Updated Results of Pivotal Phase 2 Trials of Olverembatinib (HQP1351) in Patients (Pts) with Tyrosine Kinase Inhibitor (TKI)-Resistant BCR-ABL1 T315I-Mutated Chronic- and Accelerated-Phase Chronic Myeloid Leukemia (CML-CP and CML-AP)

Abstract

Background: Management of CML with TKIs is constrained by treatment resistance, which portends a poor prognosis particularly in pts failing 2 nd-generation TKIs. Cells with BCR-ABL1 T315I mutations are insensitive to 1 st- and 2 nd -generation TKIs, and compound BCR-ABL1 mutations complicate management with all TKIs (including 3 rd-generation ponatinib). Olverembatinib is a novel, potent, 3 rd-generation, orally active BCR-ABL1 TKI with promising activity against CML , largely irrespective of genotype and has a preliminary favorable safety profile. Methods: HQP1351-CC201 and HQP1351-CC202 are Chinese open, single-arm, multicenter phase 2 trials evaluating the safety and efficacy of olverembatinib in adults with TKI-resistant (BCR-ABL1 T351-mutated) CML-CP and CML-CP, respectively. Olverembatinib was administered at 40 mg orally on alternate days for 28-day cycles. The primary outcome measure is major cytogenetic response (MCyR) and major hematologic response (MaHR) by the end of Cycle 12 in CML-CP and CML-AP, respectively. Secondary study endpoints include : complete CyR (CCyR), complete hematologic response (CHR), major molecular response (MMR), progression-free survival (PFS), overall survival (OS), and safety, including treatment-related adverse events (TRAEs) and serious AEs (SAEs). Results: Baseline characteristics Study CC201 （CML-CP ） On the study cutoff date of August 25,2020, 41 pts were enrolled, of whom 32 (78%) completed ≥ 12 cycles and 21 (51.2%) were male. The median (range) follow-up was 13 (3.1-16.3) months, age was 47 (22-70) years, and interval from CML diagnosis to first olverembatinib dose was 5.31 (0.6-23.2) years. In all, 32 (78.1%) pts had received ≥ 2 prior TKIs and 9 pts withdrew because of progressive disease (PD), intolerance, or consent withdrawal before Cycle 12. Study CC202 （CML-AP ） On the cut-off date of July 27, 2020, 23 pts were enrolled, of whom 14 (61%) had completed ≥ 12 cycles and 18 (78.3%) were male. The median (range) follow-up was 13.5 (1.4-15.2) months, age was 41 (21-74) years, and interval from CML diagnosis to first olverembatinib dose was 4.96 (0.4-10.2) years. In all, 18 (78.3%) pts had received ≥ 2 prior TKIs, and 11 pts withdrew because of PD or intolerance before Cycle 12. Efficacy Study CC201 （CML-CP ） After ≥ 12 treatment cycles in pts without responses at baseline, all 31 (100%) experienced CHR (10 other pts had CHR at baseline); 31/41 (75.6%) MCyR; 28/41 (68.3%) CCyR; and 23/41 (56.1%) MMR (Figure 1). The median time to CHR was 1 (95% CI = 1.0-1.9) month, the median time to MCyR was 2.8 (95% CI = 2.8-5.6) months, and the median time to MMR was 6.5 (95% CI = 2.8 to not reached [NR]) months. At 12 months, the PFS rate was 89.3% (95% CI = 73.9%-95.8%), and the OS was 100% (95% CI = 100%-100%). Study CC202 （CML-AP ） After ≥ 12 treatment cycles in pts without responses at baseline, 17/23 (73.9%) experienced MaHR (65.2% CHR and 8.7% no evidence of leukemia [NEL]); 12/23 (52.2%) MCyR; 11/23 (47.8%) CCyR; and 9/23 (39.1%) MMR (Figure 1). The median time to MaHR was 2.8 (95% CI = 1.0-4.7) months, the median time to MCyR was 5.6 (95% CI = 2.00-NR) months, and the median time to MMR was 13.1 (95% CI = 5.6-NR) months. At 12 months, the PFS rate was 74.1% (95% CI = 48.2%-88.4%), and the OS was 91.3% (95% CI = 69.5%-97.8%). Safety Study CC201 （CML-CP ） Frequent TRAEs (all grades; grade 3-4; SAEs) included thrombocytopenia (70.7%; 48.8%; 7.3%), followed by anemia (61%; 26.8%; 2.4%), leukopenia (43.9%; 17.1%; 0), and neutropenia (36.6%; 19.5%; 0). Common nonhematologic TRAEs (all grades; G3-4) included skin pigmentation (56.1%, 0%) and elevations in creatine kinase (51.2%, 14.6%), ALT (39%, 2.4%) and AST (34.1%, 0) (Table 1). No deaths occurred. Study CC202 （CML-AP ） Common TRAEs (all grades; G3-4; SAEs) included thrombocytopenia (73.9%; 56.5%; 17.4%), anemia (60.9%; 34.8%; 13.0%), leukopenia (56.5%; 30.4%; 0), and neutropenia (26.1%; 21.7%; 0). Common nonhematologic AEs included skin pigmentation (69.6%), hypocalcemia (52.2%), proteinuria (47.8%), hypertriglyceridemia (56.5%), hyperphosphatemia (47.8%), hyperuricemia (21.7%), and arthralgia (34.8%), of which most were grade 1-2 (Table 2). Conclusions: Olverembatinib was efficacious and well tolerated when administered as monotherapy in pts with TKI-resistant CP-CML and AP-CML and the BCR-ABL1 T315Imutation. Internal study identifiers: HQP1351-CC201-CC202. ClinicalTrials.gov identifiers: NCT03883087 and NCT03883100. Figure 1 Figure 1. Disclosures Chen: Ascentage Pharma (Suzhou) Co., Ltd: Current Employment, Current equity holder in publicly-traded company. Niu: Ascentage Pharma (Suzhou) Co., Ltd: Current Employment, Current equity holder in publicly-traded company. Men: Ascentage Pharma (Suzhou) Co., Ltd.: Current Employment, Current equity holder in publicly-traded company. Yang: Ascentage Pharma (Suzhou) Co., Ltd: Current Employment, Current equity holder in publicly-traded company, Other: Leadership and other ownership interests, Patents & Royalties, Research Funding. Zhai: Ascentage Pharma Group Inc.: Current Employment, Current equity holder in publicly-traded company, Other: Leadership and other ownership interests, Patents & Royalties, Research Funding; Ascentage Pharma (Suzhou) Co., Ltd.: Current Employment, Current equity holder in publicly-traded company, Other: Leadership and other ownership interests, Patents & Royalties, Research Funding.

Novel third-generation tyrosine kinase inhibitor for newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia: a case study

“…No bleeding or death developed. The most frequent nonhematologic adverse event was skin hyperpigmentation, hypertriglyceridemia, pyrexia and proteinuria for olverembatinib in the treatment of CML [9,10]. In this study, no patients developed nonhematologic adverse events.…”

“…Olverembatinib, as a novel third-generation TKI, has shown good efficacy in the treatment of CML with or without the T315I mutation [8][9][10]. However, the efficacy of olverembatinib in newly diagnosed patients with Ph + -ALL is unknown.…”

“…Although ponatinib, as a third-generation TKI, has demonstrated efficacy for patients with Ph + ALL, the sensitivity is poor for patients with ≥2 mutations accompanied by the T315I mutation and has a dose-dependent, increased risk of serious cardiovascular events [5,15,16]. Olverembatinib treated patients with CML with or without the T315I mutation with a slight adverse effect without cardiovascular [7][8][9], which seemed a higher safety and efficacy. Therefore, treatment with a third-generation TKI for the newly diagnosed Ph + ALL may lead to a better result.…”

“…Olverembatinib has also shown efficacy against many other mutations [11]. Olverembatinib also has good efficacy for patients without or with ≥2 mutations accompanied by the T315I mutation [9,10]. On the other hand, olverembatinib can effectively inhibit proliferation and induce apoptosis by inhibiting the SRC kinase and phosphatidylinositol 3-kinase/AKT pathways in Ph + -ALL cell lines [12].…”

“…Thus, novel and well-tolerated TKIs should be explored. Olverembatinib (HQP1351), a novel third-generation TKI, has been approved by the National Medical Product Administration in China for the treatment of patients with chronic myeloid leukemia (CML) with the T315I mutation with slight adverse effects without cardiovascular events [8][9][10]. Olverembatinib has also shown efficacy against many other mutations [11].…”