A proactive side-effect management strategy enabled many patients with high-risk renal cell carcinoma (RCC) to stay on adjuvant sunitinib therapy in a recent clinical trial, researchers report.
With dose interruptions, dose reductions, and supportive medical therapy, adverse events on adjuvant sunitinib were predictable, manageable, and reversible, according to their report on the S-TRAC (Sunitinib as Adjuvant Treatment for High-Risk Renal Cell Carcinoma Following Nephrectomy) trial.
Patients did report reduced health-related quality of life, but with the exception of diarrhea and loss of appetite, those changes were generally not clinically significant, the investigators wrote. The report is in Annals of Oncology.
The safety profile for sunitinib was acceptable in adjuvant RCC treatment in S-TRAC, with no safety signals observed, said Michael Staehler, MD, PhD, department of urology, Ludwig Maximilian University of Munich, and his coauthors.
“It is likely proactive management contributed to preservation of global health status and quality of life, and alleviation of treatment-related symptoms, thereby enabling patients to remain on effective adjuvant therapy,” Dr. Staehler and his coauthors said.
Sunitinib is approved by the Food and Drug Administration for adjuvant treatment of patients at high risk of recurrent RCC after nephrectomy. That was based in part on previously reported results of the phase 3 S-TRAC study, which showed a 24% reduction in risk of a disease-free survival event versus placebo.
For the 306 patients randomized to sunitinib, 71% stayed on treatment for at least 8 months, reaching cycle 6 of therapy, while 56% finished the full year of treatment, Dr. Staehler and his coauthors said in this new report on S-TRAC focused on adverse events and patient-reported outcomes.
The most common adverse events in the sunitinib arm of S-TRAC included diarrhea in 56.9%, versus 21.4% in the placebo arm, palmar-plantar erythrodysesthesia (PPE) in 50.3% versus 10.2% for placebo, and hypertension in 36.9% versus 11.8% for placebo. The frequency of serious adverse events was similar between arms, according to the investigators, at 21.9% for sunitinib and 17.1% for placebo.
Adverse events were the most common reason for dose reduction, cited in 34.6% of cases, and for dose interruption, reported in 46.4%, they said.
Treatment discontinuations due to adverse events occurred in 28.1%, usually because of PPE.
The S-TRAC study investigators used the EORTC QLQ-C30 instrument to evaluate patient experience during treatment.
That evaluation included an analysis of global health status/quality of life score that favored placebo, with a mean difference in the overall means of –4.76. Although statistically significant (P greater than or equal to .0001), the point estimate of the difference was below the commonly accepted threshold that would indicate clinically meaningful deterioration, investigators said.
Similar patterns that were statistically significant but not clinically meaningful were seen for symptoms including fatigue and pain. However, patient-reported scores for diarrhea and loss of appetite did reach the level of a clinically meaningful difference.
But only one patient permanently discontinued sunitinib because of diarrhea, and none permanently discontinued because of loss of appetite, Dr. Staehler and his coauthors noted.
The work was sponsored by Pfizer. Dr. Staehler reported honoraria, consulting fees, and research grants from Pfizer, Bayer, GSK, Roche, BMS, Novartis, Exelixis, and AVEO. Coauthors reported disclosures related to Merck, Sanofi, Astellas, Celldex, Acerta, Janssen, and others.
SOURCE: Staehler M et al. Ann Oncol. 2018 Aug 23. doi: 10.1093/annonc/mdy329.