Citations

Mantle cell lymphoma is a rare subtype of B-cell non-Hodgkin’s lymphomas that is generally classified as an aggressive lymphoma requiring front-line chemo-immunotherapy with stem cell rescue. Despite effective treatment, many patients relapse or are refractory to front-line therapy. In addition, these patients may also develop drug resistance requiring novel modalities for subsequent lines. Bruton’s tyrosine kinase inhibitors have demonstrated a well-tolerated safety and efficacy profile across several B-cell malignancies. Ibrutinib, acalabrutinib, and zanubrutinib are FDA-approved as treatment options for patients with Mantle cell lymphoma following one prior line of therapy. Various factors should be considered which include the adverse event profile of these agents and ability to adhere to therapy. In this article, we review the role of Bruton’s tyrosine kinase inhibitors for the management of Mantle cell lymphoma and review the clinical pharmacology, pharmacokinetics, safety and efficacy, and future directions.

Abstract Background: Bimiralisib is a balanced dual panPI3K/mTOR inhibitor, which demonstrated anti-cancer activity in a number of preclinical models. Pharmacokinetic (PK) data suggested that intermittent targeting of the PI3K/mTOR pathway could be preferable to continuous daily dosing. Preclinical models in squamous cell head and neck cancer (SCCHN) demonstrated that NOTCH1 Loss of Function (LoF) mutations were associated with efficacy of bimiralisib and other PI3K inhibitors. Methods: We conducted a first-in-human dose-escalation study (3+3 design) to identify the maximum tolerated dose (MTD), recommended phase 2 dose (RP2D), dose-limiting toxicities (DLT) and overall safety (CTCAE v4) of bimiralisib administered either as a continuous (80 mg – 120 mg daily) or one of two intermittent schedules (schedule A: twice weekly 80 mg – 200 mg on Day 1 and 2, or schedule B: twice weekly 80mg – 200 mg on Day 1 and 4) until disease progression or unacceptable adverse events (AEs). Eligible patients had histologically confirmed solid cancers refractory to standard therapies, ECOG <1, life expectancy >12 weeks, adequate bone marrow, liver, and renal functions, HgbA1c <7%, and fasting plasma glucose < 7.0mmol/L. Tumor responses were evaluated according to RECIST v1.1 every 6 weeks. PK and blood biomarkers were analyzed. Results: 70 patients (female, 70%; white, 93%; median age 57 years [range, 49-65]) with heavily pretreated advanced solid cancers were enrolled (continuous schedule, 21; intermittent schedule A, 25; intermittent schedule B, 24). The MTD for the continuous schedule was established as 80 mg daily. For all treatment groups, DLTs included grade 2 and 3 fatigue. Clinically significant treatment-related AEs included fatigue in the continuous schedule, none in the intermittent schedule A and diarrhea, hyperglycemia in the intermittent schedule B. Intermittent schedules A and B did not reach the MTD, and after review of PK data, 140 mg administered in schedule A was selected as the RP2D for further exploration. Day 1 peak plasma concentration proportionally increased with increasing doses of bimiralisib only up to 140mg. Weekly AUC on intermittent dosing at all dose levels studied were considerably lower than continuous daily dosing at 80mg. There was one partial response (PR, -85% per RECIST) in a heavily pretreated patient with SCCHN and NOTCH1 LoF mutation, which was maintained for 8.2 months until death from pulmonary artery rupture in the setting of known fistula (assessed as unrelated to bimiralisib). In addition, 30 (42.9%) pts achieved stable disease (SD) including one with anal SCC carrying a NOTCH1 LoF mutation. SD > 6 months was observed in five pts (23.8%) in continuous schedule, 12 (48%) in intermittent schedule A, and 13 (54.2%) in intermittent schedule B. Results on patients, who consented to the serial circulating tumor DNA collection will be presented. Conclusions: Bimiralisib was well tolerated and RP2D of 140 mg given orally twice weekly on Days 1 and 2 was selected for further studies. In agreement with our preclinical models, there was an encouraging activity in a SCCHN patient with NOTCH1 LoF mutation and this observation is now being validated in a proof-of-concept phase 2 study (NCT03740100). Citation Format: Filip Janku, Faye M. Johnson, Mateusz Opyrchal, Afshin Dowlati, Cinta Hierro, Martin Forester, Sarah P. Blagden, Andreas Wicki, Debora Schmitz, Alex A. Adjei. Oral dual PI3K/mTOR inhibitor bimiralisib demonstrates tolerability and a signal of activity in head and neck squamous cell cancer with NOTCH1 loss-of-function mutation [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 B109. doi:10.1158/1535-7163.TARG-19-B109

Abstract Purpose In breast MRI, contrast enhancement of normal fibroglandular tissue is referred to as background parenchymal enhancement (BPE). Hormonal status significantly affects the degree of BPE, potentially due to the association with mammary vascularity and activity1-5. Studies have shown that BPE may be associated with breast cancer survival6, treatment response to neoadjuvant chemotherapy (NAC)7,8 and future breast cancer risk9. In most patients undergoing NAC, BPE is suppressed by the nonspecific anti-proliferative effects of chemotherapy on normal breast and/or ovary5,10. However, some patients exhibit equivalent or even stronger BPE post-NAC compared to pre-NAC. We hypothesized that non-suppressed BPE in post-NAC MRI may be associated with inferior treatment response. This study aimed to investigate the association between BPE suppression and treatment response as defined by pathologic complete response (pCR). Methods This study included patients with stage II/III breast cancer enrolled in the I-SPY 2 TRIAL being treated with standard NAC with or without investigational agents. The whole cohort was split into two subgroups based on hormone receptor status (HR+, n= 536; HR-, n=452). Patients underwent dynamic contrast enhanced MRIs at four time points during NAC: baseline (T0), after 3 weeks of the first regimen (T1), inter-regimen (T2), and pre-surgery (T3). Using in-house software, the contralateral breast parenchyma was automatically segmented for the entire breast volume. Quantitative BPE (qBPE) was calculated as the mean early (~150s post-contrast injection) percent enhancement of the central 50% of the axial slices. A breast radiologist reviewed all exams and excluded those where automated segmentation failed to accurately define tissue. For T1, T2 and T3, BPE was categorized based on the change from T0 as suppressed (qBPE < qBPE[T0]) or non-suppressed (qBPE ≥ qBPE[T0]). Chi-squared test was used to examine the association between BPE suppression and pCR, with p<0.05 considered statistically significant. Results HR+ cohort: pCR rates were lower for patients with non-suppressed BPE than those with suppressed BPE at every visit (T1-T3) (Table 1). The difference was statistically significant at T2 (p=0.04) and T3 (p=0.01). Table 1: HR+ cohortpCR rate (%)No. of pCR patientsNo. of non-pCR patientsTotal number of patientsP valueOverall22.8122414536BPE at T1suppressed23.6822663480.45non-suppressed20.532124156BPE at T2suppressed25.7972803770.04*non-suppressed16.01789106BPE at T3suppressed25.7982833810.01*non-suppressed12.5128496 HR- cohort: pCR rates were slightly lower for the non-suppressed BPE group, but no statistically significant association was found (Table 2). Table 2: HR- cohortpCR rate (%)No. of pCR patientsNo. of non-pCR patientsTotal number of patientsP valueOverall44.7202250452BPE at T1suppressed46.81411603010.66non-suppressed44.45265117BPE at T2suppressed48.81441512950.79non-suppressed47.3434891BPE at T3suppressed49.31461502960.94non-suppressed48.9434588 Conclusion In HR+ breast cancer, lack of BPE suppression may indicate inferior treatment response. The contrasting results in HR+ and HR- cohorts are noteworthy in terms of the possible relationship between suppression of normal mammary and ovarian activity and treatment response in HR+ cancer. Reference Radiographics 2014; 34: 234-47. Radiology 1997; 203: 137-44. Radiology 1997; 203: 145-9. Breast J 2005; 11: 236-41. AJR Am J Roentgenol 2015; 204: 669-73. Eur Radiol 2018; 28: 4705-16. Eur Radiol 2016; 26: 1590-6. Transl Oncol 2015; 8: 204-9. J Clin Oncol 2019; : JCO1800378. Radiology 2015; 277: 687-96. Citation Format: Natsuko Onishi, Wen Li, David C. Newitt, Roy Harnish, Jessica Gibbs, Ella F. Jones, Alex Nguyen, Lisa Wilmes, Bonnie N. Joe, Michael J. Campbell, Amrita Basu, Laura J. van’t Veer, Angela DiMichele, Douglas Yee, Donald A. Berry, Kathy S. Albain, Judy C. Boughey, A. Jo Chien, Amy S. Clark, Kirsten K. Edmiston, Anthony D. Elias, Erin D. Ellis, David M. Euhus, Heather S. Han, Claudine Isaacs, Qamar J. Khan, Julie E. Lang, Janice Lu, Jane L. Meisel, Zaha Mitri, Rita Nanda, Donald W. Northfelt, Tara Sanft, Erica Stringer-Reasor, Rebecca K. Viscusi, Anne M. Wallace, Rachel Yung, Michelle E. Melisko, Jane Perlmutter, Hope S. Rugo, Richard Schwab, W. Fraser Symmans, Smita M. Asare, Julie E. Yau, Christina Yau, Laura J. Esserman, Nola M. Hylton. Lack of background parenchymal enhancement suppression in breast MRI during neoadjuvant chemotherapy may be associated with inferior treatment response in hormone receptor positive breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD9-05.

Abstract Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is an uncommon histologic variant, and the optimal treatment of stage I-II NLPHL is undefined. We conducted a multicenter retrospective study including patients ≥16 years of age with stage I-II NLPHL diagnosed from 1995 through 2018 who underwent all forms of management, including radiotherapy (RT), combined modality therapy (CMT; RT+chemotherapy [CT]), CT, observation after excision, rituximab and RT, and single-agent rituximab. End points were progression-free survival (PFS), freedom from transformation, and overall survival (OS) without statistical comparison between management groups. We identified 559 patients with median age of 39 years: 72.3% were men, and 54.9% had stage I disease. Median follow-up was 5.5 years (interquartile range, 3.1-10.1). Five-year PFS and OS in the entire cohort were 87.1% and 98.3%, respectively. Primary management was RT alone (n = 257; 46.0%), CMT (n = 184; 32.9%), CT alone (n = 47; 8.4%), observation (n = 37; 6.6%), rituximab and RT (n = 19; 3.4%), and rituximab alone (n = 15; 2.7%). The 5-year PFS rates were 91.1% after RT, 90.5% after CMT, 77.8% after CT, 73.5% after observation, 80.8% after rituximab and RT, and 38.5% after rituximab alone. In the RT cohort, but not the CMT cohort, variant immunoarchitectural pattern and number of sites >2 were associated with worse PFS (P < .05). Overall, 21 patients (3.8%) developed large-cell transformation, with a significantly higher transformation rate in those with variant immunoarchitectural pattern (P = .049) and number of involved sites >2 (P = .0006). OS for patients with stage I-II NLPHL was excellent after all treatments.

e20077 Background: Small cell lung cancer (SCLC) accounts for about 10% to 15% of lung cancers among women and men. Though heavily associated with smoking, its incidence in women is rapidly increasing despite a decline in cigarette exposure. Given the changing demographics of SCLC and hormonal factors associated with other forms of lung cancer, we studied differences between sexes in SCLC. Methods: Utilizing the National Cancer Database, we identified all incident SCLC cases from 2004 to 2014. Patients were classified as limited stage (LS) or extensive stage (ES). Women were stratified by menopausal status (≥55 years = postmenopausal). Kaplan-Meier method and Cox regression were used for overall survival (OS) and multivariable analysis. Results: 161,978 patients were identified. No significant sociodemographic differences were observed between sexes. The majority of patients were non-Hispanic whites (89.1%), followed by non-Hispanic blacks (7.5%). Men were more likely to be diagnosed with ES disease than women (63% vs. 56%). Both sexes initiated treatment within a similar time frame from diagnosis (chemotherapy, median: 18 days, IQR 8-32). Women had better median OS compared to men in both LS (15.2 vs. 12.7 months, HR: 0.85, 95% CI 0.83-0.86, p < 0.0001) and ES (6.4 vs. 5.7 months, HR: 0.88, 95% CI 0.87-0.90, p < 0.0001). No racial or ethnic disparities in OS were observed, overall and when examined within sex and disease stage groups. Differences between sexes in OS were also observed when comparing patients within the same racial/ethnic group (women having better OS). When divided by menopausal status, postmenopausal women with LS and ES had worse OS than premenopausal women (14.7 vs. 22 months, HR: 1.50, 95% CI 1.44-1.56; 6.1 vs. 9.8 months, HR: 1.41, 95% CI: 1.37-1.46, respectively). We also observed worse OS in older men when divided by age ( < 55 years and ≥55 years). In multivariable analysis, older age, postmenopausal status, and Medicaid as primary insurance were associated with worse OS for both LS and ES. Conclusions: In this large cohort, women with SCLC had better OS compared to men. Post-menopausal women had worse OS compared to pre-menopausal women. Since older men had a similar trend of worse survival compared to younger men, age might exert a more significant influence on survival than hormonal status in SCLC. Further studies with data on sexual hormone levels are necessary to better understand their role in women with SCLC.

e19503 Background: The risk of venous thromboembolic events (VTE) despite mandatory thromboprophylaxis (TPx) in patients with multiple myeloma (MM) receiving contemporary lenalidomide (Len)-based regimens is not well-defined. Methods: Medline, Embase, and CENTRAL databases were queried to identify phase 1-3 clinical trials of Len-based regimens with mandatory TPx published until April 2018. Random effects meta-analysis was performed using CMAv3 software to obtain crude, and per 100 patient-cycle incidence rate (IR). Prespecified subgroup analyses were performed to obtain IR for VTE by (1) line of treatment (newly diagnosed [ND], relapsed/refractory [RR] and maintenance [Mx] phase) and (2) different Len-based regimens. Results: We screened 1069 citations and analyzed data from 43 trials with 8696 patients, including 17 in ND, 23 in RR and 3 in Mx phase. 12 out of 43 were Phase 3 randomized controlled trials. The overall incidence of VTE in 8696 patients was 4.6% (95% CI, 3.7-5.8%), with 1.0 event (95% CI, 0.7-1.4%) per 100 patient cycles. In patients with NDMM (n = 3295), 193 (5.9%) experienced VTE with a pooled IR of 0.9 (95% CI, 0.3-2.3) per 100 patient-cycle. Among RRMM patients (n = 3981), 251 (6.3%) experienced VTE with a pooled IR of 1.0 (95% CI, 0.4-2.3) per 100 patient-cycle. The incidence of VTE was highest with the following triplet regimens: Rd + Proteasome inhibitor (PIs) and Rd + Anthracycline (Ac) [+/- Vincristine], with the latter having a high risk of VTE regardless of the treatment phase (table). With Len Mx (n = 1420), 38 (2.7%) patients had VTE, with a pooled IR of 0.2 (95% CI, 0-2.1) per 100 patient-cycle. Conclusions: Patients with MM undergoing treatment with Len-based regimens remain at risk of VTE despite current TPx strategies. The estimates of VTE IR provided by this analysis can guide clinicians in assessing treatment-related risk of VTE in this setting. [Table: see text]

TPS7574 Background: Pts with LBCL who have persistent disease assessed by dynamic PET after rituximab-based induction therapy have an increased risk of death (Casasnovas, et al. Blood. 2017). Axi-cel is an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy approved for the treatment of pts with relapsed/refractory LBCL with ≥ 2 prior systemic therapies. In ZUMA-1, the registrational study of axi-cel in pts with refractory LBCL, the objective response rate (ORR) was 91% (70% complete response [CR] rate) in pts with double-expressor or high-grade LBCL with ongoing responses in 48% after a median follow-up of 27.1 mos (Locke FL, et al. Lancet Oncol 2019). Furthermore, pts with fewer prior lines of therapy and lower tumor burden had higher rates of ongoing responses and manageable safety (Locke et al. ASCO 2018. 3039). ZUMA-12 will investigate the efficacy and safety of axi-cel as a first-line therapy in newly diagnosed pts with high-risk LBCL who have PET-positive disease after 2 cycles of induction therapy. Methods: This Phase 2 study has a planned enrollment of ≈40 pts aged ≥ 18 y with high-risk LBCL, defined by the presence of MYC and BCL2 and/or BCL6 translocations by FISH or an IPI score ≥ 3 any time before enrollment, and an ECOG performance status of 0 – 1. Before enrollment, pts must have a Deauville score of 4 – 5 (Barrington SF et al. J Clin Oncol. 2014) after 2 cycles of chemoimmunotherapy that includes an anti-CD20 monoclonal antibody and anthracycline. After leukapheresis, pts with bulky or rapidly progressing disease may receive optional non-chemotherapy bridging therapy. Following conditioning therapy with cyclophosphamide (500 mg/m2) and fludarabine (30 mg/m2) for 3 days, pts will receive a single infusion of axi-cel at a target dose of 2 × 106 CAR T cells/kg. The primary endpoint is investigator-assessed CR rate per the Lugano classification (Cheson et al. J Clin Oncol. 2014). Key secondary endpoints include ORR, duration of response, event-free survival, progression-free survival, overall response, safety, relapse with CNS disease and levels of blood CAR T cells and serum cytokines over time. Accrual is ongoing. Clinical trial information: NCT03761056.

TPS7570 Background: The DIAL study is testing the efficacy of dual immunomodulation in patients with advanced B cell non-Hodgkin lymphoma (B-NHL). Developed by the Cancer Therapy Evaluation Program (CTEP), the trial combines the use of a programmed cell death protein 1 (PD-1) inhibitor (nivolumab) with an agonist of the CD27 receptor (varlilumab) in a randomized phase 2 design. CD27, a co-stimulatory receptor, regulates T cell activation through interaction with CD70. T cell exhaustion plays a major role in immune evasion in B-NHL. Varlilumab is an agonistic IgG1 monoclonal antibody that recognizes CD27 leading to prevention or reversal of exhaustion. Varlilumab also demonstrates direct anti-tumoral activity in xenograft models of human lymphoma cell lines via antibody-dependent cell-mediated cytotoxicity. Phase 1 data supports the safety and tolerability of single-agent varlilumab in advanced hematologic malignancies. We hypothesize that CD27 activation synergizes with PD-1 inhibition resulting in a superior anti-lymphoma effect compared to PD-1 blockade alone. The study will also evaluate the effect of these agents on tumor and immune cells using IHC, mass cytometry (CyTOF), multiplex ELISA, imaging mass cytometry, and whole exome sequencing. Methods: The trial is enrolling patients with advanced aggressive B-NHL. Standard inclusion criteria and prior treatment with at least 2 lines of standard therapy are required. Prior autologous stem cell transplant and/or chimeric antigen receptor (CAR) T cell therapy is allowed. Patients with active CNS disease are excluded. Eligible patients will be randomized to treatment with single-agent nivolumab (group 1) or dual immunotherapy with nivolumab and varlilumab. Group 1 is allowed to cross-over at the time of progression. Nivolumab will be administered intravenously (IV) every 2 weeks (240 mg) for 4 months followed by monthly dosing thereafter (480 mg). Varlilumab will be given IV every 4 weeks (3 mg/kg). Response assessment will be done by PET-CT scan every 12 weeks. Primary outcome is overall response rate (ORR) according to the LYRIC criteria. The trial will enroll 48 patients per arm, allowing 80% power to detect at least 20% increase in ORR in the experimental arm (group 2) assuming a 25% ORR in the control arm (group 1). The trial is registered and open to participation to members of ETCTN and EDDOP. Clinical trial information: NCT03038672.