The Growing Challenge of Clear Cell Gynaecological Cancers
Ovarian clear cell carcinoma (OCCC) and endometrial clear cell carcinoma (ECCC) represent rare yet particularly aggressive subtypes of gynaecological malignancies. These cancers are notorious for their resistance to standard platinum-based chemotherapy, which is the cornerstone treatment for most ovarian and endometrial cancers. In Asia, OCCC accounts for 10 to 12 percent of epithelial ovarian cancers, significantly higher than the roughly 5 percent incidence in Western populations. Patients with recurrent disease face dismal outcomes, with median progression-free survival often under six months on conventional therapies. The distinct molecular profile of these tumours, characterised by proficient mismatch repair systems and immunosuppressive microenvironments, has long hindered effective treatment strategies.
Singaporean researchers, in close partnership with leading institutions in South Korea, have now illuminated a promising path forward through innovative combination therapy. This breakthrough underscores the pivotal role of academic collaboration in tackling unmet needs in oncology, particularly for understudied rare cancers.
Unveiling the LARA Trial: A Beacon of Collaborative Innovation
The LARA trial, formally known as Lenvatinib plus pembrolizumab in Recurrent Advanced gynaecological cArcinoma, stands as a landmark multicentre phase 2 study. Launched in March 2021 and concluding recruitment in October 2023, it spanned tertiary hospitals in Singapore and South Korea, enrolling 27 patients who had progressed after at least one line of platinum chemotherapy. Participants received pembrolizumab, an immune checkpoint inhibitor targeting the PD-1 pathway on T-cells to unleash anti-tumour immune responses, administered intravenously every three weeks at 200 mg, alongside lenvatinib, a multi-targeted tyrosine kinase inhibitor blocking vascular endothelial growth factor receptor (VEGFR) pathways to starve tumours of blood supply, taken orally daily at 20 mg.
This dual-pathway blockade approach synergistically addresses the dual hallmarks of these cancers: angiogenesis-driven growth and immune evasion. Coordinated under the Asia Pacific Gynecologic Oncology Trials Group (APGOT), the trial exemplifies regional synergy, with principal investigators from Singapore's National University Cancer Institute (NCIS) and Korean centres driving protocol design and execution.
Study Design and Patient Cohort: Rigorous Methodology Meets Real-World Need
Designed as a single-arm, open-label phase 2 trial following Simon's two-stage minimax design, LARA prioritised objective response rate (ORR) at 24 weeks as the primary endpoint, assessed via investigator-reviewed RECIST 1.1 criteria. Eligibility required histologically confirmed recurrent clear cell gynaecological carcinoma (CCGC), Eastern Cooperative Oncology Group performance status of 0-1, and no prior immune checkpoint exposure. Of 30 screened patients, 27 initiated treatment, with 25 evaluable for the primary outcome.
The cohort reflected the disease's epidemiology: median age 52 years, 89 percent with primary OCCC and 11 percent ECCC, all proficient mismatch repair/microsatellite stable. Diverse ethnic representation—44 percent Chinese, 44 percent Korean—enhanced generalisability across Asian populations. Median follow-up reached 21 months at data cutoff in March 2025, providing robust survival insights.
Striking Clinical Results: Response Rates and Survival Outcomes
The trial delivered compelling efficacy signals. Within 24 weeks, 40 percent of evaluable patients (10 of 25; 95% CI 21-61%) achieved confirmed objective responses, far surpassing historical benchmarks like 9.7 percent for single-agent immunotherapy or 18.8 percent for chemotherapy in similar cohorts. Disease control rate stood at an impressive 74 percent, with median progression-free survival (PFS) of 6.4 months—50 percent of patients remaining progression-free beyond this mark.
Notably, responses occurred even in patients previously exposed to anti-angiogenic agents, suggesting non-overlapping mechanisms. Bioinformatic analyses from Singapore's Cancer Science Institute (CSI Singapore) at NUS correlated RNA sequencing data with outcomes, identifying molecular subtypes and pathway activations predictive of benefit. These findings align with a concurrent US DART trial reporting comparable activity, validating the regimen's potential.
Safety and Tolerability: Manageable Profile Supports Broader Use
Toxicity was anticipated for this combination but remained clinically manageable. Grade 3-4 treatment-related adverse events affected 52 percent of patients, predominantly hypertension (22 percent), thrombocytopenia (7 percent), and transaminitis (7 percent each). Serious events occurred in 19 percent, including immune-mediated hepatitis (7 percent) and thrombocytopenia (7 percent), all reversible with dose modifications or supportive care. Crucially, no treatment-related deaths were reported, affirming the regimen's feasibility in a vulnerable, pretreated population.
- Common grade 1-2 events: fatigue, diarrhoea, hypothyroidism.
- Dose reductions: 41 percent for lenvatinib, 15 percent for pembrolizumab.
- Discontinuations due to toxicity: 22 percent.
This profile positions dual blockade as a viable option where chemotherapy options dwindle.
Photo by TSquared Lab on Unsplash
Molecular Insights Driving Precision Oncology
Leveraging NUS's advanced bioinformatics capabilities, the study dissected tumour biology via RNA sequencing and pathway analysis. Clear cell tumours exhibited heterogeneous immune landscapes, with responders showing enriched interferon-gamma signatures and exhausted T-cell profiles amenable to PD-1 release. Lenvatinib's VEGFR inhibition complemented this by normalising vasculature, enhancing immune infiltration.
These correlates not only explain efficacy but pave the way for biomarkers, potentially sparing non-responders toxicity. The integration of Singapore's CSI Singapore resources highlights how academic platforms accelerate translational research from bench to bedside.
For the full study details, refer to the publication in The Lancet Oncology.
Singapore's Leadership in Regional Cancer Research
Assoc Prof David Tan, Senior Consultant at NCIS and Associate Professor at NUS Yong Loo Lin School of Medicine, spearheaded LARA as principal investigator and corresponding author. "This trial represents a triumph of regional collaboration," he noted. "By pooling expertise and patients across borders, we've generated level 2 evidence for a therapy that could transform care for these orphan diseases."
First author Dr Natalie Ngoi, NCIS Consultant, emphasised patient-centric design: "Our Asian cohort addresses a gap in global data, where Western trials underrepresented these subtypes." Korean co-lead Prof Byoung-Gie Kim of Chung-Ang University praised APGOT's framework: "Cross-border trials like LARA expedite answers for rare cancers affecting our populations disproportionately."
Implications for Patients and Clinical Practice
For patients with recurrent CCGC, LARA offers tangible hope. Where prior options yielded ORRs below 20 percent, 40 percent tumour shrinkage heralds a paradigm shift. Median PFS doubling historical norms suggests delayed progression, potentially extending quality life years. As NCIS pushes for NCCN guideline inclusion, access in Singapore could accelerate via compassionate use or expanded trials.
Real-world translation involves multidisciplinary care: oncologists monitoring hypertension, endocrinologists managing hypothyroidism. Patient advocacy groups in Singapore hail the results as empowering, urging subsidised access through the nation's robust healthcare framework.
Broader Impact on Singapore's Higher Education Landscape
NUS's pivotal role exemplifies Singapore's ascent as a biomedical hub. CSI Singapore's computational prowess, coupled with NCIS clinical infrastructure, positions local universities at the vanguard of precision oncology. This trial bolsters Singapore's research ecosystem, attracting talent and funding while training next-gen clinician-scientists.
Government investments in platforms like APGOT foster pan-Asian networks, enhancing Singapore's soft power. For higher education, LARA demonstrates how interdisciplinary teams—spanning medicine, public health, pathology—drive innovation, preparing graduates for global challenges.
Future Directions: Paving the Way for Phase 3 Validation
LARA's success demands randomised phase 3 confirmation against standard care. Planned expansions target immunotherapy-naïve patients and explore triplets with PARP inhibitors, given CCC's occasional homologous recombination deficiencies. Biomarker-driven trials, leveraging NUS's genomics expertise, will refine patient selection.
Regionally, APGOT eyes basket trials for other rare subtypes. Singapore's vision: integrate dual blockade into national guidelines, reducing overseas treatment burdens. Ongoing monitoring via ClinicalTrials.gov (NCT04699071) ensures long-term data accrual.
Photo by Danist Soh on Unsplash
Stakeholder Perspectives and Global Resonance
Cancer patients' voices echo optimism: "Finally, a therapy tailored to our fight," shared one OCCC survivor. Policymakers note economic ripple effects—reduced hospitalisations, bolstered biotech. Globally, LARA influences Western guidelines, bridging Asia-West data gaps.
In Singapore's academic sphere, it reinforces university-industry ties, with pharmaceutical partners funding expansions. As NUS scales trials, it cements Singapore's role in equitable oncology advancement.