Anne-Sophie Longin

BACKGROUND: mutations occur in approximately 40% of patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. The PI3Kα-specific inhibitor alpelisib has shown antitumor activity in early studies. METHODS: -mutated cancer. Secondary end points included overall response and safety. RESULTS: -mutated cancer was greater with alpelisib-fulvestrant than with placebo-fulvestrant (26.6% vs. 12.8%); among patients with measurable disease in this cohort, the percentages were 35.7% and 16.2%, respectively. In the overall population, the most frequent adverse events of grade 3 or 4 were hyperglycemia (36.6% in the alpelisib-fulvestrant group vs. 0.7% in the placebo-fulvestrant group) and rash (9.9% vs. 0.3%). Diarrhea of grade 3 occurred in 6.7% of patients in the alpelisib-fulvestrant group, as compared with 0.3% of those in the placebo-fulvestrant group; no diarrhea of grade 4 was reported. The percentages of patients who discontinued alpelisib and placebo owing to adverse events were 25.0% and 4.2%, respectively. CONCLUSIONS: -mutated, HR-positive, HER2-negative advanced breast cancer who had received endocrine therapy previously. (Funded by Novartis Pharmaceuticals; SOLAR-1 ClinicalTrials.gov number, NCT02437318.).

TPS618 Background: The phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway is frequently activated in hormone receptor-positive (HR+) BC and is associated with resistance to endocrine therapy. The combination of the PI3Kα-specific inhibitor alpelisib (BYL719) and fulvestrant showed promising activity in a phase I study of HR+/human epidermal growth factor 2-negative (HER2–) BC, with the strongest treatment benefit in patients (pts) with PIK3CA-mutant tumors (Janku et al. SABCS 2014, Abstract PD5-5). Further data are required to confirm these observations. Methods: In the phase III, randomized, double-blind SOLAR-1 study (NCT02437318), men and postmenopausal women with HR+/HER2– advanced BC are randomized (1:1) to alpelisib or placebo (300 mg once daily) + fulvestrant (500 mg intramuscularly on Days 1 and 15 of Cycle 1 [28 days], and Day 1 of Cycles ≥ 2) until disease progression or discontinuation for other reason. Pts are assigned to 2 cohorts (PIK3CAmutant vs non-mutant status in tumor tissue) prior to randomization, and stratified by presence of liver and/or lung metastases, and prior CDK4/6 inhibitor treatment. Key inclusion criteria include disease progression/recurrence on or after prior aromatase inhibitor therapy, and Eastern Cooperative Oncology Group performance status ≤ 1. Exclusion criteria include symptomatic visceral disease, or disease burden precluding endocrine therapy, and prior therapy with fulvestrant, chemotherapy, ([neo] adjuvant permitted) or PI3K/mTOR/AKT inhibitors. The primary and key secondary endpoints are progression-free survival (PFS; local assessment, RECIST v1.1) and overall survival, respectively. Other secondary endpoints include PFS, as per blinded independent review, PFS based on PIK3CA status in circulating tumor DNA, overall response rate, clinical benefit rate, safety, pharmacokinetics, and global health status/quality of life. Analysis of the primary endpoint will be performed with a stratified log-rank test (95% confidence interval). Global recruitment of the planned 820 pts is ongoing. Clinical trial information: NCT02437318.

TPS9144 Background: Kirsten rat sarcoma viral oncogene homolog ( KRAS) is the most frequent mutated oncogene in non-small cell lung cancer (NSCLC). KRAS G12C is the most common KRAS variant, present in ~13% of patients (pts) with non-squamous NSCLC. KRAS G12C mutations cause the accumulation of active, GTP-bound KRAS, which leads to activation of downstream pathways involved in cell proliferation and invasiveness. JDQ443 is a potent, structurally novel, selective KRAS G12C inhibitor that irreversibly traps KRAS G12C in its inactive, GDP-bound form. Data from the JDQ443 monotherapy arm of the first-in-human KontRASt-01 study demonstrated encouraging anti-tumor activity and an acceptable safety profile of JDQ443 in pts with previously treated, KRAS G12C-mutated, advanced NSCLC. For pts with advanced NSCLC who progress following first-line immunotherapy or doublet platinum-based chemotherapy, single agent docetaxel remains a standard option, although it presents modest activity and is generally poorly tolerated. In this context, alternative treatment options are needed to improve pt outcomes. Methods: KontRASt-02 (NCT05132075) is a global, Phase III, open-label, randomized, multicenter study evaluating JDQ443 as a monotherapy in comparison to docetaxel in pts with KRAS G12C-mutated, advanced NSCLC previously treated with PD-(L)1 inhibitors and platinum-based chemotherapy (either in combination or as sequential treatments). Approximately 360 pts stratified by ECOG performance status (0 vs 1 and 2) and prior therapy (platinum-based chemotherapy and immunotherapy combined vs sequential) will be randomized at 1:1 to receive 200 mg oral JDQ443 twice daily continuously or 75 mg/m 2 intravenous docetaxel once every 21 days. The primary endpoint of this study is progression-free survival (PFS) per Blinded Independent Review Committee (BIRC) according to RECIST version 1.1. The key secondary endpoint is overall survival (OS); other secondary endpoints include objective response rate, disease control rate, time to response, duration of response, PFS on subsequent therapy, safety of JDQ443 monotherapy, pt-reported outcomes, pharmacokinetics, time to deterioration of ECOG performance status, and safety in pts who crossover from docetaxel to JDQ443. Exploratory objectives include biomarker analyses aimed at investigating predictors of responsiveness to JDQ443. Pts randomized to docetaxel will be allowed to crossover to JDQ443 following confirmed disease progression per BIRC. To allow more pts to be treated with JDQ443, crossover will also be offered to all patients on docetaxel if the primary endpoint (PFS) is met. Treatment beyond progression will be allowed for pts receiving JDQ443 according to investigator judgement. The KontRASt-02 study is currently enrolling pts. Clinical trial information: NCT05132075 .

TPS1111 Background: Patients (pts) with HR+ breast cancer (BC) often havedysregulatedphosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway, which further leads to resistance to endocrine therapy (ET). In a phase 1 study, alpelisib (BYL719), a PI3Kα-specific inhibitor in combination with fulvestrant (FUL) has demonstrated antitumor activity in pts with estrogen receptor-positive, HER2– advanced BC (ABC) with PIK3CA-altered tumors. SOLAR-1 (NCT02437318) aims to assess the efficacy of ALP + FUL in PIK3CA-mutant and non-mutant tumors in HR+, HER2– ABC setting. Methods: SOLAR-1 is a phase 3, randomized, double-blind study conducted in men and postmenopausal women with HR+, HER2– ABC. Pts are randomly (1:1) allocated to oral alpelisib/placebo (300 mg qd) and intramuscular FUL (500 mg) until disease progression or treatment (tx) discontinuation. Stratification factors are presence of liver and/or lung metastases and prior use of CDK4/6 inhibitors. The eligibility criteria for the targeted BC patient population are shown in the Table. The primary endpoint is progression-free survival (PFS; RECIST v1.1; local assessment), while overall survival (OS) is a key secondary endpoint in the PIK3CA-mutant cohort. Other secondary endpoints are PFS and OS in the PIK3CA non-mutant cohort, the association between PFS and baseline PIK3CAstatus in ctDNA, overall response rate, clinical benefit rate, and safety. Recruitment of the planned 560 pts is currently ongoing. Clinical trial information: NCT02437318. [Table: see text]

Background: In patients with chronic myeloid leukemia in chronic phase (CML-CP), the efficacy of ATP-competitive tyrosine kinase inhibitors (TKIs) has resulted in treatment-free remission (TFR) as a primary treatment goal for those with a sustained deep molecular response (DMR). However, most patients treated with imatinib fail to achieve a sustained DMR, meaning that they cannot benefit from TFR. Asciminib is a potent and specific inhibitor of BCR-ABL1. Unlike BCR-ABL1 TKIs that target the ATP binding site, asciminib binds to the myristate pocket of ABL1. Preclinical data showed that the combination of asciminib with ATP-competitive TKIs may provide more potent BCR-ABL1 inhibition and prevent emergence of resistance mutations (Wylie et al. Nature. 2017;543:733-737). In an ongoing phase 1 study (NCT02081378), asciminib demonstrated clinical activity and was well tolerated as a single agent (Hughes et al. Blood. 2016;128 [abstract 625]). In the same study, asciminib in combination with imatinib showed promising preliminary efficacy and a good safety profile in patients resistant/intolerant of ≥2 prior TKIs (Cortes et al. HemaSphere. 2019;3(S1) [abstract S388]). These findings informed the dose of asciminib to be further evaluated in combination with imatinib. An ongoing phase 3 study (NCT03106779) is evaluating asciminib vs bosutinib in patients previously treated with ≥2 ATP-binding site TKIs (Mauro et al. J Clin Oncol. 2019;37 [abstract TPS7070]). Here, we describe the ASCiminib add-on 4-arm study evaluating MOlecular REsponse (ASC4MORE) in patients. This is a phase 2 study evaluating the efficacy of adding asciminib to ongoing imatinib therapy in patients with CML-CP who have not achieved DMR with long-term frontline imatinib (CABL001E2201; NCT03578367). Methods: Study participants are aged ≥18 years, have CML-CP, and have been treated with frontline imatinib for ≥12 months. Study entry requires patients to be receiving imatinib 400 mg once daily (QD) at randomization, have BCR-ABL1 transcript levels in the range of ≤1% to >0.01% on the International Scale (IS), no prior achievement of MR4 (BCR-ABL1IS ≤0.01%) confirmed by two consecutive tests, and no prior treatment failure. Overall, ~80 patients will be randomized 1:1:1:1 to one of four arms (Figure): either asciminib 40 mg QD or 60 mg QD added to imatinib 400 mg QD; continued treatment with imatinib 400 mg QD; or switch to nilotinib 300 mg twice daily. Study treatment will continue until treatment resistance or intolerance, or up to 96 weeks after the last randomized patient has begun treatment. The primary objective of this study is to assess whether asciminib add-on to imatinib is more effective than imatinib continuation; the primary endpoint is the rate of MR4.5 (BCR-ABL1IS ≤0.0032%) at 48 weeks. Secondary objectives include: to estimate the efficacy of switch to nilotinib; to estimate the difference in efficacy between asciminib add-on to imatinib and switch to nilotinib; and to characterize the safety of asciminib add-on to imatinib. Exploratory objectives include TFR eligibility at the end of the study and patient-reported outcomes. Patients in the imatinib continuation arm who have not achieved MR4.5 at 48 weeks may cross over to receive add-on asciminib. This study is ongoing, with 23 patients randomized as of 22 July 2019. Disclosures Saglio: BMS: Consultancy; Novartis: Consultancy; Ariad: Consultancy; Incyte: Consultancy; Pfizer: Consultancy; Jansen: Consultancy; Celgene: Consultancy. Hughes:Novartis, Bristol-Myers Squibb, Celgene: Research Funding; Novartis, Bristol-Myers Squibb: Consultancy, Other: Travel. Geissler:Novartis: Consultancy, Research Funding, Speakers Bureau; Pfizer: Consultancy, Research Funding, Speakers Bureau; Roche: Consultancy; Amgen: Consultancy; Incyte: Research Funding; Takeda: Research Funding; Biomarin: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; UCB: Consultancy, Speakers Bureau; Servier: Consultancy. Kapoor:Novartis: Employment. Longin:Novartis: Employment. Mukherjee:Novartis: Employment. Cortes:Novartis: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; BiolineRx: Consultancy; Jazz Pharmaceuticals: Consultancy, Research Funding; Merus: Consultancy, Honoraria, Research Funding; Forma Therapeutics: Consultancy, Honoraria, Research Funding; Immunogen: Consultancy, Honoraria, Research Funding; Astellas Pharma: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Biopath Holdings: Consultancy, Honoraria; Sun Pharma: Research Funding; Pfizer: Consultancy, Honoraria, Research Funding.