Trial characteristics and results reporting among oncology clinical trials involving African countries.

1589 Background: Sub-Saharan Africa (SSA) faced ~801,000 new cancer cases and ~520,000 cancer deaths in 2020, with deaths projected to reach 1 million annually by 2030. African trial activity remains scarce (<1% of global trials), with sparse reporting. We measured results reporting for oncology trials involving African sites and identified trial characteristics associated with results disclosure. Methods: Using ClinicalTrials.gov, we identified 1,140 completed oncology trials (1992-2023) involving ≥1 African site. We classified trials by country, institution, region, and funder, reporting proportions, ORs (95% CI), and multivariable logistic regression. Results: Among 1,140 trials across 38 countries, most were single-country (93.7%), single-institution (76.7%), and North Africa only (58.2%). Most were non-industry-sponsored (68.8%), interventional (79.5%) and randomized (61.1%). Enrollment was ≤100 participants in 666 trials (58.4%). Overall, 25.2% posted results. Multi-country trials reported more than single-country (59.7% vs 22.8%); multi-institution exceeded single-institution (60.5% vs 14.4%). SSA-only (48.0%) and both-region trials (72.1%) exceeded North-Africa-only (7.2%). Industry-funded reported more than non-industry (70.5% vs 4.6%). Phase III exceeded other phases (64.0% vs 10.6%). In multivariable analysis, industry sponsorship, multi-institution and multi-country configuration, SSA region, and phase 3 status were independently associated with results posting (Table 1). Conclusions: Nearly three-quarters of completed oncology trials conducted in Africa have not publicly reported results, highlighting substantial research waste and a critical ethical failure to translate participant contributions into accessible evidence. This analysis identifies independent, actionable determinants of reporting transparency. Strengthening African clinical trial infrastructure and coupling reporting requirements with systematic monitoring and accountability are essential to improve evidence generation and promote equity as the continent’s cancer burden continues to rise. Multivariable predictors of results reporting. Predictor Adjusted OR (95% CI) p-value Industry funding (ref: non-industry) 28.40 (19.1-42.2) 0.001 Multi-institution (ref: single) 5.81 (4.08-8.26) 0.001 Multi-country (ref: single) 2.12 (1.18-3.81) 0.012 Sub-Saharan only (ref: North Africa) 6.82 (4.68-9.94) 0.001 Both regions (ref: North Africa) 8.46 (3.45-20.7) 0.001 Phase 3 (ref: other/NA) 3.24 (2.26-4.64) 0.001 Interventional (ref: observational) 4.12 (1.48-11.5) 0.007 Enrollment >100 (ref: ≤100) 1.89 (1.32-2.71) 0.001