Abstract 4022: PT2385, a novel HIF-2α antagonist, combines with checkpoint inhibitor antibodies to inhibit tumor growth in preclinical models by modulating myeloid cells and enhancing T cell infiltration

Targeting HIF-2 Alpha in Renal Cell Carcinoma

OPINION STATEMENT

Current treatment options for patients with metastatic renal cell carcinoma (mRCC) are limited to immunotherapy with checkpoint inhibitors and targeted therapies that inhibit the vascular endothelial growth factor receptors (VEFG-R) and the mammalian target of rapamycin (mTOR). Despite significantly improved outcomes over the last few decades, most patients with mRCC will ultimately develop resistance to these therapies, thus highlighting the critical need for novel treatment options. As part of the VHL-HIF-VEGF axis that rests at the foundation of RCC pathogenesis, hypoxia-inducible factor 2α (HIF-2α) has been identified as a rationale target for mRCC treatment. Indeed, one such agent (belzutifan) is already approved for VHL-associated RCC and other VHL-associated neoplasms. Early trials of belzutifan indicate encouraging efficacy and good tolerability in sporadic mRCC as well. The potential inclusion of belzutifan and other HIF-2α inhibitors into the mRCC treatment armamentarium either as a single agent or as combination therapy would be a welcome addition for patients with mRCC.

Revisiting mechanisms of resistance to immunotherapies in metastatic clear-cell renal-cell carcinoma

Renal-cell carcinoma (RCC) remains a leading cause of cancer-related mortality worldwide. Though newer therapeutic combinations of immune checkpoint inhibitors and targeted therapies have greatly improved outcomes, resistance to these therapies is becoming a challenge for long-term control. Mechanisms of resistance have been explored in a variety of solid tumors, including RCC. Based upon our review of the current literature on the mechanisms of resistance to immunotherapies for the management of metastatic clear-cell renal cell carcinomas (mccRCC), the ensuing conclusions have been made: The management of mccRCC has progressed substantially with the advent of checkpoint inhibitors and targeted oral therapies, alone and/or in combination. Nevertheless, innate or developed resistance to these therapies remains an ongoing challenge, particularly to immune checkpoint inhibitors (ICIs). Several of the known mechanisms of resistance have been well defined, but recent progression in cellular therapies helps to expand the armamentarium of potential combination options that may overcome these modes of resistance and improve long-term disease control and survival for an otherwise dismal disease. In the ensuing review and update of the literature on the mechanisms of resistance to immunotherapies in mccRCC, we have revisited the known resistance mechanisms of immunotherapies in metastatic clear-cell RCC and explored ongoing and future strategies to overcome them.

Optimal Choice of Adjuvant Treatment for Renal Cell Carcinoma Following Nephrectomy

Renal cell carcinoma (RCC) is the fourteenth most common cancer worldwide. In about 55% of cases, it is diagnosed at a localised and/or locally advanced stage and therefore amenable to a curative approach. Although nephrectomy still represents the cornerstone of non-metastatic RCC (nmRCC) treatment, a relapse is observed in about 25–30% of patients undergoing curative surgery. Prognosis is drastically influenced by lymph nodal involvement. After the first disappointing results with a cytokine-based strategy, tyrosine kinase inhibitors (TKIs) were tested as adjuvant agents. Despite their efficacy in the metastatic setting, results in terms of disease-free survival (DFS) are not unequivocal and the overall survival (OS) benefit has not been demonstrated. Moreover, their toxicity profile induced a remarkable percentage of patients to discontinue the treatment. On the contrary, the KEYNOTE-564 trial showed the benefit of adjuvant pembrolizumab compared with placebo in terms of DFS with promising results in term of OS. Patients included were at intermediate or high risk of relapse, or patients with no evidence of disease after metastasectomy (M1 NED). The updated analysis presented at the American Society of Clinical Oncology Genito-Urinary (ASCO GU) 2022 confirmed the benefit of pembrolizumab versus placebo over time, although OS data are still immature. A longer follow-up and the several ongoing trials with immune checkpoint inhibitors (ICIs) will provide further data about adjuvant immuno-oncology (IO). Furthermore, the patients’ selection based on clinical or biological features will be crucial in order to identify who benefits most from treatments.