SLC-0111

A synergy screen was conducted using CA9 inhibitor SLC-0111 and HDAC inhibitors panobinostat, vorinostat, entinostat, and pyroxamide. Additionally, the combination therapy induced a greater reduction in intracellular pH than either agent alone. Data from this study suggest that the combination of SLC-0111 and pyroxamide holds promise for treating experimental DIPG, and further investigation of this combination therapy in preclinical models is warranted to evaluate its potential as a viable treatment for DIPG.

The representative compound 9o exhibited more potent inhibitory activity and selective against CA IX over off-target CA II, compared with positive control SLC-0111...Notably, in vivo studies demonstrated that 9o effectively inhibited tumor growth and metastasis in a highly metastatic murine breast cancer 4 T1 xenograft model. Taken together, this study suggests that compound 9o represents a potent and selective CA IX inhibitor and ferroptosis inducer for the treatment of TNBC.

Sulfonamide-based derivatives, 4, 7 and 9 exhibited promising activity against HepG-2 and MCF-7 (IC50 = 8.39-16.90 μM against HepG-2 and 19.57-21.15 μM against MCF-7) comparing with doxorubicin (IC50 = 13.76 ± 0.45, 17.44 ± 0.46 μM against HepG-2 and MCF-7, rescpectively). Compoumds 7 and 9 gave favorable potency (IC50 = 1.33, 0.38 μM against VEGFR-2, 66, 40 nM against hCA IX and 7.6, 3.2 nM against hCA XII, respectively), comparing with sorafenib and SLC-0111 (IC50 = 0.43 μM, 53 and 4.8 nM, respectively). Moreover, the docking simulation was assessed to supply better rationalization and gain insight into the binding affinity between the promising derivatives and their targeted enzymes that was used for further modification in the anticancer field.

P1/2, N=6, Terminated, British Columbia Cancer Agency | Phase classification: P1b --> P1/2 | N=30 --> 6 | Trial completion date: Aug 2025 --> May 2024 | Recruiting --> Terminated | Trial primary completion date: Feb 2025 --> May 2024; Changing treatment landscape: The availability of nab-paclitaxel with gemcitabine in the second-line setting has changed the feasibility of further recruitment and potential long-term development opportunities of SLC-0111 with gemcitabine alone.

Molecular docking studies were performed to demonstrate the presence of numerous hydrogen bonds and hydrophobic interactions between the compounds and the active site of hCA. Absorption, distribution, metabolism, excretion (ADME) predictions showed that all of the compounds had good pharmacokinetic and physicochemical properties.

The IC50 values of J16 for MDA-MB-231 and MCF-7 cells, under normoxic condition were 6.3 and 3.7 µM respectively, which are 1.9/3.3 and 15.8 times better than U-4-Nitro and SLC-0111 respectively...Expression of the other apoptosis markers Bcl-2, Bim, caspase 9 and caspase 3 substantiated the apoptosis mechanism. However, decreased transcription/expression of HIF1A/HIF-1α and hCA-IX/XII also implies the inhibition of the extracellular signal-regulated kinase pathway by J2 and J16.

Many studies in multiple solid tumour models have demonstrated that targeting CAIX activity with the selective CAIX/XII inhibitor, SLC-0111, results in anti-tumour efficacy, particularly when used in combination with chemotherapy or immune checkpoint blockade, and has now advanced to the clinic...Importantly, the data from these models demonstrates that CAIX inhibition may sensitize tumour cells to cytotoxic drugs and evidence now points to ferroptosis, an iron-dependent form of regulated cell death (RCD) that results from accumulation of toxic levels of phospholipid peroxidation as a major mechanism involved in CAIX-mediated sensitization to cancer therapy. In this mini-review, we discuss recent advances demonstrating the mechanistic role CAIX plays in sensitizing cancer cells to ferroptosis.

The presence of a 4-F-CH moiety, also found in SLC-0111, afforded an excellent selectivity towards the tumor-associated hypoxia-induced hCA isoform XII with an inhibition constant (K) of 4.5 nM. The 2-naphthyl derivative was the most potent inhibitor against hCA IX (K = 6.2 nM), 4-fold stronger than AAZ (K = 25 nM) with very good selectivity. Some compounds were chosen for antiproliferative activity testing against a panel of 3 human tumor cell lines, one compound showing anti-proliferative activity on glioblastoma, triple-negative breast cancer, and pancreatic carcinoma cell lines.

In a cohort of GC patients who received perioperative FLOT (i.e., Leucovorin, 5-Fluouracil, Docetaxel, and Oxaliplatin) or FOLFOX (i.e., Leucovorin, 5-Fluouracil, and Oxaliplatin), non-responder patients showed an increased expression of tumor CAIX compared to responder group. Moreover, GC cell lines induced to be resistant to 5-Fluouracil, Paclitaxel, Cisplatin, or the combination of 5-Fluorouracil, Oxaliplatin, and Docetaxel, overexpressed CAIX compared to the control...Notably, SLC0111 significantly improved the therapy response of both wild-type and resistant GC cells. Overall, these data suggest a correlation between CAIX and GC drug resistance highlighting the potential of SLC-0111 in re-sensitizing GC cells to pCT.

Promising candidates were assessed for VEGFR-2 inhibition and selectivity and further evaluated on breast cancer cell lines (MCF-7 and T-47D) and the non-tumorigenic (MCF-10A) cells. Molecular docking studies explored the binding modes of the sulfonamides against hCA IX/XII and VEGFR-2 kinase.

A host of new preclinical data and several clinical trials of antibodies and small molecule inhibitors are ongoing, which connected with the large number of new chemotypes/procedures discovered to be effective, may lead to a breakthrough in this therapeutic area. The scientific/patent literature has been searched for on PubMed, ScienceDirect, Espacenet and PatentGuru, from 2018 to 2023.

P1b, N=30, Recruiting, British Columbia Cancer Agency | Suspended --> Recruiting | Trial completion date: Dec 2024 --> Aug 2025 | Trial primary completion date: Jul 2024 --> Feb 2025

SLC-0111, a ureido benzenesulfonamide, is a selective human carbonic anhydrase (hCA) IX inhibitor in clinical trials for the treatment of hypoxic malignancies...Thereafter, Annexin V-FITC apoptosis detection, cell cycle, TUNEL, and qRT-PCR, colony formation, and wound healing assays were applied to gain mechanistic insights and to understand the behavior of colorectal cancer cells upon the treatment of compound 8g. Also, a molecular docking analysis was conducted to provide in silico insights into the reported hCA IX inhibitory activity and selectivity.

The model considers treatment with the small molecule CAIX inhibitor SLC-0111 in combination with ICIs...Concluding, we have developed a model that reproduces experimental findings and enables the investigation of combination therapies. Our model suggests that transient CAIX inhibition may induce tumor regression, given a sufficient immune infiltrate in the tumor, which can be boosted with ICIs.

Inhibition of CA IX by SLC-0111 reduced the expression levels of PDL-1, p-STAT3, and Glut-1, and reversed TE-ADSC-induced acidic TME in TNBC cells.ConclusionTaken together our results demonstrate the crucial role played by TE-ADSCs in promoting immune surveillance by inducing an acidic TME in TNBC. Furthermore, we highlight the possibility to sensitize tumor cells to ICIs by targeting CAIX using SLC-0111.

Importantly, CA IX inhibitors strongly reduced the growth and survival also of Bortezomib-resistant MM cells, and CA IX inhibitors combined with Bortezomib exerted an increased anti-myeloma activity compared to single treatments. Finally, both SLC-0111 and FC-531 significantly reduced the growth of MM tumor xenografts in NOD/SCID mice. ConclusionOur data suggest that CA IX inhibitors as single agents or in combination with proteasome inhibitors may represent a valid therapeutic approach for both naïve and proteosome inhibitor-refractory MM patients.

In addition, combined CAIX/CAXII knockdown and more effective treatment with SLC-0111 reduced clonogenic survival of CMS3 modelling single cells. In conclusion, the preclinical data support the clinical approach of targeted CAIX/CAXII inhibition by showing linkage of expression with response and suggest that patients with CMS3-classified tumors would most benefit from such treatment.

Transcriptomic changes triggered by SLC-0111 administration differed under normoxic vs. hypoxic conditions, although SLC-0111 elicited upregulation of several tumor suppressor genes under both conditions. Hypoxia induces CAIX expression in HB cells, and the CAIX inhibitor SLC-0111 has in vitro activity against these malignant cells.

Cell treatment with cisplatin plus SLC-0111 was able to block these mechanisms, as well as the signaling pathways underlying them, such as p-AKT, p-ERK, CD44, MMP-2, vimentin, β-catenin, and N-cadherin, more effectively than treatment with single agents. In addition, a significant enhancement of apoptosis assessed by annexin V, caspase-3 expression and activity was also shown. Taken together, our results demonstrated the possibility, through CA IX inhibition, of returning TNBC cells to a more chemosensitive state.

Interestingly, the addition of SLC-0111 to cisplatin caused a greater reduction of tumor growth and 18F-FDG uptake in a TNBC murine model as assessed by molecular imaging. Conclusion Our overall results highlighted the possibility to reversal cisplatin-resistant caused by hypoxic TME in TNBC by an integrated therapeutic approach

P1b, N=30, Suspended, British Columbia Cancer Agency | Trial completion date: Jul 2022 --> Dec 2024 | Recruiting --> Suspended | Trial primary completion date: Jun 2022 --> Jul 2024

Desmond's molecular dynamics simulations studies for 100 ns of compound 27 compared to reference SLC0111 provided useful structural insights of human carbonic anhydrase IX inhibition...In addition, MM-PBSA and MM-GBSA also affirm the docking results. We propose the designed compound 27 (predicted Ki = ∼0.07 nM) as the best theoretical lead which may further be experimentally studied for selective inhibition.

The system was successfully used for consecutive drug response monitoring with isothermal microcalorimetry. The described approach for drug testing, relying on an advanced 3D culture system combined with a rapid and highly sensitive metabolic assessment, can facilitate development of personalized treatment strategies for neuroblastoma.

Our results highlight the ability of SLC-0111 to sensitize HNSCC to cisplatin by hindering hypoxia-induced signaling network that are shared among mechanisms involved in therapy resistance and metastasis.

In the present work, different cell lines representing glioblastoma, bladder and pancreatic cancer have been exploited to compare the inhibitory and antiproliferative effect of primary sulphonamide acetazolamide (AAZ), the Phase Ib/II clinical grade sulphonamide SLC-0111, and a membrane-impermeant positively charged, pyridinium-derivative (C18). New hints regarding the possibility to exploit CA inhibitors in these cancer types are proposed.

We analyzed intracellular pH with or without CA9 inhibitor SLC-0111...Pancreatic cancer cells may inhibit the infiltration of CD8+ T cells through CA9. Further exploration of its related mechanisms can be used to explore the immune escape pathway of pancreatic cancer and provides new perspectives immune targeted therapy.

All these phenomena consequent to CA IX inhibition triggered apoptosis and autophagy in HeLa cells. Taken together, these results further endorse the previous findings that CAIX inhibitors represent an important therapeutic strategy, which is worth pursuing in different cancer types, considering that presently only one sulphonamide inhibitor, SLC-0111, has arrived in Phase Ib/II clinical trials as an antitumour/antimetastatic drug.

P1b, N=30, Recruiting, British Columbia Cancer Agency | Trial primary completion date: Aug 2020 --> Jun 2022

A similar effect on cell death is observed by blocking glutamine metabolism using inhibitors such as V-9302 (ASCT2 inhibitor) or CB-839 (Glutaminase-1 inhibitor) with SLC-0111. These results suggest that CAIX depletion causes increased cellular stress and to overcome this, cells increase glutamine uptake in part for GSH synthesis. In summary, we show that CAIX and ASCT2 coordinate their functions in hypoxic cancer cells to support tumor growth, and co-targeting them could be beneficial in treating solid tumors.

However, the combined treatment with 3-AC and CAI strongly enhanced radiosensitivity, increased cytotoxicity, inhibited cell motility and enhanced DNA damage. Our findings suggest that the combination of two bioactive drugs 3-AC and a CAI, such as OCT or SLC-0111, could be a promising therapeutic approach for targeting hypoxic tumor cells.

SLC-0111 was safe in patients with previously treated, advanced solid tumors. The safety and pharmacokinetic data support 1000 mg/d as the recommended phase 2 dose for SLC-0111.

Particular focus was on the identification of lead compounds and various inhibitor classes, and the measurement of CA inhibitory on-/off-target effects. In addition, the preclinical data that resulted in the identification of SLC-0111, a sulfonamide in Phase Ib/II clinical trials for the treatment of hypoxic, advanced solid tumors, are detailed.