Tracon’s (NASDAQ:TCON) TRC105 combination with Pfizer’s (NYSE:PFE) Inlyta may have potential in 2nd line RCC but possible emerging therapies will likely displace the combo to later lines, experts said.
It was too early to predict the use of other investigational drugs in the VEGF TKI class, but immunotherapies may be preferred due to their curative potential, experts said. Adoption of drugs like BristolMyersSquibb’s (NYSE:BMY) Opdivo (nivolumab) or Exelixis’ (NASDAQ:EXEL) Cometriq (cabozantinib) in the second line space could raise benchmarks and push an Inlyta combination into later lines of therapy, they said.
If the TRC105/Inlyta combination doesn’t add toxicity and extends the PFS by 30%, it would be significant, said Dr Tanya Dorff, assistant professor of Clinical Medicine, University of Southern California Norris Comprehensive Cancer Center and Hospital. The field views a four-months improvement as a significant one, said Posadas. While some experts agreed that currently a three-to-four month improvement in PFS is a clinically significant benchmark, they pointed to the changing treatment landscapes. The benchmark of a three-to-four month improvement is no longer applicable for second line therapies, said Dr Neeraj Agarwal associate professor, division of Oncology, University of Utah School of Medicine, noting this was because of other trials like Eisai’s (TYO:4523) Lenvima (lenvatinib) which demonstrated a mPFS of 14.6 months in combination with Afinitor. But others, including Dorff, said the data is still early and not yet practice changing, said Dorff.