Follow-Up Shows Continued Efficacy in RCC With Pembrolizumab/Axitinib

Brian I. Rini, MD, professor of medicine and inaugural chief of Clinical Trials at Vanderbilt-Ingram Cancer Center, discusses the benefits of long-term follow-up for trials and the results from 42-month follow-up of the KEYNOTE-426 study (NCT02853331) of pembrolizumab (Keytruda) plus axitinib (Inlyta) versus sunitinib (Sutent) as first-line therapy for patients with advanced clear cell renal cell carcinoma (RCC).

The data for KEYNOTE-426 presented at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting were from the second long-term follow-up of this trial. Long-term follow-up is important for combination therapies especially, according to Rini. The other main combination therapy in RCC is nivolumab (Opdivo) plus ipilimumab (Yervoy). The trial for that combination has longer follow-up than pembrolizumab plus axitinib because it was conducted before KEYNOTE-426. Rini says the long follow-up, duration of response, and durability are important.

The 2021 ASCO data had a minimum of 3 years follow-up and a median of 3.5 years. Rini says this is not quite long term, but it’s starting to get to that range to see how durable responses will be. Pembrolizumab was given for 35 doses or 2 years. An important question for this trial is how durable responses will be after stopping pembrolizumab; knowing the required duration of therapy will be vital to know going forward. Once there are longer-term outcomes, the data can be compared with other regimens in RCC as well.

The updated KEYNOTE-426 data have shown it is a standard of care in RCC and the efficacy has held up over time. There were advantages in overall survival, progression-free survival, overall response rates, and complete response rates for patients receiving the combination versus sunitinib. Those benefits have continued even after pembrolizumab was stopped. Although there is still more work to be done, these updates are encouraging, according to Rini.