Citations

Abstract Anti-PD-1 monoclonal antibodies have shown promising results in several hematologic malignancies. As a result, these agents are being tested in a growing number of clinical trials across multiple diseases and settings. Many participants in these trials will at some point become candidates for allogeneic hematopoietic stem cell transplant (HSCT); however, the safety and efficacy of HSCT may differ in patients previously exposed to PD-1 inhibitors given their immunomodulatory mechanism and long tissue half-life. Specifically, residual PD-1 inhibition post-HSCT could enhance allogeneic T-cell responses, which could augment the graft-vs-tumor (GVT) effect but also increase the incidence, severity or manifestations of graft-vs-host disease (GVHD) and other immune complications of HSCT. To report our experience in this setting, we retrospectively analyzed the outcomes of patients who had received a PD-1 inhibitor prior to HSCT. Between 2013 and 2015, 19 patients who previously participated in clinical trials with either pembrolizumab or nivolumab (administered in combination with ipilimumab in 1 patient) were transplanted at Brigham and Women's Hospital/Dana-Farber Cancer Institute. Median age at HSCT was 32 (range 22-67). Histologies included HL (n=11), DLBCL (n=2), FL (n=2), PMBCL (n=2), EATL (n=1), and MCL (n=1). Patients had received a median of 4 (2-8) lines of therapy prior to PD-1 blockade. 79% of patients had received a previous autologous stem cell transplant (21% as part of planned tandem procedure). Patients received a median of 8 (3-20) cycles of a PD-1 inhibitor; 74% had intervening salvage therapy between PD-1 blockade and HSCT, and transplant occurred a median of 130 (range 7-260) days after the last dose of PD-1 inhibitor. At HSCT, 63% of the patients were in CR and 16% had refractory disease. All patients received reduced intensity conditioning (RIC). 5 (26%) received marrow grafts from haploidentical sibling donors; the remaining 14 received peripheral blood stem cells, 5 from a matched sibling, 7 from a matched, 1 from a unidirectional host-versus-graft and 1 from a bidirectional mismatched unrelated donor. 3 cases of veno-occlusive disease (VOD) (16% of patients) were observed, one of them fatal. The 180-day cumulative incidences of grade 2-4 and grade 3-4 acute GVHD were 32% and 11%, respectively, and the 1-year cumulative incidence of chronic GVHD was 30%. There were 4 treatment-related deaths, (1 from VOD, 3 from severe acute GVHD occurring within 14 days of HSCT). In addition, 6 patients developed a febrile syndrome with elevated transaminases (n=3), rash (n= 4), and arthralgias (n=1) shortly after transplant, which required prolonged courses of steroids. Only 3 patients relapsed. After a median follow-up of 10 (3-23) months for survivors, the 1-year overall (OS) and progression-free survivals (PFS) were 78% (95CI, 52-91) and 67% (95CI, 41-84), respectively (Figure). The 1-year cumulative incidences of relapse and non-relapse mortality (NRM) were 11% (95CI, 2-30) and 22% (95CI, 6-43), respectively. In conclusion, HSCT is feasible in patients previously treated with PD-1 inhibitors, with acceptable PFS and OS. Despite the heterogeneous patient population, small sample size, and limited follow-up to date, our results raise the possibility of important differences in the post-HSCT course of those patients. First, the relapse rate compares favorably to that expected for this cohort (1-year expected relapse rate based on Disease Risk Index mix 28%). Although this finding is at best suggestive given the sample size and follow-up time, it could reflect accentuation of GVT by prior PD-1 blockade. We also observed a high rate of severe complications including fatal early acute GVHD and VOD, with a higher NRM than expected in a RIC HSCT population. Furthermore, we noted the frequent occurrence of a steroid-responsive febrile syndrome. These possible effects of prior PD-1 blockade (including GVHD, VOD, febrile syndrome) did not appear related to the time from PD-1 treatment to HSCT, and were not reduced by intervening treatment before HSCT. As we accumulate experience with HSCT after PD-1 blockade, our early results may be relevant when considering the decision to proceed to HSCT and for the choice of transplantation strategies. We are presently expanding this analysis through a multi-center international collaborative study. Updated results will be presented at the meeting. Figure 1. Figure 1. Disclosures Zinzani: Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; J&J: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Perales:Takeda: Honoraria; Astellas: Honoraria; Amgen: Honoraria; Merck: Honoraria; NMDP: Membership on an entity's Board of Directors or advisory committees. Soiffer:Gentium SpA/Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Armand:Sequenta, Inc.: Research Funding; Merck: Consultancy, Research Funding; Infinity: Consultancy, Research Funding; BMS: Research Funding.

Abstract Purpose: Deep vein thrombosis (DVT) is increasingly recognized as a major complication of thalidomide (T; Thal) and lenalidomide (R; Rev) based therapy for multiple myeloma. Estimated incidence varies widely in the literature. There is no consensus on specific risk factors, indications for thromboprophylaxis or the agent of choice for DVT prophylaxis. The purpose of this study was to develop a consensus among members of the IMWG. Patients and Methods: A survey was electronically mailed to 67 IMWG members on July 21, 2006 and consisted of 24 multiple-choice questions. Results: Twenty-three IMWG members (34%) sent in their responses by the cut-off date. All (100%) felt that DVT was an important question, but most (95%) did not avoid Thal/Rev based therapy because of the DVT risk. Overall results are summarized in the Table below. A majority of physicians felt that concomitant therapy with high dose dexamethasone (90% of physicians), alkylators (55%), doxorubicin/liposomal doxorubicin (90%), and erythropoietin (75%) increase the risk of DVT associated with Thal or Rev based therapy. Aspirin (81 mg or 325 mg per day) was the preferred choice of prophylaxis when necessary. However, 65% of respondents preferred warfarin to a therapeutic INR or LMW heparin if either doxorubicin or liposomal doxorubicin was added to the regimens. Most (95–100%) felt that DVT prophylaxis was not indicated for: VAD, MP, bortezomib +/− dexamethasone regimens. Seventy-five percent felt it to be safe to resume therapy with Thal/Rev after therapeutic anticoagulation. Most (95%) believed randomized trials were needed. Conclusion: DVT is recognized as a major clinical problem associated with Thal/Rev containing regimens. Most respondents felt that the DVT risk did not warrant any prophylaxis when either Thal or Rev were used as single agents. Aspirin was the preferred form of DVT prophylaxis for most Thal/Rev containing regimens, except when doxorubicin/liposomal doxorubicin or melphalan were added. Additional responses will be analyzed both electronically and by conference call prior to the meeting. Therapy Estimated incidence of DVT (% respondents) Choice of thromboprophylaxis (% respondents) Single agent thal <5% (61%) None (65%) Single agent Rev <5% (80%) None (65%) Thal-Dex 10–20% (52%) Aspirin (60%) Rev-Dex 10–20% (48%) Aspirin (60%) MPT 10–20% (65%) Aspirin (40%) R-MP 5–10% (57%) Aspirin (70%)

PURPOSE In a professional setting, the introduction of female speakers without their professional title may have an impact on the public’s perception of the female speaker. We examined how professional titles were used during speakers’ introductions at the ASCO Annual Meeting. METHODS We conducted a retrospective, observational study of video-archived speaker introductions at the 2017 and 2018 ASCO Annual Meetings. A “professional address” was defined as the professional title followed by the speaker’s full name or last name. Multivariable logistic regressions were used to identify factors associated with the form of address. RESULTS Of 2,511 videos reviewed, 781 met inclusion criteria. Female speakers were addressed less often by their professional title compared with male speakers (62% v 81%; P < .001). Males were less likely to use a professional address when introducing female speakers compared with females when introducing male speakers (53% v 80%; P < .01). When women performed speaker introductions, no gender differences in professional address were observed (75% v 82%; P = .13). Female speakers were more likely to be introduced by first name only (17% v 3%; P < .001). Male introducers were more likely to address female speakers by first name only compared with female introducers (24% v 7%; P < .01). In a multivariable regression including gender, degree, academic rank, and geographic location of the speaker’s institution, male speakers were more likely to receive a professional address compared with female speakers (odds ratio, 2.43; 95% CI, 1.71 to 3.47; P < .01). CONCLUSION When introduced by men, female speakers were less likely to receive a professional address and more likely to be introduced by first name only compared with their male peers.

Treatment of HL-60 human leukemia cells with etoposide induces apoptotic cell death and activation of at least 18 electrophoretically distinct cysteine-dependent aspartate-directed protease (caspase) isoforms, several of which differ only in their isoelectric points. The purpose of the present study was to determine whether activated caspases are phosphorylated. Phosphatase treatment of cytosolic extracts containing active caspases followed by affinity labeling with N-(N-benzyloxycarbonylglutamyl-N-biotinyllysyl)aspartic acid [(2,6-dimethylbenzoyl)oxy] methyl ketone (Z-EK(bio)D-aomk) showed a mobility shift in several of the labeled species, suggesting that phosphorylated forms of these enzymes are present in the extracts. Metabolic labeling with 32P followed by etoposide treatment and subsequent affinity purification of affinity-labeled caspases confirmed that at least three caspase species were phosphorylated. To detect effects of the phosphorylation on enzymatic activity, caspase-mediated cleavage of aspartylglutamylvalinylaspartyl-7-amino-4-trifluoromethylcoumarin (DEVD-AFC) and poly(ADP-ribose) polymerase (PARP) by phosphorylated and dephosphorylated extracts was measured. No significant changes in Km or vmax were detected using DEVD-AFC. In contrast, a slight, but significant enhancement of PARP cleavage was observed in dephosphorylated extracts, suggesting that phosphorylation of active caspases could have an inhibitory effect on enzyme activity. These observations, which provide the first evidence that caspases are phosphoproteins, suggest that caspases may be targets for some of the growing list of protein kinases that are involved in apoptotic events.© 1998 by The American Society of Hematology.

Abstract Background: Lenalidomide with dexamethasone (Rd) is a standard of care used for pts with relapsed multiple myeloma (RMM). The randomized, open-label, multicenter, phase 3 study ASPIRE (NCT01080391) is comparing carfilzomib, lenalidomide, and dexamethasone (KRd) to Rd in pts with RMM. The primary end point is progression-free survival (PFS; assessed by an independent review committee). Secondary end points include overall survival (OS), overall response rate (ORR), duration of response (DOR), health-related quality of life (EORTC QLQ-C30 Global Health Status/QoL), and safety. Methods: Adults with RMM who received 1–3 prior regimens were eligible. Pts were randomized (1:1) to receive KRd or Rd and were stratified by β2-microglobulin levels (<2.5 vs ≥2.5 mg/L), prior bortezomib (no vs yes), and prior R (no vs yes). All pts received lenalidomide (25 mg) on days 1–21 and dexamethasone (40 mg) on days 1, 8, 15, and 22 of a 28-day cycle. In addition, KRd pts received K as a 10-min infusion on days 1, 2, 8, 9, 15, and 16 during cycles 1–12 (20 mg/m2 [days 1 and 2 of cycle 1]; 27 mg/m2 thereafter); K was omitted on days 8 and 9 during cycles 13–18 and was not administered beyond 18 cycles. Cycles were repeated until disease progression, unacceptable toxicity, or withdrawal of consent. The study had 90% power to detect a 25% reduction in risk for PFS events for KRd vs Rd (hazard ratio [HR]=0.75) at a 1-sided significance level of 0.025. A stratified log-rank test was used for the PFS comparison. Results: Data are presented for KRd followed by Rd throughout the abstract. Between July 2010 and March 2012, 792 pts from 20 countries were randomized. Baseline characteristics were balanced between the 2 groups. Median age was 64.0 years (range: 31.0‒91.0). Pts received a median of 2 prior regimens in each group. In both the KRd and Rd groups, 66% of pts received prior bortezomib; 20% of pts in each arm received prior R. Median treatment exposure was 22 cycles (KRd) and 14 cycles (Rd). At the time of the prespecified interim analysis, the study met the primary end point for PFS (HR=0.69; 95% confidence interval [CI]: 0.57–0.83; P<.0001), with a longer duration of median PFS in the KRd group (26.3 months [mo]; 95% CI: 23.3–30.5) compared with the Rd group (17.6 mo; 95% CI: 15.0–20.6). Median OS was not reached in either group; however, there was a trend toward longer OS with KRd compared with Rd (HR=0.79; 95% CI: 0.63–0.99; P=.018), which did not meet the prespecified statistical boundary at the interim analysis of survival (P=.005). The Kaplan-Meier OS event-free rates at 24 mo were 73.3% (95% CI: 68.6‒77.5) and 65.0% (95% CI: 59.9‒69.5). The ORR was 87.4% (95% CI: 83.7–90.5) with KRd and 66.9% (95% CI: 62.0–71.5) with Rd. Median DOR was 28.6 mo (95% CI: 24.9–31.3) and 21.2 mo (95% CI: 16.7–25.8). In the KRd and Rd groups, 31.8% vs 9.4% achieved a stringent complete response (sCR) or complete response (CR) (sCR: 14.1% vs 4.3%; CR: 17.7% vs 5.1%), and 70.4% and 40.7% achieved ≥very good partial response. KRd consistently improved Global Health Status/QoL compared with Rd over 18 cycles of treatment (P=.0001). Treatment discontinuation due to an adverse event (AE) occurred in 15.2% (KRd) and 17.4% (Rd) of pts. In each group, 7.7% and 8.5% of pts died while still on study treatment or within 30 days of receiving the last dose of study treatment. The most common hematologic treatment-emergent AEs (TEAEs) (≥grade 3) included neutropenia (29.6% vs 26.5%), anemia (17.9% vs 17.2%), and thrombocytopenia (16.6% vs 12.3%). The most common nonhematologic TEAEs (all grade) included diarrhea (42.3% vs 33.7%), fatigue (32.9% vs 30.6%), and cough (28.8% vs 17.2%). The most common nonhematologic TEAEs (≥grade 3) included pneumonia (12.5% vs 10.5%), hypokalemia (9.4% vs 4.9%), and hypophosphatemia (8.4% vs 4.6%). Other TEAEs of interest (grouped terms; all grade) included dyspnea (22.4% vs 18.0%), hypertension (preferred term; all grade: 14.3% vs 6.9%; grade 3: 4.3% vs 1.8%), acute renal failure (8.4% vs 7.2%), cardiac failure (6.4% vs 4.1%), and ischemic heart disease (5.9% vs 4.6%). Rates of peripheral neuropathy (PN) (grouped terms; all grade) were 17.1% and 17.0%; ≥grade 3 PN was infrequent (2.6% and 3.1%). Conclusion: The addition of carfilzomib to lenalidomide and dexamethasone in pts with RMM resulted in a statistically significant and clinically meaningful improvement in PFS. KRd had an acceptable safety and tolerability profile and represents a potential new standard of care. Disclosures Stewart: Novartis: Consultancy; Array BioPharma: Consultancy; BMS: Consultancy; Millenium: Research Funding; Celgene: Consultancy. Off Label Use: Carfilzomib is approved in the United States for the treatment of patients with multiple myeloma who have received at least two prior therapies including bortezomib and an immunomodulatory agent and have demonstrated disease progression on or within 60 days of completion of the last therapy. ASPIRE is a randomized, multi-center, phase 3 study investigating the use of carfilzomib in combination with lenalidomide and dexamethasone for the treatment of patients with relapsed multiple myeloma who have received 1–3 prior regimens.. Dimopoulos:Celgene: Consultancy, Honoraria; Onyx: Consultancy, Honoraria. Masszi:Janssen Cilag: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Spicka:Janssen-Cilag: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Oriol:Celgene: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau. Hájek:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees. Rosiñol:Celgene: Honoraria; Janssen: Honoraria. Siegel:Onyx: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Millennium: Honoraria, Speakers Bureau. Niesvizky:Onyx Pharmaceuticals: Consultancy, Research Funding, Speakers Bureau; Millennium: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Jakubowiak:Onyx Pharmaceticals: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. San Miguel:Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; MSD: Membership on an entity's Board of Directors or advisory committees; Millinnium: Membership on an entity's Board of Directors or advisory committees. Ludwig:Celgene: Research Funding, Speakers Bureau; Takeda Celgene: Research Funding, Speakers Bureau; Bristol-Myers: Research Funding, Speakers Bureau. Zojwalla:Onyx Pharmaceticals, an Amgen subsidiary: Employment, Equity Ownership. Tonda:Onyx Pharmaceticals, an Amgen subsidiary: Employment, Equity Ownership. Xing:Onyx Pharmaceticals, an Amgen subsidiary: Employment, Equity Ownership. Moreau:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees. Palumbo:Onyx Pharmaceuticals: Consultancy, Honoraria; Millennium Pharmaceuticals: Consultancy, Honoraria; Janseen-Cilag: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Genmab A/S: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Amgen, Inc,: Consultancy, Honoraria; Array BioPharma: Honoraria.

Abstract Next-generation sequencing (NGS) has revealed new insight into the complexity of clonal and subclonal architecture of multiple myeloma (MM). The introduction of targeted studies allows the detection of mutations with very low allele frequencies at affordable price. However, there is few information about the prognostic impact of this mutational profile in series of homogeneously treated MM patients. In this study, we analyzed the most frequently mutated genes in MM from patients included in a randomized clinical trial applying the highest read depth to date. We performed a correlation study between our results and cytogenetics aberrations and clinical outcomes. We used Ampliseq Library Kit 2.0 to target 77 genes (M3Pv2.0 panel) related to critical pathophysiological pathways, associated to drug resistance or targetable with molecular drugs in MM. We sequenced DNA (15ng) from CD138+ purified plasma cells from 80 MM patients at diagnosis included in GEM2010MAS65 clinical trial. We sequenced at an average read depth of 1500X and using Ion Proton sequencer (Thermo Fisher, USA, PaloAlto, CA). We used Ion Reporter software applying in-house modifications in call variants process. We also sequenced DNA from CD138 negative population in 30% of patients in order to filter out potential artifacts and stablish conditions for excluding germline variants. We first fitted a cox-proportional hazard model to predict survival and a second approach using a penalized regression LASSO. We identified 137 gene mutations in the 80 patients analyzed, 54 mutations were predicted pathogenic by Shif and Poliphen and 65 have been described in COSMIC database. 85% of patients harbored at least 1 mutation. The most frequently mutated genes were KRAS (16%), DIS3 (15%), NRAS (13%), BRAF (6%), and TP53 (5%), accounting for the 54% of the total number of mutations. The most frequently mutated pathways were RAS and NFKB in 34% and 28% of patients respectively. Mutational allele frequency for KRAS, BRAF and TP53 was, in all cases, lower than 50% while DIS3 showed mutations in a broad range (from 2 to 85%). Only one patient presented one mutation in NRAS at 73 % of allele frequency. For patients with more than one mutation, two different scenarios have been found. Some patients showed several genes mutated in a similar allele frequency values. On the contrary, a complex subclonal structure was confirmed in 3 patients, with mutations at very different clonal frequency. CD138 negative fraction was sequenced to confirm that these mutations were exclusive of plasma cells. The first of them had two mutations in DIS3 at 8 and 53% of allele frequency, second in KRAS and DIS3 at 13 and 63% respectively and the third in NRAS and IFNGR2 at 5 and 37% respectively. We found no differences in the survival based on pathway, mutational allele frequency or number of mutations. We also investigated pairwise associations between events and we not found significant correlations (Figure 1). Cox-proportional hazard model only showed a negative impact in survival of patients with TP53 mutations. This ultra-deep targeted sequencing strategy is able to detect mutations in most of patients, at very low allele frequency and using a minimal amount of DNA. Despite of its huge capacity to detect mutations, we have not identified new prognostic factors in MM patients treated with highly efficient therapies. However, this study again confirms the complexity of the genomic landscape of MM and the great heterogeneity between patients. The role of theses mutations at relapse as well as in the subsequent treatment effectiveness remains unknown and should be preferably investigated in larger cohorts of homogeneously treated MM patients. Figure 1 Figure 1. Disclosures Martínez-López: Novartis: Honoraria, Speakers Bureau. Oriol:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Stewart:celgene: Consultancy.

Abstract Abstract LBA-6 Background: Multiple myeloma (MM) patients who have become refractory to bortezomib (BORT) and refractory or otherwise ineligible for thalidomide or lenalidomide (LEN) have a poor prognosis, with a median overall survival (OS) of 9 months (Kumar. Leukemia. 2012). There is no standard treatment available for these patients. Pomalidomide (POM) is a novel immunomodulatory drug that has shown activity in LEN- and BORT-refractory patients (Vij. ASCO 2012). MM-003 is an open-label, multicenter, phase 3 trial designed to compare the efficacy and safety of POM + low-dose dexamethasone (LoDEX) vs high-dose dexamethasone (HiDEX) in a population of patients who are refractory to both LEN and BORT. Here we present the final progression-free survival (PFS) and interim OS analysis of MM-003. Methods: Eligible patients with primary refractory or relapsed and refractory disease were enrolled. All patients with documented disease progression during treatment or within 60 days of completing their last myeloma therapy (including ≥ 2 consecutive cycles of LEN and BORT either alone or in combination), were randomized 2:1 to receive either POM + LoDEX (arm A) or HiDEX alone (arm B). Patients progressing on HiDEX had the opportunity to receive POM in the companion trial, MM-003C. Patients in arm A received POM 4 mg on days 1–21 and DEX 40 mg (20 mg for patients > 75 years of age) on days 1, 8, 15, and 22 in a 28-day cycle. Patients in arm B received DEX 40 mg (20 mg for patients > 75 years of age) on days 1–4, 9–12, and 17–20 in a 28-day cycle. Treatment was continued until progressive disease or unacceptable toxicity. Patients were stratified by age (≤ 75 vs > 75 years), disease population (refractory vs refractory and relapsed vs refractory and intolerant [intolerant to BORT only]), and number of prior therapies (2 vs > 2). The primary endpoint was PFS; secondary endpoints included safety, OS, overall response rate (ORR; ≥ partial response) by IMWG and EBMT criteria, duration of response, time to progression, and quality of life. OS was to be tested only if PFS would be statistically significant; therefore, alpha was controlled at 0.05 2-sided for both PFS and OS. Results: The Data and Safety Monitoring Board (DSMB) reviewed the protocol-specified final analysis results. 455 patients were randomized from March 2011 to Sept 2012. 302 patients received POM + LoDEX, and 153 patients received HiDEX. At the time of analysis, 45% of patients in arm A and 25% of patients in arm B remained on study. The median number of prior therapies was 5 (range, 1–17). 72% of patients were refractory to both LEN and BORT. At the PFS final analysis, with a median follow-up of 18 weeks, PFS was significantly longer with POM + LoDEX vs HiDEX alone (median 15.7 vs 8.0 weeks; 267 total events; hazard ratio [HR], 0.45; P <.001). OS interim analysis was performed as planned; OS also was significantly longer with POM + LoDEX vs HiDEX alone (median not reached vs 34 weeks; 134 events; HR, 0.53; P<.001), crossing the prespecified O’brien-Fleming superiority boundary. This includes 45 pts who received POM after progressing on HiDEX. Median duration of treatment was 12.4 weeks in arm A and 8 weeks in arm B. Following DSMB review of the data, immediate crossover of arm B patients to arm A was recommended. Overall, 25% of patients in arm A and 38% in arm B died, with progressive disease and infections as the primary reasons. Frequent grade 3/4 hematologic toxicities included neutropenia (42% in arm A vs 15% in arm B), thrombocytopenia (21% vs 24%), and febrile neutropenia (7% vs 0%). Other toxicities (grade 3/4) were predominantly infections (24% vs 23%), hemorrhage (3% vs 5%), glucose intolerance (3% vs 7%), neuropathy (1% vs 1%), and venous thromboembolism (1% vs 0%). The primary reason for discontinuation was progressive disease: 35% arm A and 49% arm B. Complete results will be presented at the meeting. Conclusions: POM + LoDEX significantly increased PFS and OS compared with HiDEX in patients who are refractory to LEN and BORT, a population with limited treatment options. The OS superiority boundary was crossed. Based on these data, POM + LoDEX should become the new standard of care in patients who have exhausted the novel agents, LEN and BORT. Disclosures: Dimopoulos: Celgene: Honoraria. Off Label Use: Pomalidomide is an investigational drug and is not approved for the treatment of patients with any condition. Lacy:Celgene: Research Funding. Moreau:Celgene: Honoraria, Speakers Bureau. Weisel:Celgene: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding. Song:Celgene: Honoraria, Membership on an entity’s Board of Directors or advisory committees. Delforge:Celgene: Consultancy, Honoraria, Speakers Bureau; Janssen-Cilag: Consultancy, Honoraria; OrthoBiotech: Consultancy, Honoraria, Speakers Bureau. Karlin:Celgene: Consultancy. Goldschmidt:Novartis: Honoraria, Speakers Bureau; Janssen: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding, Speakers Bureau. Yu:Celgene: Employment. Sternas:Celgene: Employment, Equity Ownership. Jacques:Celgene: Employment, Equity Ownership. Zaki:Celgene: Employment, Equity Ownership. San Miguel:Onyx: Membership on an entity’s Board of Directors or advisory committees; Janssen: Membership on an entity’s Board of Directors or advisory committees; Millennium: Membership on an entity’s Board of Directors or advisory committees; Celgene: Membership on an entity’s Board of Directors or advisory committees; Novartis: Membership on an entity’s Board of Directors or advisory committees.

Abstract Abstract 743 Background There has been considerable recent focus upon the molecular classification of myeloma. However, the prognostic impact of molecular changes has mostly been assessed from small and/or incomplete studies from single institutions or groups. There has been no large scale analysis of molecular features linked to ISS stage. Methods In order to clarify the overall impact of molecular changes we undertook a collective analysis of 9,897 patients through the International Myeloma Working Group (IMWG). Within this population 2,295 patients had presence of cytogenetic abnormalities (Any CA); 1,713 hypodiploidy; 1,673 hyperdiploidy; 2,309 cytogenetic deletion 13; 3,226 deletion 13 by FISH; 1,573 FISH t(4;14); 1,486 FISH del p17; 1, 683 FISH t(11:14); and 366 FISH t(4;16). Enrolled patients had complete clinical and treatment details available including baseline standard prognostic factors, ISS stage, as well as both progression free survival (PFS) and overall survival (OS) information. Data came from 14 sites: 3 from the US and the remainder from Europe, Asia, and Latin America as for the ISS staging system analyses. Univariate and multivariate analyses were performed. Results Each of the known adverse molecular features had a negative impact upon both PFS and OS (p=002 - <0.0001). Among the deleterious FISH abnormalities the t(4;14) abnormality was the most highly correlated with poorer outcomes by PFS: 4 year estimate: 32% vs. 60% (p<0.0001). The t(4;14) abnormality combined with ISS Stage also significantly enhanced predictive capability: ISS Stage I without t(4;14) OS 81% @ 4 years; ISS Stage III with t(4;14) OS 22% @ 4 years (P<0.0001) [Figure 1]. The best outcomes were for ISS Stage I in the presence of t(11;14): OS 89% @ 4 years. Absence of any one adverse feature correlated with 80-81% OS @ 4 years for Stage I. Presence of any one adverse feature had a more variable impact and correlated with 22%-40% OS at 4 years for Stage III. In univariate correlations the most predictive correlations with OS were presence of Any CA, t(4;14), 17p-, hypodiploidy, cytogenetic 13q- with R2 values of 6.9%, 4.5%, 4.1% and 3.8% respectively. In multivariate analyses, ISS stage provided the best predictions: R2 values = 13.3%. The added contributions from molecular features were: t(4;14) 3.8%; cytogenetic 13q- 2.9%; Any CA 2.3%; and 17p- 1.0%. The maximum total R2 for OS was 22%. Conclusions This large multicenter analysis confirms the correlations between abnormal molecular findings and outcomes. Combinations with ISS Stage provide the best predictive capability. Presence of Any CA, t(4;14), 17p-, hypodiploidy and cytogenetic 13q- contribute to poorer outcomes by ISS stage. The presence of hyperdiploidy and/or t(11;14) contribute to better outcomes. There is thus validation of prior molecular studies related to prognosis utilizing this large IMWG database. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 788 FLT3 mutations are common in AML and are associated with poor prognosis. Lestaurtinib is a multi-targeted kinase inhibitor with potent activity against FLT3. In an attempt to definitively establish whether or not there is clinical benefit for FLT3 inhibition in the relapse setting, we conducted a randomized trial of chemotherapy followed by lestaurtinib for patients with FLT3 mutant AML in first relapse. Patients were randomized to receive either chemotherapy alone, consisting of mitoxantrone, etoposide, and cytarabine (MEC) or high-dose cytarabine (HiDAc) depending on the duration of CR1) or chemotherapy followed by 80 mg lestaurtinib orally BID. Patients on the chemotherapy only arm were eligible for crossover if they were refractory to therapy. Patients on the lestaurtinib arm received the drug for up to 112 days on study (they could continue to receive the drug through a separate extension protocol). The primary objective was complete remission (CR/CRp). Secondary objectives included overall survival (OS), safety, and tolerability. From January 2004 through December 2008, 224 patients at 52 different centers were enrolled and randomized, with 220 patients actually receiving therapy. Blood samples from patients on the lestaurtinib arm were obtained at baseline, on Day 15, and on Day 42 for pK studies and for determination of in vivo FLT3 inhibition and measurement of plasma FLT3 ligand (FL) and alpha-1 acid glycoprotein (AGP) levels. The median age for all patients enrolled was 55 years (53.5 in the control arm, 58.5 in the lestaurtinib arm), with 88% having FLT3/ITD mutations, 8% having D835 mutations, and 4% having both. The duration of CR1 was less than 6 months in 47% of patients in each arm. On the lestaurtinib arm, 107 patients received at least 1 week of lestaurtinib (mean 60.1 days, range 8-418), with 17 of these patients receiving drug on the extension protocol. On the chemotherapy only arm, 7 patients crossed over to receive lestaurtinib, and 31 patients went on to receive lestaurtinib on the extension protocol after outcome evaluation. Lestaurtinib was generally well tolerated following chemotherapy, with 104 Grade 3/4 adverse events in the lestaurtinib arm versus 99 in the control arm. There were 61 serious adverse events in the lestaurtinib arm versus 49 in the control arm. Early death (by Day 42) occurred in 22 lestaurtinib patients (2 progressive leukemia, 14 infectious, 6 organ failure) and16 control patients (6 progressive leukemia, 5 infectious, 5 organ failure). By intention to treat analysis, there were 29 CR/CRp in the lestaurtinib arm and 23 in the control arm (26% versus 21%; p = 0.35), with no difference in OS (4.73 months versus 4.57 months) between the two arms. Blood samples from 79 of the 107 lestaurtinib-treated patients obtained on Day 15 were analyzed for FLT3 inhibitory activity (plasma inhibitory activity [PIA] assay), as well as FLT3 ligand (FL), lestaurtinib, and AGP concentrations. Mean lestaurtinib plasma concentration was 12 uM at Day 15 and fell to 7.5 uM on Day 42. Mean lestaurtinib concentration at Day 15 was 13.3 uM in patients achieving CR/CRp and 11.5uM in non-responders. A target of >85% inhibition of FLT3 maintained at trough (pre-dose) was defined from previous studies. Of the 79 patients tested, 46 (58%) achieved this degree of FLT3 inhibition on Day 15. FL concentrations rose from baseline (15.6 pg/mL) to Day 15 (1148 pg/mL), and AGP concentrations rose by an average of 52% over the same period, both of which may have reduced the degree of FLT3 inhibition. Of the 46 patients with target FLT3 inhibition on Day 15, 18 (39%) achieved CR/CRp, while only 3 (9%) of the 32 patients with below target FLT3 inhibition achieved CR/CRp. Thus, in patients with FLT3 mutant AML at first relapse, pharmacokinetic factors and possible physiologic factors (FL and AGP) limit lestaurtinib's ability to effectively inhibit FLT3. FLT3 inhibition by lestaurtinib, when achieved, correlates with better CR rates, but in this trial that benefit was negated by a poor CR rate in those patients for whom the drug did not reach the target level of FLT3 inhibition. Overall, lestaurtinib treatment following re-induction chemotherapy failed to increase response rates or prolong survival of patients with FLT3 mutant AML in first relapse. Disclosures: Levis: Cephalon: Clinical Advisory Board member. Ravandi:Cephalon: Honoraria, Member, clinical advisory board, Research Funding. Erba:Cephalon: Research Funding, Speakers Bureau. Baccarani:Novartis Pharma, Bristol Myers Squibb, Merck Sharp & Dome, Pfizer: Consultancy, Speakers Bureau. Stone:Cephalon: ad hoc consultancy; Novartis: Research Funding, ad hoc consultancy. Advani:Cephalon: Research Funding. Douer:Cephalon: Honoraria, Research Funding, Speakers Bureau. Litzow:Cephalon: Research Funding. Tremmel:Cephalon: Employment, Equity Ownership. Bensen-Kennedy:cephalon: Employment. Smith:Cephalon: Research Funding.

Gliosis and fibrosis after spinal cord injury (SCI) lead to formation of a scar that is thought to present both molecular and mechanical barriers to neuronal regeneration. The scar consists of a meshwork of reactive glia and deposited, cross-linked, extracellular matrix (ECM) that has long been assumed to present a mechanically “stiff” blockade. However, remarkably little quantitative information is available about the rheological properties of chronically injured spinal tissue. In this study we utilize atomic force microscopy microindentation to provide quantitative evidence of chronic mechanical stiffening after SCI. Using the results of this tissue characterization, we assessed the sensitivity of both mouse and human astrocytes in vitro and determined that they are exquisitely mechanosensitive within the relevant range of substrate stiffness observed in the injured/uninjured spinal cord. We then utilized a novel immune modifying nanoparticle (IMP) treatment as a tool to reveal fibrotic scarring as one of the key drivers of mechanical stiffening after SCI in vivo . We also demonstrate that glial scar-forming astrocytes form a highly aligned, anisotropic network of glial fibers after SCI, and that IMP treatment mitigates this pathological alignment. Taken together, our results identify chronic mechanical stiffening as a critically important aspect of the complex lesion milieu after SCI that must be considered when assessing and developing potential clinical interventions for SCI.