Targeted Therapy

Patients with confirmed cancer diagnoses and actionable biomarkers are candidates. This includes EGFR mutations, HER2 amplification, ALK rearrangements, BRAF V600 mutations, BCR-ABL translocation, BRCA mutations, and PD-L1 expression. Biomarker testing is mandatory before treatment initiation. Most patients require ECOG performance status 0-2 and adequate organ function.

Selection is based on comprehensive biomarker testing results, cancer type and stage, prior treatment history, patient factors (performance status, organ function, comorbidities), and drug availability. Next-generation sequencing can identify multiple actionable targets simultaneously. Your oncologist will match your specific molecular profile to the most effective available therapy.

Required testing includes NGS-based comprehensive genomic profiling (FoundationOne CDx covers 324 genes), single-gene testing for specific mutations (EGFR, BRAF, KRAS), IHC for protein expression (HER2, PD-L1), and FISH for gene rearrangements (ALK, ROS1). Liquid biopsy is available when tissue is insufficient. Turnaround time is typically 10-14 days for tissue NGS and 5-10 days for liquid biopsy.

Treatment duration varies significantly by therapy type and response. Many patients continue treatment for 12-24 months until disease progression or intolerance. Some achieve long-term disease control lasting years—CML patients on imatinib can achieve sustained remission for 10+ years. First response evaluation typically occurs at weeks 8-12 with imaging reassessment.

Side effects vary by drug class. EGFR inhibitors commonly cause skin rash (50-100%) and diarrhea (20-40%). VEGFR inhibitors cause hypertension (30-80%) and hand-foot syndrome (30-60%). HER2 agents may cause cardiotoxicity (3-27% LVEF decline). Most toxicities are manageable with supportive care, dose modifications, or treatment holds. Only 5-15% of patients discontinue due to adverse events.

Thailand offers 70-80% cost savings with comparable outcomes. Oral TKIs cost $7,000-$15,000/year versus $40,000-$100,000 in the US. Thai centers have JCI accreditation, ESMO designation, and access to all major targeted agents. Biomarker testing turnaround is 1-3 weeks with no wait times. Bumrungrad was ranked Best Specialized Hospital APAC - Oncology by Newsweek 2023-2024.

Yes, for oral agents you can continue treatment at home after initial monitoring in Thailand (typically 2-4 weeks). You'll receive a supply of medication, detailed monitoring instructions, and coordination with your home oncologist. IV infusions require periodic returns to Thailand or arrangement with a local infusion center. Telemedicine follow-up is available for ongoing management.

For HER2-targeted agents (trastuzumab, pertuzumab), baseline echocardiogram with LVEF measurement is mandatory, repeated every 3 months during treatment and annually for 5 years after completion. For QT-prolonging TKIs, baseline 12-lead ECG is required with periodic monitoring. Patients with prior cardiac history or anthracycline exposure need more intensive cardiology follow-up.

Resistance typically develops within 12-24 months. Management includes repeat biomarker testing (often via liquid biopsy) to identify resistance mechanisms, switching to next-generation agents (e.g., osimertinib for EGFR T790M), combination therapies, or clinical trial enrollment. Some resistance mechanisms have specific targeted solutions, while others may require transition to chemotherapy or immunotherapy.

Success rates vary by cancer type and biomarker. EGFR+ NSCLC: 70-80% response rate, 18.9 month PFS. ALK+ NSCLC: 80-90% response rate, 25-34 month PFS. HER2+ breast cancer: 65-75% response rate. CML: 83% 10-year survival. BRCA+ ovarian cancer: 56 month median PFS with PARP inhibitors. Disease control (response + stable disease) rates reach 70-90% for most biomarker-selected populations.

Coverage varies by insurance provider and policy. Most international insurance plans cover targeted therapy when medically indicated with appropriate biomarker documentation. Thai hospitals can provide detailed cost estimates and coordinate with insurance companies. Payment plans are available at some hospitals, and upfront payment for medications is typically required.

Bring complete medical records including pathology reports, prior imaging CDs/files, previous treatment summaries, current medication list, and any existing biomarker/genomic test results. If available, bring tissue blocks or slides for additional testing. A list of questions and a support person for the consultation is also helpful.