Programmed death-1 inhibition in renal cell carcinoma: clinical insights and future directions.

The treatment of metastatic renal cell carcinoma (mRCC) has evolved markedly over the past decade, broaden- ing beyond immune-based strategies (eg, interleukin-2 and interferon-α) to include targeted agents (eg, sunitinib [Sutent, Pfizer] and sorafenib [Nexavar, Bayer]). Recently, there has been a renewed interest in immune-based strategies, with clinical trials underway to assess vaccines and other immunomodulatory agents. Of particular interest are agents that inhibit the interaction between the programmed death-1 (PD-1) receptor and its ligand (PD-L1) at the T-cell/antigen-presenting cell interface. This interaction produces T-cell anergy and therefore stifles the antitumor immune response. Monoclonal antibodies to PD-1 (eg, nivolumab, lambrolizumab, and pidilizumab) and PD-L1 (MPDL3280A and BMS-936559) are in various stages of clinical development. The clinical trajectory of these agents is discussed herein, with specific attention to the potential placement of PD-1/ PD-L1 inhibition in the crowded therapeutic landscape of mRCC.

A new age for vaccine therapy in renal cell carcinoma.

Over the past several years, the dominant paradigm in drug development for metastatic renal cell carcinoma (mRCC) has been to more selectively and potently target moieties such as the vascular endothelial growth factor receptor. The effectiveness of this strategy appears to be nearing a plateau, however, underscoring the need for novel approaches. Vaccine-based therapies represent one such approach. Several distinct vaccines are currently being examined in mRCC, each using a distinct mechanism of action. For instance, the autologous dendritic cell vaccine AGS-003 uses patient-specific antigens derived from primary tumor tissue. In contrast, the poxvirus vaccine TG4010 produces an antigenic response to MUC1, a cell surface glycoprotein that reduces cell-cell interactions and thereby precludes contact inhibition. Other vaccines elicit a response to a broader spectrum of antigens-for instance, the vaccine IMA901 is based on 9 tumor-associated peptides identified from a novel biotechnology platform combining mass spectroscopy, microarray analysis of RNA expression, and immunogenicity assays. Herein, the current status of vaccine-based therapies for mRCC is described in detail. Furthermore, challenges to clinical implementation (eg, cost, optimal pairing with targeted agents, appropriate sequencing) are presented.