The following article features coverage from the European Society of Medical Oncology (ESMO) 2017 Congress in Madrid, Spain. Click here to read more of Cancer Therapy Advisor’s conference coverage.

The non-inferiority of the sorafenib (So) and pazopanib (Pa) sequence was not demonstrated compared to pazopanib-sorafenib in patients with metastatic renal cell carcinoma (mRCC), according to a study presented at the European Society for Medical Oncology (ESMO) 2017 Congress.1

Sequential therapy is the standard of therapy for advanced RCC, and various sequential strategies must be assessed to determine clinical efficacy as new therapies become available.

For this phase 3 study (ClinicalTrials.gov Identifier: NCT01613846), researchers evaluated the effect of administering sorafenib-pazopanib and pazopanib-sorafenib in 377 patients with RCC who had not previously received systemic therapy.

The sorafenib-pazopanib arm achieved a median total progression-free survival (tPFS) of 8.6 months (95% CI, 7.7-10.2) compared to 12.9 months (95% CI, 10.8-15.2) for patients in the pazopanib-sorafenib arm (hazard ratio [HR], 1.36; upper limit of one-sided 95% CI, 1.68). Non-inferiority was defined as hazard ratio (HR) less than 1.225 as a one-sided 95% confidence interval, and therefore the study was unable to demonstrate non-inferiority.

Patients receiving pazopanib-sorafenib experienced significant benefits in total time to progression, first line disease control rate, and PFS, but not for overall survival or second-line PFS. Fifty-six percent of patients who received sorafenib-pazopanib as first-line treatment received pazopanib as second-line therapy, and 46% of patients in the pazopanib-sorafenib arm received sorafenib as second-line therapy.

The most frequently reported adverse events for the sorafenib arm were diarrhea, fatigue, and hand-foot skin reaction. In the pazopanib arm they were diarrhea, fatigue, and hypertension.

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The study authors concluded by saying “non-inferiority of the sequence [sorafenib-pazopanib] compared to [pazopanib–sorafenib] in terms of the primary endpoint of tPFS was not met. However, superiority of the sequence [pazopanib-sorafenib] over [sorafenib-pazopanib] for tPFS was not proven either because the study design was computed with a HR of < 1.225 as a one-sided 95% CI.”

Read more of Cancer Therapy Advisor‘s coverage of the European Society of Medical Oncology (ESMO) 2017 Congress by visiting the conference page.

Reference

  1. Retz M, Bedke J, Herrmann E, et al. Phase III randomized, sequential, open-label study to evaluate the efficacy and safety of sorafenib-pazopanib versus pazopanib-sorafenib in the treatment of metastatic renal cell carcinoma (SWITCH-II). Presented at: European Society for Medical Oncology (ESMO) 2017 Congress; September 8-12, 2017; Madrid, Spain.