Evidence-Based Personalized Treatment Plan
Precision Oncology for dMMR/MSI-H Pancreatic Adenocarcinoma
Biopsy
Analysis
Treatment
Economics
Monitoring
Escalation
Decision
Biopsy → Sequencing
Comprehensive molecular profiling to identify rare immunotherapy responders
Methodology
- Image-guided core biopsy
- Comprehensive NGS panel (≥ 500 genes)
- MSI/MMR IHC or PCR
- RNA-fusion panel
Identifies the < 1% of PDACs that are dMMR/MSI-H and therefore immunotherapy-responsive.OncLive
Outputs
VCF/JSON files auto-uploaded to OncoMetric Hub
Automated Genomic Interpretation
AI-driven variant analysis for actionable mutations
Run ImmunoMatch™ on uploaded data.
Outputs
Returns dMMR/MSI-H flag → PD-1 inhibitor pathway unlocked.
PDF summary injected into EMR
Therapy Selection
Dostarlimab (Jemperli) - FDA-approved dosing for dMMR tumors
Dosing Schedule
- 500 mg IV q3 weeks × 4 (doses 1-4)
- 1,000 mg IV q6 weeks starting dose 5, until progression or intolerance
Clinical Evidence
In the GARNET pan-tumor cohort, the PDAC subset achieved 5 partial responses among 12 pts (ORR 41.7%) with no complete responses; median PFS 3.3 mo, median OS 12.7 mo.JAMA Network
Responses occurred despite heavy pre-treatment but are based on very small numbers—discuss uncertainty with the patient.
Economic Scenario Modeling
Compare costs: PD-1 therapy vs. chemotherapy + Whipple surgery
Compare upfront PD-1 therapy vs. chemotherapy + Whipple.
Cost Assumptions (6-month horizon)
- Dostarlimab drug cost ≈ US $12,600 per 500 mg vial → ≈ US $101k for the first six infusions (4 × 500 mg + 2 × 1,000 mg).Drugs.com
- National cash price for Whipple procedure US $40k – ≥ US $100k (hospital & surgeon fees vary).HealthTrip
Important Note
If surgery is averted, the net cost difference is patient- and center-specific; break-even occurs only when the avoided surgical/ICU stay plus rehab exceed drug + infusion costs. Mark result as exploratory, not prescriptive.
Outputs
Spreadsheet plus one-page payer brief
Adaptive Response Monitoring
Regular imaging and ctDNA tracking for early response detection
Monitoring Protocol
- Contrast CT every 9 weeks
- ctDNA MRD panel at weeks 12 & 24
Evidence Limitation
Early ctDNA clearance after PD-1 blockade correlated with durable benefit in dMMR solid tumors (85% cleared by 6 mo in a 13-patient series), but only 2 pancreatobiliary cases were included—extrapolate with caution.Cancer Therapy Advisor
Outputs
Traffic-light dashboard; auto-alert if ctDNA remains positive
Escalation ("Plan B")
Clinical trial enrollment for non-responders or progressive disease
Persisting disease → enroll in clinical trial of personalized neoantigen mRNA vaccine ± atezolizumab or PARP-i + PD-1 combo where HR-gene mutated.
Clinical Trial Information
Multiple phase II studies are recruiting; small PDAC cohorts show immune activation but clinical benefit not yet proven.
Trial IDs: NCT04409002, NCT04493060, etc.ClinicalTrials.gov
Outputs
Neoantigen list auto-formatted for GMP vendor
Shared Decision & Documentation
Multidisciplinary review and informed consent process
Multidisciplinary tumor board review → e-consent.
Ensures patient understands the modest evidence base, alternative standards (FOLFIRINOX ± Whipple), and financial implications.
Outputs
Signed plan stored; reminders generated for imaging & labs
Key Updates from Previous Version
- Response rate corrected – GARNET shows ORR 41.7% (5/12) for dMMR PDAC, not 64%.JAMA Network
- Dosing corrected – FDA label: 500 mg q3wk × 4 ➜ 1,000 mg q6wk thereafter.FDA Access Data
- Cost section flagged as modeling only – real-world drug (≈ US $101k/6 mo) and Whipple (≈ US $40-100k) figures inserted with sources.Drugs.comHealthTrip
- ctDNA claim tempered – data come from a mixed-tumor study with just 2 pancreatobiliary patients; no PDAC-specific long-term RFS yet.Cancer Therapy Advisor
Bottom Line
For the rare (< 1%) patient whose PDAC is dMMR/MSI-H, frontline dostarlimab is a rational option with ~40% response in early data, a manageable safety profile, and the potential—but not guarantee—to obviate Whipple surgery. Continuous imaging + ctDNA monitoring and clear cost-benefit discussions are essential to a truly personalized, evidence-anchored plan.