Boni, Valentina

5589 Background: Imlunestrant is a next-generation oral SERD designed to deliver continuous estrogen receptor (ER) target inhibition aimed to improve outcomes for patients (pts) with ER+ cancers. In the first-in-human Phase 1a/1b EMBER trial (NCT04188548), imlunestrant showed favorable safety, pharmacokinetics, and clinical benefit in pre-treated pts with ER+ advanced breast cancer or EEC. Here, we report updated imlunestrant monotherapy data and the first clinical data of imlunestrant + abemaciclib in ER+ EEC pts from EMBER. Methods: Eligible pts had ER+ EEC previously treated with (or deemed inappropriate for) platinum-containing chemotherapy. Prior fulvestrant or aromatase inhibitor therapy was not allowed. In Phase 1a, pts received imlunestrant alone, and in Phase 1b, pts were randomized (1:1) to imlunestrant alone or with abemaciclib. Plasma samples were collected at baseline (all pts) and at cycle 2 (monotherapy pts) for ctDNA analysis (Guardant 360 assay) to correlate with clinical benefit. Primary endpoints were RP2D of imlunestrant monotherapy and in combination. Secondary endpoints included safety, tolerability, and overall response rate (ORR), clinical benefit rate (CBR: complete or partial response, or stable disease ≥24 weeks), and progression-free survival (PFS) using RECIST v1.1. Results: Overall, 72 pts were treated; 39 pts received monotherapy (33 at 400mg [RP2D] and 6 at 800mg po daily) and 33 pts received imlunestrant (29 at 400mg and 4 at 800mg po daily) + abemaciclib (150mg po twice daily). Baseline characteristics, safety, and preliminary efficacy are presented (Table). For monotherapy, the most common TEAEs (all grade/grade 3) were nausea (36%/3%), diarrhea (26%/0), urinary tract infection (26%/3%), and abdominal pain (21%/8%). For imlunestrant + abemaciclib, the most common TEAEs (all grade/grade 3) were diarrhea (88%/3%), nausea (67%/0), fatigue (49%/9%) and anemia (46%/12%). In the monotherapy arm, pts with deeper (≥ 50%) declines in ctDNA variant allele frequency had a higher CBR (4/7 vs 4/17). Conclusions: Imlunestrant, as monotherapy or with abemaciclib, appears safe and tolerable with preliminary evidence of efficacy in pts with metastatic ER+ EEC. Clinical trial information: NCT04188548 . [Table: see text]

Abstract Purpose: To report on the first-in-human phase I study of VIP152 (NCT02635672), a potent and highly selective cyclin-dependent kinase 9 (CDK9) inhibitor. Patients and Methods: Adults with solid tumors or aggressive non–Hodgkin lymphoma who were refractory to or had exhausted all available therapies received VIP152 monotherapy as a 30-minute intravenous, once-weekly infusion, as escalating doses (5, 10, 15, 22.5, or 30 mg in 21-day cycles) until the MTD was determined. Results: Thirty-seven patients received ≥ 1 VIP152 dose, with 30 mg identified as the MTD based on dose-limiting toxicity of grade 3/4 neutropenia. The most common adverse events were nausea and vomiting (75.7% and 56.8%, respectively), all of grade 1/2 severity. Of the most common events, grade 3/4 events occurring in > 1 patient were neutropenia (22%), anemia (11%), abdominal pain (8%), increased alkaline phosphatase (8%), and hyponatremia (8%). Day 1 exposure for the MTD exceeded the predicted minimum therapeutic exposure and reproducibly achieved maximal pathway modulation; no accumulation occurred after multiple doses. Seven of 30 patients with solid tumors had stable disease (including 9.5 and 16.8 months in individual patients with pancreatic cancer and salivary gland cancer, respectively), and 2 of 7 patients with high-grade B-cell lymphoma with MYC and BCL2/BCL6 translocations (HGL) achieved durable complete metabolic remission (ongoing at study discontinuation, after 3.7 and 2.3 years of treatment). Conclusions: VIP152 monotherapy, administered intravenously once weekly, demonstrated a favorable safety profile and evidence of clinical benefit in patients with advanced HGL and solid tumors.

9068 Background: The phase 2 SUMMIT basket trial (NCT01953926) demonstrated efficacy of neratinib in patients with EGFR exon 18-mutant NSCLC [Boni et al. WCLC 2020]. Neratinib also has documented activity in HER2+ metastatic breast cancer with CNS metastases [Saura et al. SABCS 2020 & J Clin Oncol 2020]. Here we report neratinib efficacy in a subgroup of patients with EGFR exon 18-mutant NSCLC and CNS involvement from SUMMIT. Methods: Patients with EGFR exon 18-mutant NSCLC were treated with single-agent neratinib (240 mg po daily). Prior EGFR tyrosine kinase inhibitors (TKIs), chemotherapy, and checkpoint inhibitors (IO) were allowed. Patients with stable, asymptomatic CNS metastasis were enrolled. Study endpoints: objective response rate (ORR) at week 8 (±1 week); ORR (RECIST 1.1 confirmed); duration of response (DOR); clinical benefit rate (CBR); progression-free survival (PFS); safety; biomarkers. Results: Baseline characteristics of 11 patients with EGFR exon 18-mutant NSCLC: median age 67 (range 56–83) years; ECOG PS 0/1 (45%/55%). Prior lines of therapies: 2 (range 1–3): EGFR TKIs (91%); chemotherapy (55%); IO (27%). 3/11 patients had baseline CNS metastasis and received radiation 8–22 months prior to study enrollment. Best CNS response in these 3 patients was stable disease with overall individual PFS of 1.9 (censored), 6.9 and 9.1 months and OS of 2.6 (censored), 17.7 (censored), and 17.9 months. Efficacy is summarized in Table. Efficacy summary: TKI-pretreated EGFR exon 18-mutant NSCLC cohort receiving neratinib monotherapy. Conclusions: Activity of single-agent neratinib was observed in prior TKI-exposed patients with EGFR exon 18-mutant NSCLC. Despite the small sample size of only 3 patients with baseline CNS metastases, findings suggest a potential role for neratinib as a systemic treatment option for patients with NSCLC and difficult-to-treat uncommon mutations with CNS involvement. The SUMMIT trial continues to enroll patients with EGFR exon 18-mutant NSCLC. Clinical trial information: NCT01953926. [Table: see text]

PURPOSEMutations in the HRAS (m HRAS) proto-oncogene occur in 4%-8% of patients with recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). Tipifarnib is a farnesyltransferase inhibitor that disrupts HRAS function. We evaluated the efficacy of tipifarnib in patients with R/M m HRAS HNSCC.METHODSWe enrolled 30 patients with R/M HNSCC in a single-arm, open-label phase II trial of tipifarnib for m HRAS malignancies; one additional patient was treated on an expanded access program. After an ad hoc analysis of the first 16 patients with HNSCC with m HRAS variant allele frequency (VAF) data, enrollment was limited to those with a m HRAS VAF of ≥ 20% (high VAF). The primary end point was objective response rate. Secondary end points included assessing safety and tolerability. Patients received tipifarnib 600 or 900 mg orally twice daily on days 1-7 and 15-21 of 28-day cycles.RESULTSOf the 22 patients with HNSCC with high VAF, 20 were evaluable for response at the time of data cutoff. Objective response rate for evaluable patients with high-VAF HNSCC was 55% (95% CI, 31.5 to 76.9). Median progression-free survival on tipifarnib was 5.6 months (95% CI, 3.6 to 16.4) versus 3.6 months (95% CI, 1.3 to 5.2) on last prior therapy. Median overall survival was 15.4 months (95% CI, 7.0 to 29.7). The most frequent treatment-emergent adverse events among the 30 patients with HNSCC were anemia (37%) and lymphopenia (13%).CONCLUSIONTipifarnib demonstrated encouraging efficacy in patients with R/M HNSCC with HRAS mutations for whom limited therapeutic options exist ( NCT02383927 ).

Abstract Background: This Phase 2 study (NCT02383927) is a multi-institutional, open-label trial to determine the efficacy and safety of tipifarnib in patients (pts) with locally advanced/unresectable and/or metastatic solid tumors that carry HRAS missense mutations. HRAS is a proto-oncogene that is overexpressed and mutated in head and neck squamous cell carcinomas (HNSCC) and other SCCs. Tipifarnib is a potent and highly selective inhibitor of farnesyltransferase, a critical enzyme for HRAS activity. Methods: Pts received tipifarnib at a starting dose of 600 – 900 mg orally twice daily on days 1-7 and 15-21 of 28-day cycles. Disease assessments were conducted according to RECIST v1.1 criteria. Null hypothesis and objective response of interest were respectively 10% and 30%. Prior to its completion, this study met its primary objective and, based on preliminary efficacy results (Ho, et. al, ESMO 2018), was amended to continue enrolling only pts with HNSCC (Cohort 2) and other SCC tumors (Cohort 3) carrying HRAS missense mutations at a high variant allele frequency (VAF >35% or ≥20% if baseline serum albumin is >3.5 g/dL). Results: As of May 1, 2019, 23 pts with HNSCC and 10 pts with tumors with other SCC histologies have been treated with tipifarnib. Pts had relapsed/refractory disease with a median of 2 prior regimens. Of note, no objective partial responses were observed on their last therapy prior to study entry, including platinum, immunotherapy and cetuximab +/- chemotherapy. In 15 HNSCC pts meeting the HRAS mutation high VAF inclusion criteria, a 53% overall response rate (ORR) was observed, with 8 confirmed partial responses (PR) and 5 disease stabilizations (SD). Two pts await first on-study tumor response assessment. Overall median progression free survival (PFS) was 5.4 mos (95% CI 4.5 to 19.5 mos, N=15); 19 mos (95% CI 5.3 to 19.5 mos) for pts experiencing a PR and 4.5 mos (95% CI 1.6 to 5.4 mos) for those experiencing SD. Median PFS on last prior therapy was 3.2 mos. All pts had at least 1 treatment-emergent adverse event (TEAE). The most frequently observed drug-related Grade >3 TEAEs occurring in ≥10% pts were blood and lymphatic system disorders, gastrointestinal disorders and renal disorders. Conclusions: Encouraging activity of tipifarnib was observed in HRAS mutant HNSCC. Based on these data, a pivotal study (AIM-HN and SEQ-HN Study, NCT03719690) evaluating the efficacy of this agent in HRAS mutant HNSCC (AIM-HN) and the impact of HRAS mutations on first line therapy of HNSCC (SEQ-HN) has been initiated. Citation Format: Alan Ho, Irene Brana, Robert Haddad, Jessica Bauman, Keith Bible, Laurence Faugeras, Sjoukje Oosting, Deborah J Wong, Myung-Ju Ahn, Valentina Boni, Caroline Even, Jerome Fayette, Maria Jose Flor, Kevin Harrington, Sung-Bae Kim, Lisa Licitra, Ioanna Nixon, Nabil F Saba, Cyrus Sayehli, Pol Specenier, Francis Worden, Binaifer Balsara, Jeanne Britt, Vishnu Mishra, Catherine Scholz, Antonio Gualberto. Preliminary results from a phase 2 trial of tipifarnib in squamous cell carcinomas (SCCs) with HRAS mutations [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr PR08. doi:10.1158/1535-7163.TARG-19-PR08

TPS2618 Background: Tipifarnib is a potent and highly selective inhibitor of farnesyltransferase (FT). FT catalyzes the post-translational attachment of farnesyl groups to signaling proteins that are requisite for localization to the inner cell membrane. While all RAS isoforms (KRAS/NRAS/HRAS) are FT substrates, only HRAS is exclusively dependent upon farnesylation for membrane localization and signaling activation, making HRAS mutant tumors uniquely susceptible to tipifarnib mediated inhibition of FT. Tipifarnib has demonstrated robust activity in HRAS mutant head and neck squamous cell carcinoma (HNSCC) and HRAS mutant squamous non-small cell lung cancer (NSCLC) patient derived xenograft (PDX) models resistant to standard therapies. Methods: This is a multi-institutional, open-label Phase II trial evaluating the efficacy and safety of tipifarnib for pts with HRAS mutant solid tumors. Pts must have either unresectable, locally advanced or metastatic non-hematological malignancies that harbor a missense HRAS mutation. The primary endpoint of the study is overall response rate. Secondary endpoints include safety and tolerability, PFS, duration of response. Two cohorts (N = 18 each) are enrolling, each being evaluated with a Simon two-stage design. Cohort 1 is for patients with malignant thyroid tumors of any histology. Cohort 2 was originally designated for pts with any other solid tumor. The prespecified activity goal for the first stage of accrual in Cohort 2 was met. Based on data observed in the first stage of this group, enrollment to the second stage of Cohort 2 has been limited to HRAS mutant HNSCC since August 2016. Enrolled patients are treated with tipifarnib 900 mg administered orally twice daily on days 1-7 and 15-21 of 28-day treatment cycles until progression of disease or unacceptable toxicity. Clinical trial information: NCT02383927.

Abstract Background: HRAS is a proto-oncogene that is mutated in head and neck, bladder, thyroid, and salivary gland tumors, among others. While discovered over 40 years ago, no specific therapies have yet been developed targeting mutant HRAS. Tipifarnib is a potent and highly selective inhibitor of farnesyltransferase, a critical enzyme requisite for HRAS activation. Over 5,000 patients (pts) have been treated with tipifarnib; although responses have been documented in several tumor indications, the mechanisms of response are still poorly understood. Tipifarnib has demonstrated robust activity in HRAS mutant patient derived xenograft (PDX) models of head and neck squamous cell carcinoma (HNSCC) and squamous non-small cell lung cancer that are resistant to standard therapies. This Phase 2 study (NCT02383927) was conducted to test the hypothesis that inhibition of mutant HRAS oncogenic activity with tipifarnib could translate to objective responses in HNSCC pts driven by the HRAS oncogene. Methods: The study was originally designed to enroll pts into 2 single-arm study cohorts: Cohort 1 (thyroid cancer) and Cohort 2 (other solid tumors), each one with a 2-stage design (11+7 evaluable pts) to determine overall response rate (ORR) as the primary objective. This design has 80% power to detect a difference between 10% and 30% ORR at one-sided significance level of 0.087. Two objective responses were needed to be observed in the first stage for each cohort to proceed to stage 2. The study is considered positive if at least 4 responses are observed in one of the 2 cohorts (N=18 each, stages 1 and 2 combined). The prespecified activity goal for the first stage of accrual in Cohort 2 was met and based on data observed in the first stage of this Cohort, ongoing enrollment to the second stage of Cohort 2 was limited to HRAS mutant HNSCC. For enrollment, pts must have an HRAS mutant, locally advanced/unresectable and/or metastatic solid tumor malignancy and RECIST v1.1 measurable disease. Tipifarnib is given at 900 mg orally twice daily on days 1-7 and 15-21 of 28-day cycles. Response assessments are conducted every 8 weeks. Results: As of August 30, 2017, 28 pts have been enrolled. Tipifarnib was generally well tolerated with myelosuppression, gastrointestinal disturbances (nausea, vomiting and diarrhea) and fatigue constituting the most common adverse events (≥30% of pts, all grades). Twenty four pts are currently evaluable for efficacy: 10 in Cohort 1 and 14 in Cohort 2. Stage 1 enrollment continues in Cohort 1. The primary objective was met for Cohort 2 prior to completing full enrollment, with 4 confirmed responses observed out of 14 evaluable pts. Notably, of the 6 pts in Cohort 2 with HNSCC currently evaluable for efficacy, 4 (67%) achieved a confirmed partial response. Three of these pts remain on treatment in cycles 3, 5, and 19, and one subject discontinued at Cycle 21. Two (33%) pts had disease stabilization as best response (4 cycles, ongoing and 7 cycles). Importantly, 4 of these pts were refractory to prior therapies, including regimens containing immunotherapy (pembrolizumab, nivolumab) or cetuximab +/- chemotherapy. None of the 6 HNSCC patients experienced an objective partial response on their last prior therapy. Conclusions: These data suggest that HRAS mutant HNSCC pts may be refractory to standard therapies but can derive prolonged clinical benefit from tipifarnib treatment. Based on the encouraging activity of tipifarnib in pts with HNSCC with HRAS mutations, enrollment continues in this cohort. Citation Format: Alan Ho, Nicole Chau, Deborah J. Wong, Maria E. Cabanillas, Jessica Bauman, Marcia S. Brose, Keith Bible, Valentina Boni, Irene Brana, Charles Ferte, Caroline Even, Francis Burrows, Linda Kessler, Vishnu Mishra, Kelly Magnuson, Catherine Scholz, Antonio Gualberto. Preliminary results from a phase 2 proof of concept trial of tipifarnib in tumors with HRAS mutations [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-A10.