Live from ASH 2022 | Ascentage Pharma Delivers Oral Report on the First Dataset from the US Study of Olverembatinib (HQP1351) with Promising Efficacy Observed in Patients Who Failed Prior Treatment with Ponatinib

Ascentage Pharma (6855.HK) today announced that it has released preliminary results of olverembatinib (HQP1351) in patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), in an Oral Presentation at the American Society of Hematology (ASH) 64th Annual Meeting and Exposition (New Orleans, LA), marking the first data readout from the US study.

The ASH Annual Meeting is one of the largest gatherings of the international hematology field, featuring world-class advances on cutting-edge scientific and clinical research in hematology. As a leading member of the Chinese hematology and oncology research community that has been increasingly active on the global stage, Ascentage Pharma had results from 5 of its clinical trials selected for 4 Oral Presentations at this year’s ASH Annual Meeting, attracting widespread interest at the event. In total, Ascentage Pharma will have 8 presentations at ASH 2022, including 4 Oral and 4 Poster Presentations (with 3 poster presentations submitted independently by investigators based on real-world evidence).

Preliminary results announced at this year’s meeting suggested that olverembatinib has favorable efficacy and a manageable safety profile in US patients with drug-resistant CML and Ph+ ALL, and showed the drug’s potential as a “salvage” therapy in patients with prior resistance to third-generation tyrosine kinase inhibitor (TKI) ponatinib and allosteric STAMP inhibitor asciminib. These data showed that close to 80% patients with CML had received at least three lines of treatment, and over 50% had failed prior treatment with ponatinib. Even in heavily pre-treated patients with drug-resistant CML, those with chronic-phase CML (CML-CP) achieved complete cytogenetic response (CCyR) and major molecular response (MMR) rates of 77.8% and 43.5%, respectively; while patients with CML-CP who had failed prior treatment with ponatinib have achieved a CCyR and an MMR rate of 83.3% and 42.9%, respectively.

In addition, olverembatinib was well-tolerated. The safety data from this US study were similar to previously published results from Chinese studies and showed no new safety signals. In particular, olverembatinib demonstrated excellent tolerability in patients who were intolerant of ponatinib, which also exemplifies olverembatinib’s positive safety profile.

Developed by Ascentage Pharma, olverembatinib is a potential best-in-class novel drug that has been designated a Major New Drug Project by China’s Ministry of Science and Technology. As the first approved third-generation BCR-ABL inhibitor in China and the second in any country globally, olverembatinib is recommended by both the Guidelines of the Chinese Society of Clinical Oncology (CSCO) and the China Anti-Cancer Association’s (CACA) Guidelines for the Holistic Integrative Management of Cancers, for the treatment of patients with TKI-resistant CML harboring the T315I mutation (while the CACA Guidelines also recommend olverembatinib for the treatment of patients with CML intolerant/resistant to at least two TKIs).

Globally, despite approvals for ponatinib and asciminib, patients with CML still have enormous unmet medical needs because of limited accessibility as well as adverse events of these two drugs. Taken together, these limitations have recently stimulated strong interest in clinical progress with olverembatinib among the global hematology community. At present, olverembatinib is being evaluated in a US Phase Ib study for the treatment of drug-resistant CML. Furthermore, olverembatinib has been granted one Fast Track designation and three Orphan Drug designations by the US Food and Drug Administration (FDA), and one Orphan Drug designation by the European Medicines Agency (EMA).

As olverembatinib is not yet approved anywhere outside China, Ascentage Pharma is pressing ahead with global clinical development of olverembatinib and advancing the drug toward approvals in a number of countries to help address the unmet medical needs of patients with CML globally. Driven by a sense of urgency to facilitate early access by patients with malignancies that currently lack treatment options, Ascentage Pharma and Tanner Pharma Group (a global pharmaceutical services provider of specialty access solutions) jointly launched an innovative Named Patient Program (NPP) for olverembatinib in July 2022. This collaboration will allow access to olverembatinib on a named patient basis in more than 140 countries and regions where the drug is not yet commercially accessible, in a manner that is reliable, responsible, ethical, and in accordance with all country-specific regulatory requirements.

“These findings suggest that olverembatinib is a potentially effective ‘salvage’ therapy for patients with prior CML treatment failure,” according to Prof. Elias Jabbour, MD, Department of Leukemia, The University of Texas MD Anderson Cancer Center (Houston, TX). “The favorable safety and tolerability profile of olverembatinib are important because many patients with CML experience intolerance, including potentially concerning cardiovascular events, when using certain other BCR-ABL1 inhibitors.”

“The first batch of data from the first US study of olverembatinib released at ASH 2022 are very promising, indeed, as they show olverembatinib’s exciting potential as a best-in-class drug that can overcome resistance to ponatinib and asciminib in patients with CML and Ph⁺ ALL. We are encouraged by these results because they further validate that olverembatinib can potentially bring a long-awaited change to the treatment paradigm for CML and Ph⁺ ALL globally.” according to Dr. Yifan Zhai, Chief Medical Officer of Ascentage Pharma.

 

“At this year’s ASH Annual Meeting, we released data of olverembatinib and our Bcl-2 inhibitor for CLL/SLL, lisaftoclax, in four Oral Presentations. We are very proud of this achievement, which underscores our robust capabilities in global innovation,” she remarked. “Moving forward, we will remain committed to the mission of addressing unmet clinical needs in China and around the world, and continue to accelerate our clinical development programs with the hope of bringing more safe and effective therapeutics to patients in need,” Dr. Zhai noted.

Data from the US studies of olverembatinib reported in Oral Presentations at this year’s ASH Annual Meeting are as follows (for detailed results from the study of lisaftoclax and the China study of olverembatinib, please refer to other two press releases to be published during ASH 2022):

Olverembatinib (HQP1351) Overcomes Ponatinib Resistance in Patients with Heavily Pretreated/Refractory Chronic Myeloid Leukemia (CML) and Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia (Ph+ ALL)

 

  • Format: Oral Presentation
  • Abstract: #162387
  • Session: 632. Chronic Myeloid Leukemia: Clinical and Epidemiological: Novel Agents
  • Time: Saturday, December 10, 2022, 10:15 AM (Eastern Time) / Saturday, December 10, 2022, 11:15 PM (Beijing Time)
  • Highlights
  • Olverembatinib is a novel third-generation BCR-ABL1 TKI with antitumor activity against CML and Ph+ ALL and a favorable safety profile

 

  • This multicenter, open-label, randomized trial is the first to report on the safety, efficacy, and pharmacokinetics (PK) of olverembatinib in patients with CML and Ph+ ALL outside China, who were intolerant or resistant to at least 2 BCR-ABL1 inhibitors, including ponatinib and asciminib, except for those whose disease harbors the T315I mutation, for whom the number of prior lines of therapy was not limited. Study participants were randomized in a ratio of 3:3:2 to receive olverembatinib 30, 40, or 50 mg QOD in 28-day cycles.

 

  • As of Dec 5, 2022, a total of 51 patients have been enrolled, including 38 with CML-CP, and 13 with CML-AP, CML blast phase (-BP), or Ph+ ALL. The median treatment duration was 32.4 (range, 0-119) weeks. 54.9% (28/51) of patients were men, and the median age was 51 (range, 21-79). In all, 7 (13.7%), 14 (27.5%), and 25 (49%) patients received 2, 3, and ≥ 4 prior lines of treatment, respectively. A total of 28 (54.9%) patients were pretreated with the third-generation TKI ponatinib, including 21 (75.0%) with resistance and 7 (25.0%) with intolerance; a total of 19 (37.3%) had T315I mutations; 28 (54.9%) had cardiovascular diseases at baseline, and 18 (35.3%) had hypertension.

 

  • PK analysis indicated a dose-proportional increase in olverembatinib plasma exposure from 30 to 50 mg QOD and comparable plasma exposures between the Chinese and US CML populations.

 

  • Safety: Olverembatinib was well tolerated. 34 patients experienced treatment related adverse events (TRAEs) of any grade, the incidence of which tended to be dose-dependent. Most of the nonhematologic TRAEs were grade 1/2. Common grade 3/4 nonhematologic TRAEs included thrombocytopenia (18.9%), neutropenia (16.2%), and decreased leukopenia counts (13.5%). 8 olverembatinib-related serious adverse events (SAEs) were observed in 6 patients, and none of these SAEs led to treatment discontinuation.

 

  • Preliminary efficacy: Olverembatinib conferred potent antileukemic activity in patients with CML and Ph+ ALL. Of 23 efficacy-evaluable patients with CML-CP, 14/18 (77.8%) had a CCyR; 10/23 (43.5%) had a MMR. Olverembatinib was effective in patients with either the T315I-mutant (87.5%, CCyR; 55.6%, MMR) or T315I un-mutant (70.0%, CCyR; 35.7%, MMR), and its effectiveness was not compromised by prior use of ponatinib or asciminib. Among patients who were previously treated with ponatinib, 10/12 (83.3%) experienced CCyR and 6/14 (42.9%) experienced MMR. In particular, among patients with diseases resistant to ponatinib, 7/9 (77.8%) experienced CCyR, and 5/10 (50%) experienced MMR. In patients who were previously treated with asciminib, 1 experienced CCyR and MMR. In the 7 efficacy-evaluable patients with Ph+ leukemia in progressive phase (including CML-AP, CML-BP, and Ph+ ALL), 2 experienced CCyR and MMR. Both patients were resistant to ponatinib and neither harbored the T315I mutation. Of them, 1 patient with Ph+ ALL achieved CCyR after just one cycle of treatment with olverembatinib.

 

  • Conclusions: Olverembatinib monotherapy is efficacious and well tolerated in patients with TKI-refractory CML and Ph+ ALL. Even in patients with CML who were ponatinib or asciminib resistant, or who had T315I mutations, olverembatinib also showed strong efficacy.