Targeted therapy development for rare, molecularly defined cancers raises specific challenges for clinical evaluation. The article focuses on trials in FGFR2‑rearranged cholangiocarcinoma to illustrate how promising targeted agents can be affected by slow accrual, shifting standards of care and the constraints of conventional trial design.
The phase III FIGHT-302 trial compared the FGFR inhibitor pemigatinib with first‑line chemotherapy in patients with advanced FGFR2‑rearranged cholangiocarcinoma. Reported results indicate that pemigatinib improved progression‑free survival and response rates relative to chemotherapy. Despite these favourable comparative outcomes, the trial experienced slow patient accrual and was closed early after chemoimmunotherapy emerged as the new standard of care for advanced biliary tract cancer.
This experience demonstrates a disconnect that can occur when a randomized trial for a biomarker‑defined, low‑incidence population is underway while the broader treatment landscape changes. The timing of trial conduct, the rarity of the target population and competing contemporaneous advances in standard regimens together undermined the trial's planned execution.
FIGHT-302 was not an isolated case. The article notes two similarly terminated phase III trials, including PROOF 301 (infigratinib versus gemcitabine/cisplatin), which were ended early. The authors use these terminations to underscore that conventional randomized controlled trials can be vulnerable when evaluating targeted agents in rare genomic subgroups. Early stopping of multiple trials raises challenges in interpreting evidence, in regulatory decision making and in ensuring timely patient access to effective therapies.
Key obstacles described include slow accrual attributable to the low prevalence of specific genomic alterations such as FGFR2 rearrangements, competition among trials and rapid evolution of standard treatments. These factors increase the likelihood that a randomized trial will be underpowered, delayed or rendered less relevant by contemporaneous changes in care.
The authors argue that these operational realities require regulatory frameworks that can accommodate non‑traditional evidence generation and provide pathways for efficient evaluation and approval of targeted therapies in small populations. The article highlights the need for flexibility from regulators and sponsors to avoid losing opportunities to bring effective targeted agents to patients because of rigid trial expectations.
A figure included in the article (Fig. 1) summarizes challenges and potential solutions for clinical trials in rare molecular tumour subtypes, pointing to operational, statistical and regulatory approaches. While the article does not present exhaustive protocols, it advocates for adoption of innovative trial designs and adaptive strategies tailored to low‑incidence, biomarker‑selected groups.
Suggested directions include trial designs and evidence pathways that recognize smaller populations, enable more efficient accrual, and allow for rapid integration of evolving standards of care. The cited literature in the article frames these approaches within broader conversations about molecular reclassification of cancer and novel trial methodologies.
Beyond randomized phase III experiences, the article references work on mechanisms of acquired resistance to FGFR inhibitors in cholangiocarcinoma, underscoring that durability of benefit and resistance patterns are critical considerations when assessing targeted agents.
The authors also cite phase I results from a multicentre, open‑label study of gemcitabine and cisplatin combined with either ivosidenib or pemigatinib for advanced cholangiocarcinoma, indicating active investigation of combination strategies that integrate targeted FGFR inhibition with conventional chemotherapy backbones.
The commentary is authored by Fen Saj (Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center) and Lipika Goyal (Division of Oncology, Stanford Cancer Center). Competing‑interest disclosures note multiple contracted research and consultancy relationships for L.G.; F.S. declares no competing interests.
Conclusion
The collective experience of FIGHT-302 and other terminated FGFR2 randomized trials illustrates the limitations of standard randomized controlled trial models when applied to rare, biomarker‑defined cancers. The authors call for innovative trial designs and flexible regulatory frameworks to ensure rigorous, efficient evaluation of targeted therapies and to improve access for patients with rare genomic subtypes such as FGFR2‑rearranged cholangiocarcinoma. Figure 1 in the article provides a concise schematic of challenges and potential solutions for this context.
Note: This rewrite summarizes content and references reported in the source article. Detailed numerical results, full protocols and specific regulatory proposals were not reported in the accessible source text and therefore are not stated here.