OpenOnco · Treatment Plan

Treatment plan — Gastric and gastroesophageal junction adenocarcinoma

PLAN-AUTO-GASTRIC-001-V1 · v1 · 2026-07-26

Patient

AUTO-GASTRIC-001 · Algorithm: ALGO-GASTRIC-METASTATIC-1L

DiagnosisGastric and gastroesophageal junction adenocarcinoma

MOH / ICD-10C16

ICD-O-38140/3; C16

Clinical significance of mutations (ESCAT)

Tumor-board context — the engine does not use these tiers to rank tracks

✅ Covered biomarkers (matched in KB)

Biomarker	Variant	ESCAT	Evidence	Clinical significance	Drugs	Sources
No clinically actionable variants matched in this profile.

⚠️ Not included in plan

Biomarker	Status
BIO-HER2-SOLID	BIO definition in KB; no ESCAT BMA entry — verify with clinician

Primary current-line option

Aggressive plan

★ DEFAULT

Indication

IND-GASTRIC-METASTATIC-1L-HER2-TOGA

Regimen

Trastuzumab + capecitabine + cisplatin (TOGA / KEYNOTE-811)

Drugs + NSZU

Trastuzumab (DRUG-TRASTUZUMAB) 8 mg/kg IV loading then 6 mg/kg q3w · IV day 1 every 21d · IV ✓ NSZU covered
Capecitabine (DRUG-CAPECITABINE) 1000 mg/m² PO BID days 1-14 · PO days 1-14 · PO ✓ NSZU covered
Cisplatin (DRUG-CISPLATIN) 80 mg/m² · IV day 1 q3w · IV ⚠ NSZU — not for this indication

Reason

Primary current-line option per algorithm ALGO-GASTRIC-METASTATIC-1L: selected default was filtered; promoted first remaining current-line track

Other current-line alternatives (1 tracks)

Same treatment line; review when biomarker, access, contraindication, or patient-context assumptions change.

Aggressive plan

Indication

IND-GASTRIC-METASTATIC-1L-CLDN18-2-ZOLBETUXIMAB

Regimen

Zolbetuximab + mFOLFOX6 (SPOTLIGHT) — 1L CLDN18.2-positive HER2-negative gastric/GEJ

Drugs + NSZU

Zolbetuximab (DRUG-ZOLBETUXIMAB) Loading 800 mg/m² IV cycle 1 day 1; maintenance 600 mg/m² IV q2w · IV q2w (with mFOLFOX6 backbone) · IV ✗ Not registered in UA
Oxaliplatin (DRUG-OXALIPLATIN) 85 mg/m² IV day 1 · IV day 1 q2w · IV ✓ NSZU covered
Leucovorin (DRUG-LEUCOVORIN) 400 mg/m² IV day 1 · IV day 1 q2w · IV ⚠ NSZU — not for this indication
5-Fluorouracil (DRUG-5-FLUOROURACIL) 400 mg/m² IV bolus day 1, then 2400 mg/m² IV continuous infusion over 46 h · IV q2w · IV ✓ NSZU covered

Supportive care

SUP-ANTIEMETIC-PREMED

Reason

Current-line alternative presented for HCP consideration

Pre-treatment investigations

Investigations before treatment start · critical / standard / desired · merged across tracks

ID	Name	Priority	Category	Where to order	Needed for
TEST-CBC	Complete Blood Count with Differential	Critical	lab	—	all tracks
TEST-CMP	Comprehensive Metabolic Panel	Critical	lab	—	all tracks
TEST-CT-CHEST-ABDOMEN-PELVIS	CT chest + abdomen + pelvis with IV contrast	Critical	imaging	—	all tracks
TEST-LFT	Liver Function Tests (ALT, AST, bilirubin, ALP, GGT, albumin)	Critical	lab	—	all tracks
TEST-HER2-IHC-ISH-IF-RAS-WT	HER2 IHC + reflex ISH (gastric scoring criteria)	Standard	histology	CSD Lab ✓ (code TBC)	all tracks
TEST-NGS-COMPREHENSIVE	Comprehensive NGS tumor panel (DNA + RNA, ≥300 genes)	Desired	histology	CSD Lab: M065	desired (aggressive)

Red flags — PRO / CONTRA aggressive

PRO-AGGRESSIVE

Triggers that push toward the aggressive track

CLDN18.2 expression positive (≥75% of tumor cells with 2+/3+ membranous staining on VENTANA CLDN18 (43-14A) RxDx) in HER2-negative metastatic / unresectable gastric or GEJ adenocarcinoma — eligibility for zolbetuximab + fluoropyrimidine/oxaliplatin 1L (SPOTLIGHT mFOLFOX6 mOS 18.2 vs 15.5 mo HR 0.75; GLOW CAPOX mOS 14.4 vs 12.2 mo HR 0.77). Treatment-defining for the ~38% of HER2-negative gastric cohort. Hierarchy: HER2+ trastuzumab supersedes; MSI-H pembrolizumab supersedes; otherwise CLDN18.2+ → zolbetuximab.
Companion diagnostic VENTANA CLDN18 (43-14A) RxDx required (FDA- approved alongside zolbetuximab Oct 2024). Cutoff: ≥75% of tumor cells with 2+/3+ membranous staining. Major toxicity: nausea/vomiting (~70% any grade — severe in cycle 1…
RF-GASTRIC-CLDN18-2-ACTIONABLESRC-NCCN-GASTRIC-2025SRC-ESMO-GASTRIC-2024
Treatment-defining biomarkers in metastatic gastric/GEJ adenocarcinoma: HER2+ (IHC 3+ OR 2+/ISH+) → trastuzumab+chemo TOGA / T-DXd 2L+; CLDN18.2+ (≥75% of tumor cells with 2+ membranous staining) → zolbetuximab+chemo SPOTLIGHT/GLOW; MSI-H → pembrolizumab mono; EBV+ subtype (TCGA molecular class) — distinct biology, ICI-favorable.
Sequential biomarker test cascade: HER2 IHC → ISH if 2+; PD-L1 CPS; MSI-H reflex; CLDN18.2 IHC. EBV by EBER-ISH if MSI-WT non-classic signet-ring. Multiple actionable biomarkers can co-exist (HER2+ MSI-H ~3% — ICI + trastuzumab…
RF-GASTRIC-HIGH-RISK-BIOLOGYSRC-NCCN-GASTRIC-2025SRC-ESMO-GASTRIC-2024

CONTRA-AGGRESSIVE

Hard contraindications to escalation

What NOT to do

Explicit prohibitive rules, each grounded in a regimen / supportive care / contraindication entity

Aggressive plan (IND-GASTRIC-METASTATIC-1L-HER2-TOGA)

Do NOT use without baseline LVEF — trastuzumab cardiotoxic (q3-mo echo monitoring)
Do NOT combine with anthracycline (cumulative cardiotoxicity)
Do NOT initiate during ongoing GI bleed / obstruction

Aggressive plan (IND-GASTRIC-METASTATIC-1L-CLDN18-2-ZOLBETUXIMAB)

Do not start zolbetuximab without confirmed CLDN18.2 ≥75% 2+/3+ by VENTANA RxDx — outside this range benefit is not proven.
Do not prescribe zolbetuximab in HER2+ patients — TOGA trastuzumab+chemo takes priority.
Do not prescribe zolbetuximab in MSI-H patients 1L — pembrolizumab (KEYNOTE-859) takes preference.
Do not start without triplet antiemetic prophylaxis (5-HT3 + NK1-RA + dex) for cycle 1 — nausea/vomiting severe without it.
Do not combine with ipilimumab/ICI outside of trials — combination safety unknown.
Do not confirm the plan without funding pathway — zolbetuximab not registered in UA.

Timeline

Treatment timeline — derived from regimen + monitoring schedule

Aggressive plan

Induction · Trastuzumab + capecitabine + cisplatin (TOGA / KEYNOTE-811)

21-day cycles × Until progression / unacceptable toxicity (chemo backbone often capped at 6-8 cycles, trastuzumab continues mono)

Aggressive plan

Induction · Zolbetuximab + mFOLFOX6 (SPOTLIGHT) — 1L CLDN18.2-positive HER2-negative gastric/GEJ

14-day cycles × Until progression / unacceptable toxicity (oxaliplatin commonly capped at 8-12 cycles for cumulative neuropathy; zolbetuximab + 5-FU/LV maintenance continues)

MDT brief

Discussion questions (2, 0 blocking)

OQ-LDH-CURRENT
What is the current LDH? Marker of tumor burden and transformation.
LDH is part of the prognostic indices of indolent lymphomas.
→ hematologist
OQ-BIOMARKER-CLDN18-2
What is the status of Claudin-18.2 expression (CLDN18.2) (BIO-CLDN18-2)? It is required by track(s): IND-GASTRIC-METASTATIC-1L-CLDN18-2-ZOLBETUXIMAB. Expected value: positive — ≥75% of tumor cells with 2+/3+ membranous staining (VENTANA CLDN18 (43-14A) RxDx).
A treatment-track biomarker requirement is missing from the patient profile; the MDT should verify the test result, method, specimen, and date before relying on this option.
→ pathologist

MDT talk tree (3 steps)

#	Owner	Topic	Action
1	hematologist	Staging / disease burden	What is the current LDH? Marker of tumor burden and transformation.
2	pathologist	Biomarker status	What is the status of Claudin-18.2 expression (CLDN18.2) (BIO-CLDN18-2)? It is required by track(s): IND-GASTRIC-METASTATIC-1L-CLDN18-2-ZOLBETUXIMAB. Expected value: positive — ≥75% of tumor cells with 2+/3+ membranous staining (VENTANA CLDN18 (43-14A) RxDx).
3	clinical_pharmacist	Specialist review	Chemoimmunotherapy regimen — drug-drug interactions, dose adjustments, premedication.

Skills (recommended) — for consideration (1)

Clinical pharmacist recommended
Chemoimmunotherapy regimen — drug-drug interactions, dose adjustments, premedication.

Data quality

Usable with caveats. No critical default-track gap was found, but the MDT should review the listed caveats before final sign-off.

Biomarker coverage: 1/2 known (50%), 1 missing, 0 default-track gaps
Unevaluated RedFlags: RF-ACTIVE-AUTOIMMUNE-DISEASE-ICI-RISK, RF-BREAST-CDH1-LOBULAR-CANDIDATE, RF-CASCADE-FAP-FDR-POSITIVE, RF-CASCADE-LYNCH-FDR-POSITIVE, RF-CHRONIC-ATROPHIC-GASTRITIS-PREVENTION, RF-CHRONIC-H-PYLORI-MALIGNANCY-PREVENTION, RF-CRONKHITE-CANADA-CONFIRMED, RF-FAP-CONFIRMED-CARRIER, RF-FAP-FAMILY-HISTORY-SUSPICION, RF-GASTRIC-CLDN18-2-ACTIONABLE, RF-GASTRIC-EMERGENCY-BLEED-OBSTRUCTION, RF-GASTRIC-FRAILTY-AGE, RF-GASTRIC-HIGH-RISK-BIOLOGY, RF-GASTRIC-INFECTION-SCREENING, RF-GASTRIC-PDL1-CPS-1-PLUS, RF-GASTRIC-TRANSFORMATION-PROGRESSION, RF-HDGC-CDH1-CONFIRMED-CARRIER, RF-IATROGENIC-LONG-TERM-PPI-GASTRIC-NET-PREVENTION, RF-JPS-CONFIRMED-CARRIER, RF-LIFESTYLE-SALTY-PICKLED-DIET-GASTRIC-PREVENTION, RF-LYNCH-CONFIRMED-CARRIER, RF-LYNCH-FAMILY-HISTORY-SUSPICION, RF-OLIGOMET-DEFINITION, RF-PEUTZ-JEGHERS-CONFIRMED-CARRIER, RF-PEUTZ-JEGHERS-FAMILY-HISTORY-SUSPICION

Missing biomarker	Label	MDT owner	Default track	Required by	Next action
`BIO-CLDN18-2`	Claudin-18.2 expression (CLDN18.2)	pathologist	no	IND-GASTRIC-METASTATIC-1L-CLDN18-2-ZOLBETUXIMAB	Verify result, method, specimen, and report date before sign-off. Expected/constraint: positive — ≥75% of tumor cells with 2+/3+ membranous staining (VENTANA CLDN18 (43-14A) RxDx)

Technical MDT skill metadata (1/16 activated in this plan)

All registered virtual specialists. ✓ — activated for this case; ○ — not activated (available for other clinical scenarios).

Specialist	skill_id	Version	Last reviewed	Domain
Cellular therapy specialist (CAR-T)	`cellular_therapy_specialist`	v0.1.0	2026-04-25	cellular_therapy
Clinical pharmacist	`clinical_pharmacist`	v0.1.0	2026-04-25	clinical_pharmacy
Hematologist / oncohematologist	`hematologist`	v0.1.0	2026-04-25	hematology_oncology
Hematopathologist (lymphoma / leukemia / myeloma)	`hematopathologist`	v0.1.0	2026-04-25	hematopathology
Infectious disease / hepatology	`infectious_disease_hepatology`	v0.1.0	2026-04-25	infectious_diseases
Medical oncologist (solid-tumor chemotherapist)	`medical_oncologist`	v0.1.0	2026-04-25	solid_oncology
Molecular geneticist / molecular oncologist	`molecular_geneticist`	v0.1.0	2026-04-25	molecular_oncology
Palliative care	`palliative_care`	v0.1.0	2026-04-25	palliative_care
Pathologist (general)	`pathologist`	v0.1.0	2026-04-25	pathology
Primary care / family physician	`primary_care`	v0.1.0	2026-04-25	primary_care
Psycho-oncologist	`psychologist`	v0.1.0	2026-04-25	psychosocial
Radiation oncologist	`radiation_oncologist`	v0.1.0	2026-04-25	radiation_oncology
Radiologist	`radiologist`	v0.1.0	2026-04-25	diagnostic_imaging
Social worker / case manager	`social_worker_case_manager`	v0.1.0	2026-04-25	psychosocial
Surgical oncologist	`surgical_oncologist`	v0.1.0	2026-04-25	surgical_oncology
Transplant specialist (BMT)	`transplant_specialist`	v0.1.0	2026-04-25	cellular_therapy

Sources cited

SRC-ESMO-GASTRIC-2024: ESMO Gastric Cancer (2024)
SRC-NCCN-GASTRIC-2025: NCCN Gastric Cancer (v.3.2025)

Experimental options (clinical trials)

Third plan track — open-enrollment trials from ClinicalTrials.gov. Render-time metadata; engine selection is not affected by this block (CHARTER §8.3). Last synced: 2026-07-26.

NCT	Title	Phase	Status	Sponsor	UA	Signals
NCT07315750	A Study of Disitamab Vedotin Combined With Trastuzumab and Tislelizumab Versus Chemotherapy Combined With Trastuzumab With or Without Pembrolizumab in HER2-high Expression Advanced Gastric or Gastroesophageal Junction Adenocarcinoma.	PHASE3	RECRUITING	RemeGen Co., Ltd.	—	Surrogate endpoint only Single country
NCT07179484	To Evaluate the Efficacy of CT041 in Sequential Treatment After First-line Treatment of Advanced Gastric/Esophagogastric Junction Adenocarcinoma	N/A	RECRUITING	Beijing GoBroad Hospital	—	Small N (<50) Single country
NCT07432295	Givastomig Combined With Nivolumab and Chemotherapy in Adults With CLDN18.2 Positive Metastatic Gastric Cancer (GIVA-2)	PHASE2	RECRUITING	I-Mab Biopharma US Limited	—	Surrogate endpoint only
NCT06005493	Study of AZD5863 in Adult Participants With Advanced or Metastatic Solid Tumors	PHASE1 / PHASE2	RECRUITING	AstraZeneca	—	Surrogate endpoint only
NCT06932068	Phase II Trial of Iparomlimab/Tuvonralimab (QL1706) + XELOX in HER2-Negative, Low PD-L1 G/GEJ Adenocarcinoma	PHASE2	RECRUITING	Qilu Hospital of Shandong University	—	Surrogate endpoint only Single country
NCT07655024	TAIC FOLFOX for Locally Advanced G/GEJA	PHASE2	RECRUITING	Guang'anmen Hospital of China Academy of Chinese Medical Sciences	—	Small N (<50) Single country
NCT06572319	Disitamab Vedotin Plus Trastuzumab in Patients With HER2 Positive GC/GEJ Patiens	PHASE1 / PHASE2	RECRUITING	Zhejiang Cancer Hospital	—	Small N (<50) Surrogate endpoint only Single country
NCT06177041	M108 Plus CAPOX Versus Placebo Plus CAPOX as First-line Treatment for Claudin (CLDN) 18.2-Positive, HER2-Negative, PD-L1 CPS<5, Locally Advanced Unresectable or Metastatic Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma.	PHASE3	RECRUITING	FutureGen Biopharmaceutical (Beijing) Co., Ltd	—	Surrogate endpoint only Single country
NCT06764875	A Phase Ⅲ Study of Rilvegostomig in Combination With Fluoropyrimidine and Trastuzumab Deruxtecan as the First-line Treatment for HER2-positive Gastric Cancer	PHASE3	RECRUITING	AstraZeneca	—	—
NCT04982276	A Study of AK109 and AK104 in Advanced Gastric Adenocarcinoma or Gastroesophageal Junction Adenocarcinoma	PHASE1 / PHASE2	RECRUITING	Akeso	—	Surrogate endpoint only Single country

Verify recruitment status directly with the trial site. ctgov data can lag behind current UA-site status.

Option availability in Ukraine

Per-track UA registration · NSZU · cost · access pathway. Render-time metadata; engine selection does not depend on these fields (CHARTER §8.3).

Option	UA registration	NSZU	Cost orientation	Access pathway
Aggressive plan Trastuzumab + capecitabine + cisplatin (TOGA / KEYNOTE-811) (REG-TRASTUZUMAB-CHEMO-TOGA)	✓ registered	✓ covered	₴-? — verify pathway	NSZU formulary
Aggressive plan Zolbetuximab + mFOLFOX6 (SPOTLIGHT) — 1L CLDN18.2-positive HER2-negative gastric/GEJ (REG-ZOLBETUXIMAB-CHEMO) 1/4 component drug(s) not registered in Ukraine +1	✗ not registered	✗ out-of-pocket	₴-? — verify pathway	not recorded
Trial · NCT07315750 A Study of Disitamab Vedotin Combined With Trastuzumab and Tislelizumab Versus Chemotherapy Combined With Trastuzumab With or Without Pembrolizumab in HER2-high Expression Advanced Gastric or Gastroesophageal Junction Adenocarcinoma. No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor
Trial · NCT07179484 To Evaluate the Efficacy of CT041 in Sequential Treatment After First-line Treatment of Advanced Gastric/Esophagogastric Junction Adenocarcinoma No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor
Trial · NCT07432295 Givastomig Combined With Nivolumab and Chemotherapy in Adults With CLDN18.2 Positive Metastatic Gastric Cancer (GIVA-2) No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor
Trial · NCT06005493 Study of AZD5863 in Adult Participants With Advanced or Metastatic Solid Tumors No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor
Trial · NCT06932068 Phase II Trial of Iparomlimab/Tuvonralimab (QL1706) + XELOX in HER2-Negative, Low PD-L1 G/GEJ Adenocarcinoma No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor
Trial · NCT07655024 TAIC FOLFOX for Locally Advanced G/GEJA No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor
Trial · NCT06572319 Disitamab Vedotin Plus Trastuzumab in Patients With HER2 Positive GC/GEJ Patiens No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor
Trial · NCT06177041 M108 Plus CAPOX Versus Placebo Plus CAPOX as First-line Treatment for Claudin (CLDN) 18.2-Positive, HER2-Negative, PD-L1 CPS<5, Locally Advanced Unresectable or Metastatic Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma. No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor
Trial · NCT06764875 A Phase Ⅲ Study of Rilvegostomig in Combination With Fluoropyrimidine and Trastuzumab Deruxtecan as the First-line Treatment for HER2-positive Gastric Cancer No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor
Trial · NCT04982276 A Study of AK109 and AK104 in Advanced Gastric Adenocarcinoma or Gastroesophageal Junction Adenocarcinoma No UA site listed — international referral required	— unknown	— unknown	self-pay: ₴0/course	Trial sponsor

Cost information is orientation. Verify with a specific pharmacy / foundation / trial site. Status updated: 2026-07-26.

plan_id: PLAN-AUTO-GASTRIC-001-V1 | version: 1 | generated: 2026-07-26T09:28:48.427804+00:00

Per FDA non-device CDS positioning (CHARTER §15): Outpatient oncology treatment planning to support tumor-board discussion. Not a medical device; not for autonomous clinical decision-making.

Per FDA non-device CDS positioning (CHARTER §15): Both treatment options below are presented for review. The engine's selection of a 'recommended' default does not constitute a clinical decision. Final treatment selection requires HCP judgment incorporating information not available to the system.

This document is an informational resource supporting tumor-board discussion (per CHARTER §11). It is not a system that makes clinical decisions. Every recommendation must be verified by the treating physician.