P1/2, N=9, Completed, University Medical Center Groningen | Phase classification: P1b/2 --> P1/2

Specifically, CPA4 modulates AKT phosphorylation by regulating the expression of the AKT phosphatase PP2A, while inhibition of the AKT signalling pathway leads to a decreased transcription and translation levels of CPA4. Our study reveals a novel mechanism of pyroptosis induced by HGS-ETR1/2, which may provide a crucial foundation for future investigations into cancer immunotherapy.

Collectively, our findings demonstrate that treatment with CPT in combination with Dox exerts synergistic antitumor effects through activation of the caspase cascade pathway, a mechanism that is partly dependent on the Dox-induced upregulation of death receptor 4 and death receptor 5. Therefore, CPT combined with Dox may be a feasible therapeutic strategy for the management of TNBC.

Certain clues of scientific evidence have provided encouraging results about efficacy of these agonistic antibodies (lexatumumab and mapatumumab) against bladder cancer cell lines. Therefore, multipronged approaches consisting of natural products, chemotherapeutics, and agonistic antibodies will realistically and mechanistically provide proof-of-concept for the translational potential of these combinatorial strategies in well-designed clinical trials.

Our data provide evidence for synergy from the combination of ONC201 and ABT-263 against human solid tumor cell lines associated with alterations in cell death and pro-survival mediators. The combination of ONC201 and ABT-263 merits further exploration in vivo and in clinical trials against a variety of solid malignancies.

These data indicate that combination therapy with eftoza plus venetoclax to simultaneously activate the extrinsic and intrinsic apoptosis-signaling pathways may improve clinical benefit compared with venetoclax monotherapy in relapsed/refractory AML with an acceptable toxicity profile. Registered at www.clinicaltrials.gov as NCT03082209.

Venetoclax-resistant cells also exhibited an upregulation of the PI3K/Akt pathway, and pharmacological inhibition of Akt and ERK with TIC-10 led to cell death in all venetoclax-resistant cell lines. Overall, we highlight the importance of targeted therapies, such as TIC-10, against venetoclax resistance-related pathways, which might represent future therapeutic prospects.

Furthermore, ONC201 treatment significantly decreased MYCN protein expression and suppressed tumor formation with the reactivation of ATRX expression in MYCN-amplified NB-cell-derived xenograft tumors. Taken together, ONC201 could be the potential agent to provide diversified therapeutic application in NB, particularly in NB with MYCN amplification.

Together our data revealed that the effects of a single dose of ONC201 are dependent on the duration of exposure, specifically, while short-term exposure led to reversible changes; long-term exposure resulted in irreversible transformation of cells associated with the senescent phenotype. Our data further demonstrated that when used in combination with NK cells, ONC201 created a synergistic anti-cancer effect, thus suggesting its possible benefit in NK-cell based cellular immunotherapies for cancer treatment.

P1, N=24, Not yet recruiting, National Cancer Institute (NCI)

Key exclusion criteria include a history of acute graft-versus-host disease (GVHD) grade III/IV; initiation of any new systemic immunosuppressive agent for GVHD within 4 weeks of enrollment, current use of prednisone at a dose of ≥0.25 mg/kg/day; uncontrolled serious infection; active ischemic heart disease, heart failure or arrhythmia; severe chronic obstructive pulmonary disease; resting O2 saturation 2 times the upper limit of normal; and creatinine clearance <30 mL/min. Clinical studies in solid malignancies have indicated that ONC201 can expand and activate NK cells in peripheral blood, or recruit CD8+ T-cells to the tumor. Hence, the study will assess expansion and activation of NK and T cell populations in peripheral blood and utilize transcriptomic analyses of NK and T cells to explore the mechanisms behind the immunologic changes.

The adult 625 mg weekly RP2D of ONC201 scaled by body weight was well tolerated. Further investigation of ONC201 for DMG/DIPG is warranted.

P3, N=368, Recruiting, Gustave Roussy, Cancer Campus, Grand Paris | Not yet recruiting --> Recruiting

GPX4 inhibition induces ferroptosis involving mitochondrial redox machinery in AML. Combinatorial targeting of mitochondrial respiration with GPX4 inhibition exerts synergistic anti-leukemia effects. Further studies are in progress to assess the molecular mechanisms and the in-vivo efficacy of the combinatorial treatments.

In vivo, ONC201 promoted the expression of EMILIN-3, a TGF-β antagonist that is known to inhibit HLA-A/B2M expression, possibly explaining the increased MHC-I activity. This study uncovers a novel link between treatment of DMG with ONC201 and paxalisib and the role dopaminergic peripheral nerves signaling may play on the sequestration of T cells within lymphoid organs and lymphopenia.

TR-107 showed ClpP-dependent growth inhibition in the low nanomolar range that was equipotent to paclitaxel in triple-negative breast cancer (TNBC) cell models...The pharmacokinetic properties of TR-107 were compared with other known ClpP activators including ONC201 and ONC212...ClpP activation in vivo was validated by immunoblotting for TFAM and other mitochondrial proteins. In summary, we describe the identification of highly potent new ClpP agonists with improved efficacy against TNBC, through targeted inactivation of OXPHOS and disruption of mitochondrial metabolism.

P1, N=20, Recruiting, Vijaya Bhatt | Trial completion date: Jul 2024 --> Jul 2025 | Trial primary completion date: Jul 2022 --> Jul 2023

P3, N=368, Not yet recruiting, Gustave Roussy, Cancer Campus, Grand Paris

Serum analysis indicated a decrease in pro-inflammatory serum biomarkers, such as IL1β, IL6, TNFα, G-CSF, and GM-CSF, in the ONC201-treated mice compared with controls. Our data demonstrated excellent chemopreventive potential of orally administered ONC201 against intestinal tumorigenesis in the AOM-Apc mouse model.

The inhibitory activity of compound IIc (25 mg/kg) in the HCT-116 xenograft model was significantly greater than those of the positive control drugs (ONC201, chidamide). These findings suggested that development of highly TRAIL-sensitive HDAC inhibitors as colorectal tumor cancer drugs.

However, 2-day pre-treatment with epigenetic drugs (Vorinostat, Tazemetostat, Valemostat and Azacytidine) and 7-day pre-treatment with Tazemetostat + Azacytidine had no effect on Ven sensitivity...Inhibition of mTORC1 with Everolimus abrogated the toxic effect of Ven in the maternal cell lines (figure 1E), whereas TIC-10, an AKT/MEK inhibitor, partially restored Ven sensitivity in MAVER1-VR and MINO-VR cell lines (figure 1D)...The PI3K-AKT-mTOR pathway appears to be involved in Ven resistance development, since interestingly, mTOR inhibition leads to a decreased response to Ven treatment in maternal cell lines but AKT inhibition leads to an increased response in -VR cell lines. Ven resistance in MINO-VR appears to be driven primarily by decreased mitochondrial priming, whereas MAVER-VR appears to be driven by decreased mitochondrial priming combined with a switch from BCL2 to MCL1 dependence.

ONC201 is an oral selective antagonist of the dopamine D2 receptor and direct activator of caseinolytic protease P. In a phase II study, ONC021 was shown to be well tolerated with notable efficacy in patients with the rare neuroendocrine neoplasms pheochromocytomas-paragangliomas, although biomarkers for activity remain to be elucidated. See related article by Anderson et al., p. 1773.

P1, N=153, Completed, AbbVie | Active, not recruiting --> Completed

Our findings demonstrate that ONC206 has anti-tumorigenic effects in ovarian cancer as previously demonstrated by ONC201 but appears to be as well tolerated and more potent. Thus, ONC206 deserves further evaluation in clinical trials.

While these therapies showed potency against the cell lines derived from SCLC patients, it is noteworthy that the combination showed significantly less toxicity to healthy human lung epithelial cells. Future studies could explore the combination of ONC201 and lurbinectedin in SCLC cell lines, SCLC patient-derived organoids, other tumor types, including in vivo studies and clinical translation.

Since Sal003 is not yet available for clinical testing in humans, we will next investigate treatment with ONC201 and the well-tolerated ATF4 inducer fenretinide. The combination of ONC201 with another ISR activating agent has the potential to serve as a therapy for DIPG.

We are currently exploring the novel combination and potential underlying mechanisms behind the synergistic effects of the triple drug treatment. Future studies will evaluate this triple drug combination treatment in mouse models of SCLC.

These effects indicate effectiveness of the combinatorial treatment in causing DNA damage and instability, inducing double-stranded DNA breaks, as well as initiating the intrinsic apoptosis pathway through the integrated stress response, selectively in the malignant cells. Ongoing directions include testing similar concentrations of both ONC201 and lurbinectedin in additional SCLC cell lines, SCLC patient-derived organoids, and in vivo, as well as exploring immune correlates of the drug treatments.

Our data provide evidence for synergy from the combination of ONC201 and ABT-263 against human solid tumor cell lines associated with alterations in cell death and pro-survival mediators. The combination of ONC201 and ABT-263 merits further exploration in vivo in a variety of solid malignancies.

We investigated the anti-tumor effect of three imipridones (ONC201, ONC206, and ONC212), a promising new class of small molecules, in the treatment of neuroblastoma...Cell viability assays with HDAC inhibitors Vorinostat and Panobinostat demonstrated single-agent efficacy in vitro...However, further investigation is needed to determine synergy and mechanisms of synergy when histone deacetylase (HDAC) inhibitors are used in novel combinations with imipridones. Overall, our data reveals promise in imipridone therapy for neuroblastoma, and future studies are proposed to explore potential novel therapeutic combinations in this difficult-to-treat pediatric cancer.

In three subjects with H3K27M-mutant malignant glioma that received ONC201 as part of this expanded access clinical trial, we found that the study drug was quite tolerable. No serious adverse events nor radiographic responses were seen. Analyses of the larger study cohort and additional randomized controlled trials are necessary to provide insight into the safety and efficacy of this agent for this patient population.

We review the chromosomal rearrangements that represent oncogenic events in pediatric solid tumors outside of the central nervous system (CNS), such as Ewing Sarcoma, Rhabdomyosarcoma, Fibrolamellar Hepatocellular Carcinoma, and Renal Cell Carcinoma, among others. Various therapeutics such as CDK4/6, FGFR, ALK, VEGF, EGFR, PDGFR, NTRK, PARP, mTOR, BRAF, IGF1R, HDAC inhibitors are being explored among other novel therapeutic strategies such as ONC201/TIC10.

Oral ONC201 was well tolerated in patients with metastatic neuroendocrine tumors and associated with clinical benefit including tumor responses, particularly in some DSRCT patients and the majority of PC-PG patients.

Taken together, the preclinical efficacy of ONC201 and TLY012 represents a novel therapeutic option for further testing in pancreatic cancer patients. This combination showed marked efficacy in tumor cells that are both sensitive and resistant to the pro-apoptotic effects of ONC201, providing rationale to further investigate the combination of ONC201 plus TLY012 in patients with pancreatic cancer.

Metabolic targeting of medulloblastoma cells by ONC201/TIC10 can be significantly enhanced by an additional treatment with the glycolysis inhibitor 2-Deoxyglucose. Further investigations are warranted.

ONC201 is an imipridone that selectively antagonizes the G protein-coupled receptors dopamine receptor D2 and D3 (DRD2/3) and activates human mitochondrial caseinolytic protease P (ClpP). Treatment with ONC206 led to a decrease in expression of Ki67, BCL-XL and phosphorylation of S6, as well as an increase in ClpP in endometrial tumors under both obese and lean conditions. Overall, the pre-clinical efficacy of ONC206 is promising and worthy of further exploration in clinical trials for endometrioid EC.

A 14yo male with spinal cord glioma received concurrent bevacizumab with ONC201, which resulted in a decrease in tumor area but continued increase in plasma VAF, predicting radiologic progression at the next time. In summary, we present data which suggests monitoring serial CSF/plasma H3K27M tDNA is a promising clinical tool. Changes in cf-tDNAVAF over time appear to correlate with response, predict progression, and differentiate pseudo-progression.