Advanced Intrahepatic Cholangiocarcinoma

Case Stem.

A 62-year-old retired civil servant presents with right upper quadrant abdominal pain and progressive early satiety. He reports an unintentional 6 kg weight loss over three months. Examination reveals mild conjunctival icterus and firm, non-tender hepatomegaly extending 4 cm below the right costal margin. ECOG performance status is 1.

Contrast-enhanced abdominal CT demonstrates a hyper vascular 7.5 cm right hepatic lobe mass with peripheral rim enhancement and two nearby satellite nodules. The multidisciplinary tumour board deems the lesion unresectable. Core needle biopsy confirms moderately differentiated intrahepatic cholangiocarcinoma.

Total bilirubin 1.8 mg/dL; AST 64 U/L; ALT 58 U/L; CA 19-9 480 U/mL. Next-generation sequencing: microsatellite stable, no actionable FGFR2 fusion or IDH1 mutation. The patient and his family will finance all oncology care out of pocket.

Discussion Questions

1.     How does the protocol mandate to stop gemcitabine at cycle 8 in TOPAZ-1 compare structurally with the continuous maintenance allowed in KEYNOTE-966? What do the respective survival curves tell us about these different approaches?

2.     Balancing clinical efficacy with the high risk of financial toxicity in Nigeria, how do you navigate the conversation with this self-funding family when deciding between fixed duration durvalumab and potentially indefinite pembrolizumab? [See facilitator note 1.]

3.     If out-of-pocket funds become exhausted during maintenance immunotherapy, what practical dose-modification strategies or altered surveillance protocols could you implement to maximize the patient's existing tumour response?

Model Answers

Question 1 — Structure and survival curves of TOPAZ-1 vs KEYNOTE-966

The two trials are basically mirror images. TOPAZ-1 tested "stop the chemotherapy, keep the immunotherapy." KEYNOTE-966 tested "keep the chemotherapy, cap the immunotherapy."

What the curves show:

▪      Same overall shape. In both trials the curves overlap for roughly the first 6 months, then separate; the benefit lives in the tail. The median gain is only 1.3–1.8 months. The real effect is that about 1 in 10 patients becomes a longer-term survivor who otherwise would not have been.

▪      Continuing gemcitabine did not visibly help. The KEYNOTE-966 control arm, despite open-ended gemcitabine, had a median OS of 10.9 months — no better than TOPAZ-1's 8-cycle control arm (11.5 months) or ABC-02 (11.7 months).

–     Cross-trial comparison is unreliable, but there is no signal that gemcitabine beyond 24 weeks adds survival.

–     It does add cumulative myelotoxicity, more blood tests and more visits.

▪      No head-to-head comparison exists, so neither the agents nor the strategies can be ranked. Takeaway for fellows: the 8-cycle chemotherapy backbone is well supported; the immunotherapy benefit is real but modest and concentrated in a minority.

Question 2 — The conversation with a self-funding family.

1.     Start with what is affordable and evidence based. Gemcitabine-Cisplatin (ABC-02) is off-patent and locally affordable, and on its own is the standard of care. The family should hear this first, so that choosing it without immunotherapy does not feel like abandonment.

2.     Give the immunotherapy benefit in absolute terms. "Most patients gain a few weeks. About 1 in 10 lives meaningfully longer, and we cannot predict who." Then lay out the full cost: drug, infusion, travel, monitoring and toxicity management, multiplied by a realistic number of months.

3.     Establish explicitly what the family can afford. Who is paying, what will be sold or borrowed, and whether other household needs (school fees, the spouse's care) will suffer. Catastrophic health expenditure is a harm the clinician must weigh. Ask the patient about his own priorities, separately from the family if necessary.

4.     If immunotherapy is affordable, practical points favour the TOPAZ-1 schedule: q4-weekly maintenance means fewer visits and lower transport costs; gemcitabine stops at 8 cycles, so less toxicity and blood monitoring. Before deciding, confirm NAFDAC registration, reliable supply, and any manufacturer access program or Cancer Health Fund eligibility for both drugs.

5.     Agree stopping rules in advance — what happens when funds run low, at progression, or after the first restaging — so decisions are not made under acute financial pressure.

6.     A staged commitment is reasonable. Start gem-cis now, with nutrition optimized and HBV managed, and make the immunotherapy decision with the family's eyes open rather than by default.

Question 3 — If funds run out during maintenance immunotherapy.

Dose and schedule options

▪      Weight-based dosing. Pembrolizumab 2 mg/kg q3w (the original approved dose, with equivalent exposure) or durvalumab 10–20 mg/kg, rounded to the nearest vial within ~10%.

–     For a 60 kg patient: 120 mg pembrolizumab instead of 200 mg.

–     The saving is only real if pharmacy can share vials across same-day patients.

▪      Extended intervals. PD-1 receptor occupancy persists for weeks. Pharmacokinetic and retrospective data, mostly from melanoma and NSCLC, support q6-weekly or longer intervals in responding patients.

–     Pembrolizumab 400 mg q6w saves visits, not drug.

–     The saving comes from lengthening the interval at the lower dose.

▪      Low-dose nivolumab (40 mg q3w with metronomic chemotherapy) improved OS in a randomized head and neck cancer trial — a reasonable rationale to cite, but not extrapolated to cholangiocarcinoma.

Stopping and switching options

▪      Treatment holiday for good responders. Patients with a complete or deep partial response are most likely to sustain the response after stopping (data from other tumour types). Keep re-challenge at progression open.

▪      Cheap maintenance alternatives. Gemcitabine alone (as continued in KEYNOTE-966) or capecitabine — off-patent options to maintain systemic pressure.

▪      Protect funds for second-line treatment. mFOLFOX (ABC-06) is inexpensive. Spending the last of the family's money on marginal maintenance can leave nothing for a second-line regimen with proven benefit.

Altered surveillance

▪      Lengthen CT intervals to 12–16 weeks.

▪      In between, follow CA 19-9 trends (only once bilirubin has normalized), ultrasound, liver function tests and clinical review. Bring CT forward for any rise or new symptoms.

▪      Continue monitoring for immune-related adverse events after stopping: TSH, and liver function tests where hepatitis must be distinguished from progression or cholangitis.

▪      Beware pseudo progression before acting on a single equivocal scan.

Key Evidence

▪      TOPAZ-1: Oh DY et al. Durvalumab plus gemcitabine and cisplatin in advanced biliary tract cancer. NEJM Evidence 2022; plus the 3-year updated overall survival analysis.

▪      KEYNOTE-966: Kelley RK et al. Pembrolizumab with gemcitabine and cisplatin versus placebo for advanced biliary tract cancer. Lancet 2023.

▪      ABC-02: Valle J et al. Cisplatin plus gemcitabine versus gemcitabine for biliary tract cancer. NEJM 2010.

▪      ABC-06: Lamarca A et al. Second-line FOLFOX plus active symptom control after first-line chemotherapy for advanced biliary tract cancer. Lancet Oncology 2021.

▪      Low-dose nivolumab: Patil VM et al. Low-dose immunotherapy in head and neck cancer: a randomised study. Journal of Clinical Oncology 2023.

▪      Staging: AJCC Cancer Staging Manual, 8th edition. Guidelines: NCCN Hepatobiliary Cancers (current version).