NEW YORK (Reuters Health) - Adjuvant treatment of renal-cell carcinoma (RCC) after nephrectomy with sunitinib has produced no increase in overall survival, but the treatment results in less distant disease recurrence and a higher rate of disease-free survival, according to the latest data from the S-TRAC study.
By a median follow-up of 6.6 years, roughly 22% of the drug recipients and 24% of the placebo group had died, a nonsignificant difference. But distant disease developed in about 32% of sunitinib patients versus 40% of placebo recipients, according to the September 28 online report in European Urology.
Earlier results, published in The New England Journal of Medicine (https://bit.ly/2k0UdNj), showed that median disease-free survival was 6.8 years with the drug versus 5.6 years without it (P=0.03).
The authors of the updated findings, led by Dr. Robert Motzer of the Memorial Sloan Kettering Cancer Center in New York, said because 40% of RCC patients at high risk of recurrence are usually alive at 10 years, the study was too small to show an improvement in overall survival. Such a study would require 1,650 patients followed for 18.5 years.
In contrast, the 2016 ASSURE study also found no survival benefit and no increase in disease-free survival for 649 volunteers getting sunitinib therapy. The Motzer team said differences in the two studies may explain the disparity.
The cost of the treatment: more than $143,000 per year, according to prices on the website GoodRx. Pfizer, which funded the study and conducted the analyses, sells the drug under the brand name Sutent.
The study involved 615 volunteers treated at 97 sites in Europe, Asia and the Americas. Sunitinib was given on a 4-weeks-on and 2-weeks-off schedule, usually for 8 months, although 56% of participants received a full year of treatment.
The drug also seemed to produce better disease-free survival for patients under age 45 (P=0.02), those over 64 (P=0.03), and people of normal body weight (P=0.03).
Better responses were also seen when neutrophil-to-lymphocyte ratio was 3 or lower (P=0.02), Eastern Cooperative Oncology Group performance status was zero (P=0.01), and Fuhrman grade score was 3 or 4 (P=0.04).
The type of treatment did not affect the site where metastases appeared. When the cancer spread, it most often surfaced in the lung, lymph nodes, retroperitoneum, and liver.
In all, 28% of drug recipients discontinued treatment because of side effects, 7.2% because of relapse. For placebo recipients, side effects were responsible for just 5.9% of discontinuations, and relapses accounted for 19%.
"For most patients, toxicities related to adjuvant sunitinib were managed via supportive care and a dose reduction or interruption. Nevertheless, there is still a need to improve the management of some side effects in the adjuvant setting," the researchers said.
Dr. Motzer could not be reached for comment.
Eur Urol 2017.
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