Cabozantinib plus durvalumab in advanced gastroesophageal cancer and other gastrointestinal malignancies: Phase Ib CAMILLA trial results

This is the phase Ib part of the phase I/II CAMILLA trial evaluating cabozantinib plus durvalumab in advanced chemo-refractory proficient mismatch repair or microsatellite stable (pMMR/MSS) gastrointestinal malignancies including gastric/gastroesophageal junction/esophageal (G/GEJ/E) adenocarcinoma, colorectal cancer (CRC), and hepatocellular carcinoma (HCC). Thirty-five patients are enrolled. There are no observed dose-limiting toxicities during dose escalation. The overall grade 3/4 treatment-related adverse event rate is 34%. Among evaluable patients (n = 30), the objective response rate (ORR) is 30%, disease control rate (DCR) 83.3%, 6-month progression-free survival (PFS) 36.7%, median PFS 4.5 months, and median overall survival (OS) 8.7 months. Responses are seen in 4 of 17, 3 of 10, and 2 of 3 patients with CRC, G/GEJ/E adenocarcinoma, and HCC, respectively. Participants with a PD-L1 combined positive score (CPS) ≥5 have numerically higher ORR, PFS, and OS. Cabozantinib plus durvalumab demonstrates a tolerable safety profile and potential efficacy in previously treated advanced pMMR/MSS gastrointestinal malignancies.

Cabozantinib sensitizes microsatellite stable colorectal cancer to immune checkpoint blockade by immune modulation in human immune system mouse models

Immune checkpoint inhibitors have been found to be effective in metastatic MSI-high colorectal cancers (CRC), however, have no efficacy in microsatellite stable (MSS) cancers, which comprise the majority of mCRC cases. Cabozantinib is a small molecule multi-tyrosine kinase inhibitor that is FDA approved in advanced renal cell, medullary thyroid, and hepatocellular carcinoma. Using Human Immune System (HIS) mice, we tested the ability of cabozantinib to prime MSS-CRC tumors to enhance the potency of immune checkpoint inhibitor nivolumab. In four independent experiments, we implanted distinct MSS-CRC patient-derived xenografts (PDXs) into the flanks of humanized BALB/c-Rag2nullIl2rγnullSirpαNOD (BRGS) mice that had been engrafted with human hematopoietic stem cells at birth. For each PDX, HIS-mice cohorts were treated with vehicle, nivolumab, cabozantinib, or the combination. In three out of the four models, the combination had a lower tumor growth rate compared to vehicle or nivolumab-treated groups. Furthermore, interrogation of the HIS in immune organs and tumors by flow cytometry revealed increased Granzyme B+, TNFα+ and IFNγ+ CD4+ T cells among the human tumor infiltrating leukocytes (TIL) that correlated with reduced tumor growth in the combination-treated HIS-mice. Notably, slower growth correlated with increased expression of the CD4+ T cell ligand, HLA-DR, on the tumor cells themselves. Finally, the cabozantinib/nivolumab combination was tested in comparison to cobimetinib/atezolizumab. Although both combinations showed tumor growth inhibition, cabozantinib/nivolumab had enhanced cytotoxic IFNγ and TNFα+ T cells. This pre-clinical in vivo data warrants testing the combination in clinical trials for patients with MSS-CRC.

Cabozantinib for the treatment of solid tumors: a systematic review

Background:

Cabozantinib is approved, in various settings, for the treatment of renal cell carcinoma, medullary thyroid cancer, and hepatocellular carcinoma, and it has been investigated for the treatment of other cancers. With the available evidence and the real-world performance of cabozantinib compared with clinical trial data, we performed a systematic review of cabozantinib monotherapy as treatment for solid tumors in adults.

Methods:

This study was designed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and registered with PROSPERO (CRD42020144680). We searched for clinical and observational studies of cabozantinib monotherapy for solid tumors using Embase, MEDLINE, and Cochrane databases (October 2020), and screened relevant congress abstracts. Eligible studies reported clinical or safety outcomes, or biomarker data. Small studies (n < 25) and studies of cabozantinib combination therapies were excluded. Quality was assessed using National Institute for Health and Care Excellence methodology, and study characteristics were described qualitatively.

Results:

Of 2888 citations, 114 were included (52 randomized studies, 29 observational studies, 32 nonrandomized phase I or II studies or pilot trials, and 1 analysis of data from a randomized study and a nonrandomized study). Beyond approved indications, other tumors studied were castration-resistant prostate cancer, urothelial carcinoma, Ewing sarcoma, osteosarcoma, uveal melanoma, non-small-cell lung cancer, Merkel cell carcinoma, glioblastoma, pheochromocytomas and paragangliomas, cholangiocarcinoma, gastrointestinal stromal tumor, colorectal cancer, salivary gland cancer, carcinoid and pancreatic neuroendocrine tumors, and breast, endometrial and ovarian cancers. The most common adverse events were hypertension, diarrhea, and fatigue.

Conclusion:

The identified evidence demonstrates the positive efficacy/effectiveness of cabozantinib monotherapy in various solid tumor types, with safety findings being consistent with those observed with other VEGFR-targeting tyrosine kinase inhibitors. When available, real-world findings were consistent with the data reported from clinical trials. A limitation of this review is the high proportion of abstracts; however, this allowed us to capture the most up-to-date findings.

Tackling Refractory Metastatic Colorectal Cancer: Future Perspectives

Substantial improvements have characterized the systemic treatment of metastatic colorectal cancer (mCRC) over the past 20 years. Besides strong evidence that supports the use of RAS and BRAF status as prognostic and predictive indicators of disease and response, novel technologies have made possible the incorporation of emerging biomarkers for the management of mCRC. On one hand, the discovery of point mutations, amplifications, fusions, and gene expression profiles highlights the genomic and dynamic complexity of CRC. On the other, such discoveries are leading to newer biomarker-driven strategies that add to existing anti-epidermal growth factor receptor (EGFR) and anti-angiogenic approaches. In addition, the availability of a wide molecular profiling has relevant implications for patient prognosis and treatment benefits. Here, we will review the molecular underpinnings and clinical data supporting novel targeted treatments under development for refractory mCRC harboring BRAF mutations, KRAS G12C mutations, HER2 amplification, and less common molecular alterations, such as the re-arrangements of NTRK, ALK, and ROS1. Additionally, we will discuss novel strategies driving the rechallenge of EGFR antibodies and the incorporation of newer anti-angiogenic agents in the therapeutic armamentarium.