Randomized, phase III study of early intervention with venetoclax and obinutuzumab versus delayed therapy with venetoclax and obinutuzumab in newly diagnosed asymptomatic high-risk patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL): EVOLVE CLL/SLL study (SWOG S1925, NCT#04269902)

TPS7567

Background: Currently, asymptomatic patients with CLL/SLL are observed without treatment until development of symptoms or cytopenias. Historically, early intervention studies with chemoimmunotherapy have not resulted in an overall survival (OS) benefit and have resulted in toxicity. The introduction of targeted therapies, such as venetoclax and obinutuzumab (VO), have provided tolerable/efficacious options for CLL patients. In the CLL14 study, symptomatic CLL patients receiving frontline therapy with VO had longer progression-free survival (PFS) and deeper remissions [more minimal residual disease-undetectable (MRDu)] compared with those receiving chlorambucil and obinutuzumab (Fischer 2019). The CLL-International Prognostic Index (CLL-IPI; Table) is a validated prognostic model to predict which patients are highest risk for a shorter time to first therapy and shorter OS. We aim to use VO as early intervention in asymptomatic, high-risk patients with CLL to potentially lengthen OS and thus alter the natural history of the disease. Methods: On 12/14/20, we activated the S1925 study for adult patients with CLL or SLL, who were diagnosed within 12 months of enrollment. Eligible patients have a CLL-IPI score ≥ 4 (Table) or complex cytogenetics (≥3 cytogenetic abnormalities) and do not meet any criteria for initiation of treatment by the International Working Group for CLL (IWCLL; Hallek 2018) guidelines. Enrolled patients are randomized in a 2:1 manner to early versus delayed (at the time IWCLL indication for treatment is met) therapy with VO. VO is administered for a fixed duration of 12 months as previously described (Fischer 2019). The primary endpoint is OS. We hypothesize that early intervention with VO will improve the rate of 6-year OS from 60% to 80%. This design requires 222 eligible patients for 88% power (2-sided α=0.05) for the primary comparison. To allow for 10% ineligibility, we will enroll 247 patients. Estimated accrual time is 4 years. Secondary endpoints include: rates of response, PFS, and relapse-free survival; safety; time to 2nd CLL-directed therapy; and quality of life (FACT-Leukemia total score). The primary translational objective is to evaluate the prognostic association between OS and peripheral blood MRD status at 15 months after treatment initiation by flow cytometry. Additional exploratory objectives include the association of other clinical outcomes, baseline prognostic factors, and IWCLL-defined response with MRD status at multiple timepoints. Currently, enrollment is open. Clinical trial information: NCT04269902. [Table: see text]

Safety of acalabrutinib (Acala) monotherapy in hematologic malignancies: Pooled analysis from clinical trials

8064

Background: Acala is a next-generation, highly selective, covalent Bruton tyrosine kinase inhibitor approved in the US for patients (pts) with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) and previously treated mantle cell lymphoma (MCL). We evaluated the safety profile of acala monotherapy (monotx) in multiple B cell malignancies. Methods: Data from pts with activated B-cell diffuse large B-cell lymphoma, CLL, follicular lymphoma, MCL, multiple myeloma, prolymphocytic leukemia, Richter syndrome, SLL, or Waldenström macroglobulinemia treated with ≥1 dose of acala monotx in 9 studies were pooled. Acala was administered at 100 mg BID in most pts (100–400 mg total dose daily). Adverse events (AE) were assessed. Results: A total of 1040 pts were included (median age: 67 y [range: 32–90]; ECOG status ≤1: 93%; median exposure duration: 24.6 mo [range: 0–58.5]). A total of 360 (34%) pts discontinued acala, most commonly due to progressive disease (PD; 17%). AEs led to acala discontinuation in 97 (9%) pts; those in > 2 pts were pneumonia (n = 5) and thrombocytopenia (n = 4). Incidence of AEs, including the most common (any grade and grade ≥3), are shown in the Table. Events of clinical interest (ECIs) included atrial fibrillation (afib) of any grade in 46 (4%) pts and grade ≥3 in 13 (1%) pts; major hemorrhage (any grade) in 37 (4%) pts; grade ≥3 infection in 183 (18%) pts; hypertension (any grade) in 79 (8%) pts and grade ≥3 in 36 (4%) pts; and second primary malignancies (SPM) excluding non-melanoma skin cancer (NMSC; any grade) in 68 (7%) pts. Median (range) time to first onset in days for each ECI (any grade) was: afib, 522 (8–1280); major hemorrhage, 293 (4–1327); infections, 92 (1–1317); hypertension, 157 (2–1345); SPM excluding NMSC, 339 (7–1499). Death was reported in 139 (13%) pts, most commonly due to PD (6%) and AEs (5%). Conclusions: Acala monotx has a favorable tolerability profile with increased exposure across multiple mature B cell malignancies. Additional analyses will further explore the longitudinal characteristics of AEs. [Table: see text]

Acalabrutinib in treatment-naïve chronic lymphocytic leukemia: Mature results from phase II study demonstrating durable remissions and long-term tolerability

8024

Background: The next-generation Bruton tyrosine kinase inhibitor acalabrutinib was approved in patients (pts) with treatment-naïve (TN) and relapsed/refractory chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) based on two complementary phase 3 studies, ELEVATE-TN and ASCEND. This report of ACE-CL-001 (NCT02029443), the first phase 2 study of acalabrutinib, provides the longest safety and efficacy follow-up to date in symptomatic TN CLL pts. Methods: Adults with TN CLL/SLL were eligible if they met iwCLL 2008 criteria for treatment, were inappropriate for/declined standard chemotherapy and had ECOG performance status 0–2. Pts received acalabrutinib 100 mg BID or 200 mg QD, later switching to 100 mg BID, until progressive disease (PD) or unacceptable toxicity. Primary endpoint was safety. Events of clinical interest (ECI) were based on combined AE terms for infections, bleeding events, hypertension, and second primary malignancies (SPM) excluding non-melanoma skin, and on a single AE term for atrial fibrillation. Additional endpoints included investigator-assessed overall response rate (ORR), duration of response (DOR), time to response (TTR), and event-free survival (EFS). Results: Ninety-nine pts (n = 62 100 mg BID; n = 37 200 mg QD), were treated [median age: 64 years, 47% Rai stage 3–4 disease, 10% del(17p), 62% unmutated IGHV]. At median follow-up of 53 months (range, 1–59), 85 (86%) pts remain on treatment; most discontinuations were due to AEs (n = 6) or PD (n = 3 [n = 1 Richter transformation]). Most common AEs (any grade) were diarrhea (52%), headache (45%), upper respiratory tract infection (44%), arthralgia (42%), and contusion (42%). All-grade and grade ≥3 ECIs included infection (84%, 15%), bleeding events (66%, 3%), and hypertension (22%, 11%). Atrial fibrillation (all grades) occurred in 5% of pts (incidence: 1% in years 1, 2, 4; 3% in year 3). SPMs excluding non-melanoma skin (all grades) occurred in 11%. Serious AEs were reported in 38% of pts; those in > 2 pts were pneumonia (n = 4) and sepsis (n = 3). ORR was 97% (7% complete response; 90% partial response). Median TTR was 3.7 months (range, 2–22). Response rates were similar across high-risk groups. Median DOR and median EFS were not reached; 48-month DOR rate was 97% (95% CI, 90%–99%), and 48-month EFS rate was 90% (95% CI, 82%–94%). Conclusions: Long-term data from ACE-CL-001 further support the favorable results with acalabrutinib in phase 3 studies and demonstrate durable responses with no new long-term safety issues. Clinical trial information: NCT02029443 .

Inotuzumab ozogamicin (InO) treatment in patients with relapsed/refractory acute lymphoblastic leukemia (R/R ALL): Outcomes of patients treated in salvage one with a long duration of first remission

7029

Background: In R/R ALL, data are limited supporting targeted therapies like InO as first salvage in patients (pts) who had a long first complete remission (CR1). InO, a calicheamicin-conjugated antibody, targets CD22 on ALL blasts. Here we report outcomes in pts with ALL in first salvage (S1) who had a long CR1 before receiving InO vs standard of care chemotherapy (SC). Methods: Adults with CD22+ R/R ALL, stratified by salvage and length of remission (CR1 ≥ or < 12 mos), were randomized to receive InO (n = 164) or SC (n = 162). Methods were previously described (Kantarjian et al, NEJM 2016), with data shown up to the last patient last visit (January 4, 2017). Outcomes including complete remission (CR)/CR with incomplete hematologic recovery (CRi) and overall survival (OS) were determined for S1 pts who achieved CR1 ≥ 12 mos and CR1 ≥ 18 mos. Results: For S1 pts with CR1 ≥ 12 mos or CR1 ≥ 18 mos, InO and SC arms had generally comparable baseline characteristics. For S1 pts with CR1 ≥ 12 mos and CR1 ≥ 18 mos, fewer pts had received a prior stem cell transplant in the InO vs SC arm (10.4% vs 25.0% and 9.7% vs 21.4%). For S1 pts with CR1 ≥ 12 mos and CR1 ≥ 18 mos respectively, InO vs SC treatment led to a higher CR/CRi rate (85.4% vs 27.5% [ P< 0.0001] and 83.9% vs 32.1% [ P< 0.0001]) and improved OS (HR = 0.547 [ P= 0.0086] and 0.504 [ P= 0.0163]), with veno-occlusive liver disease reported in 12.5% and 12.9% of InO pts Clinical trial information: NCT01564784. Conclusions: Improved outcomes were seen with InO vs SC among S1 pts who had a long first complete remission (CR1 ≥ 12 mos or CR1 ≥ 18 mos), supporting the benefit of InO vs SC in this population.[Table: see text]

Final analysis from RESONATE: Six-year follow-up in patients (pts) with previously treated chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) on ibrutinib

7510

Background: Ibrutinib (ibr), a first-in-class, once-daily Bruton’s tyrosine kinase inhibitor, has redefined treatment paradigms for CLL/SLL. We report final analysis with up to 6 years of follow-up on ibr from the phase 3 RESONATE study of single-agent ibr vs ofatumumab (ofa) in pts with relapsed/refractory (R/R) CLL/SLL. Methods: Pts were randomized to receive oral ibr 420 mg daily until PD or intravenous ofa for up to 24 weeks. Long-term efficacy endpoints were investigator-assessed. Results: Among 391 pts randomized to receive ibr (n=195) or ofa (n=196), 86% and 79%, respectively, were in the genomic high-risk population (del(17p), del(11q), TP53 mutation, and/or unmutated IGHV). At final analysis, median follow-up was 64 mo (range, 0.3-72) on ibr. Of pts randomized to ofa, 68% crossed over to receive ibr. Significant sustained PFS benefit was observed with ibr vs ofa, with median PFS 44.1 vs 8.1 mo (HR 0.15; 95% CI 0.11-0.20; P˂0.0001) and was consistent across baseline subgroups. Median PFS in genomic high-risk population was 44.1 vs 8.0 mo on ibr vs ofa (HR 0.11; 95% CI 0.08-0.15). ORR with ibr was 88% (CR/CRi in 11%). Initial ibr treatment conferred better OS than ofa when censored for crossover (HR 0.64; 95% CI 0.42-0.98). Median duration of ibr was 41 mo (range 0.2-71); 41% of pts received ibr >4 yrs. AE profile with ibr remained consistent with prior reports. Cumulatively during long-term ibr therapy, all-grade (grade ≥3) hypertension and atrial fibrillation occurred in 21% (9%) and 12% (6%) of pts, respectively; major hemorrhage occurred in 10%. Most common reasons for ibr discontinuation (DC) prior to study closure were PD (37%) and AEs (16%); DC due to AEs occurred in 6%, 3%, 4%, 4%, 6% and 4% of pts during yrs 0-1, 1-2, 2-3, 3-4, 4-5 and 5-6, respectively. Conclusions: With up to 6 years of follow-up, extended ibr treatment showed sustained efficacy in pts with R/R CLL, including in pts with high-risk genomic features. Safety remained acceptable with low rates of DC due to AEs, and with no new safety signals over long-term therapy. These results establish long-term benefit and tolerability for continuous ibr treatment in pts with R/R CLL. Clinical trial information: NCT01578707.

ALPINE: Phase III zanubrutinib (BGB-3111) versus ibrutinib in patients with relapsed/refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL)

TPS7572

Background: Inhibition of Bruton tyrosine kinase (BTK) has emerged as a strategy for targeting B-cell malignancies including CLL/SLL. Zanubrutinib, an investigational inhibitor of BTK, was specifically engineered to optimize selectivity, half-life and solubility in an effort to decrease toxicities and better penetrate tumor tissue. Early clinical data suggested that zanubrutinib treatment in patients with treatment-naïve (TN; n = 16) or R/R (n = 50) CLL/SLL induced deep responses: 94% overall response rate (ORR), including 6% and 2% complete response rates in TN and R/R CLL/SLL, respectively (ICML 2017). This study is designed to evaluate whether zanubrutinib monotherapy exhibits non-inferior and potentially superior efficacy based on the ORR vs ibrutinib monotherapy in patients with R/R CLL/SLL. Methods: This ongoing phase 3, randomized, open-label, global study (NCT03734016, BGB-3111-305) is comparing the efficacy and safety of zanubrutinib vs ibrutinib in adult patients with R/R CLL/SLL. Approximately 400 patients will be randomized, 1:1 to each arm and stratified by age (< 65 vs ≥ 65 years), refractory status (yes vs no), geographic region, and del(17p)/ TP53 mutation status (present vs absent). Key inclusion criteria include R/R CLL/SLL requiring treatment per iwCLL criteria, ECOG PS 0-2, and adequate hematologic function. The primary endpoint is ORR as determined by an independent review committee according to iwCLL guidelines, with modification for treatment-related lymphocytosis for patients with CLL and per 2014 Lugano Classification for patients with SLL. The study is powered to test the non-inferiority and superiority of the ORR for zanubrutinib vs ibrutinib. Secondary endpoints include progression-free survival, safety, duration of response, and overall survival. Recruitment is ongoing. Clinical trial information: NCT03734016.

Fetal head position and perineal distension associated with the use of the BD Odon Device™ in operative vaginal birth: a simulation study

Objective

To investigate (i) the placement of the BD Odon Device on the model fetal head, and (ii) perineal distention during simulated operative vaginal births conducted with the BD Odon Device

Design

Observational simulation study

Setting

North Bristol NHS Trust, UK

Population or Sample

440 simulated operative vaginal births

Methods

Three bespoke fetal mannequins were developed to represent (i) bi-parietal diameter of the 50^th centile at term (ii) bi-parietal diameter at the 5^th centile at term and (iii) 50^th centile head with 2 cm of caput. Siting of the BD Odon Device on model heads was determined before and after 400 simulated operative vaginal births. Variables were analysed to determine their effect on device siting and movement during birth.

The fetal mannequins were placed inside a maternal mannequin (PROMPT Flex, Limbs & Things, Bristol, UK) and the BD Odon Device was placed around the fetal head as per the instructions for use. The location of the air cuff was determined before and after the head was delivered. Perineal distension was determined by recording maximum perineal distention during a simulated operative vaginal birth using the same procedure, as well as scenarios employing an inappropriately non-deflated air cuff (for the BD Odon Device), the Kiwi ventouse and non-rotational forceps.

Main Outcome Measures

Site and displacement during birth of the BD Odon Device on a model head. Maximal perineal distension during birth.

Results

The BD Odon Device was reliably sited in a standard over the fetal head position (approximately 40mm above the fetal chin) for all stations, head sizes and positions with no significant displacement. In occipito-posterior births, compared to occipito-anterior or transverse, the BD Odon Device routinely sited further down the fetal head (toward the chin).

The BD Odon Device was not associated with more perineal distension than forceps or Kiwi ventouse (21mm vs 26mm vs 21mm at posterior fourchette).

Conclusions

The BD Odon Device reliably sited over a safe area of the fetal head in 400 simulated births representative of clinical practice. The BD Odon Device generates similar levels of perineal distension compared to Kiwi ventouse when used correctly.

Pressure and traction on a model fetal head and neck associated with the use of forceps, Kiwi™ ventouse and the BD Odon Device™ in operative vaginal birth: a simulation study

Objective

To determine the pressure and traction forces exerted on a model fetal head by the BD Odon Device, forceps and Kiwi ventouse during simulated births.

Design

Simulation study.

Setting

Simulated operative vaginal birth.

Population or Sample

84 simulated operative vaginal births.

Methods

A bespoke fetal mannequin with pressure sensors around the head and strain gauge across the neck was used to investigate pressure applied over the head, and traction across the neck during 84 simulated births using the BD Odon Device, non-rotational forceps and Kiwi ventouse.

Main Outcome Measures

Peak pressure on the fetal face and lateral aspects of the head during correct use of the BD Odon Device and forceps. Peak pressure on orbits and neck during misplacement of the BD Odon Device and forceps. Peak traction force generated until instrument failure using the BD Odon Device, forceps and Kiwi ventouse.

Results

When correctly sited and using 80kPa inflation pressure on the cuff, the BD Odon Device generated a lower peak pressure on the fetal head than forceps (83kPa vs 146kPa). When instruments were purposefully misplaced over the orbits the BD Odon Device generated a lower peak pressure on the orbits than forceps (70kPa vs 123kPa). When purposefully misplaced over the neck the BD Odon Device, compared to forceps, generated a greater peak pressure on the anterio-lateral aspect of the neck (56kPa vs 17kPa) and a lower peak pressure on the posterior aspect of the neck (76kPa vs 93kPa) than forceps. In cases of true cephalic disproportion the BD Odon Device ‘popped-off’ at a lower traction force than forceps (208N vs 270N).

Conclusions

In simulated assisted vaginal birth with correctly placed instruments the peak pressure exerted on the fetal head by a BD Odon Device is lower than pressure exerted by non-rotational forceps. In cases in which delivery of the fetal head is not possible due to cephalo-pelvic disproportion lower traction forces could be applied using the BD Odon Device than with forceps before the procedure was abandoned due to device failure.

Design and development of the BD Odon DeviceTM : a human factors evaluation process

OBJECTIVE

To (1) determine how intended users interact with and use the BD Odon Device in simulation, (2) use these findings to alter progressively the design of the BD Odon Device and (3) validate that these changes have improved the ability of practitioners to use the BD Odon Device.

DESIGN

Human factors evaluation study.

SETTING

Simulation suite designed to mimic delivery room.

POPULATION OR SAMPLE

Three hundred and ninety simulated operative births, performed by 100 practising clinicians.

METHODS

Simulated operative vaginal births performed using the BD Odon Device and the device Instructions for use were subjected to three formative human factors evaluations and one human factors validation test. Following each evaluation, findings were reviewed and the design of the BD Odon Device and Instructions for use were modified.

MAIN OUTCOME MEASURES

Successful performance of an operative vaginal birth using the BD Odon Device in accordance with provided training and Instructions for use.

RESULTS

Using version two of the BD Odon Device, and following exposure to face-to-face training and written instructions, 25% of accouchers were able successfully to perform a simulated operative vaginal birth. In the final evaluation, following device design and training material alterations, all accouchers were able successfully to perform a simulated operative vaginal birth using version four of the BD Odon Device.

CONCLUSIONS

Human factors evaluations have enabled a multi-professional device and training materials design team to alter the design of the BD Odon Device and the Instructions for use in an evidence-based fashion. This process has resulted in a device which has a predictable and likely safe pattern of use.

TWEETABLE ABSTRACT

Human Factors evaluations help make the BD Odon Device safe and usable for clinical practice.

Inotuzumab ozogamicin for the treatment of patients with acute lymphocytic leukemia

Inotuzumab ozogamicin is an antibody-drug conjugate comprised of a humanized anti-CD22 monoclonal antibody conjugated to calicheamicin, a cytotoxic antibiotic agent. Inotuzumab ozogamicin binds to CD22-expressing tumor cells, resulting in apoptotic cell death. Based on the results of the pivotal, phase III INO-VATE trial in acute lymphoblastic leukemia (ALL), approval of inotuzumab ozogamicin was recently granted for the treatment of patients with relapsed or refractory ALL, a group that otherwise has a poor prognosis with standard chemotherapy. Several ongoing clinical trials are now testing whether outcomes can be further improved by combining inotuzumab ozogamicin with low-dose chemotherapy or by including inotuzumab ozogamicin in the front-line setting. In this article we discuss the preclinical, clinical and safety data of inotuzumab ozogamicin.

Inotuzumab ozogamicin (IO) combined with mini-hyper-CVD as salvage therapy for patients (pts) with R/R acute lymphoblastic leukemia (ALL)

7025

Background: Outcome of pts with R/R ALL is poor. IO, a CD22 monoclonal antibody bound to a toxin, calicheamicin, has single-agent activity in R/R ALL with response rate of 80% and median survival of 7.7 months. Adding IO to low-intensity chemotherapy might further improve clinical outcomes. Methods: Pts ≥18 years with R/R ALL were eligible. Chemotherapy was of lower intensity than standard hyper-CVAD and referred to as mini-hyper-CVD (cyclophosphamide and dexamethasone at 50% dose reduction (DR), no anthracycline, methotrexate at 75% DR, cytarabine at 0.5 g/m2 x 4 doses). Rituximab (if CD20+ blasts) and intrathecal chemotherapy were given for first 4 courses. IO was given on day 3 of each of the first 4 courses at a dose of 1.8 mg/m2 for cycle 1 then 1.3 mg/m2 for subsequent cycles. After the occurrence of veno-occlusive disease (VOD), IO was modified to 1.3 mg/m2 for cycle 1 followed by 1.0 mg/m2 for subsequent cycles. Results: Sixty pts with a median age of 35 years (range 18-87) were treated. Overall, 47 pts (80%) responded, 32 of them (54%) achieving complete response. The overall minimal residual disease negativity rate among responders was 82%. Grade 3-4 toxicities included prolonged thrombocytopenia (79%), infections during induction and consolidations (52%, and 73% respectively), and hyperbilirubinemia (13%). VOD of any grade occurred in 9 patients (15%). At a median follow-up of 19 months, the median relapse-free survival (RFS) and overall survival (OS) were 9 and 11 months, respectively. The 2-year RFS and OS rates were 33% and 38%. The 2-year OS rates for patients treated in salvage (S)1, S2, and S3 and beyond were 53%, 0%, and 34%, respectively (p = 0.005). When compared to IO monotherapy in a similar pts population, a significant improvement in OS was observed (11 and 6 months, respectively; p = 0.003). Conclusions: The combination of IO with low-intensity mini-hyper-CVD chemotherapy is effective in pts with R/R ALL. Results are encouraging and appear superior to those obtained with IO alone, particularly in pts treated in S1. The risk of VOD should be considered carefully for transplant candidates and pts with previous liver damage. Lower dose of weekly schedules of IO are being explored Clinical trial information: NCT01371630.

Ibrutinib, fludarabine, cyclophosphamide, and obinutuzumab (GA101) (iFCG) for previously untreated patients with chronic lymphocytic leukemia (CLL) with mutated IGHV and non-del (17p)

7522

Background: Pts with mutated IGHV ( IGHV-M) have favorable long-term outcomes after FCR. Methods: We designed an investigator-initiated phase II trial with ibrutinib, fludarabine, cyclophosphamide, and obinutuzumab (iFCG) for previously untreated pts with IGHV-M CLL (NCT02629809). The intent was to limit FC to 3 courses, potentially reducing short- and long-term toxicity, while maintaining efficacy through addition of ibrutinib and obinutuzumab. Key eligibility included age ≥18, IGHV-M, no del17p. Pts received 3 courses of iFCG. G-CSF was not mandated. Primary endpoint: CR/CRi with bone marrow (BM) MRD-neg (4-color flow-cytometry) after 3 courses of iFCG. Pts meeting primary endpoint received ibrutinib with obinutuzumab (iG) for C3-6, then ibrutinib C7-12. Pts not achieving primary endpoint received iG (C4-12). All pts who are MRD neg at 1 year will stop all therapy, including ibrutinib. Pts MRD+ at 1 year may continue ibrutinib. Historic C3 BM MRD-neg with FCR in IGHV-M 26% (Strati, Blood 2014). Target BM MRD-neg after iFCG x3 is 45%. Sample size 45. Results: 23 pts started treatment. Median age 59 yrs (25-71). Prognostic markers [del13q (n=17), negative (n=3); trisomy 12 (n=3)]. 18 pts completed 3 courses of iFCG and had initial response assessment (the remaining 5 pts too early). All 18 pts had a response; 14/18 (78%) achieved MRD-neg in BM at 3 month with 7/18 achieving CR/CRi (all MRD neg). No pt has progressed, and all but one continue to receive treatment. Of the 23 pts, 11 pts had G3-4 neutropenia and 5 pts had G3-4 thrombocytopenia. 4 pt had neutropenic fever. 1 pt who achieved MRD-neg CR developed pulmonary MAC infection, and declined further therapy. 1 pt had atrial fibrillation. G3 ALT developed in 3 pts. FC was dose reduced in 10 pts; ibrutinib dose-reduced in 2 pts. Conclusions: iFCG achieves high rate of MRD-neg remission after 3 courses. Pt enrollment continues, and updated results will be presented at the ASCO meeting. Clinical trial information: NCT02629809. [Table: see text]

Idarubicin and cytarabine with clofarabine or fludarabine in adults with newly diagnosed acute myeloid leukemia: Updated results of a randomized phase II study

7037

Background: The purine nucleoside analogues fludarabine and clofarabine are effective agents in the treatment of acute myeloid leukemia (AML). This study evaluated the efficacy and safety of combining idarubicin and cytarabine with either clofarabine (CIA) or fludarabine (FIA) in adults with newly diagnosed AML. Methods: Using a Bayesian adaptive design, patients (pts) deemed suitable for intensive chemotherapy were randomized to receive CIA (n = 106) or FIA (n = 76). All pts received idarubicin 10 mg/m2 IV daily on Days 1-3 and cytarabine 1 g/m2 IV daily on Days 1-5. Clofarabine and fludarabine were given at 15 mg/m2 and 30 mg/m2, respectively, IV daily on Days 1-5. Pts with FLT3 mutations could receive sorafenib. Up to 6 cycles of consolidation were allowed for responding pts. Results: Baseline characteristics were similar comparing CIA to FIA with a median age of 53 years (range, 20-66) vs 49 years (range, 18-66) respectively and ELN risk intermediate-2/adverse of 57% and 58% respectively. With a median follow-up of 27 months (range, 1-58), the CIA and FIA arms had a similar CR/CRp rate (80% and 82%, respectively). MRD negativity rate by multiparameter flow cytometry at the time of CR/CRp was higher comparing CIA to FIA (80% vs. 65%, respectively, P = 0.07). The median EFS were 13 months and 12 months, respectively (P = 0.91), and the median OS were 24 months and not reached, respectively (P = 0.23). There were more adverse events (all grades) associated with CIA, particularly AST/ALT elevation (29% vs 4%), hyperbilirubinemia (26% vs 9%) and rash (31% vs 9%). Early mortality was similar in the 2 arms (60-day mortality: 4% for CIA vs 1% for FIA; P = 0.32). Comparing the 2 arms to a historical cohort of pts treated with IA showed similar response rates, EFS and OS excluding pts with FLT3 mutations from this analysis. However, in pts < 50 years of age, FIA was associated with improved survival compared with IA (2-year EFS rate: 58% vs 30%, P = 0.05; 2-year OS rate: 72% vs 36%; P = 0.009). Conclusions: CIA and FIA have similar efficacy in younger pts with newly diagnosed AML. FIA is associated with a better toxicity profile and may improve survival compared to IA in pts < 50 years of age. Clinical trial information: NCT01289457.

Long-term efficacy and safety with ibrutinib (ibr) in previously treated chronic lymphocytic leukemia (CLL): Up to four years follow-up of the RESONATE study

7510

Background: Ibr, a first-in-class, once-daily inhibitor of Bruton’s tyrosine kinase, is FDA-approved for all pts with CLL/SLL. We report updated safety and efficacy results with up to 4 y follow-up from the ph III RESONATE trial of ibr vs ofatumumab (ofa). Methods: Pts had ≥1 prior therapy. Pts received 420 mg ibr PO until PD or ofa up to 24 wks. At interim analysis (median 9 mo follow-up), the DMC declared superiority of ibr vs ofa for PFS and OS, and ibr access was recommended for all ofa pts. Long-term follow-up efficacy endpoints are per investigator assessment. Ofa pts were censored at crossover for OS. Results: 391 pts were randomized to receive ibr (n = 195) or ofa (n = 196). Median age was 67 y (40% ≥70 y); 57% had Rai stage III/IV. With median follow-up of 44 mo (53 mo max) for ibr arm, PFS was significantly longer for ibr vs ofa (median NR vs 8 mo, [HR 0.133; P< 0.0001]; 3-y PFS 59% vs 3%) with significant benefit across subgroups. PFS with ibr for del11q subgroup trended to have the most favorable outcome; however, PFS was not statistically different for pts with del17p or del11q or without these FISH abnormalities. At analysis, with the majority of pts (68%) randomized to ofa crossing over to ibr, OS was longer for ibr vs ofa (median OS NR for either arm). The OS rate for ibr at 3 y was 74%. ORR for ibr was 91% with CR/CRi rates (now 9%) increasing over time. Baseline cytopenias improved with extended ibr therapy for hemoglobin (85%), platelet (95%), and absolute neutrophil counts (95%). AE profile of ibr was consistent with previous reports. Major hemorrhage, Gr ≥3 atrial fibrillation, and Gr ≥3 hypertension occurred in 6%, 6%, and 8% of pts, respectively, over a follow-up of up to 4 y. Incidence of most Gr ≥3 AEs decreased from y 1 vs y 2-3: neutropenia- 18% vs 8%; pneumonia- 11% vs 4%; atrial fibrillation- 4% vs 2%, respectively. Discontinuations were most frequently PD (27%) and AE (12%). At analysis, 90 ibr pts (46%) continue ibr on study. Conclusions: Long-term treatment with ibr in this international ph III RESONATE study is tolerable and continues to show sustained PFS and OS regardless of high-risk cytogenetics. Ph III results in relapsed del17p and del11q pts compare favorably to prior ph II reports. Clinical trial information: NCT01578707.

Tolerability and activity of chemo-free triplet combination of TGR-1202, ublituximab, and ibrutinib in patients with advanced CLL and NHL

7511

Background: Novel targeted agents are emerging for B-cell malignancies, but few studies have safely combined these agents. Ublituximab (UTX) is a novel glycoengineered mAb targeting a unique epitope on the CD20 antigen. TGR-1202 is a next generation, once daily PI3Kδ inhibitor, demonstrating a favorable safety profile compared to prior inhibitors, including in long-term follow up (Burris, 2016). This Ph 1 trial evaluates the safety/efficacy of the triplet combination of a novel anti-CD20 mAb + PI3Kδ + BTK inhibitor (ibrutinib) in pts with B-cell malignancies. Methods: Eligible pts had CLL or rel/ref NHL w/o limit to prior therapies, including those ref to prior PI3Kδ or BTK inhibitors. UTX dosed on D1, 8, 15 of C1; D1 of C2-6, and C9 & 12. TGR-1202 dose escalated (400/600/800mg QD), ibrutinib dosed at 420mg (CLL) or 560mg (NHL), both on C1D1. Results: 38 pts were enrolled: 20 CLL/SLL and 18 NHL, including 6 follicular (FL), 6 DLBCL, 4 mantle cell (MCL) and 2 marginal zone (MZL). Med age 65 yrs (range 32-85); 29 M/9 F; med prior tx = 3 (range 0-6). 2 pts were ref to prior PI3Kδ and 2 were prev treated with ibrutinib (1 ref/1 rel). MTD was not reached. Most common ( > 20%) all causality AE’s were fatigue (42%), diarrhea (39%), dizziness (34%), nausea (32%), neutropenia, pyrexia, rash, infusion reaction, insomnia (each at 29%), thrombocytopenia, cough (each at 26%), anemia (24%) and sinusitis (21%). GR 3/4 AE’s were minimal, the only event > 10% was neutropenia (16%). ORR amongst 36 evaluable pts is shown in the table below. 53% of evaluable CLL pts had high-risk cytogenetics and 4/6 DLBCL pts were non-GCB. One CLL pt (17p/11q del) ref to both PI3Kδ and ibrutinib achieved a CR. Med time on study is 10 mos (range 1 – 27+ mos). Med DOR not reached (range 3 – 24+ mos). Conclusions: This is the first known triple combination of an anti-CD20 mAb + PI3Kδ + BTK inhibitor. The combination of UTX, TGR-1202, and ibrutinib has been well tolerated with activity observed across heavily pre-treated and high-risk B-cell malignancies. Expansion cohorts at the highest dose (800mg TGR-1202 + full dose ibrutinib) are underway. Future trials for the triplet are warranted. Clinical trial information: NCT02006485. [Table: see text]

Frontline hyper-CVAD plus ponatinib for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia: Updated results of a phase II study

7013

Background: The combination of chemotherapy plus a TKI is highly effective in Ph+ ALL. In this phase II study, we evaluated the safety and efficacy of HCVAD in combination with the third-generation pan- BCR-ABL inhibitor, ponatinib. Methods: Patients (pts) with newly diagnosed Ph+ ALL received 8 cycles of HCVAD alternating with high dose MTX/Ara-C every 21 days. Ponatinib was given at 45 mg daily for the first 14 days of cycle 1. Initially ponatinib 45 mg daily was given indefinitely beginning at cycle 2. Due to concern for vascular events, a protocol amendment was made in which, beginning in cycle 2, pts in CR received 30mg daily and pts in CMR received 15mg daily. Rituximab and IT chemotherapy were given with the first 4 courses. After 8 cycles of HCVAD, pts in CR received maintenance with ponatinib, vincristine and prednisone for 2 years followed by indefinite ponatinib. Results: 64 pts have been treated, 10 of whom had received prior treatment with another regimen (8 in CR, 2 not in CR). Median age was 48 years (range, 21-80) and median follow-up was 33 months (range, 2-62). Median cycles received was 6 (range, 2-8). 63 pts (98%) achieved CR after 1 cycle; 1 pt achieved CRp. CCyR was achieved in 98%, MMR in 97% and CMR in 77%. Median time to CMR was 10 weeks (range, 2-96). Median times to platelet and ANC recovery in cycle 1 were 22 and 18 days, respectively, and for subsequent cycles were 22 and 16 days, respectively. Grade ≥3 pancreatitis was observed in 12 pts (19%), thrombotic events in 4 (6%) and MI in 3 (5%). 8 pts have died, with 2 deaths attributed to ponatinib (both from MI). No grade ≥3 vascular events occurred after the protocol amendment. 38 pts continue to receive treatment (7 in consolidation, 14 in maintenance and 17 post-maintenance). 10 pts (16%) underwent allogeneic SCT in CR1. 7 pts have relapsed, 3 of whom were still receiving ponatinib. The 3-year continued remission and OS rates were 79% and 76%, respectively. In a landmark analysis at 4 months, CR duration and OS did not differ significantly in pts with or without allogeneic SCT. Conclusions: HCVAD plus ponatinib is highly effective in pts with newly diagnosed Ph+ ALL, resulting in high rates of CMR and promising long-term survival. Clinical trial information: NCT01424982.

Updated results of a phase I/II study of inotuzumab ozogamicin in combination with low-intensity chemotherapy (mini-hyper-CVD) as frontline therapy for older patients with acute lymphoblastic leukemia

7014

Background: Inotuzumab ozogamicin (InO) is an anti-CD22 antibody-toxin conjugate that is effective in patients (pts) with relapsed/refractory ALL. Given the poor tolerance of elderly pts to intensive chemotherapy, we evaluated the safety and efficacy of low-intensity chemotherapy (mini-hyper-CVD) plus InO as frontline treatment for older pts with newly diagnosed ALL. Methods: Pts ≥60 years of age with newly diagnosed Ph-negative pre-B ALL received mini-hyper-CVD (no anthracycline, dose reductions of cyclophosphamide, dexamethasone, MTX and Ara-C). Pts received InO 1.3-1.8 mg/m2 on day 3 of cycle 1 and 0.8-1.3 mg/m2 on day 3 of cycles 2-4. Rituximab (if CD20+) and prophylactic IT chemotherapy were given for the first 4 cycles. Responding pts received POMP maintenance for up to 3 years. Results: 47 pts have been treated, 4 of whom were in CR at enrollment. Median age was 68 years (range, 60-81) and median CD22 expression was 97% (range, 72-100%). Among 43 pts evaluable for response, 41 (95%) achieved CR or CRp (CR, n = 36, CRp, n = 5). 1 pt achieved CRi and 1 did not respond. MRD negativity by 6-color flow cytometry was achieved in 31/41 pts (76%) after 1 cycle and in 44/46 pts (96%) overall. Median times to platelet and ANC recovery in cycle 1 were 23 and 16 days, respectively, and for subsequent cycles were 22 and 17 days, respectively. Prolonged thrombocytopenia ( > 6 weeks) occurred in 37 pts (79%). 4 pts (9%) developed VOD, 1 after allogeneic stem cell transplant (ASCT) and 3 unrelated to ASCT. Only 1 pt developed severe VOD. Among 46 responders, 6 (13%) relapsed, 3 (7%) underwent ASCT in CR1, 27 (59%) remain on treatment or have completed maintenance, and 10 (22%) died in CR/CRp. With a median follow-up of 24 months, the 3-year continued remission and OS rates were 72% and 54%, respectively. Compared to a historical cohort of older pts treated with hyper-CVAD ± rituximab (n = 79), mini-hyper-CVD + InO resulted in significantly higher 3-year OS (54% vs 31%; P = 0.007). Conclusions: Mini-hyper-CVD plus InO is safe and effective in elderly pts with newly diagnosed ALL and appears to improve outcomes compared to hyper-CVAD in this population. Clinical trial information: NCT01371630.

Updated results of frontline ofatumumab-hyper-CVAD in adults with CD20+ acute lymphoblastic leukemia

7033

Background: Chemoimmunotherapy is an effective frontline therapy for acute lymphoblastic leukemia (ALL). Ofatumumab (O) binds to a proximal small-loop epitope on CD20 and is more potent in vitro than rituximab. Here we report interim results of its combination with hyper-CVAD (HCVAD) in adult patients (pts) with CD20+ ALL. Methods: Since 7/2011, we have enrolled 63 pts with Ph-negative CD20+ ALL (59 newly diagnosed, 4 previously treated). For the intensive phase, pts received 4 cycles (cy) of HCVAD (odd cy 1, 3, 5, 7) alternating with 4 cy of methotrexate-cytarabine (MTX-Ara-C, even cy 2, 4, 6, 8), and ofatumumab during cy 1-4. For maintenance, pts received POMP for ~30 months (mos), and intensification with MTX/PEGylated asparaginase on mos 6 and 18, and O-HCVAD on mos 7 and 19. Intrathecal MTX-Ara-C was used for CNS prophylaxis. Bulky mediastinal disease was irradiated when indicated. Results: Median age was 41 years (range: 18-71) and median WBC count was 4.6 x109/L (range: 0.6-201 x109/L). 22 pts (35%) had diploid cytogenetics and 8/35 pts (23%) had TP53 mutation. CD20 expression was > 20% in 38 pts (60%), 10-20% in 6 pts (10%) and 1-10% in 16 pts (25%). Median follow-up was 20 mos (range: 1-58) and median number of cy was 8 (range: 1-8). 3 pts (5%) were in CR at the time of enrollment. Of 60 pts evaluable for response, 58 pts (97%) achieved CR; 1 pt achieved CRp and 1 pt died during cy 1 from sepsis. Flow cytometric minimal residual disease (MRD) was negative in 57/62 pts (92%) overall, and in 36/57 pts (57%) at CR. Median time to negative MRD was 0.7 mos. Median time to platelet and neutrophil recovery in cy 1 was 21 and 18 days, respectively. The most common grade 3/4 non-hematological toxicities were infections during induction (49%) and consolidation (72%), elevated transaminases (35%), and hyperbilirubinemia (21%). 5 pts (7%) experienced a grade 3/4 transfusion reaction. 8 pts (13%) received stem cell transplantation in CR1. 10 pts (16%) have relapsed (8 morphological, 2 MRD only). Overall survival and 2-year CR duration rates were 80% and 81%, respectively. Survival outcomes were independent of percentage of CD20 expression. Conclusions: O-HCVAD is safe, effective and results in durable responses in pts with CD20+ ALL. Clinical trial information: NCT01363128.

Abstract B19: Population pharmacokinetic-pharmacodynamic (PKPD) modeling of ibrutinib in patients with B-cell malignancies

Ibrutinib (IBRU) is an oral Bruton's tyrosine kinase (BTK) inhibitor, approved by US FDA for the treatment of chronic lymphocytic leukemia (CLL/SLL) and mantle cell lymphoma (MCL) patients having received at least one prior therapy. A nonlinear mixed-effects population model was developed to describe the PK of IBRU in patients with B-Cell malignancies and to establish the effect of pathophysiological covariates on its PK behavior. The relationship between PK and BTK engagement in peripheral blood mononuclear cells (PBMC) was also explored. IBRU PK data (3477 observations in 245 patients) were available in patients with MCL, CLL/SLL and recurrent B-cell malignancies at dose levels from 1.25 to 12.5 mg/kg and at fixed doses from 420 to 840 mg once daily. An additional phase 2 study in 119 patients with MCL (772 observations) treated at 560 mg once daily was used to validate the PK model. BTK occupancy was assessed (694 observations in 127 patients) in PBMCs using a fluorescent affinity probe. Various models were tested on the data using the first-order conditional estimation method as implemented in NONMEM version 7.1.

A 2-compartment linear model with sequential zero-first order absorption and first order elimination was able to accommodate available PK data, including those of the validation dataset (prediction errors &lt;15%). PK was dose- and time- independent. IBRU was rapidly absorbed, extensively distributed (volume of distribution at steady-state ~ 10,000 L) and cleared (apparent oral clearance ~1000 L/h). Relative bioavailability in the fasting state was about one third lower compared to the fed condition used in the clinical trials. No significant effect of other pathophysiological covariates on the PK was found (including sex, age or indication) except for body weight and coadministration of antacids, which had a marginal effect on the volume of distribution and duration of absorption, respectively. Analysis of PK-BTK engagement suggested that IBRU is a potent inhibitor of the BTK activity and that its interaction with BTK is rapid and durable.

Citation Format: Italo Poggesi, Maria Luisa Sardu, Eleonora Marostica, Juthamas Sukbuntherng, Betty Y. Chang, Jan de Jong, Xavier Woot de Trixhe, An Vermeulen, Giuseppe De Nicolao, Susan Mary O'Brien, John C Byrd, Ranjana H Advani, Danelle Frances James, William Deraedt, Darrin Beaupre, Michael Wang. Population pharmacokinetic-pharmacodynamic (PKPD) modeling of ibrutinib in patients with B-cell malignancies. [abstract]. In: Proceedings of the AACR Special Conference on Hematologic Malignancies: Translating Discoveries to Novel Therapies; Sep 20-23, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(17 Suppl):Abstract nr B19.

Randomized comparison of ibrutinib versus ofatumumab in relapsed or refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma: Results from the phase III RESONATE trial

LBA7008

Background: Treatment options for CLL/ SLL patients (pts) who fail chemoimmunotherapy are limited. We report interim results from a phase III randomized study of ibrutinib (ibr), a first in class covalent BTK inhibitor, vs ofatumumab (ofa) in R/R CLL/SLL. The Data Monitoring Committee recommended this analysis be considered final, based on meeting the primary and a key secondary endpoint. Methods: R/R CLL/SLL pts who failed ≥1 therapy received 420 mg oral ibr daily until progression or IV ofa 300/2000mg for 12 doses. Primary endpoint was progression-free survival (PFS) assessed by an independent review committee (IRC). Secondary endpoints included overall survival (OS), IRC assessed overall response rate (ORR) and safety. Results: Of 391 pts enrolled (median age 67 years; 40% ≥70 years; 57% Rai stage III/IV disease; 30% del 17p), 195 were randomized to ibr and 196 to ofa. Ibr pts had median 3 prior therapies vs 2 for ofa. Median follow-up was 9.4 months (m). Ibr significantly lengthened PFS (median not reached vs 8.1 m; HR 0.215, CI 0.146–0.317, p<0.0001; 78.5% risk reduction), and significantly improved OS (median not reached; HR 0.434, CI 0.238–0.789, p=0.0049) compared with ofa. ORR was 42.6 vs 4.1% (p<0.0001) and ORR+PR with lymphocytosis was 62.6 vs 4.1% for ibr vs ofa. Similar effects were seen in del17p and purine analog refractory subsets. In each arm 2 pts had confirmed Richter’s transformation. Most frequent adverse events (AE) for ibr vs ofa were diarrhea (47.7 vs 17.8%) fatigue (27.7 vs 29.8%), and nausea (26.2 vs 18.3%). Atrial fibrillation was more frequent with ibr (5.1 vs 0.5%). Major hemorrhages were reported in 1.0 vs 1.6% for ibr vs ofa. Drug discontinuation due to AE was 4.1 vs 3.6% for ibr vs ofa. 86% of ibr pts were continuing treatment. 57 pts randomized to ofa with confirmed PD had initiated ibr at cross-over. Conclusions: Compared with ofa, ibr significantly improved PFS, OS and ORR in pts with R/R CLL/SLL. The safety profile was comparable with that previously reported (Byrd NEJM 2013). These results support ibr as a beneficial therapy for R/R CLL patients irrespective of del 17p or purine analog refractory disease. Clinical trial information: NCT01578707.