The discussion and individualized selection of starting doses for drugs in the metastatic cancer setting varies among practicing oncologists. More than half (56.6%) of respondents to a recent survey indicated that they reduced the initial dose of a drug to avoid potential toxicity. These findings were published in JCO Oncology Practice.
“Most oncologists believe that the starting dose of a drug in patients with metastatic cancer should be based on patients’ preferences for balancing efficacy and toxicity,” the researchers explained in their report. “These findings, coupled with the experiences reported by patient advocates, suggest a need for dose optimization both in drug development and clinical practice.”
The researchers conducted a self-administered anonymous survey of American Society of Clinical Oncology (ASCO) members, based in the US or internationally, who treated metastatic breast and/or gastrointestinal cancers. The survey included questions about respondents’ clinical practice and views toward dose reduction.
Of the 3099 eligible oncologists, 367 (12%) responded. Fifty-two percent reported using dose reduction at initiation at least 10% of the time to minimize toxicities. Gastrointestinal specialists were more likely to report using dose reduction 10% or more of the time, compared with generalists or breast cancer specialists (72% vs 50% vs 51%; P <.005).
For breast cancer, capecitabine was the most commonly dose-reduced drug (41.3% usually reduced). For gastrointestinal cancer, regorafenib was the most commonly dose-reduced drug (48.7% usually reduced).
Of the respondents who reported using dose reduction 10% or more of the time, 89% said they discussed the potential tradeoffs between efficacy and toxicity with patients.
Sixty-five percent of respondents said it was acceptable to lower starting doses to reduce side effects even if it compromised efficacy.
“Oncologists most frequently cited patients’ medical conditions, potential side effects, published data, and their prior experience with a drug as having the greatest influence on initial dose selection,” the researchers wrote.
The majority of respondents expressed support for future clinical trials looking at the optimal effective dose, rather than the maximum tolerated dose.
Disclosures: This research was supported by ASCO. Please see the original reference for a full list of disclosures.
Jimenez RB, Schenkel C, Levit LA, et al. Oncologists’ perspectives on individualizing dose selection for patients with metastatic cancer. JCO Oncol Pract. Published online September 20, 2022. doi:10.1200/OP.22.00427.