Prior Tyrosine Kinase Inhibitor Research Articles

Asciminib monotherapy in patients with chronic-phase chronic myeloid leukemia with the T315I mutation after ≥1 prior tyrosine kinase inhibitor: 2-year follow-up results.

Asciminib targets the BCR::ABL1 myristoyl pocket, maintaining activity against BCR::ABL1T315I, which is resistant to most approved adenosine triphosphate-competitive tyrosine kinase inhibitors. We report updated phase I results (NCT02081378) assessing safety/tolerability and antileukemic activity of asciminib monotherapy 200 mg twice daily in 48 heavily pretreated patients with T315I-mutated chronic-phase chronic myeloid leukemia (CML-CP; data cutoff: January 6, 2021). With 2 years' median exposure, 56.3% of patients continued receiving asciminib. Overall, 62.2% of evaluable patients achieved BCR::ABL1 ≤1% on the International Scale (IS); 47.6% and 81.3% of ponatinib-pretreated and -naive patients, respectively, achieved BCR::ABL1IS ≤1%. Of 45 evaluable patients, 48.9% achieved a major molecular response (MMR, BCR::ABL1IS ≤0.1%), including 34.6% and 68.4% of ponatinib-pretreated and -naive patients, respectively. MMR was maintained until data cutoff in 19 of 22 patients who achieved it. The most common grade ≥3 adverse events (AEs) included increased lipase level (18.8%) and thrombocytopenia (14.6%). Five (10.4%) patients experienced AEs leading to discontinuation, including 2 who discontinued asciminib and died due to COVID-19; these were the only deaths reported. These results show asciminib's effectiveness, including in almost 50% of ponatinib pretreated patients, and confirm its risk-benefit profile, supporting its use as a treatment option for T315I-mutated CML-CP.

Real-world outcomes of ponatinib treatment in 724 patients with CML and Ph+ ALL: a post-marketing surveillance study with a special interest in arterial occlusive events in Japan.

In September 2016, ponatinib was approved in Japan for the treatment of patients with chronic myeloid leukemia with resistance/intolerance to prior tyrosine kinase inhibitors and patients with relapsed or refractory Philadelphia chromosome-positive acute lymphoblastic leukemia. We conducted a post-marketing all-case surveillance to study the safety and efficacy of ponatinib in clinical practice, focusing on arterial occlusive events. Data from 724 patients were collected for 2years from the initiation of ponatinib. The arterial occlusive events were reported in 6.49% (47/724) with an exposure-adjusted incidence rate of 6.8/100 person-years. The risks associated with arterial occlusive events were age and comorbidities including hypertension and diabetes. At 104weeks, the cumulative major molecular response rate in patients with chronic-phase chronic myeloid leukemia was 67.2% and the complete cytogenetic response in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia was 80.0%. Furthermore, the estimated 1-year overall survival rate was 98.5% for chronic-phase chronic myeloid leukemia and 68.6% for Philadelphia chromosome-positive acute lymphoblastic leukemia. This surveillance demonstrated that ponatinib has a favorable safety and efficacy profile in Japanese patients and also showed the necessity of closely monitoring arterial occlusive events in older adults and patients with predisposing factors for atherosclerosis.

Ponatinib-review of historical development, current status, and future research.

Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with high potency against Philadelphia chromosome (Ph)-positive leukemias, including T315I-mutated disease, which is resistant to first- and second-generation TKIs. Ponatinib was approved for T315I-mutated chronic myeloid leukemia (CML), CML resistant/intolerant to ≥2 prior TKIs, advanced phase CML and Ph-positive acute lymphoblastic leukemia (ALL) where no other TKIs are indicated, and T315I-mutated CML and Ph-positive ALL. The response-based dosing of ponatinib in chronic phase CML (CP-CML) improved treatment tolerance and reduced the risk of toxicities, including cardiovascular risks. Ponatinib-based therapy also resulted in significantly better outcomes in frontline Ph-positive ALL compared with prior TKIs and is becoming a new standard of care in this setting. As the clinical development of third-generation TKIs and their rational combinations progresses, we envision further transformative changes in the treatment of CML and Ph-positive ALL.

Abstract PO3-18-11: A011801 (CompassHER2 RD): Postneoadjuvant T-DM1 + tucatinib/placebo in patients with residual HER2-positive invasive breast cancer

Abstract Background: Patients with HER2+ early breast cancer (EBC) and invasive residual disease (RD) after neoadjuvant therapy (NAT) have a higher risk of relapse than patients who have a pathologic complete response (pCR). Escalation of therapy in patients with RD using post-neoadjuvant T-DM1 has become the new standard of care, leading to improved invasive disease-free survival (iDFS), but patients with estrogen receptor (ER)-negative or nodal RD have suboptimal outcomes, and central nervous system recurrences are a challenge. More effective treatment strategies are urgently needed. Alliance A011801 (CompassHER2 RD) is an escalation trial for patients with high-risk HER2+ RD after neoadjuvant systemic therapy, evaluating the addition of the HER2 selective tyrosine kinase inhibitor (TKI) tucatinib to post-neoadjuvant T-DM1. Methods: Eligibility and Intervention: Patients with high-risk HER2+ RD (i.e., ER-, node-positive, or both) after a predefined course of neoadjuvant HER2-directed treatment are randomized 1:1 to adjuvant T-DM1 + placebo, vs. T-DM1 and tucatinib with adjuvant RT +/- ET. Eligibility criteria include completion of ≥ 6 cycles of NAT, including ≥ 9 weeks of paclitaxel and trastuzumab +/- pertuzumab. All chemotherapy (CT) must be completed preoperatively unless participating in EA1181 (~15-30% will be participants in the CompassHER2 pCR de-escalation companion trial [NCT04266249]; these patients must receive postoperative CT to complete ≥ 6 cycles prior to enrollment on A011801). Patients who received prior HER2-targeted TKIs or antibody-drug conjugates are ineligible. Objectives: The primary objective is to determine if iDFS is improved with addition of tucatinib to T-DM1 in patients with HER2+ EBC with RD after neoadjuvant systemic therapy; secondary endpoints include overall survival, breast cancer free survival, distant recurrence-free survival, brain metastases-free survival and disease-free survival. Correlative objectives include the association of i) tumor infiltrating lymphocyte (TILs) levels in the primary tumor and RD with iDFS, ii) TILs with tucatinib benefit, iii) iDFS and circulating tumor cells (CTC) at serial timepoints and iv) the magnitude of benefit of tucatinib (iDFS) in patients with/without detectable pretreatment CTCs. Quality of life and pharmacokinetic endpoints are also being evaluated. Statistics: A011801 is a prospective, double-blind, randomized, phase III superiority trial; stratified by i) receipt of postoperative CT (Y/N), ii) hormone receptor-status (+/-), and iii) pathologic lymph node status (+/-). The study targets an absolute difference of 5% in iDFS (control vs. experimental arm 82% & 87%, HR = 0.7), with a two-sided alpha of 0.05 and power of 80%. The sample size is 981; target accrual = 1031 patients; activation and estimated completion dates are 01/6/21 and ~ 01/2028. Accrual as of 7/10/2023: 438 patients. Support: U10CA180821, U10CA180882; Seagen Inc; https://acknowledgments.alliancefound.org. ClinicalTrials.gov Identifier: NCT04457596 Citation Format: Ciara O'Sullivan, Karla Ballman, Linda McCall, Tyler Zemla, Anna Weiss, Melissa Mitchell, Victoria Blinder, Nadine Tung, William Irvin, Myounghee Lee, Sailaja Kamaraju, Matthew Goetz, W. Fraser Symmans, Virginia Borges, Ian Krop, Ann Partridge, Lisa Carey. A011801 (CompassHER2 RD): Postneoadjuvant T-DM1 + tucatinib/placebo in patients with residual HER2-positive invasive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-18-11.

Abstract CT282: MK-2870-004: A phase 3 study of MK-2870 (SKB264) versus chemotherapy for previously treated advanced or metastatic nonsquamous non-small-cell lung cancer (NSCLC) with EGFR mutations or other genomic alterations

Abstract Background: Trophoblast cell-surface antigen 2 (TROP2), a cell surface glycoprotein involved in the regulation of tumor growth and invasion, is broadly expressed and upregulated in several cancers, including NSCLC. MK-2870 (SKB264) is an antibody-drug conjugate (ADC) composed of the humanized anti-TROP2 monoclonal antibody, a hydrolytically cleavable linker, and the cytotoxic drug KL610023. MK-2870 has demonstrated encouraging antitumor activity and manageable toxicity in phase 1 and 2 studies of patients with solid tumors, including heavily pretreated EGFR-mutant NSCLC. We describe the design of the ongoing phase 3 MK-2870-004 study (NCT06074588) that will evaluate the efficacy and safety of MK-2870 vs chemotherapy for previously treated advanced or metastatic nonsquamous NSCLC with EGFR mutations or other genomic alterations. Trial design: The global, randomized, open-label, phase 3 MK-2870-004 study will enroll ~556 patients, including 456 with exon 19del or L858R EGFR mutations, and 100 with other genomic alterations. Eligible patients are aged ≥18 years with histologically or cytologically documented advanced (stage III not eligible for resection or curative radiation) or metastatic nonsquamous NSCLC with exon 19del or exon 21 L858R EGFR mutations or other genomic alterations in ALK, ROS1, BRAF V600E, NTRK, MET exon 14 skipping, or RET and those with less common EGFR mutations (exon 20 S768I, exon 21 L861Q, and/or exon 18 G719X). Patients must have progressive disease on or after 1 or 2 lines of prior tyrosine kinase inhibitor (TKI) therapy and a platinum-based therapy (may contain anti-PD-[L]1), measurable disease per RECIST v1.1, an available tumor sample, and adequate organ function. Prior EGFR TKI therapy must include a third-generation TKI for patients with T790M EGFR-mutant NSCLC. Patients with active central nervous system metastases or carcinomatous meningitis are ineligible, although those with previously treated and untreated stable brain metastasis are eligible for enrollment. Patients will be randomized (1:1) to MK-2870 4 mg/kg Q2W on Days 1, 15, and 29 of every 6-week cycle, or chemotherapy (docetaxel 75 mg/m2 Q3W or pemetrexed 500 mg/m2 Q3W) on Days 1 and 22 of every 6-week cycle. Randomization will be stratified by EGFR mutations with prior third generation TKI vs EGFR mutations with no prior third generation TKI vs other genomic alterations, brain metastasis (yes vs no), and TROP2 expression (low vs medium vs high). Dual primary endpoints are PFS (per RECIST v1.1 by blinded independent central review) and OS in patients with EGFR-mutant NSCLC. Key secondary endpoints include PFS and OS in all patients with NSCLC, ORR, DOR, patient-reported outcomes, and safety. Enrollment started in November 2023 and is currently ongoing. Citation Format: Federico Cappuzzo, Edward B. Garon, Myung-Ju Ahn, Shun Lu, Terufumi Kato, Enriqueta Felip, Parneet Cheema, Nicolas Girard, Mark Shamoun, Guoqing Wang, Bin Zhao, Rina Hui. MK-2870-004: A phase 3 study of MK-2870 (SKB264) versus chemotherapy for previously treated advanced or metastatic nonsquamous non-small-cell lung cancer (NSCLC) with EGFR mutations or other genomic alterations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT282.

Efficacy and safety of bosutinib in patients treated with prior imatinib and/or dasatinib and/or nilotinib: Subgroup analyses from the phase 4 BYOND study

The BYOND study evaluated the efficacy and safety of bosutinib 500 mg once daily in patients with chronic myeloid leukemia (CML) resistant/intolerant to prior tyrosine kinase inhibitors (TKIs). These post-hoc analyses assessed the efficacy and safety of bosutinib by resistance or intolerance to prior TKIs (imatinib-resistant vs dasatinib/nilotinib-resistant vs TKI-intolerant), and cross-intolerance between bosutinib and prior TKIs (imatinib, dasatinib, nilotinib), in patients with Philadelphia chromosome–positive chronic phase CML. Data are reported after ≥3 years’ follow-up. Of 156 patients with Philadelphia chromosome–positive chronic phase CML, 53 were imatinib-resistant, 29 dasatinib/nilotinib-resistant, and 74 intolerant to all prior TKIs; cumulative complete cytogenetic response rates at any time were 83.7%, 61.5%, and 86.8%, and cumulative major molecular response rates at any time were 72.9%, 40.7%, and 82.4%, respectively. Of 141, 95, and 79 patients who received prior imatinib, dasatinib, and nilotinib, 64 (45.4%), 71 (74.7%), and 60 (75.9%) discontinued the respective TKI due to intolerance; of these, 2 (3.1%), 5 (7.0%), and 0 had cross-intolerance with bosutinib. The response rates observed in TKI-resistant and TKI-intolerant patients, and low cross-intolerance between bosutinib and prior TKIs, further support bosutinib use for patients with Philadelphia chromosome–positive chronic phase CML resistant/intolerant to prior TKIs. Trial registrationClinicalTrials.gov: NCT02228382

Safety and efficacy of SNK01 (autologous natural killer cells) in combination with cytotoxic chemotherapy and/or cetuximab after failure of prior tyrosine kinase inhibitor in non-small cell lung cancer: non-clinical mouse model and phase I/IIa clinical study

BackgroundChoosing treatments for epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) patients with osimertinib resistance is challenging. We evaluated the safety and efficacy of SNK01 (autologous natural killer...

Tyrosine kinase inhibitor resistance in de novo BCR::ABL1–positive BCP-ALL beyond kinase domain mutations

AbstractA better understanding of ABL1 kinase domain mutation–independent causes of tyrosine kinase inhibitor (TKI) resistance is needed for BCR::ABL1–positive B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Although TKIs have dramatically improved outcomes, a subset of patients still experiences relapsed or refractory disease. We aimed to identify potential biomarkers of intrinsic TKI resistance at diagnosis in samples from 32 pediatric and 19 adult patients with BCR::ABL1–positive BCP-ALL. Reduced ex vivo imatinib sensitivity was observed in cells derived from newly diagnosed patients who relapsed after combined TKI and chemotherapy treatment compared with cells derived from patients who remained in continuous complete remission. We observed that ex vivo imatinib resistance was inversely correlated with the amount of (phosphorylated) BCR::ABL1/ABL1 protein present in samples that were taken at diagnosis without prior TKI exposure. This suggests an intrinsic cause of TKI resistance that is independent of functional BCR::ABL1 signaling. Simultaneous deletions of IKZF1 and CDKN2A/B and/or PAX5 (IKZF1plus), as well as deletions of PAX5 alone, were related to ex vivo imatinib resistance. In addition, somatic lesions involving ZEB2, SETD2, SH2B3, and CRLF2 were associated with reduced ex vivo imatinib sensitivity. Our data suggest that the poor prognostic value of IKZF1(plus) deletions is linked to intrinsic mechanisms of TKI resistance other than ABL1 kinase domain mutations in newly diagnosed pediatric and adult BCR::ABL1–positive BCP-ALL.

Асциминиб у больных хроническим миелолейкозом, не имеющих альтернативных методов лечения: результаты исследования в рамках программы расширенного доступа МАР (Managed Access Program, NCT04360005) в России

Aim. To assess the efficacy and tolerability of asciminib in chronic myeloid leukemia (CML) patients after failure of ≥ 2 lines of tyrosine kinase inhibitors (TKIs) therapy under the МАР (Managed Access Program, NCT04360005) in Russia. Materials & Methods. The study enrolled 68 patients with Ph-positive CML chronic phase (CF), over 18 years of age, after failure of ≥ 2 lines of TKI therapy. The analysis was conducted on data from 50 patients who were followed-up for at least 3 months and did not undergo allo-HSCT. Dosing regimens were prescribed depending on T315I mutation. Asciminib 200 mg per os was administered twice a day to 20 patients with this mutation, and asciminib 40 mg per os was administered twice a day to 30 patients without this mutation. By the time of admission into the MAP, there were 42 (82 %) CF CML patients as well as 8 patients with second CF after accelerated phase (AF, n = 7) and myeloid blast crisis (BC, n = 1). None of them could be treated with any therapeutic alternative. 92 % of patients had received ≥ 3 lines of prior TKI therapy. Overall survival (OS) and discontinuation-free survival were estimated by the Kaplan-Meier method. A cumulative incidence function (CIF) was used to calculate the probability of achieving response. Multivariate analysis was based on Cox regression model. Results. The median asciminib treatment duration was 11 months (range 4–30 months). The probable 2-year OS was 96 %. After 12 and 24 months, discontinuation-free survival was 92 % and 70 %, respectively. On asciminib therapy, complete cytogenetic (CCyR/МR2), major molecular (MMR), and deep molecular (MR4) responses were achieved in 17 (42 %), 14 (30 %), and 9 (19 %) patients who had not responded to prior treatment at the point of enrollment. After completing the 12- and 24-month therapy, the probability of CCyR/МR2 achievement was 44 % and 62 %, that of MMR achievement was 32 % and 40 %, and that of MR4 achievement was 26 % and 37 %, respectively. The patients treated with different doses did not significantly differ in achieving either CCyR/МR2 or MMR. By multivariate analysis, the independently significant factor impacting the probability of achieving MMR on asciminib treatment was the best MR (BCR::ABL1 < 1 % vs. 1–10 % vs. ≥ 10 %) after prior TKI therapy (hazard ratio 7.5873; p = 0.0072). In 22 (44 %) patients, adverse events (AEs) of all grades were observed, and 8 (16 %) patients showed AEs grade 3/4 (predominantly thrombocythemia and neutropenia). None of the patients discontinued asciminib treatment due to AEs. Conclusion. Asciminib demonstrated highly promising efficacy in previously TKI-treated patients with T315I mutation (200 mg BID) and without it (40 mg BID). Asciminib can be regarded as therapeutic option after failure of other TKIs. Different doses of asciminib were equally well tolerated, which makes it applicable for patients with intolerance to other TKIs and also provides ground for considering dose increases in non-responders. Good prospects are also expected for studying asciminib efficacy at earlier treatment stages (in first or second lines) as well as in combination with ATP-binding TKIs in CML patients with insufficient response to TKI treatment.

Результаты применения асциминиба, первого аллостерического ингибитора BCR::ABL1-тирозинкиназы, у больных хроническим миелолейкозом со множественной резистентностью к предшествующей терапии

Currently, there is a crucial need for new treatment approaches to overcome the resistance and intolerance of several tyrosine kinase inhibitor (TKI) therapy lines in chronic myeloid leukemia (CML) patients. Asciminib, the first in its class BCR::ABL1-tyrosine kinase inhibitor specifically targeting ABL myristoyl pocket (STAMP), demonstrated efficacy and safety in CML patients with prior TKI therapy failure, including the cases with pan-resistant T315I mutation in the chimeric BCR::ABL1 gene. The present review focuses on the asciminib mechanism of action, the results of both preclinical and clinical phase I and III studies. Due to the favorable cardiovascular toxicity profile of asciminib, the scope of its application can be extended to patients with cardiovascular co-morbidities. Asciminib is registered in the Russian Federation in January 2023, so treatment algorithms for CML patients with ineffectiveness or intolerance of prior therapy should be updated in line with this new option.

Tyrosine kinase inhibitors for radioiodine refractory differentiated thyroid cancer: A systematic review and meta-analysis.

The poor overall prognosis of radioiodine refractory thyroid cancer is an inevitable challenge in managing this disease. A series of trials have demonstrated the antitumor activity of tyrosine kinase inhibitors (TKIs)in radioiodine refractory differentiated thyroid cancer (RAIR-DTC).However, the available evidence cannot determine the optimal choice of TKI in RAIR-DTC. This study searched PubMed, EMBASE, Cochrane databases, and the ClinicalTrials website. The Cochrane bias risk tool was used to assess the risk of bias, and to evaluate randomized clinical trials (RCT)of RAIR-DTCpatients treated with the TKI system. Outcomes, including progression-free survival (PFS),overall survival (OS),and adverse events (AEs)were reported. Seven studies involving 1310 patients with RAIR-DTCwas conducted to compare the PFS and OS of various TKImonotherapies with placebo. The results showed that all TKI monotherapies had a statistically significant benefit in terms of PFS compared with placebo, with lenvatinib demonstrating the greatest benefit (hazard ratio [HR]0.19, 95% credible interval [CrI] 0.14-0.25). In terms of OS, only apatinib (HR 0.42, 95% CrI 0.18-0.97) and anlotinib (HR0.36, 95% CrI 0.18-0.73) showed statistically significant benefits compared with placebo. TKIs also had a higher incidence of AEs of grade 3 or higher compared with placebo. The findings suggest that lenvatinib may be the preferred TKI for the treatment of RAIR-DTC,although its high incidence of AEs should be considered. The results also indicate that TKI treatment may be similarly effective in RAIR-DTCpatients with BRAF or RAS mutations and in those with papillary or follicular subtypes of the disease, regardless of prior TKI treatment. The results of this meta-analysis suggest that targeted therapy with TKIs may be beneficial for patients with radioiodine-refractory advanced or metastatic differentiated thyroid cancer. Among the TKIs analyzed, lenvatinib appeared to be the most effective at improving PFS, although it also had the highest incidence of AEs. Further research through direct randomized controlled trials is needed to determine the optimal choice of TKI for treating patients with RAIR-DTC.This study is beneficial for formulating patients' treatment plans and guides clinicians' decision-making.

A Comparative Study Evaluating the Quality of Life and Survival Outcomes in Patients Receiving Chemotherapy Versus Oral Tyrosine Kinase Inhibitor in the Third Line and Beyond Setting for Advanced NSCLC

IntroductionThe outcomes in advanced NSCLC have improved owing to the availability of more effective systemic and improved supportive care. This has increased the number of patients who seek treatment in the third line and beyond setting. We conducted this study to compare the quality of life (QoL), toxicity, and outcomes in patients receiving chemotherapy and EGFR tyrosine kinase inhibitors (TKIs) in this setting. MethodsIn this phase 3, randomized, open-label study, patients with stage III or IV NSCLC with disease progression on at least two prior lines of chemotherapy, with a life expectancy of at least 3 months, without prior EGFR TKI exposure, and stable brain metastases (if any) were included. Patients were randomized to receive chemotherapy (gemcitabine or docetaxel or paclitaxel or vinorelbine) or an EGFR TKI (erlotinib or gefitinib). The primary end point was the change in QoL at 8 to 10 weeks; the secondary outcomes were safety and overall survival (OS). Patients underwent clinical evaluation at every visit, and toxicity was assessed as per Common Terminology Criteria for Adverse Events version 4.03. A radiological tumor response assessment was done every 8 to 12 weeks from the start of therapy. The QoL was assessed using the EORTC QLQ C30 and LC13 questionnaires. The change in QoL scores was calculated as the difference between scores at baseline and scores at 8 to 10 weeks (Δ) for each QoL domain. The Mann-Whitney U test was used to compare the mean difference (Δ) for each domain. OS and progression-free survival (PFS) were determined using the Kaplan-Meier method and Cox proportional regression analysis. ResultsA total of 246 patients were enrolled in the study, with 123 in each arm. There was a male predominance with 69.1% male patients in the chemotherapy arm and 70.7% in the EGFR TKI arm. The median age of patients in the chemotherapy arm was 54 years and 55 years in the chemotherapy and EGFR TKI arms, respectively. There was no significant difference in the change in QoL at baseline and the second visit (Δ) in both arms in all domains of EORTC QLQ C30 except cognitive function (p = 0.0045) and LC13 except alopecia (0.01249). The mean Δ Global Health Status was −28 in the chemotherapy arm and −26.8 in the EGFR TKI arm; this was not statistically significant (p = 0.973). The median follow-up was 88.1 months (95% confidence interval [CI]: 39.04–137.15). On the intention-to-treat analysis, the median PFS was 3.13 months (95% CI: 2.15–4.11) in the chemotherapy arm and 2.26 months (95% CI: 2.1–2.43) in the EGFR TKI arm, with hazard ratio at 1.074 (95% CI: 0.83–1.38) (p = 0.58). There were 120 deaths in each arm. The median OS was 7.63 months (95% CI: 5.96–9.30) in the chemotherapy arm and 7.5 months in the EGFR TKI arm (95% CI: 5.85–9.14); hazard ratio at 1.033 (95% CI: 0.80–1.33) (p = 0.805). The toxicity profile was similar in both arms except for a significantly higher incidence of fatigue (p = 0.043), peripheral neuropathy (0.000), alopecia, hypokalemia (0.037), and pedal edema (0.007) in the chemotherapy arm and dry skin (p = 0.000) and skin rash (p = 0.019) in the EGFR TKI arm. ConclusionsThere was no significant difference in most QoL scales (except cognitive function and alopecia), OS, and PFS of patients with advanced NSCLC receiving an EGFR TKI as compared with chemotherapy TKI in the third-line setting. The toxicity profile is consistent with the known toxicities of the agents.

Abstract PR003: Repotrectinib in patients with ROS1 fusion-positive (ROS1+) non-small cell lung cancer (NSCLC): Update from the pivotal phase 1/2 TRIDENT-1 trial

Abstract Introduction: Repotrectinib, a next-generation ROS1 tyrosine kinase inhibitor (TKI), has demonstrated durable activity and manageable safety in patients (pts) with locally advanced/metastatic ROS1+ NSCLC in the pivotal phase 1/2 TRIDENT-1 trial (NCT03093116). We report efficacy with a minimum follow-up of 14 months (mo) from start of treatment in two ROS1+ NSCLC primary efficacy cohorts and safety in all pts treated at the recommended phase 2 dose (RP2D). Methods: Pts with ROS1+ NSCLC were assigned to 4 cohorts by treatment history: TKI-naïve, 1 TKI and no chemo, 1 TKI and 1 platinum-based chemo, and 2 TKIs and no chemo. Repotrectinib RP2D was 160 mg once daily for 14 days, then 160 mg twice daily. Phase 2 primary endpoint was confirmed objective response rate (cORR) by Blinded Independent Central Review per RECIST v1.1. Secondary endpoints included duration of response (DOR), progression-free survival (PFS), intracranial ORR, cORR in TKI-pretreated pts with ROS1 G2032R NSCLC, and safety. Efficacy analyses included pts with ≥14 mo follow-up. Safety assessments included pts treated at RP2D across all study cohorts. Results: At data cutoff (December 19, 2022), median (range) follow-up in the primary efficacy cohorts was 24.0 (14.2–66.6) mo in the TKI-naïve cohort (n=71) and 21.5 (14.2–58.6) mo in the 1 prior TKI and no chemo cohort (n=56). In the TKI-naïve cohort, cORR was 79% (95% CI, 68–88). Median (95% CI) DOR was 34.1 (25.6–not estimable [NE]) mo; estimated 12- and 18-mo DOR rates were 83% (73–93) and 79% (68–90), respectively. Median PFS (95% CI) was 35.7 (27.4–NE) mo; estimated 12- and 18-mo PFS rates were 77% (66–87) and 70% (59–81), respectively. In the 1 prior TKI and no chemo cohort, cORR was 38% (95% CI, 25–52). Median DOR (95% CI) was 14.8 (7.6–NE) mo; estimated 12-mo DOR rate was 56% (34–77). Median PFS (95% CI) was 9.0 (6.8–19.6) mo; estimated 12-mo PFS rate was 41% (27–56). The median (range) time to response was 1.8 (0.9–5.6) mo in the TKI-naïve cohort and 1.8 (1.6–3.6) mo in the 1 prior TKI and no chemo cohort. Among pts with measurable brain metastasis at baseline, intracranial ORR was 89% (95% CI, 52–100) in the TKI-naïve cohort (n=9), and 38% (95% CI, 14–68) in the 1 prior TKI and no chemo cohort (n=13). In pts with TKI-pretreated ROS1 G2032R NSCLC (n=17), cORR was 59% (33–82). Among pts receiving repotrectinib at RP2D (n=426), treatment-emergent adverse events (TEAEs) occurred in 422 (99%), most commonly dizziness (62%). Grade ≥3 TEAEs occurred in 216 (51%) and were considered treatment-related in 122 (29%). TEAEs led to dose reduction and treatment discontinuation in 38% and 7% of pts, respectively. Additional analysis in CNS efficacy and by subsequent therapies will be presented. Conclusion: With a minimum follow-up of 14 mo in TRIDENT-1, repotrectinib continued to demonstrate durable efficacy in pts with ROS1+ NSCLC, including intracranial activity, in both TKI-naïve and 1 prior TKI and no chemo cohorts. Safety in pts treated at RP2D was manageable, consistent with previous reports in all treated pts. Prior:WCLC(Sep 10). Citation Format: Jessica J Lin, Byoung Chul Cho, D. Ross Camidge, Sang-We Kim, Benjamin Solomon, Rafal Dziadziuszko, Benjamin Besse, Koichi Goto, Adrianus Johannes de Langen, Jürgen Wolf, Ki Hyeong Lee, Sanjay Popat, Christoph Springfeld, Misako Nagasaka, Enriqueta Felip, Nong Yang, Shun Lu, Steven Kao, Vamsidhar Velcheti, Parneet Cheema, Shanna Stopatschinskaja, Minal Mehta, Denise Trone, Felipe Ades, Christophe Y. Calvet, Alexander Drilon. Repotrectinib in patients with ROS1 fusion-positive (ROS1+) non-small cell lung cancer (NSCLC): Update from the pivotal phase 1/2 TRIDENT-1 trial [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr PR003.

Abstract B024: KO-2806, a next-generation farnesyltransferase inhibitor, potentiates the antitumor activity of cabozantinib in clear cell renal cell carcinoma models

Abstract Conventional treatments for advanced clear cell renal cell carcinoma (ccRCC) include tyrosine kinase inhibitors (TKI) that target angiogenesis, a critical element for ccRCC tumor growth and survival. Cabozantinib, a TKI that inhibits VEGFR, AXL, and MET, is an approved therapy in advanced RCC. However, cabozantinib has limited therapeutic benefit; for example, patients with prior VEGFR TKI therapy had an overall response rate of 21% and median progression-free survival of 7.4 months. Thus, there is an urgent need to identify combination drug partners that can improve the depth and/or durability of clinical responses to cabozantinib. Here, we present preclinical evidence that supports combining the farnesyltransferase inhibitor (FTI), KO-2806, with cabozantinib in ccRCC. KO-2806 is a next-generation farnesyltransferase inhibitor with increased potency and improved pharmacokinetic properties relative to earlier FTI drug candidates and is poised to enter a first-in-human clinical trial. We demonstrate that addition of KO-2806 enhanced tumor growth inhibition of cabozantinib in multiple ccRCC cell line- and patient-derived xenograft models, resulting in either tumor stasis or regression. Immunohistochemical analysis of angiogenic markers in 786-O tumors revealed that, consistent with its mechanism of action, cabozantinib significantly reduced angiogenesis, an effect that was deepened by KO-2806. In support of this, cell viability experiments performed in primary human endothelial cells showed that the combination of KO-2806 and cabozantinib was more effective in reducing cell viability than cabozantinib alone. In addition, we investigated the mechanism underlying the improved response of tumors with the KO-2806-cabozantinib combination by analyzing the major growth signaling pathways in 786-O tumors. Cabozantinib alone reduced both MAPK and PI3K/AKT/mTOR signaling, but addition of KO-2806 resulted in enhanced inhibition of mTOR signaling and increased cell cycle arrest compared to either agent alone. We hypothesize that exposure to anti-angiogenic TKIs render ccRCC tumors more hypoxic, and thus more reliant on compensatory, oncogenic mechanisms like mTOR signaling that allow them to adapt to a nutrient- and oxygen-deprived environment. Mechanistically, KO-2806 potently inhibits the farnesylation, and hence the activity, of the farnesylation-dependent protein RHEB, a positive regulator of mTOR, suggesting that the improved anti-tumor efficacy of the combination may arise through RHEB inhibition in this model. Further in vitro and in vivo studies are underway to establish the scope and mechanistic underpinnings of the effects of the KO-2806-cabozantinib combination and strengthen the therapeutic rationale for the investigation of this approach in the treatment of patients with ccRCC. Citation Format: Jovylyn Gatchalian, Linda Kessler, Hetika Patel, Stacia Chan, Francis Burrows, Shivani Malik. KO-2806, a next-generation farnesyltransferase inhibitor, potentiates the antitumor activity of cabozantinib in clear cell renal cell carcinoma models [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B024.

Abstract B154: Safety and preliminary activity of the selective ALK inhibitor NVL-655 in patients with ALK fusion-positive solid tumors

Abstract Background: Oncogenic ALK alterations drive diverse tumor types, including ALK fusions in 3-5% of non-small cell lung cancers (NSCLCs). While 3 generations (1G, 2G, 3G) of ALK tyrosine kinase inhibitors (TKIs) are approved globally for ALK fusion-positive (ALK+) NSCLC, they are limited by acquired ALK resistance mutations, CNS relapses, and for the 3G TKI lorlatinib, neurologic adverse events attributed to off-target TRK inhibition. A rationally designed ALK TKI that overcomes these limitations is needed. Preclinically, NVL-655 is a brain-penetrant, ALK-selective, and TRK-sparing TKI that exhibits activity against diverse ALK fusions and resistance mutations, including lorlatinib-refractory compound mutations. Materials and Methods: ALKOVE-1 (NCT05384626) is a global phase 1/2 trial of NVL-655. The ongoing phase 1 dose escalation enrolls patients (pts) with a previously treated ALK+ solid tumor, including NSCLC treated with ≥1 prior 2G or 3G ALK TKI. Primary objectives are to determine the safety/tolerability, recommended phase 2 dose (RP2D), and if applicable, the maximum tolerated dose (MTD). Additional objectives include assessments of pharmacokinetics (PK), pharmacodynamics, and preliminary activity by investigator-assessed tumor response (RECIST v1.1). Data cut: June 12, 2023. Results: 57 pts (54 NSCLC, 3 other solid tumors) received NVL-655 orally at 15-200 mg once daily (QD). Pts previously received a median of 4 (range: 1-8) prior anticancer therapies, including a 2G or 3G ALK TKI (100%); ≥1 2G ALK TKI + lorlatinib (77%); ≥3 ALK TKIs (53%); and chemotherapy (60%). At baseline, 51% had a history of CNS metastases. 47% had known ALK resistance mutations and 32% had compound ALK mutations, as per available local testing or central analyses of baseline circulating tumor DNA (ctDNA). Treatment-related adverse events (TRAEs) were generally mild; most frequent were nausea (12%), transaminase elevation (12%), fatigue (9%), and constipation (7%). Grade ≥3 TRAEs were transaminase elevation (n=2), CPK elevation (n=1), and fatigue (n=1). NVL-655 PK analyses demonstrated dose-proportional exposure. Partial responses (PR) were observed in 45% (15/33; 8 pending confirmation) of efficacy-evaluable pts with ALK+ NSCLC (15-150 mg QD), in 65% (11/17) with baseline ALK resistance mutations, and in 41% (12/29) post-lorlatinib, including cases with compound resistance mutations. CNS activity, including complete resolution of CNS metastases, has been observed. ctDNA analyses showed reductions, including clearance, of ALK fusion and mutation variants. Neither the MTD nor RP2D has been identified; phase 1 continues. Conclusions: NVL-655 has been well-tolerated up to 200 mg daily with favorable PK. Preliminary activity has been demonstrated in heavily pretreated pts with ALK+ NSCLC, including those who previously received 2G ALK TKI(s) + lorlatinib, with brain metastases, or with single/compound ALK resistance mutations. Citation Format: Jessica J Lin, Melissa Johnson, Enriqueta Felip, Sai-Hong Ignatius Ou, Benjamin Besse, Christina Baik, Julien Mazieres, Yasir Elamin, Joshua E. Reuss, Anna Minchom, Aurelie Swalduz, Nick Pavlakis, Geoffrey Liu, Shirish Gadgeel, D. Ross Camidge, Jennifer A Green, Junwu Shen, John Soglia, Yuting Sun, Viola W Zhu, Alexander Drilon. Safety and preliminary activity of the selective ALK inhibitor NVL-655 in patients with ALK fusion-positive solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B154.

Abstract C025: Trial in progress: First-in-human study of BBT-207 in advanced non-small cell lung cancer harboring EGFR mutation after treatment with EGFR TKI

Abstract Background: There is a high unmet need for an effective therapy for the treatment of non-small cell lung cancer (NSCLC) following osimertinib or other 3rd generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) failure, especially when resistance is driven by the occurrence of the C797S mutation. BBT-207 is a fourth-generation EGFR inhibitor. Preclinically BBT-207 has shown activity against treatment-emergent complex EGFR mutations containing T790M and/or C797S as well as drug-naïve mutants providing a possibility to overcome resistance to prior TKIs. Activity to intracranial lesions is also anticipated from animal models. Methods: Study BBT207-ONC-001 is an open-label, phase 1/2 study evaluating safety, tolerability, pharmacokinetic profile, pharmacodynamic characterization, and preliminary antitumor activity of BBT-207 monotherapy in approximately 92 patients with EGFR-mutant NSCLC. It consists of 3 phases: Phase 1a (dose escalation), phase 1b (recommended phase 2 dose selection), and phase 2 (dose expansion). Key eligibility criteria include patients ≥18 years of age with advanced stage and refractory NSCLC with an activating EGFR mutation, documented partial response, complete response, or durable stable disease after treatment of an EGFR TKI, and previous treatment with all standard therapeutic options and at least one third-generation EGFR TKI. There is no limit on the number of previous treatments received. Phase 1a requires confirmation that the tumor harbors a classical EGFR mutation (19Del or L858R), and phase 1b and phase 2 require confirmation that the tumor or the blood harbors complex EGFR mutations containing C797S. Patients with asymptomatic brain metastases who are on stable dose of corticosteroid are eligible. Primary endpoints are to determine recommended dose range (RDR) which is defined between the minimal reproducibly active dose, and the maximum tolerated dose or maximum administered dose and to characterize the overall safety and tolerability of BBT-207 (phase 1a); to determine the recommended phase 2 dose (phase 1b); to evaluate preliminary antitumor activity with objective response rate (phase 2). Phase 1a dose escalation will be guided by Bayesian logistic regression model. The safety monitoring committee will determine RDR and two recommended dose levels (RDs) within the RDR to be explored in phase 1b. In phase 1b, up to 20 patients will be randomized to each of the two RDs. At the end of phase 1b, a futility test will be performed in the dose level to be treated with the RP2D using Bayesian analysis. Phase 2 will be a non-randomized, open-label phase with up to 20 patients. Patients may receive treatment until disease progression or unacceptable toxicity. Treatment continuation beyond progression will be allowed if potential benefits are justified. Investigational new drug application was cleared by the U.S. FDA. Patient enrollment will begin in approximately August 2023 in the U.S. and Republic of Korea. Clinical trial information: NCT05920135. Citation Format: NaEun Jeon, Alexander Spira, Douglas Orr, Lyudmila Bazhenova, Misako Nagasaka, Jin Seok Ahn, Dong-Wan Kim, Yu Jung Kim, Jimin Cho, Agnes Jung, Eunsoo Jung, Chul-Won Kim, Taiguang Jin, Yong-Hee Lee, Sang-Yoon Lee. Trial in progress: First-in-human study of BBT-207 in advanced non-small cell lung cancer harboring EGFR mutation after treatment with EGFR TKI [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C025.

Sustained Efficacy and Safety with Asciminib (ASC) after Almost 4 Years of Median Follow-up from Ascembl, a Phase 3 Study of ASC Vs Bosutinib (BOS) in Patients (Pts) with Chronic Myeloid Leukemia in Chronic Phase (CML-CP) after ≥2 Prior Tyrosine Kinase Inhibitors (TKIs): An End of Study Treatment (EOS Tx) Update, Including Results from Switch Population

CONCLUSIONS CML requires chronic therapy, emphasizing the need for Txs that are characterized by high, durable efficacy and a low adverse event (AE) burden. ASC, the first BCR::ABL1 inhibitor Specifically Targeting the ABL Myristoyl Pocket (STAMP), demonstrated significantly superior efficacy and better safety/tolerability compared with BOS in pts with CML-CP who received ≥2 prior TKIs in the phase 3 ASCEMBL study. Major molecular response (MMR) rate was 25.5% with ASC vs 13.2% with BOS at wk 24, meeting the primary objective, and 37.6% vs 15.8% at wk 96, meeting the key secondary objective. Despite the longer duration of exposure to ASC, safety/tolerability remained consistently better with ASC vs BOS, with fewer all-grade and grade ≥3 AEs and AEs leading to Tx discontinuation observed. After a median follow-up of 3.7 y, we report EOS Tx results from ASCEMBL (cutoff: March 22, 2023). We also report the first available data from pts who experienced Tx failure on BOS and switched to ASC. Adults (aged ≥18 y) with CML-CP after ≥2 prior TKIs, with intolerance or lack of efficacy per 2013 ELN recommendations were randomized 2:1 to receive either ASC 40 mg twice daily or BOS 500 mg once daily. Pts who met Tx failure criteria per 2013 ELN while on BOS could switch to ASC and were analyzed separately. Pts who discontinued BOS due to intolerance could not switch. EOS will occur 5 y from when the last enrolled pt received first Tx dose. A total of 233 pts were randomized to ASC (n=157) or BOS (n=76). The most common reason for discontinuation was lack of efficacy in 40 (25.5%) pts on ASC and 28 (36.8%) on BOS. At the time of EOS Tx cutoff, Tx with ASC and BOS was ongoing in 77 (49.4%) and 8 (10.5%) pts, respectively; pts deriving benefit from study Tx at EOS TX, per investigator assessment, continued receiving posttrial access. MMR rate at wk 156 continued to be higher with ASC (33.8%) than with BOS (10.5%) (Figure 1). The difference after adjusting for baseline (BL) major cytogenetic response was 23.2%(95% CI, 13.1%-33.2%; 2-sided P<.001). The BCR::ABL1IS ≤1% rate at wk 156 in pts without this level of response at BL also continued to be higher with ASC (43.0%) than with BOS (11.1%). Despite the longer median duration (range) of exposure to ASC (156.0 [0.1-256.3] wk) vs BOS (30.5 [1.0-239.3] wk), safety/tolerability of ASC continued to be better compared with BOS and were consistent with previous analyses. Two new pts had AEs leading to Tx discontinuation since the wk 96 cutoff (1 pt on ASC reported pregnancy; 1 pt on BOS reported diarrhea), and rates remained lower with ASC vs BOS (8.3% vs 27.6%). The most frequent (≥10%) grade ≥3 AEs with ASC vs BOS were thrombocytopenia (22.4% vs 9.2%), neutropenia (18.6% vs 14.5%), diarrhea (0% vs 10.5%), and increased alanine aminotransferase (0.6% vs 14.5%). Most AEs occurred within the first 6 months (Figure 2). Exposure-adjusted incidence rates of arterial occlusive events (AOEs) with ASC decreased since the wk 96 cutoff, from 3.0 to 2.2 per 100 pt-y, and no new AOEs occurred with ASC, indicating that the risk of AOEs did not increase over time. Among pts who discontinued Tx due to lack of efficacy or disease progression, no new mutations occurred since the wk 96 cutoff. Of 28 pts who discontinued BOS for lack of efficacy, 25 switched to ASC. Almost all switch pts (96%) had BL BCR::ABL1IS >10% prior to switch. No switch pts achieved MMR at or by wk 48 post switch. However, at wk 48, 24% achieved BCR::ABL1IS ≤10% and 8% achieved BCR::ABL1IS ≤1%. The safety profile of ASC in switch pts was consistent with that in pts receiving ASC in the randomized period. Most frequent (≥10%) grade ≥3 AEs were neutropenia (32.0%) and thrombocytopenia (24.0%). AEs leading to Tx discontinuation occurred in 8.0% of switch pts. With almost 4 y of follow-up in ASCEMBL, ASC continued to show greater efficacy and better safety/tolerability than BOS in pts with CML-CP after ≥2 prior TKIs. The robust safety profile of ASC was sustained through each analysis in ASCEMBL (wk 24, wk 96, and EOS Tx), confirming that pts receiving ASC can maintain a high level of response and continue Tx without experiencing late-emerging AEs. Results in the switch population support the use of ASC early in the Tx paradigm. ASCEMBL EOS Tx results continue to strongly support ASC as the therapy of choice for pts with suboptimal responses and/or intolerance to ≥2 prior TKIs, allowing more pts to remain on Tx and achieve their Tx goals without needing to switch.

Safety and Efficacy of Tgrx-678, a Potent BCR-ABL Allosteric Inhibitor in Patients with Tyrosine Kinase Inhibitor (TKI) Resistant/Refractory Chronic Myeloid Leukemia (CML): Preliminary Results of Phase I Study

Background: TGRX-678 is a novel allosteric inhibitor of ABL kinases, specifically targeting the ABL Myristoyl Pocket (STAMP). In vitro data supports TGRX-678 targeting the most common BCR-ABL mutations, including T315I. Here we report an open-label, first-in-human study to evaluate the safety, preliminary efficacy, and pharmacokinetic properties of orally administered TGRX-678 in patients with resistant/refractory CML. Methods: This study included dose escalation and expansion phases. During dose escalation patients with CML in chronic or accelerated phase (CP or AP) and who had failed ≥3 prior TKIs were enrolled. Patients received orally a single dose, after a 3-5 day observation, continuously daily doses ranging from 10 to 80 mg (BID) or 40 to 240 mg (QD) were given. Dose escalation followed an adaptive Bayesian logistic regression model based on dose-limiting toxicities (DLTs) occurring in cycle 1 (28 Days). Dose-expansion had three cohorts: CML-CP without T315I mutation with ≥2 prior TKIs, CML-CP with T315I with ≥1 prior TKIs, and CML-AP with ≥1 prior TKIs. The eligible patients received continuous treatments until disease progression, intolerant toxicity, consent withdrawal, or death. Results: From April 30, 2021 to July11, 2023, 95 (CP n = 58, AP n = 37) patients were treated with TGRX-678 at the BID doses including 10 mg (n = 3), 20 mg (n = 6), 40 mg (n = 5), and 80 mg (n = 3), and QD doses including 40mg (n=18), 80 mg (n = 6), 160mg (n= 4) and 240mg (n=50). 40 (42%) patients were female. The median age was 45 (range 35-52) years and the median interval from diagnosis to initial TGRX-678 treatment was 97 (range 28-136) months. Median treatment duration was 8 (range 6-13) months. At baseline, 93 (98%) patients had received ≥2 lines of prior TKI therapy, among them, 78 (82%) received ≥3 lines of prior TKIs, 44 (46%) received ≥4 lines of prior TKIs. 46 (48%) patients had ≥1 ABL mutation and 28 (30%) had T315I mutation. Of 58 patients with CML-CP, 16 (89%) achieved complete hematologic responses (CHR), 25 (43%) major cytogenetic responses (MCyR), 19 (33%) complete cytogenetic responses (CCyR), and 11 (19%) major molecular responses (MMR). Of 14 CML-CP patients with T315I mutation, 9 (100%) achieved CHR, 9 (62%) MCyR, 8 (57%) CCyR and 7 (50%) MMR. Of 35 CML-CP patients without any ABL mutations, 12 (100%) achieved CHR, 11 (31%) MCyR, 6 (17%) CCyR and 1 (3%) MMR (Fig. A). Of 9 CML-CP patients with other ABL mutations, 4 (67%) achieved CHR, 5 (56%) MCyR, 5 (56%) CCyR and 3 (33%) MMR (Fig. B). Of 37 CML-AP patients, 31 (84%) had major hematologic response, 13 (35%) MCyR, and 9 (24%) CCyR (Fig. C). There were 22 CML-CP and 23 CML-AP patients previous received 3 rd Gen TKIs (ponatinib or HQP1351) or asciminib. Of 22 CP patients, 21 (95%) achieved CHR, 4 (18%) MCyR and 3 (14%) CCyR. Of 23 CML-AP patients, 17 (74%) achieved CHR, 5 (22%) MCyR and 3 (13%) CCyR. The PK results suggested that TGRX-678 exposure (C max and AUC tau) was dose-proportional within range of 10mg~80mg BID or 40mg~240mg QD. The elimination of TGRX-678 in human plasma is slow, and the half-life (T1/2) of which is about 120 hours. At steady state, the accumulation ratios of C max and AUC tau are 3.7-8.0 and 5.4-11.8, respectively. The high accumulation ratio of TGRX-678 resulted in not only an increase of plasma exposure, but also a decrease of the gap between C max and C trough (Fig. D). 7 DLTs were observed, one case of elevated alanine aminotransferase at 20 mg BID and five cases of thrombocytopenia at 40mg QD (1), 40mg BID (2) and 80mg QD (2) and one hepatic function abnormal at 240 mg QD. However, MTD was not reached according to protocol criteria. Most treatment-related adverse events (TRAEs) were grade 1-2. AEs ≥ grade 3 that happened more than 5% were thrombocytopenia (50%), neutropenia (42%), anemia (24%) and hypertriglyceridemia (9%). In total 15 patients discontinued the study due to disease progression (5, all APs), intolerance (2), physician's decision (2), consent withdrawal (6). There was one death occurred which was not drug related. Conclusions: Clinical activity of TGRX-678 was seen in all cohorts and across TKI-resistant mutations including T315I, providing a promising treatment option for CML CP/AP patients, including those who failed ponatinib or asciminib. Its unique PK properties might bring additional benefit to patients. TGRX-678 was well tolerated in heavily pretreated CML patients. Currently two doses were selected to optimize the RP2D. Study Identifier: NCT05434312.

Update of Olverembatinib (HQP1351) Overcoming Ponatinib and/or Asciminib Resistance in Patients (Pts) with Heavily Pretreated/Refractory Chronic Myeloid Leukemia (CML) and Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia (Ph + ALL)

Background Olverembatinib, a novel, potent BCR::ABL1 tyrosine kinase inhibitor (TKI), shows strong antitumor activity in pts with CML and Ph + ALL. Here, we report on the safety, efficacy, and pharmacokinetic (PK) profiles of olverembatinib in pts with CML (all phases) and Ph + ALL outside of China, particularly in pts previously treated with ponatinib and/or asciminib. Methods Olverembatinib was administered orally once every other day (QOD) in continuous 28-day cycles. In the monotherapy cohort, pts were enrolled after treatment failure on at least 2 prior TKIs and randomized to olverembatinib QOD 30, 40, or 50 mg. In the combination cohort, pts with Ph + B-cell precursor (BCP) ALL or lymphoid CML-BP (CML-LBP) resistant to at least 1 TKI were enrolled and received olverembatinib (30 or 40 mg) QOD in combination with blinatumomab. Results As of June 30, 2023, 76 pts were enrolled, including 57 with CML-CP and 19 with advanced Ph + leukemia. The median (range) age was 54.5 (21-80) years, and 56.6% of pts were male. In all, 11 (14.5%), 23 (30.3%), and 39 (51.3%) pts had received 2, 3, and ≥ 4 prior TKIs, respectively. A total of 52.6% of pts were previously treated with ponatinib, of whom 67.5% were resistant and 25.0% intolerant to the drug, and 7.5% experienced treatment failure for other reasons. A total of 27.6% of pts were previously treated with asciminib, of whom 71.4% were resistant and 19.1% intolerant to the agent, and 9.5% experienced treatment failure for other reasons. At baseline, 32% of pts had T315I mutations, 38% hypertension, and 17.1% other cardiovascular comorbidities. Median (range) treatment duration was 24.1 (0-134) weeks, and PK profiles were similar to historical PK data on Chinese pts. Twelve pts with CML-CP and 7 with advanced Ph + leukemia discontinued treatment: 4 because of AEs, 7 disease progression, and 8 other reasons. A total of 54 of 65 (83.1%) pts who received ≥ 1 dose of olverembatinib experienced any-grade TRAEs. Grade ≥ 3 AEs occurring in ≥ 3 pts (≥ 4.6% incidence) included thrombocytopenia (17%); neutropenia (13.8%); elevated blood creatine phosphokinase (13.8%); leukopenia (7.7%); and anemia and elevated lipase (4.6% each). Ten (15.4%) pts experienced olverembatinib treatment-related serious AEs, of which each were experienced by 1 (1.5%) pt. Two (3.1%) pts discontinued the study because of TRAEs. No TRAE-associated deaths were reported. Olverembatinib showed sustained antileukemic activity in pts with CML and Ph + ALL (Table 1). Among 50 efficacy-evaluable pts with CML-CP, the rate of complete cytogenetic response (CCyR) was 57% (25/44) and major molecular response (MMR) 43% (21/49). Efficacy improved over time; the MMR rate in pts with CML-CP treated for 6 months was 66% and 88% in pts treated for 12 months. Among pts whose disease failed ≥ 4 prior TKIs, CCyR and MMR rates were 57% (13/23) and 42% (11/26), respectively. In pts with CML-CP harboring the T315I mutation, rates of CCyR and MMR were 60% (9/15) and 44% (7/16), respectively, and 55% (16/29) and 42% (14/33) in pts without the T315I mutation. Among evaluable ponatinib-failed pts, 8/15 (53%) achieved CCyR and 6/16 (38%) MMR. Among pts who failed asciminib therapy, 3/7 (43%) achieved CCyR and 3/8 (38%) MMR. Of 8 pts with CML-CP who had prior exposure to both ponatinib and asciminib, 2 (25%) achieved MMR. At 24 months, PFS was 75% (95% CI, 56.1-86.7) and OS was 97.6% (95% CI, 90.8-99.4). Thirteen pts with advanced Ph + leukemia were efficacy-evaluable, of whom 3 (23%) achieved MMR; only 1 of 3 pts with the T315I mutation achieved MMR; the other 2 were also resistant to ponatinib treatment. The median (95% CI) PFS of efficacy-evaluable pts with advanced leukemia was 12.7 (4-19.5) months. In the combination cohort, 2 pts with Ph + BCP ALL received olverembatinib 30 mg QOD with blinatumomab; both achieved CCyR and 1 achieved a negative MRD status after 1 treatment cycle. Conclusions Olverembatinib alone or combined with blinatumomab was efficacious and well tolerated in pts with heavily pretreated CML or Ph + ALL . Olverembatinib monotherapy was potent in pts who were either resistant or intolerant to ponatinib and/or asciminib, regardless of T315I mutation status. Olverembatinib may provide an effective new treatment option for pts after failure of 2 or more TKIs. Internal study identifier: HQP1351-CU101. Clinicaltrials.gov identifier: NCT04260022.

Asciminib (ASC) in Combination with Imatinib (IMA), Nilotinib (NIL), or Dasatinib (DAS) May be a Potential Treatment (Tx) Option in Patients (Pts) with Philadelphia Chromosome-Positive Chronic Myeloid Leukemia in Chronic Phase or Accelerated Phase (Ph+ CML-CP/AP): Final Results from the Asciminib Phase 1 Study

Asciminib (ASC) in Combination with Imatinib (IMA), Nilotinib (NIL), or Dasatinib (DAS) May be a Potential Treatment (Tx) Option in Patients (Pts) with Philadelphia Chromosome-Positive Chronic Myeloid Leukemia in Chronic Phase or Accelerated Phase (Ph+ CML-CP/AP): Final Results from the Asciminib Phase 1 Study