Genomics-Informed Treatment Prolongs Time to Treatment Discontinuation, Study Says

With a lack of randomized controlled trials for evaluating the comparative efficacy of precision oncology, researchers of a recent study used difference-in-difference (DID) analysis to determine causal estimates of time-varying treatment outcomes, finding that treatment based on genomic sequencing has a profound impact on the time to treatment discontinuation (TTD) and consequently increasing costs.

DID analysis, relying on within-cohort data, analyzes pre- and post-sequencing outcomes to estimate net increments effects that are adjusted for baseline differences across groups and aggregate factors causing changes over time.

Based on DID analysis, genomics-informed treatment increased TTD by an estimated 3 months and increased costs by an estimated C$90,000—equivalent to approximately $70,000—compared with standard care treatment. The increase in TTD is promising in these metastatic cancer settings, as the measure typically correlate with improved response and survival.

“Genomics-informed treatments cost more than standard care treatments, primarily owing to longer durations of use rather than high prices of on-patent treatments. This effect was most prominent in gastrointestinal cancers,” wrote the researchers. “Higher treatment costs combined with upfront sequencing costs will have implications on cancer care budgets and the ability to pay for genomics-guided interventions, whether by public healthcare systems, private payers, or patients. Such pressures may introduce equity and access issues for patients within and across jurisdictions.”

The Canadian study included 346 patients—140 who received genomics-informed treatment following sequencing and 206 who received standard care treatment—who were enrolled in the single-arm British Columbia Cancer Personalized OncoGenomics program between 2012 and 2017, all of which were followed for at least 1 year.

Cancer types included breast, gastrointestinal, lung, sarcoma, pancreas, gynecological, and other. According to the researchers, the estimated effects of genomics-informed treatment varied based on cancer type. For example, genomics-informed treatment led to significantly longer TTD and time to next treatment (TTNT) in gastrointestinal cancers, led to longer but not significant TTD in others, and had no effect on breast cancer.

“The benefits of tumor-agnostic precision oncology will, thus, be driven by heterogeneous responses across cancer subtypes. Our results confirm that uniform coverage of genomic sequencing across all indications is unlikely to yield equal effectiveness or cost-effectiveness for all patients,” explained the researchers. “Shifting focus to phenotypes most likely to benefit from genomics- informed treatment will balance the need to maximize population health outcomes with the recognition that sequencing introduces opportunity costs.”

Overall, TTNT was higher following genomics-informed treatment but the different was not significant, said the researchers, who explained that the estimates suggested less durable response and lower efficacy for standard care treatment.

Reference

Weymann D, Pollard S, Chan B, et al. Clinical and cost outcomes following genomics-informed treatment for advanced cancers. Cancer Med. Published online June 21, 2021. doi: 10.1002/cam4.4076