide confidence intervals. More patients in the serplulimab arm had liver metastases (49.5% vs 40.0%).
Is serplulimab FDA approved?
No. Serplulimab is not approved by the FDA. FDA granted it orphan drug designation for small cell lung cancer in 2022. Henlius said in October 2025 that completing ASTRIDE enrollment paves the way for a Biologics License Application to the FDA. In the European Union, serplulimab (HETRONIFLY, marketed by Accord Healthcare) was authorized in February 2025 with carboplatin and etoposide for first-line ES-SCLC, based on ASTRUM-005. The comparator regimen, atezolizumab (TECENTRIQ) plus carboplatin and etoposide, is FDA approved for first-line ES-SCLC.
How did the safety profiles compare?
Safety was similar. Grade ≥3 treatment-emergent adverse events occurred in 73.7% of 99 treated patients with serplulimab vs 73.0% of 100 with atezolizumab; serious events in 44.4% vs 46.0%; events leading to discontinuation in 16.2% vs 12.0%; and immune-related adverse events in 21.2% vs 23.0%. Two deaths in each arm were attributed to the PD-(L)1 antibody.
How does ASTRIDE relate to ASTRUM-005?
ASTRUM-005 was the international, double-blind phase 3 trial of serplulimab (4.5 mg/kg) vs placebo, each with carboplatin-etoposide, in 585 patients; median OS was 15.4 vs 10.9 months (HR 0.63, 95% CI 0.49–0.82; interim analysis, JAMA 2022). ASTRUM-005 enrolled at 114 sites in 6 countries; ASTRIDE used a 300 mg flat dose, an active comparator (atezolizumab) and an all-US population. The presenter concluded that ASTRIDE supports the applicability of the ASTRUM-005 findings to US patients.
Physician Opinions
Key KOL Sentiments - ASTRIDE
2 positive, 3 neutral and 0 negative posts from physicians, each shown verbatim.
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 3809O abstract and presentation slides, ClinicalTrials.gov, Henlius releases, the EMA and FDA records or the ASTRUM-005 publication, with the source labelled.
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