Safety and efficacy of belantamab mafodotin with pembrolizumab in patients with relapsed or refractory multiple myeloma

BACKGROUND

Belantamab mafodotin (belamaf) has shown promising antimyeloma activity in relapsed or refractory multiple myeloma (RRMM) as a single agent. It was hypothesized that its multimodal activity may be enhanced by programmed cell death protein 1 pathway inhibition and activation of T cell-mediated antitumor responses. This study investigated the efficacy and safety of belamaf with pembrolizumab in patients with RRMM.

METHODS

DREAMM-4 (NCT03848845) was an open-label, single-arm, phase 1/2 study divided into dose-escalation (part 1) and dose-expansion (part 2) phases. Patients were ≥18 years old with ≥3 prior lines of therapy including a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 agent. Patients received belamaf (2.5 or 3.4 mg/kg, part 1; 2.5 mg/kg, part 2) and 200 mg pembrolizumab for ≤35 cycles.

RESULTS

Of 41 enrolled patients, 34 (n = 6 part 1, n = 28 part 2) who received 2.5 mg/kg belamaf plus pembrolizumab were included in this final analysis. Sixteen patients (47%) achieved an overall response. Minimal residual disease negativity was achieved in three of 10 patients who had very good partial response or better. Five of eight patients who had prior anti-B-cell maturation antigen therapy achieved partial response or better, including two who had B-cell maturation antigen-refractory disease. Common grade ≥3 adverse events were keratopathy (38%) and thrombocytopenia (29%). Despite belamaf-related ocular events, quality-of-life measures remained stable over time. No new safety signals were observed.

CONCLUSIONS

The results of DREAMM-4 demonstrated clinical activity and a favorable safety profile of belamaf plus pembrolizumab in patients with RRMM. This trial is registered at www.

CLINICALTRIALS

gov as NCT03848845.

Single-agent belantamab mafodotin in patients with relapsed/refractory multiple myeloma: Final analysis of the DREAMM-2 trial

BACKGROUND

Patients with relapsed/refractory multiple myeloma (RRMM) have a high unmet treatment need. Belantamab mafodotin (belamaf), a first-in-class, B-cell maturation antigen-binding antibody-drug conjugate, eliminates myeloma cells through direct cell killing and an anti-myeloma immune response.

METHODS

DREAMM-2 (NCT03525678) was a phase 2, two-arm, open-label trial in patients with heavily pretreated RRMM who had three or more prior therapies, were refractory to an immunomodulatory agent and a proteasome inhibitor, and refractory or intolerant to an anti-CD38 monoclonal antibody. Belamaf was given at 2.5 or 3.4 mg/kg every 3 weeks. The primary end point was overall response rate (ORR); secondary end points included progression-free survival (PFS), overall survival (OS), safety, ocular symptoms, and health-related quality of life (HRQOL).

RESULTS

This final analysis (cutoff date, March 31, 2022), N = 223, with median follow-up of 12.5 and 13.8 months, demonstrated an ORR of 32% and 35%, median PFS of 2.8 and 3.9 months, and median OS of 15.3 and 14.0 months in the 2.5 mg/kg and 3.4 mg/kg cohorts, respectively. Median duration of response was 12.5 and 6.2 months. No new safety signals were observed; the most common Grade 3 and 4 adverse events were keratopathy (29% vs. 25%), thrombocytopenia (22% vs. 29%), and anemia (21% vs. 28%). HRQOL outcomes suggest that overall global health status/quality of life, physical and role functioning, and overall disease symptoms were maintained or improved during treatment.

CONCLUSIONS

This final analysis of DREAMM-2 confirms that in patients with triple-class refractory RRMM, single-agent belamaf results in durable and clinically meaningful responses with a manageable safety profile.

Efficacy and safety of single-agent belantamab mafodotin versus pomalidomide plus low-dose dexamethasone in patients with relapsed or refractory multiple myeloma (DREAMM-3): a phase 3, open-label, randomised study

BACKGROUND

Multiple myeloma remains incurable, and heavily pretreated patients with relapsed or refractory disease have few good treatment options. Belantamab mafodotin showed promising results in a phase 2 study of patients with relapsed or refractory multiple myeloma at second or later relapse and a manageable adverse event profile. We aimed to assess the safety and efficacy of belantamab mafodotin in a phase 3 setting.

METHODS

In the DREAMM-3 open-label phase 3 study, conducted at 108 sites across 18 countries, adult patients were enrolled who had confirmed multiple myeloma (International Myeloma Working Group criteria), ECOG performance status of 0-2, had received two or more previous lines of therapy, including two or more consecutive cycles of both lenalidomide and a proteasome inhibitor, and progressed on, or within, 60 days of completion of the previous treatment. Participants were randomly allocated using a central interactive response technology system (2:1) to receive belantamab mafodotin 2·5 mg/kg intravenously every 21 days, or oral pomalidomide 4·0 mg daily (days 1-21) and dexamethasone 40·0 mg (20·0 mg if >75 years) weekly in a 28-day cycle. Randomisation was stratified by previous anti-CD38 therapy, International Staging System stage, and number of previous therapies. The primary endpoint was progression-free survival in all patients who were randomly allocated. The safety population included all randomly allocated patients who received one or more doses of study treatment. This trial is registered with ClinicalTrials.gov, NCT04162210, and is ongoing. Data cutoff for this analysis was Sept 12, 2022.

FINDINGS

Patients were recruited between April 2, 2020, and April 18, 2022. As of September, 2022, 325 patients were randomly allocated (218 to the belantamab mafodotin group and 107 to the pomalidomide-dexamethasone group); 184 (57%) of 325 were male and 141 (43%) of 325 were female, 246 (78%) of 316 were White. Median age was 68 years (IQR 60-74). Median follow-up was 11·5 months (5·5-17·6) for belantamab mafodotin and 10·8 months (5·6-17·1) for pomalidomide-dexamethasone. Median progression-free survival was 11·2 months (95% CI 6·4-14·5) for belantamab mafodotin and 7·0 months (4·6-10·6) for pomalidomide-dexamethasone (hazard ratio 1·03 [0·72-1·47]; p=0·56). Most common grade 3-4 adverse events were thrombocytopenia (49 [23%] of 217) and anaemia (35 [16%]) for belantamab mafodotin, and neutropenia (34 [33%] of 102) and anaemia (18[18%]) for pomalidomide-dexamethasone. Serious adverse events occurred in 94 (43%) of 217 and 40 (39%) of 102 patients, respectively. There were no treatment-related deaths in the belantamab mafodotin group and one (1%) in the pomalidomide-dexamethasone group due to sepsis.

INTERPRETATION

Belantamab mafodotin was not associated with statistically improved progression-free survival compared with standard-of-care, but there were no new safety signals associated with its use. Belantamab mafodotin is being tested in combination regimens for relapsed or refractory multiple myeloma.

FUNDING

GSK (study number 207495).

Patient-Reported Outcomes With Belantamab Mafodotin Treatment in Patients With Triple-Class Refractory Multiple Myeloma

In the randomized phase II DREAMM-2 study, single-agent belantamab mafodotin demonstrated deep and durable responses and a manageable safety profile in triple-class refractory relapsed/refractory multiple myeloma (RRMM). We present patient-reported outcomes (PROs) from this study for patients treated with the approved dose of belantamab mafodotin (2.5 mg/kg q3w). Disease and treatment-related symptoms, health-related quality of life (HRQOL), functioning, and patient-reported ocular changes were assessed using questionnaires (European Organisation for Research and Treatment of Cancer Quality of Life questionnaires EORTC-QLQ-C30 and EORTC-QLQ-MY20, Ocular Surface Disease Index [OSDI], and the National Eye Institute Visual Functioning Questionnaire 25 [NEI VFQ-25]) at baseline, during treatment (every 3 or 6 weeks), and at the end of treatment (EOT). Eye examinations were conducted at baseline, prior to each treatment cycle, and at EOT. Patients reported ocular symptoms in the OSDI and NEI VFQ-25 questionnaires, with the median time to worst severity of 45 to 64 days depending on symptoms considered. Some limitations in driving and reading were reported. Ocular symptoms were improved and median time to recovery was 23.5 to 44.0 days. EORTC-QLQ-C30 data suggest core MM symptoms (including fatigue and pain), overall HRQOL, and patient functioning were maintained while patients continued belantamab mafodotin treatment, even if meaningful worsening of vision-related symptoms occurred. These PRO results, together with the clinical efficacy of belantamab mafodotin, support its use in patients with RRMM and further evaluation of its use at earlier lines of therapy.

Exploring alternative dosing regimens of single-agent belantamab mafodotin on safety and efficacy in patients with relapsed or refractory multiple myeloma: DREAMM-14

TPS8073

Background: Belantamab mafodotin (belamaf: BLENREP) is a first-in-class, monomethyl auristatin F (MMAF)-containing, B-cell maturation antigen (BCMA)-directed antibody–drug conjugate (ADC). In the DREAMM-2 study, belamaf showed deep responses with a manageable safety profile in patients with relapsed/refractory multiple myeloma (RRMM). At 13 months of follow-up, the median duration of response was 11 months and overall survival was 13.7 months at the 2.5 mg/kg Q3W dose. Corneal events are common and expected with belamaf and other MMAF-containing ADCs. In DREAMM-2, corneal events were managed with dose modifications. Clinical responses were observed even with prolonged dose holds, suggesting alternative dosing regimens may lower corneal event rates without compromising efficacy. The DREAMM-14 study (NCT05064358) will investigate if an improved benefit/risk profile of single-agent belamaf can be achieved by modifying the dose, schedule, or both, relative to the approved dosing regimen (2.5 mg/kg Q3W). Methods: This Phase II, randomized, open-label study will include adults with RRMM who had ≥3 prior lines of therapy (LOT), including an anti-CD38 monoclonal antibody, an immunomodulatory agent, and a proteasome inhibitor. Patients with corneal epithelial disease (except nonconfluent superficial punctate keratitis) or with prior exposure to BCMA-targeted therapies, or ADCs will be excluded. Patients will be randomized into Arms A–D (n=40 each) and Arm E (n=20) in parallel and stratified by the International Staging System (I vs II vs III) and prior LOT (3 vs ≥4). Belamaf will be administered as follows—Arm A: 2.5 mg/kg Q3W; Arm B: 1.9 mg/kg Q3W; Arm C: 2.5 mg/kg Q6W; Arm D: 1.9 mg/kg Q6W; Arm E: 1.9 mg/kg Q6W with ocular event-related dose modifications based on oncology staff assessment of ocular symptoms (patient-reported symptoms using the Ocular Surface Disease Index), and visual acuity (Snellen chart or equivalent) in addition to corneal findings assessed by an eye care specialist. Patients in all Arms will have response assessments, safety assessments, and ophthalmic exams performed by an eye care specialist Q3W regardless of dosing schedule. Ocular event-related dose modifications (except in Arm E) will be guided by a modified Keratopathy and Visual Acuity scale. The primary endpoint will be incidence of ocular events. Key secondary endpoints include ocular safety and tolerability, overall safety and tolerability, pharmacokinetics, and efficacy outcomes. Follow-up for progression-free survival will be Q3W until progressive disease, start of new anticancer therapy, withdrawal of consent, end of study, or death. Status: Recruitment is ongoing. Funding: GSK (Study 209628); drug linker technology licensed from Seagen Inc.; mAb produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT05064358.

Safety and clinical activity of belantamab mafodotin with lenalidomide plus dexamethasone in patients with relapsed/refractory multiple myeloma (RRMM): DREAMM-6 arm-A interim analysis

8017

Background: Belantamab mafodotin (belamaf; BLENREP) is a B-cell maturation antigen-targeting antibody–drug conjugate approved for patients (pts) with RRMM as monotherapy at 2.5 mg/kg Q3W. Preclinical data demonstrate synergy between belamaf and lenalidomide (Len), suggesting added benefit when combined with standard of care such as Len + dexamethasone (Dex). DREAMM-6 (NCT03544281) Arm A is evaluating belamaf in combination with LenDex in pts with RRMM. Methods: This ongoing, two-part, two-arm, open-label study included pts with RMMM previously treated with ≥1 line of therapy (LOT). Pts received 4 belamaf doses/schedules (1.9 mg/kg Q8W or Q4W; 2.5 mg/kg Q4W or Q4W SPLIT dose [50% on Days (D)1, 8] IV) in combination with Len (20 mg PO D1–21) and Dex (20 mg PO/IV D1, 8, 15, 22). Primary objectives were safety (including treatment-related [TR]AEs related to the combination belamaf and LenDex), tolerability, and efficacy (including overall response rate [ORR] defined as ≥partial response). Results: As of this interim analysis (data cut: July 23, 2021), 45 pts received ≥1 dose (12 at 1.9 mg/kg Q8W; 4 at 1.9 mg/kg Q4W; 16 at 2.5 mg/kg Q4W; 13 at 2.5 mg/kg Q4W SPLIT). Across cohorts, the median age was 68 y (range: 36–80). Thirteen pts (29%) had high-risk cytogenetics and 6 (13%) had extramedullary disease. Median prior LOT was 3 (range: 1–11) and 26 (58%) had prior Len treatment. The median duration of follow-up and ORR ranged across cohorts (Table). The median duration of response was only reached in the 1.9 mg/kg Q4W cohort (11.1 mo [95% CI: 3.7–not reached [NR]). At the time of data cut, median progression-free survival was not reached in the 1.9 mg/kg Q8W or 2.5 mg/kg Q4W cohorts. Gr ≥3 TRAEs occurred in 42–85%. Gr ≥3 keratopathy occurred in 0 pts in 1.9 mg/kg Q8W, 1 pt (25%) in 1.9 mg/kg Q4W, 8 pts (50%) in 2.5 mg/kg Q4W, and 6 pts (46%) in 2.5 mg/kg Q4W SPLIT cohorts. Conclusions: Belamaf + LenDex had a tolerable safety profile, with no new safety signals identified in pts with RRMM. AEs, including keratopathy, were common but manageable with dose modifications. Encouraging clinical activity is observed with this combination in pts with RRMM. Follow-up/correlative studies are ongoing. Funding: GSK (Study 207497); drug linker technology licensed from Seagen Inc.; mAb produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT03544281. [Table: see text]

Belantamab Mafodotin (GSK2857916) Drives Immunogenic Cell Death and Immune-mediated Antitumor Responses In Vivo

B-cell maturation antigen (BCMA) is an attractive therapeutic target highly expressed on differentiated plasma cells in multiple myeloma and other B-cell malignancies. GSK2857916 (belantamab mafodotin, BLENREP) is a BCMA-targeting antibody-drug conjugate approved for the treatment of relapsed/refractory multiple myeloma. We report that GSK2857916 induces immunogenic cell death in BCMA-expressing cancer cells and promotes dendritic cell activation in vitro and in vivo GSK2857916 treatment enhances intratumor immune cell infiltration and activation, delays tumor growth, and promotes durable complete regressions in immune-competent mice bearing EL4 lymphoma tumors expressing human BCMA (EL4-hBCMA). Responding mice are immune to rechallenge with EL4 parental and EL4-hBCMA cells, suggesting engagement of an adaptive immune response, immunologic memory, and tumor antigen spreading, which are abrogated upon depletion of endogenous CD8⁺ T cells. Combinations with OX40/OX86, an immune agonist antibody, significantly enhance antitumor activity and increase durable complete responses, providing a strong rationale for clinical evaluation of GSK2857916 combinations with immunotherapies targeting adaptive immune responses, including T-cell-directed checkpoint modulators.

Exposure-Response Analyses for Therapeutic Dose Selection of Belantamab Mafodotin in Patients With Relapsed/Refractory Multiple Myeloma

Belantamab mafodotin is an antibody–drug conjugate comprising a humanized anti‐B‐cell maturation antigen (BCMA) monoclonal antibody conjugated to monomethyl auristatin F (MMAF) via a protease‐resistant maleimidocaproyl linker. Single‐agent belantamab mafodotin showed clinically meaningful activity and manageable safety in patients with heavily pretreated relapsed/refractory multiple myeloma (RRMM) in the phase I DREAMM‐1 and phase II DREAMM‐2 studies and is approved by the US Food and Drug Administration and European Medicines Agency for RRMM treatment. To support monotherapy dose selection, the relationship between Cycle 1 exposure (derived using a population pharmacokinetic model) and clinical response (for multiple efficacy and safety end points) was explored. In DREAMM‐2, efficacy end points (probability of response (PoR) and progression‐free survival (PFS)) were associated with exposure in univariate evaluation; however, once disease burden factors were included in the model (e.g., baseline soluble BCMA, ß₂‐microglobulin), exposure was no longer significant. Patients with higher disease burden had lower exposure. In DREAMM‐1, belantamab mafodotin exposure was the only variable to correlate with PoR and PFS. Probability of corneal events (keratopathy), but not dry eye or blurred vision, was strongly associated with belantamab mafodotin exposure (DREAMM‐2). Higher cys‐mcMMAF maximum plasma drug concentration (C_max) and lower baseline platelet count were associated with increased probability of thrombocytopenia (DREAMM‐1 and DREAMM ‐2). In general, safety end points were more strongly associated with belantamab mafodotin exposure than efficacy end points, particularly after disease factors and patient characteristics were taken into account. Overall, these findings supported the monotherapy dose recommendation of belantamab mafodotin as 2.5 mg/kg every 3 weeks in patients with RRMM who have received four or more prior therapies.

Population pharmacokinetics of belantamab mafodotin, a BCMA-targeting agent in patients with relapsed/refractory multiple myeloma

Belantamab mafodotin (belamaf) is an antibody-drug conjugate (ADC) targeting B-cell maturation antigen (BCMA). Nonlinear mixed-effects models were developed to characterize the population pharmacokinetics (PopPK) of ADC, total monoclonal antibody (mAb), and cysteine-maleimidocaproyl-MMAF (cys-mcMMAF) after 0.03-4.6 mg/kg dosing every 3 weeks in heavily pretreated patients with relapsed/refractory multiple myeloma (RRMM; DREAMM-1, n = 73; DREAMM-2, n = 218). Sequential modeling methodology was used. Individual post hoc parameter estimates from the final ADC model were used to develop total mAb and cys-mcMMAF models. Formal covariate selection used a modified stepwise forward inclusion method with backward elimination. A linear, two-compartment PopPK model with a time-varying clearance (CL) described ADC PK. Initial ADC typical value for CL for a DREAMM-2 patient was 0.936 L/day with a half-life of 11.5 days, over time CL was reduced by 28% resulting in a half-life of 14.3 days. Time to 50% maximal CL change was ~ 50 days. Baseline soluble BCMA (sBCMA), immunoglobulin (IgG), albumin, and bodyweight impacted ADC CL. Cys-mcMMAF concentrations were described with a linear two-compartment model linked to ADC; input rate was governed by deconjugation/intracellular proteolytic degradation of ADC represented by an exponentially decreasing MMAF:mAb (drug antibody ratio [DAR]) after each dose. Time to 50% DAR reduction was 10.3 days. Baseline sBCMA and IgG impacted cys-mcMMAF central volume of distribution. In conclusion, ADC, total mAb, and cys-mcMMAF concentration-time profiles in RRMM were well-described by PopPK models, and exposure was most strongly impacted by disease-related characteristics.

Longer term outcomes with single-agent belantamab mafodotin in patients with relapsed or refractory multiple myeloma: 13-month follow-up from the pivotal DREAMM-2 study

Background

On the basis of the DREAMM‐2 study (ClinicalTrials.gov identifier NCT03525678), single‐agent belantamab mafodotin (belamaf) was approved for patients with relapsed or refractory multiple myeloma (RRMM) who received ≥4 prior therapies, including anti‐CD38 therapy. The authors investigated longer term efficacy and safety outcomes in DREAMM‐2 after 13 months of follow‐up among patients who received belamaf 2.5 mg/kg.

Methods

DREAMM‐2 is an ongoing, phase 2, open‐label, 2‐arm study investigating belamaf (2.5 or 3.4 mg/kg) in patients with RRMM who had disease progression after ≥3 lines of therapy and were refractory to immunomodulatory drugs and proteasome inhibitors and refractory and/or intolerant to an anti‐CD38 therapy. The primary outcome was the proportion of patients that achieved an overall response, assessed by an independent review committee.

Results

As of January 31, 2020, 10% of patients still received belamaf 2.5 mg/kg. Thirty‐one of 97 patients (32%; 97.5% confidence interval [CI], 21.7%‐43.6%) achieved an overall response, and 18 responders achieved a very good partial response or better. Median estimated duration of response, overall survival, and progression‐free survival were 11.0 months (95% CI, 4.2 months to not reached), 13.7 months (95% CI, 9.9 months to not reached), and 2.8 months (95% CI, 1.6‐3.6 months), respectively. Response and survival outcomes in patients who had high‐risk cytogenetics or renal impairment were consistent with outcomes in the overall population. Outcomes were poorer in patients with extramedullary disease. In patients who had a clinical response and prolonged dose delays (>63 days; mainly because of corneal events), 88% maintained or deepened responses during their first prolonged dose delay. Overall, there were no new safety signals during this follow‐up.

Conclusions

Extended follow‐up confirms sustained clinical activity without new safety signals with belamaf in this heavily pretreated patient population with RRMM.

Extended follow‐up of patients enrolled in the ongoing phase 2 DREAMM‐2 study confirms sustained clinical activity without new safety signals in patients with relapsed or refractory multiple myeloma who receive belantamab mafodotin 2.5 mg/kg every 3 weeks. These data show that belantamab mafodotin has the potential to shift the treatment paradigm in this heavily pretreated, anti‐CD38 monoclonal antibody–exposed patient population, which has a poor prognosis and few alternative treatment options.

Management of belantamab mafodotin-associated corneal events in patients with relapsed or refractory multiple myeloma (RRMM)

Belantamab mafodotin (belamaf) demonstrated deep and durable responses in patients with heavily pretreated relapsed or refractory multiple myeloma (RRMM) in DREAMM-2 (NCT03525678). Corneal events, specifically keratopathy (including superficial punctate keratopathy and/or microcyst-like epithelial changes (MECs), eye examination findings with/without symptoms), were common, consistent with reports from other antibody–drug conjugates. Given the novel nature of corneal events in RRMM management, guidelines are required for their prompt identification and appropriate management. Eye examination findings from DREAMM-2 and insights from hematology/oncology investigators and ophthalmologists, including corneal specialists, were collated and used to develop corneal event management guidelines. The following recommendations were formulated: close collaboration among hematologist/oncologists and eye care professionals is needed, in part, to provide optimal care in relation to the belamaf benefit–risk profile. Patients receiving belamaf should undergo eye examinations before and during every treatment cycle and promptly upon worsening of symptoms. Severity of corneal events should be determined based on corneal examination findings and changes in best-corrected visual acuity. Treatment decisions, including dose modifications, should be based on the most severe finding present. These guidelines are recommended for the assessment and management of belamaf-associated ocular events to help mitigate ocular risk and enable patients to continue to experience a clinical benefit with belamaf.

Relationship between corneal exam findings, best-corrected visual acuity (BCVA), and ocular symptoms in patients with relapsed or refractory multiple myeloma (RRMM) receiving belantamab mafodotin (belamaf)

8033

Background: Belantamab mafodotin (GSK2857916; belamaf; BLENREP) is a B-cell maturation antigen (BCMA)-targeting antibody–drug conjugate approved in the US and EU as a monotherapy for the treatment of adult patients with RRMM. Ocular events (OEs) during the pivotal DREAMM-2 trial (NCT03525678) included corneal exam findings (punctate keratopathy and microcyst-like epithelial changes), BCVA changes, and ocular symptoms. Dose reductions or delays based on corneal exam findings and BCVA were used to manage OEs. Here we performed a post hoc investigation of relationships between corneal exam findings, BCVA changes, and patient-reported ocular symptoms to explore if BCVA changes and symptoms could guide dosing, rather than corneal exams. Methods: Eye evaluations (including a corneal exam and BCVA assessment of Snellen visual acuity) were performed on all patients receiving single-agent belamaf (2.5 mg/kg) by ophthalmologists at baseline and prior to each belamaf dose. Changes in the corneal epithelium (Ker) and BCVA were both assessed as per protocol-defined criteria and assessment of grade (Gr) was based on the worse eye. BCVA grading was relative to baseline. Patient-reported ocular symptoms were reported as per the Common Terminology Criteria for Adverse Events. Results: In 12.5% of eye evaluations Gr 3–4 Ker was associated with minimal or no (Gr ≤1) BCVA changes. When patient-reported ocular symptoms were also considered, only 7.5% of evaluations found Gr 3–4 Ker with Gr ≤1 BCVA changes or ocular symptoms. Mild or no (Gr ≤2) Ker was associated with Gr ≤1 BCVA changes in 59.5% of evaluations, or in 38.8% of evaluations with no ocular symptoms reported. Overall, Gr 3–4 Ker were found in 24.9% of evaluations; by contrast, patients had Gr 2–4 BCVA changes or ocular symptoms in 53.7% of evaluations. Association of corneal epithelium changes (Ker) with BCVA changes and ocular symptoms. Conclusions: These findings highlight that BCVA changes and ocular symptoms should be further investigated to determine if they can be used as alternatives (eg, frequency of eye examinations based on symptoms) for the management of belamaf dosing to potentially reduce the burden on patients and healthcare professionals. Clinical trial information: NCT03525678. [Table: see text]

Single-agent belantamab mafodotin for relapsed/refractory multiple myeloma: analysis of the lyophilised presentation cohort from the pivotal DREAMM-2 study

DREAMM-2 (NCT03525678) is an ongoing global, open-label, phase 2 study of single-agent belantamab mafodotin (belamaf; GSK2857916), a B-cell maturation antigen-targeting antibody-drug conjugate, in a frozen-liquid presentation in patients with relapsed/refractory multiple myeloma (RRMM). Alongside the main study, following identical inclusion/exclusion criteria, a separate patient cohort was enrolled to receive belamaf in a lyophilised presentation (3.4 mg/kg, every 3 weeks) until disease progression/unacceptable toxicity. Primary outcome was independent review committee-assessed overall response rate (ORR). Twenty-five patients were enrolled; 24 received ≥1 dose of belamaf. As of 31 January 2020, ORR was 52% (95% CI: 31.3–72.2); 24% of patients achieved very good partial response. Median duration of response was 9.0 months (2.8–not reached [NR]); median progression-free survival was 5.7 months (2.2–9.7); median overall survival was not reached (8.7 months–NR). Most common grade 3/4 adverse events were keratopathy (microcyst-like corneal epithelial changes, a pathological finding seen on eye examination [75%]), thrombocytopenia (21%), anaemia (17%), hypercalcaemia and hypophosphatemia (both 13%), neutropenia and blurred vision (both 8%). Pharmacokinetics supported comparability of frozen-liquid and lyophilised presentations. Single-agent belamaf in a lyophilised presentation (intended for future use) showed a deep and durable clinical response and acceptable safety profile in patients with heavily pre-treated RRMM.

MM-250: Impact of Prolonged Dose Delays on Response with Belantamab Mafodotin (Belamaf; GSK2857916) Treatment in the DREAMM-2 Study: 13-Month Follow-Up

Context:

Single-agent belamaf demonstrated deep and durable responses in the DREAMM-2 (NCT03525678) primary analysis (1) and long-term follow-up (2,3). Keratopathy (microcyst-like epithelial changes [MECs] observed on eye examination with/without symptoms) were managed through dose delays and reductions.

Objective:

To provide an update on the impact of dose delays on responses in patients receiving single-agent belamaf 2.5-mg/kg in DREAMM-2 (13-month follow-up).

Methods:

In the DREAMM-2 study (single-agent belamaf 2.5 mg/kg [n=97] or 3.4 mg/kg [n=99] Q3W), dose modifications were permitted to manage adverse events (AEs), including keratopathy (MECs), an eye examination finding that may/may not be associated with symptoms. Objective response (IMWG criteria 2016) was assessed by an independent review committee Q3W, regardless of treatment delays. Here, we report a post-hoc analysis on the impact of dose delays >63 days on clinical response in the 2.5-mg/kg arm (the selected dose for future clinical development based on risk–benefit assessment).

Results:

In patients receiving single-agent belamaf (2.5 mg/kg), dose delays (54%) and reductions (35%) due to AEs were common (2,3). Keratopathy (MECs) was the most frequent reason for dose delays (47%) and reductions (25%), leading to only 1 patient (1%) discontinuing treatment (2,3). Of 31 patients with ≥partial response, 16 had prolonged treatment interruptions (>63 days). Of these 16 patients, 14 (88%) continued experiencing a clinical benefit during the first prolonged delay: 6 (38%) deepened their response during delay (1 SD to MR; 2 PR to VGPR; 2 MR to VGPR; 1 VGPR to CR); 6 (38%) maintained the same response category as that of the last evaluable assessment during delay/first evaluable assessment after delay; 2 (13%) had increasing paraproteins during the delay but did not meet progression criteria. Two (13%) developed disease progression (1 patient 6 weeks into delay; 1 patient 3 weeks after delay).

Conclusions:

Despite dose delays lasting for several cycles to manage AEs, most responses were sustained throughout the delay, thus maintaining clinical benefit for the majority of patients.

Funding:

GlaxoSmithKline (205678). Drug linker technology licensed from Seattle Genetics; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa.

References:

[1] Lonial Lancet Oncol 2020. [2] Lonial ASCO 2020, EP436. [3] Lonial EHA 2020, EP970.

Corneal Epithelial Findings in Patients with Multiple Myeloma Treated with Antibody-Drug Conjugate Belantamab Mafodotin in the Pivotal, Randomized, DREAMM-2 Study

INTRODUCTION

Patients with relapsed or refractory multiple myeloma (RRMM) represent an unmet clinical need. Belantamab mafodotin (belamaf; GSK2857916) is a first-in-class antibody-drug conjugate (ADC; or immunoconjugate) that delivers a cytotoxic payload, monomethyl auristatin F (MMAF), to myeloma cells. In the phase II DREAMM-2 study (NCT03525678), single-agent belamaf (2.5 mg/kg) demonstrated clinically meaningful anti-myeloma activity (overall response rate 32%) in patients with heavily pretreated disease. Microcyst-like epithelial changes (MECs) were common, consistent with reports from other MMAF-containing ADCs.

METHODS

Corneal examination findings from patients in DREAMM-2 were reviewed, and the clinical descriptions and accompanying images (slit lamp microscopy and in vivo confocal microscopy [IVCM]) of representative events were selected. A literature review on corneal events reported with other ADCs was performed.

RESULTS

In most patients receiving single-agent belamaf (72%; 68/95), MECs were observed by slit lamp microscopy early in treatment (69% had their first event by dose 4). However, IVCM revealed hyperreflective material. Blurred vision (25%) and dry eye (15%) were commonly reported symptoms. Management of MECs included dose delays (47%)/reductions (25%), with few patients discontinuing due to MECs (1%). The first event resolved in most patients (grade ≥2 MECs and visual acuity [each 77%], blurred vision [67%], and dry eye [86%]), with no reports of permanent vision loss to date. A literature review confirmed that similar MECs were reported with other ADCs; however, event management strategies varied. The pathophysiology of MECs is unclear, though the ADC cytotoxic payload may contribute to on- or off-target effects on corneal epithelial cells.

CONCLUSION

Single-agent belamaf represents a new treatment option for patients with RRMM. As with other ADCs, MECs were observed and additional research is warranted to determine their pathophysiology. A multidisciplinary approach, involving close collaboration between eye care professionals and hematologist/oncologists, is needed to determine appropriate diagnosis and management of these patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier, NCT03525678.

DREAMM-1 Patient perspectives from the first-in-human study of single-agent belantamab mafodotin for relapsed and refractory multiple myeloma (RRMM)

e20531

Background: Patient-reported outcomes in RRMM remain poor, particularly for those refractory to immunomodulatory agents, proteasome inhibitors, and anti-CD38 antibodies, and there is an increased risk of cumulative toxicities in these patients. Single-agent belantamab mafodotin (GSK2857916), a first-in-class, B-cell maturation antigen–binding immunoconjugate, has demonstrated deep and durable responses with a manageable safety profile in heavily pretreated patients with RRMM (DREAMM-1, NCT02064387). Here, we present patient-reported clinical benefit/tolerability of belantamab mafodotin evaluated by trial-embedded end-of-treatment (EOT) and follow-up interviews. Methods: DREAMM-1 study design and results have been reported ( Blood Cancer J 2019). Patients in the Part 2 expansion phase were administered single-agent belantamab mafodotin 3.4 mg/kg IV once every 3 weeks for 16 cycles and invited to participate in interviews at EOT and 6-month follow-up. Patients discussed symptoms, treatment-related adverse events (AEs), treatment burden, and overall treatment satisfaction, rated 0–10 (0 = not severe to 10 = most severe/0 = not at all satisfied to 10 = extremely satisfied). Results: A total of 17/35 patients (9 female [53%]) were interviewed; 4/17 patients completed both interviews. Most patients (94%; 16/17) achieved a partial response or better. At EOT, patients reported an improvement from the worst point in symptoms of bone pain (mean change in score from 6.4 to 4.0) and fatigue (8.0 to 5.5). The most commonly reported treatment-related AE was blurred vision (76%; 13/17). Among those reporting this AE, 62% (8/13) reported resolution or steady improvement in vision after EOT; with a reduction in severity rating from 7.3 at worst to 5.3 at EOT for this event. Most patients (93%; 13/14) never considered stopping treatment owing to AEs, including ocular events. Overall treatment satisfaction was high (mean score 7.9; median 9.0). Conclusions: Despite small sample sizes, trial-embedded interviews provide valuable insight into patient experience with belantamab mafodotin. Patients treated with single-agent belantamab mafodotin reported high treatment satisfaction and improvements in symptoms. Visual symptoms were frequent but manageable, and improved or resolved after treatment. Funding: GlaxoSmithKline (117159). Drug linker technology licensed from Seattle Genetics; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT02064387.

DREAMM-2: Single-agent belantamab mafodotin (GSK2857916) in patients with relapsed/refractory multiple myeloma (RRMM) and high-risk (HR) cytogenetics

8541

Background: Patients with RRMM and HR cytogenetics have a poor prognosis and need effective therapies. In DREAMM-2 (NCT03525678), single-agent belantamab mafodotin (an immunoconjugate targeting B-cell maturation antigen) demonstrated clinically meaningful activity and a manageable safety profile in patients with heavily pretreated RRMM ( Lancet Oncol.2020). We present outcomes in patients with HR-cytogenetics (9-month follow-up). Methods: Patients with RRMM received single-agent belantamab mafodotin (2.5 or 3.4 mg/kg). For this post hoc analysis, HR-cytogenetics included t(4;14), t(14;16), 17p13del, or 1q21+ (tested locally). Results: The median number of cycles was 3 (2.5: range: 1–15) and 4 (3.4: range: 1–14). Overall response rate (ORR; ≥partial response [PR] per independent review committee) was 27% in the 2.5 mg/kg group (22% with ≥very good partial response [VGPR]) and 40% in the 3.4 mg/kg group (27% with ≥VGPR). The median duration of response (DoR) was not reached in the 2.5 mg/kg group and was 6.2 months in the 3.4 mg/kg group. The most common adverse events ( > 30% in either group) were consistent with the overall population ( Lancet Oncol.2020): keratopathy (2.5: 59%;3.4: 79%), thrombocytopenia (2.5: 44%; 3.4: 65%), nausea (2.5: 27%; 3.4: 33%), anemia (2.5: 24%; 3.4: 42%), and blurred vision (2.5: 20%; 3.4: 42%). Conclusions: Patients with HR-cytogenetics maintain deep and durable clinical responses with single-agent belantamab mafodotin, comparable to that reported in the overall population. The safety profile remained consistent with previous reports. Funding: GlaxoSmithKline (205678). Drug linker technology licensed from Seattle Genetics; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT03525678 . [Table: see text]

DREAMM-2: Single-agent belantamab mafodotin (GSK2857916) in patients with relapsed/refractory multiple myeloma (RRMM) and renal impairment

8519

Background: Renal impairment, a frequent complication and poor prognostic factor in RRMM, often leads to poor tolerability of standard regimens. We report outcomes in patients with renal impairment receiving single-agent belantamab mafodotin (2.5 or 3.4 mg/kg; B-cell maturation antigen targeting immunoconjugate not renally metabolized) from the DREAMM-2 post-hoc analysis (NCT03525678). Methods: Eligible patients with RRMM had no active renal conditions and adequate renal function (based on albumin/creatinine ratio [<500 mg/g] and eGFR [mL/min/1.73 m2]: normal [≥90], mild impairment [mild, ≥60≤90], moderate impairment [mod, ≥30≤60]). Results: Overall response rates (95% CI) in patients with mild/mod impairment (2.5 mg/kg: 32% [21.4–44.0]; 3.4 mg/kg: 36% [25.6–48.5]) were similar to those in the overall population ( Lancet Oncol.2020). The median duration of response (DoR) was not reached (NR) in 2.5 mg/kg mild/mod subgroup (95% CI estimate: 4.2 months–NR); median DoR was 7.5 months (4.9–NR) in 3.4 mg/kg mild/mod subgroup. Rates of keratopathy and albuminuria were similar regardless of renal function; rates of anemia, pyrexia, and thrombocytopenia were more frequent in patients with impaired renal function (Table). eGFR did not change or changed to normal in most patients. Conclusions: Following treatment with single-agent belantamab mafodotin, patients with mild/mod renal impairment achieved a similar efficacy and safety profile as patients with normal renal function. Funding: GlaxoSmithKline (205678). Drug linker technology licensed from Seattle Genetics; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT03525678 . [Table: see text]

DREAMM-5 platform trial: Belantamab mafodotin in combination with novel agents in patients with relapsed/refractory multiple myeloma (RRMM)

TPS8552

Background: Single-agent belantamab mafodotin (GSK2857916), a B-cell maturation antigen targeting immunoconjugate, induced deep and durable responses in patients with RRMM, with a manageable safety profile (DREAMM-2, NCT03525678, Lancet Oncol.2020). A platform trial design allows efficient evaluation of belantamab mafodotin in combination with other anti-myeloma agents, such as a humanized wild-type IgG1 anti-OX40 agonist, an IgG4 inducible T-cell costimulatory (ICOS) agonist, and a gamma-secretase inhibitor. The unique, multimodal mechanisms of action (MoAs) of belantamab mafodotin, in combination with MoAs of these agents, has the potential to achieve synergistic effects in MM, to further enhance anti-myeloma activity without compromising safety. Methods: DREAMM-5 (NCT04162210) utilizes a master protocol with separate sub-studies comprised of sequential dose exploration (DE) and cohort expansion (CE) phases, to identify promising, effective belantamab mafodotin combinations when compared with a shared belantamab mafodotin monotherapy control arm (CE phase only). DE phases consist of multiple dosing cohorts with belantamab mafodotin combinations where patients are assigned to treatment slots by predetermined algorithmic approach (modified toxicity probability interval; N≤10 per cohort). Recommended phase 2 doses (RP2D) will be based on dose-limiting toxicities, safety, and pharmacokinetics. Interim analyses, based on overall response rate (ORR), determine if a RP2D is moved forward to a CE phase (N≥35 per cohort). Patients in the CE (stratified by number of prior therapies) will be randomized equally to open sub-studies. Eligible patients will have received ≥3 prior therapy lines which must include ≥1 immunomodulatory agent, proteasome inhibitor, and anti-CD38 antibody. The primary objectives are to identify RP2D for each combination (DE phase) and ORR (≥partial response, CE phase). Sub-studies 1 (combination with GSK3174998, OX40 agonist antibody) and 2 (combination with GSK3359609, ICOS agonist antibody) are currently enrolling. Sub-study 3 (combination with nirogacestat [PF-03084014; SpringWorks Therapeutics]) is projected to begin enrollment in the first half of 2020. Additional sub-studies will be explored based on scientific rationale and/or preclinical combination study results. Funding: GlaxoSmithKline (207495). Drug linker technology licensed from Seattle Genetics; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT04162210 .

Pivotal DREAMM-2 study: Single-agent belantamab mafodotin (GSK2857916) in patients with relapsed/refractory multiple myeloma (RRMM) refractory to proteasome inhibitors (PIs), immunomodulatory agents, and refractory and/or intolerant to anti-CD38 monoclonal antibodies (mAbs)

8536

Background: Single-agent belantamab mafodotin (B-cell maturation antigen targeting immunoconjugate) showed clinically meaningful activity and manageable safety in patients with heavily pre-treated RRMM (DREAMM-2, NCT03525678, Lancet Oncol.2020). We report updated results (median follow-up 9 months). Methods: DREAMM-2 is an ongoing single-agent belantamab mafodotin (2.5 or 3.4 mg/kg) study in patients with RRMM after ≥3 prior therapy lines and refractory to an immunomodulatory agent, a PI, and refractory and/or intolerant to an anti-CD38 mAb. Primary endpoint: overall response rate (ORR; ≥partial response per independent review committee). Results: ORR was 31% in the 2.5 mg/kg (19% with ≥very good partial responses [VGPR]) and 35% (24% with ≥VGPR) in the 3.4 mg/kg groups (Table). Duration of response (DoR) was not reached (NR) in the 2.5 mg/kg and 6.2 months in the 3.4 mg/kg groups; 1-year overall survival (OS) estimate was 53%. Common Grade 3/4 AEs ( > 10% in either group) were keratopathy (2.5: 29%; 3.5: 24%), thrombocytopenia (2.5: 21%; 3.4: 32%), anemia (2.5: 20%; 3.4: 27%), pneumonia (2.5: 6%; 3.4: 13%), and neutropenia (2.5: 11%; 3.4: 16%). AEs were managed with dose delays (2.5: 54%; 3.4: 62%) and reductions (2.5: 34%; 3.4: 43%); discontinuations due to AEs were uncommon (2.5: 9%; 3.4: 12%). Conclusions: Single-agent belantamab mafodotin was well-tolerated, and clinically meaningful responses were sustained despite dose modifications with longer follow-up. Funding: GlaxoSmithKline (205678). Drug linker technology licensed from Seattle Genetics; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT03525678 . [Table: see text]

Phase I/II, open-label, 2-arm study to evaluate safety, tolerability, and clinical activity of GSK2857916 in combination with 2 standard-of-care (SoC) regimens in relapsed/refractory multiple myeloma: (DREAMM 6)

TPS8053

Background: B-cell maturation antigen (BCMA) is a validated therapeutic target in Multiple Myeloma (MM). GSK2857916 is a humanized (IgG1) anti-BCMA monoclonal antibody conjugated to monomethyl auristatin-F via protease resistant maleimidocaproyl linker and produced in afucosylated form to enhance antibody-dependent cellular cytotoxicity. In FTIH study BMA117159, GSK2857916 was well tolerated and showed unprecedented clinical activity [ORR=60%; mPFS 7.9 months (95% CI, 3.1–not estimable)] as monotherapy in heavily pretreated MM patients. GSK2857916 in combination with SoC regimens, could potentially further improve outcomes for patients with relapsed/refractory (RR) MM. Methods: DREAMM 6 is a 2-part study: Part 1 (dose escalation) is evaluating safety and tolerability of 2 doses (2.5 mg/kg and 3.4 mg/kg) of GSK2857916, in combination with SoC regimens in two independent arms: Arm A with Lenalidomide/Dexamethasone, and Arm B with Bortezomib/Dexamethasone. Modified Toxicity Probability Interval design will guide dose escalation and RP2D of GSK2857916 in each arm for Part 2 (cohort expansion). Part 2 will confirm safety, evaluate clinical activity of GSK2857916 RP2D with either combination and collect pharmacokinetic information on GSK2857916, Lenalidomide and bortezomib. Up to 90 subjects previously treated with at least 1 prior line of therapy who have undergone autologous stem cell transplant or are transplant-ineligible will be enrolled; up to 24 in Part 1 and up to 66 in Part 2. Subjects in Arm A will continue combination treatment until progression, intolerance, consent withdrawal or death. Subjects in Arm B will receive up to 8 cycles of GSK2857916 in combination with Bor/Dex and then continue GSK2857916 monotherapy until progression, intolerance, consent withdrawal, or death. Enrolment on study started in October 2018 and is ongoing. Study funded by GlaxoSmithKline; drug linker technology licensed from Seattle Genetics; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa. ClinicalTrials.gov Identifier: NCT03544281.

Abstract CT034: A phase I study of GSK2857916, a BCMA-directed monoclonal antibody conjugated to microtubule-disrupting agent in patients with relapsed, refractory multiple myeloma and other BCMA-expressing hematologic malignancies

Background: Expression of B cell maturation antigen (BCMA), a cell surface receptor belonging to the tumor necrosis factor receptor superfamily, is restricted to B cells at later stages of differentiation and is requisite for the survival of long lived plasma cells [Darce, 2007; O’Connor, 2004]. BCMA is also expressed on multiple myeloma (MM) cells and at various frequencies on cells from other B cell malignancies.

GSK2857916 is a humanized, afucosylated IgG1 anti-BCMA antibody conjugated to the microtubule disrupting agent monomethyl auristatin-F (MMAF) via a stable, protease resistant maleimidocaproyl linker. Upon binding to BCMA, GSK2857916 is rapidly internalized and active drug is released within the cell. In addition, GSK2857916 exhibits enhanced antibody-dependent cell-mediated cytotoxicity resulting from afucosylation which increases the affinity of the antibody's Fc domain to FCγRIIIa expressed on immune effector cells. The rationale for the investigation of GSK2857916 in MM and other BCMA-positive hematologic malignancies is supported by the restricted pattern of BCMA expression, and by evidence from preclinical studies [Tai, 2015].

Methods: BMA117159 is a Phase I, open-label, study evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, immunogenicity, and preliminary antitumor activity in adult patients with relapsed/refractory MM or select, BCMA-expressing hematologic malignancies. Seventeen MM patients have been enrolled as of 26 January 2016 into the ongoing dose escalation phase with the once every 3 weeks intravenous dosing schedule. A continual reassessment method applied to dose limiting toxicity findings guide dose escalation decisions and maximum tolerated dose determination. Expansion cohorts will include patients with MM and other

BCMA-expressing hematologic malignancies. Eligible MM patients are required to have undergone stem cell transplant or be considered transplant ineligible, to have received prior treatment with alkylators, proteosome inhibitors and immunomodulators, and to have documented disease progression on or within 60 days of completion of last therapy. Documented BCMA expression is required for patients with other hematologic malignancies.

ClinicalTrials.gov identifier: NCT02064387

Study is funded by GlaxoSmithKline

Citation Format: Larry D. Anderson, James Cavet, Adam D. Cohen, Yan Y. Degenhardt, Catherine E. Ellis, Fiona Germaschewski, Nikoletta Lendvai, Edward Libby, Joanna Opalinska, Rakesh Popat, Isabelle Pouliquen, Paul G. Richardson, Keith E. Stockerl-Goldstein, Heather J. Sutherland, Suzanne Trudel, Peter M. Voorhees, Jeffrey Wetherington. A phase I study of GSK2857916, a BCMA-directed monoclonal antibody conjugated to microtubule-disrupting agent in patients with relapsed, refractory multiple myeloma and other BCMA-expressing hematologic malignancies. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT034.

Aberrant epigenetic and genetic marks are seen in myelodysplastic leukocytes and reveal Dock4 as a candidate pathogenic gene on chromosome 7q

Myelodysplastic syndromes (MDS) are characterized by abnormal and dysplastic maturation of all blood lineages. Even though epigenetic alterations have been seen in MDS marrow progenitors, very little is known about the molecular alterations in dysplastic peripheral blood cells. We analyzed the methylome of MDS leukocytes by the HELP assay and determined that it was globally distinct from age-matched controls and was characterized by numerous novel, aberrant hypermethylated marks that were located mainly outside of CpG islands and preferentially affected GTPase regulators and other cancer-related pathways. Additionally, array comparative genomic hybridization revealed that novel as well as previously characterized deletions and amplifications could also be visualized in peripheral blood leukocytes, thus potentially reducing the need for bone marrow samples for future studies. Using integrative analysis, potentially pathogenic genes silenced by genetic deletions and aberrant hypermethylation in different patients were identified. DOCK4, a GTPase regulator located in the commonly deleted 7q31 region, was identified by this unbiased approach. Significant hypermethylation and reduced expression of DOCK4 in MDS bone marrow stem cells was observed in two large independent datasets, providing further validation of our findings. Finally, DOCK4 knockdown in primary marrow CD34(+) stem cells led to decreased erythroid colony formation and increased apoptosis, thus recapitulating the bone marrow failure seen in MDS. These findings reveal widespread novel epigenetic alterations in myelodysplastic leukocytes and implicate DOCK4 as a pathogenic gene located on the 7q chromosomal region.

Widespread hypomethylation occurs early and synergizes with gene amplification during esophageal carcinogenesis

Although a combination of genomic and epigenetic alterations are implicated in the multistep transformation of normal squamous esophageal epithelium to Barrett esophagus, dysplasia, and adenocarcinoma, the combinatorial effect of these changes is unknown. By integrating genome-wide DNA methylation, copy number, and transcriptomic datasets obtained from endoscopic biopsies of neoplastic progression within the same individual, we are uniquely able to define the molecular events associated progression of Barrett esophagus. We find that the previously reported global hypomethylation phenomenon in cancer has its origins at the earliest stages of epithelial carcinogenesis. Promoter hypomethylation synergizes with gene amplification and leads to significant upregulation of a chr4q21 chemokine cluster and other transcripts during Barrett neoplasia. In contrast, gene-specific hypermethylation is observed at a restricted number of loci and, in combination with hemi-allelic deletions, leads to downregulatation of selected transcripts during multistep progression. We also observe that epigenetic regulation during epithelial carcinogenesis is not restricted to traditionally defined “CpG islands,” but may also occur through a mechanism of differential methylation outside of these regions. Finally, validation of novel upregulated targets (CXCL1 and 3, GATA6, and DMBT1) in a larger independent panel of samples confirms the utility of integrative analysis in cancer biomarker discovery.

The incidence of esophageal adenocarcinoma (EA) is increasing at an alarming pace in the United States. Distinct pathological stages of Barrett's metaplasia and low- and high-grade dysplasia can be seen preceding malignant transformation. These precursor lesions provide a unique in vivo model for deepening our understanding the early steps in human neoplasia. By integrating genome-wide DNA methylation, copy number, and transcriptomic datasets obtained from endoscopic biopsies of neoplastic progression within the same individual, we are uniquely able to define the molecular events associated progression of Barrett esophagus. We show that the predominant change during this process is loss of DNA methylation. We show that this global hypomethylation occurs very early during the process and is seen even in preinvasive lesions. This loss of DNA methylation drives carcinogenesis by cooperating with gene amplifications in upregulating proteins during this process. Finally we uncovered proteins that upregulated by loss of methylation or gene amplification (CXCL1 and 3, GATA6, and DMBT1) and show their relevance by validating their levels in larger independent panel of samples, thus confirming the utility of integrative analysis in cancer biomarker discovery.

Transforming Growth Factor-βSignaling in Normal and Malignant Hematopoiesis

Transforming growth factor-beta (TGF-beta) is an important physiologic regulator of cell growth and differentiation. TGF-beta has been shown to inhibit the proliferation of quiescent hematopoietic stem cells and stimulate the differentiation of late progenitors to erythroid and myeloid cells. Insensitivity to TGF-beta is implicated in the pathogenesis of many myeloid and lymphoid neoplasms. Loss of extracellular TGF receptors and disruption of intracellular TGF-beta signaling by oncogenes is seen in a variety of malignant and premalignant states. TGF-beta can also affect tumor growth and survival by influencing the secretion of other growth factors and manipulation of the tumor microenvironment. Recent development of small molecule inhibitors of TGF-beta receptors and other signaling intermediaries may allow us to modulate TGF signaling for future therapeutic interventions in cancer.

p38 MAP kinase regulates stem cell apoptosis in human hematopoietic failure

Myelodysplastic syndromes (MDS) are clonal stem cell disorders that lead to ineffective hematopoiesis and are common causes of low blood counts in the elderly. The exact molecular mechanisms regulating increased stem apoptosis in these disorders are not well defined. p38 MAPK activation is important in regulating the growth inhibitory signals of TNF-alpha, TGF-beta and Interferons on human hematopoiesis. Our findings show that p38 MAPK is overactivated in myelodysplasia bone marrows and regulates hematopoietic stem cell apoptosis. Inhibition of p38 MAPK by genetic or pharmacologic means decreases apoptosis and stimulates in vitro hematopoiesis from primary MDS hematopoietic progenitors. These studies point to the potential efficacy of selective p38alpha inhibitor, SCIO-469, in human bone marrow failure.

Dose escalation of cyclophosphamide in patients with breast cancer: consequences for pharmacokinetics and metabolism

PURPOSE

The alkylating anticancer agent cyclophosphamide (CP) is a prodrug that undergoes a complex metabolism in humans producing both active and inactive metabolites. In parallel, unchanged CP is excreted via the kidneys. The aim of this study was to investigate the influence of dose escalation on CP pharmacokinetics and relative contribution of activating and inactivating elimination pathways.

PATIENTS AND METHODS

Pharmacokinetics of CP were assessed in 12 patients with high-risk primary breast cancer who received an adjuvant chemotherapy regimen that included four courses of conventional-dose CP (500 mg/m2 over 1 hour every 3 weeks) followed by one final course of high-dose CP (100 mg/kg over 1 hour). Plasma concentrations of CP were analyzed by high-performance liquid chromatography (HPLC), 24-hour urinary concentrations of CP, and its inactive metabolites (carboxyphosphamide, dechloroethylcyclophosphamide [dechlorethylCP], ketocyclophosphamide [ketoCP]) were determined by 31-phosphorus-nuclear magnetic resonance (31P-NMR)-spectroscopy.

RESULTS

There was no difference in dose-corrected area under the concentration-time curve (AUC) (216 v 223 [mumol.h/[mL.g]), elimination half-life (4.8 v 4.8 hours), systemic clearance (79 v 77 mL/min) and volume of distribution (0.49 v 0.45 L/kg) of CP between conventional- and high-dose therapy, respectively. However, during high-dose chemotherapy, we observed a significant increase in the renal clearance of CP (15 v 23 mL/min; P < .01) and in the formation clearance of carboxyphosphamide (7 v 12 mL/min; P < .05) and dechloroethylCP (3.2 v 4.2 mL/min; P < .05), whereas metabolic clearance to ketoCP remained unchanged (1.3 v 1.2 mL/min). Consequently, metabolic clearance to the remaining (reactive) metabolites decreased from 52 to 38 mL/min (P < .001). The relative contribution of the different elimination pathways to overall clearance of CP demonstrated wide interindividual variability.

CONCLUSION

Overall pharmacokinetics of CP are apparently not affected during eightfold dose escalation. However, there is a shift in the relative contribution of different clearances to systemic CP clearance in favor of inactivating elimination pathways, thereby indicating saturation of bioactivating enzymes during dose escalation. Besides individual enzyme capacity, hydration and concomitant medication with dexamethasone modulated CP disposition.