The Onclarity Human Papillomavirus Trial: Design, methods, and baseline results

The baseline phase of the Onclarity trial was conducted to determine the screening performance of the Onclarity human papillomavirus (HPV) assay for detecting cervical cancer and precancer (≥CIN2) during triage of women ≥21 years with ASC-US cytology, as an adjunct test in women ≥30 years with normal cytology and for primary screening (HPV alone) in women ≥25 years.

33,858 women ≥21 years were enrolled during routine clinic visits. All women with abnormal cytology, women ≥25 years that were high-risk HPV positive, and a random subset of women ≥25 years, negative by cytology and for HPV, were referred for colposcopy and cervical biopsy. Verification bias adjustment with 95% confidence intervals was applied.

ASC-US prevalence was 5.8%. The overall HPV prevalence was 14.7%; for HPV 16, 18, and the 12 other HPV types it was 2.7%, 0.8%, and 11.2%, respectively. The prevalence of ASC-US and HPV was inversely proportional with age. The verification bias adjusted prevalence of ≥CIN2 and ≥CIN3 was 1.8% and 0.8%, respectively. Overall, five cases of cervical cancer were identified (all were HPV positive). The odds ratios associated with any HPV positive genotype, or with individual genotypes HPV 16, HPV 18, and HPV 31, for ≥CIN3, were statistically significant when compared to negative histology (p < 0.0001 for all).

This report provides demographic information, cytology findings, HPV genotype information, and histopathology for participants in the baseline phase of this trial and offers further evidence to support genotype-specific screening for cervical cancer and precancer. Clinical Trial Registry URL:https://clinicaltrials.gov/ct2/show/NCT01944722.