pelcitoclax (APG-1252)

Our findings suggest that APG-1252 in combination with Cabozantinib offers a more effective treatment strategy for HCC patients, warranting further clinical investigation.

P1, N=42, Recruiting, National Cancer Institute (NCI) | Initiation date: Feb 2024 --> Sep 2023

Our data demonstrate that pelcitoclax has antitumor activity and is well tolerated, supporting its further clinical development for human solid tumors, particularly combined with agents that downregulate MCL-1.

P1, N=42, Recruiting, National Cancer Institute (NCI) | Initiation date: Nov 2023 --> Feb 2024

P1, N=42, Recruiting, National Cancer Institute (NCI) | Initiation date: Aug 2023 --> Nov 2023

Further studies are needed to elucidate the role of pelcitoclax when combined with osimertinib in treating this pt population. Internal study: APG1252NC101; CT.gov: NCT04001777.

P1, N=42, Recruiting, National Cancer Institute (NCI) | Initiation date: May 2023 --> Aug 2023

Among 52 patients with hematological malignancies the maximum tolerated dose (MTD) was not reached and no clinical TLS was observed.20 In this study of 22 evaluable patients with RR CLL there was an overall response rate (ORR) of 63.6% (14/22).20 A larger study of 114 patients with RR CLL evaluated lisaftoclax in combination with either the Bruton's tyrosine kinase inhibitor (BTKi) acalabrutinib or the anti CD20 monoclonal antibody rituximab (NCT04215809)...In CLL an overall response rate (ORR) to BGB-1147 of 100% as monotherapy was observed among 8 patients with RR disease.25 In 12 patients with RR MM, the ORR to BGB-1147 in combination with dexamethasone varied from 0–68% depending on the dose cohort.26 In combination with azacytidine in AML the ORR to BGB-11417 was 74% among those with treatment naïve (TN) disease (n=20/27) and 65% (n=13/20) in the cohort with RR disease.27 BGB-11417 monotherapy in 23 patients with RR NHL demonstrated responses in 2 patients with diffuse large B cell lymphoma (DLBCL) and one patient with marginal zone lymphoma (MZL).28 In 11 patients with RR MCL treated with BGB-11417 in combination with zanubrutinib there was a 55% (6/11) ORR.28 S55746 is a potent BAX/BAK dependent BCL2 inhibitor administered orally.18,29 Developed by Servier, it has been tested in phase I studies in CLL, NHL and AML. In a study of S55746 among 37 patients with RR NHL, no dose limiting toxicities (DLT) or TLS was observed after a medium duration of treatment of 42 days.30 FCN-338 is another orally available selective BCL2 inhibitor developed by Fochon currently undergoing phase I testing in RR CLL.18,31 Clinical outcomes with this drug are yet to be publicly reported...More recently navitoclax has been tested in RR myelofibrosis (MF) in combination with ruxolinitib with evidence of clinical response to the combination.35 AZD0466 by Astrazeneca is a nanomedicine potent dual BCL2/ BCLxL inhibitor that mediates BAX/BAK induced apoptosis36,37 and is administered intravenously...Among 9 patients reported undergoing testing for RR hematological malignancy the DLT had not yet been reached.38 Pelcitoclax or APG1252 by Ascentage is a more recent BAX/BAK dependent dual BCL2 and BCLxL inhibitor18,39,40 currently in phase I trials in RR NHL (NCT05186012)...There are multiple emerging BCL2 inhibitors currently undergoing clinical trial testing in hematological malignancies, and it remains too early to appreciate the differential efficacy and toxicity profiles that these agents may carry compared with venetoclax. It is hoped that the results seen with venetoclax can be improved upon across a raft of disease groups over the coming years.

P1, N=42, Recruiting, National Cancer Institute (NCI) | Not yet recruiting --> Recruiting

P1, N=42, Not yet recruiting, National Cancer Institute (NCI) | Trial completion date: Oct 2024 --> Jun 2026 | Trial primary completion date: Oct 2024 --> Jun 2026

Taken together, our data indicated that anti-HER2 agents could upregulate the expression of GSDME, and the combination of lapatinib and APG-1252 showed a synergistic antitumor effect against HER2-positive gastric cancer through inducing caspase-3/GSDME mediated apoptosis and pyroptosis.

P1, N=60, Recruiting, Ascentage Pharma Group Inc. | Trial completion date: Dec 2024 --> Jun 2025 | Trial primary completion date: Oct 2023 --> Jun 2024

P1, N=42, Not yet recruiting, National Cancer Institute (NCI)

This study focused on evaluating the therapeutic efficacy of the novel Bcl-2/Bcl-X dual inhibitor, APG1252-M1 (also named APG-1244; an in vivo active metabolite of APG1252 or pelcitoclax), as a single agent or in combination, against non-small cell lung cancer (NSCLC) cells. Importantly, the combination was effective in inhibiting the growth of osimertinib-resistant tumors in vivo. Collectively, these results demonstrate the efficacy of APG1252 alone or in combination against human NSCLC cells.

Deficiency of Bax in CRC cells abolished APG-1252-M1's ability to induce apoptosis, indicating that APG-1252-M1 induces Bax-dependent apoptosis. The current study thus demonstrates the potential of APG-1252-M1 as a monotherapy in the treatment of CRC, particularly those with low Mcl-1 expression, or in combination with an Mcl-1 inhibitor, warranting further evaluation in vivo and in the clinic.

Osimertinib in combination with targeted therapies has been of clinical interest to improve the outcomes of patients with EGFR-mutant NSCLC. Pelcitoclax plus osimertinib was well tolerated and showed comparable efficacy in TKI-naïve pts. Further randomized control trials are warranted to elucidate the role of pelcitoclax when combined with osimertinib.

P1, N=60, Recruiting, Ascentage Pharma Group Inc. | Not yet recruiting --> Recruiting

Simultaneous inhibition of MCL-1 (via S63845) or BCL-xL (via A155463) and BCL-2 (via venetoclax) increased BIM release and enhanced cell death in resistant clones (vs single agents), with combination index values < 0.3 in all doses. In vivo study using pelcitoclax is ongoing and will be presented at the meeting. In conclusion, we report that venetoclax resistance in MM evolves from outgrowth of persister clones displaying activation of the ERK pathway and a shift in mitochondrial dependency towards BCL-xL, which can potentially be effectively targeted via the novel BCL-2/BCL-xL inhibitor pelcitoclax (APG-1252), which is currently in clinical investigation for solid tumors (NCT03080311).

P1, N=60, Not yet recruiting, Ascentage Pharma Group Inc. | Initiation date: Jun 2021 --> Oct 2021

P1, N=24, Terminated, Ascentage Pharma Group Inc. | N=50 --> 24 | Trial completion date: Oct 2021 --> Apr 2021 | Recruiting --> Terminated | Trial primary completion date: Oct 2021 --> Nov 2020; The company adjusts strategy.

Ongoing studies are investigating the efficacy of this combination in treatment-naive and second-line patients with the EGFR T790M mutation. Internal study identifier APG1252NC101; Clinical trial registration: NCT04001777.

Mechanistically, the drug combination synergistically suppressed NPC by activating caspase-dependent pathways, blocking the phospho (p)-JAK-2/STAT3/MCL-1 signaling pathway, and inhibiting epithelial-mesenchymal transition. In conclusion, the results indicated that the combination of APG-1252 and gemcitabine has synergistic anticancer activities against NPC, providing a promising treatment modality for patients with NPC.

P1, N=60, Not yet recruiting, Ascentage Pharma Group Inc.

Current targeted therapies such as VEGFR inhibitor sunitinib and mTOR inhibitor everolimus extend progression-free survival (PFS) in patients with Grade 1 (G1) and G2 neuroendocrine tumors (NET), but the objective response rate remains low. Concurrent expression of BCL-xL and MCL-1 proteins suggests that a combination treatment targeting both proteins might be more effective in NEN. Our findings inform development of a BCL-2/BCL-xL inhibitor for NEN therapy.

The novel BH3 mimetic, APG1244 (a prodrug for APG1252), is a highly potent Bcl-2 and Bcl-XL dual inhibitor and being tested in clinical trials as a potential cancer therapeutic agent. Furthermore, blockage of caspase-8 with a caspase-8 specific inhibitor abolished cleavage of caspase-3 and PARP including attenuation of cytochrome C and Smac release induced by APG1244, suggesting a caspase-8-dependent mechanism. The current study thus demonstrates the potential of APG1244 as a monotherapy in the treatment of CRC, particularly those with low Mcl-1 expression, or in combination with a Mcl-1 inhibitor for CRC treatment, warranting further evaluation in vivo and in the clinic.

Study Objectives: The primary objective of this open-label trial is to evaluate the safety and efficacy of APG-1252, as monotherapy and when combined with ruxolitinib, in adults with histologically or cytologically confirmed MF who require therapy and are ineligible for JAK2 inhibitors (and can receive single-agent APG-1252) or have had inadequate responses to ruxolitinib-based therapy (and can receive this treatment plus APG-1252). For further information, contact: yzhai@ascentage.com. Registration: ClinicalTrials.gov Identifier NCT04354727.

P1, N=50, Completed, Ascentage Pharma Group Inc. | Active, not recruiting --> Completed

P1, N=50, Recruiting, Ascentage Pharma Group Inc. | Trial completion date: Dec 2019 --> Oct 2021 | Trial primary completion date: Dec 2019 --> Oct 2021

Our results demonstrate the on-target antitumor activity of APG-1252, the potential of BCL-xLhigh as a predictive biomarker, and the resistance mechanism conferred by MCL-1. Furthermore, the data provide a scientific rationale for the combined therapy with BCL-xL and HER2 inhibitors to achieve better clinical outcomes in a subset of HER2+ gastric cancers.

NCI-H1975-C797S derived-xenografts were treated with APG-1252, cisplatin/docetaxel or their combinations.Combination therapy with APG-1252 and cisplatin or docetaxel exhibited synergistic antitumor activity. Similar results were demonstrated in a patient-derived xenograft (PDX) tumor model derived from an osimertinib-resistant NSCLC patient harboring 19del-T790M-C797S mutations. Furthermore, the combinations also exhibited enhanced antitumor activity in an osimertinib-resistant PDX model that the resistant mechanism remained unknown.In summary, our results suggest that the combination treatment with APG-1252 and chemotherapeutics can overcome acquired resistance to osimertinib and the combination deserves further clinical evaluations.

Moreover, Ki-67 was remarkably decreased in the combination group compared to other groups. In conclusion, APG-1252-M1 had a strong antitumor effect by inducing apoptosis and was synergistic with chemotherapy.

Palcitoclax is safe and well tolerated, with a favorable platelet toxicity profile. Its promising antitumor effect supports its further development in combination therapies for treatment of patients with SCLC and other solid tumors. Research Funding: Ascentage Pharma Group Inc., Rockville, MD