Phase Ib/II Study of Lacnotuzumab in Combination with Spartalizumab in Patients with Advanced Malignancies.

Introduction: Blocking the colony-stimulating factor 1 (CSF-1) signal on tumor-associated macrophages can lead to an upregulation of checkpoint molecules, such as programmed cell death ligand 1 (PD-L1), thus causing resistance to this blockade. Combining spartalizumab (PDR001), a high-affinity, ligand-blocking, humanized anti-PD-1 immunoglobulin G4 antibody, with lacnotuzumab (MCS110), a high-affinity, humanized monoclonal antibody directed against human CSF-1 can potentially overcome this resistance. Methods: This was a multicenter, phase Ib/II trial using a combination of spartalizumab with lacnotuzumab in patients with advanced cancers, including anti-PD-1/PD-L1 treatment-resistant melanoma, and anti-PD-1/PD-L1 treatment-naïve triple-negative breast cancer, pancreatic cancer, and endometrial cancer (ClinicalTrials.gov identifier: NCT02807844). The primary objective of dose escalation phase Ib was to assess safety, tolerability, and recommended phase II dose. The primary objective of the phase II expansion study was to assess the combination's antitumor activity, including objective response rate and clinical benefit rate. Results: A total of eight patients (five in phase Ib and three in phase II) were evaluable for adverse events (AEs) at our study site. All eight patients experienced at least grade 1 AE. The most common treatment-related AEs were increased serum aspartate aminotransferase (38%), fatigue (38%), anemia (25%), increased alkaline phosphatase (25%), hyperbilirubinemia (25%), hypocalcemia (25%), and hypoalbuminemia (25%). Most of these AEs were grade 1 or 2. None of the patients experienced grade 4 AEs and no drug-related fatal AEs were reported among the eight patients treated in the study. One (13%) patient had stable disease (SD) (captured as unknown by the study sponsor because the evaluation criteria set per protocol was not met) and three (38%) patients had progressive disease. Four (50%) patients developed clinical disease progression based on investigator evaluation. One patient with pancreatic cancer achieved immune-related SD for 26 months while on the study treatments. Conclusion: The study completed phase Ib dose escalation and phase II. However, gating criteria for efficacy were not met for expansion beyond 80 patients in phase II and the sponsor did not continue development of the combination of spartalizumab and lacnotuzumab for oncology indications. The potential signal of activity in pancreatic cancer should be further explored.

Phase I study of sapanisertib (CB-228/TAK-228/MLN0128) in combination with ziv-aflibercept in patients with advanced solid tumors.

BACKGROUND: Sapanisertib is a potent ATP-competitive, dual inhibitor of mTORC1/2. Ziv-aflibercept is a recombinant fusion protein comprising human VEGF receptor extracellular domains fused to human immunoglobulin G1. HIF-1α inhibition in combination with anti-angiogenic therapy is a promising anti-tumor strategy. This Phase 1 dose-escalation/expansion study assessed safety/ tolerability of sapanisertib in combination with ziv-aflibercept in advanced solid tumors. METHODS: Fifty-five patients with heavily pre-treated advanced metastatic solid tumors resistant or refractory to standard treatment received treatment on a range of dose levels. RESULTS: Fifty-five patients were enrolled and treated across a range of dose levels. Forty were female (73%), median age was 62 (range: 21-79), and ECOG PS was 0 (9, 16%) or 1 (46, 84%). Most common tumor types included ovarian (8), colorectal (8), sarcoma (8), breast (3), cervical (4), and endometrial (4). Median number of prior lines of therapy was 4 (range 2-11). Sapanisertib 4 mg orally 3 days on and 4 days off plus 3 mg/kg ziv-aflibercept IV every 2 weeks on a 28-day cycle was defined as the maximum tolerated dose. Most frequent treatment-related grade ≥2 adverse events included hypertension, fatigue, anorexia, hypertriglyceridemia, diarrhea, nausea, mucositis, and serum lipase increase. There were no grade 5 events. In patients with evaluable disease (n = 50), 37 patients (74%) achieved stable disease (SD) as best response, two patients (4%) achieved a confirmed partial response (PR); disease control rate (DCR) (CR + SD + PR) was 78%. CONCLUSION: The combination of sapanisertib and ziv-aflibercept was generally tolerable and demonstrated anti-tumor activity in heavily pre-treated patients with advanced malignancies.

Therapeutic Role of Synthetic Lethality in ARID1A-Deficient Malignancies.

AT-rich interaction domain 1A (ARID1A), a mammalian switch/sucrose nonfermenting complex subunit, modulates several cellular processes by regulating chromatin accessibility. It is encoded by ARID1A, an immunosuppressive gene frequently disrupted in a many tumors, affecting the proliferation, migration, and invasion of cancer cells. Targeting molecular pathways and epigenetic regulation associated with ARID1A loss, such as inhibiting the PI3K/AKT pathway or modulating Wnt/ß-catenin signaling, may help suppress tumor growth and progression. Developing epigenetic drugs like histone deacetylase or DNA methyltransferase inhibitors could restore normal chromatin structure and function in cells with ARID1A loss. As ARID1A deficiency correlates with enhanced tumor mutability, microsatellite instability, high tumor mutation burden, increased programmed death-ligand 1 expression, and T-lymphocyte infiltration, ARID1A-deficient cells can be a potential therapeutic target for immune checkpoint inhibitors that warrants further exploration. In this review, we discuss the role of ARID1A in carcinogenesis, its crosstalk with other signaling pathways, and strategies to make ARID1A-deficient cells a potential therapeutic target for patients with cancer.