Buadi, Francis K.

Abstract Abstract 2950 Background: The median age of patients diagnosed with MM is approximately 70 years, and it is a relatively uncommon disease in the younger population. Both conventional chemotherapy and stem cell transplantation (SCT) have favorably impacted the overall survival (OS) of young MM patients. The median survival of patients < 40 years of age, diagnosed prior to 1993 was reportedly 54 months at our institution. However, the impact of novel agents in this patient population is not well known. We studied the outcome of young patients presenting to our institution over the last decade. Methods: Records of 1538 patients presenting between 01/99 to12/08 were reviewed. The demographics, features and therapeutic interventions in patients up to 45 years of age at diagnosis were analyzed using descriptive statistics. The survival outcome of this group was compared with the remainder of the cohort using the Kaplan-Meier method. Results: One-hundred (6.5%) out of 1538 newly diagnosed MM patients were ≤ 45 years of age at diagnosis. The median follow-up of this group of young patients was 86 months. The disease and patient characteristics are outlined in table 1. A median of 5 regimens (range 1–14) was administered, and 85% patients had received high-dose therapy. 15 patients underwent allogeneic SCT after at least one prior autologous SCT. Novel agents were used both in the front-line and relapsed setting (lenalidomide 60%, thalidomide 56%, pomalidomide 9% and bortezomib 49%), and 45% of initial regimens were novel agent based. The 5 and 7-year OS from diagnosis was 69% and 59%, respectively and the median OS was 93 months. In contrast, the median OS of patients >45 years diagnosed during this period was 53 months (P=0.001, figure 1). Conclusion: A marked improvement in OS of young patients with MM diagnosed in the novel agent era is noted in comparison to the historical control of similar age group. In addition, the age associated survival benefit in the younger patient population prevails in the era of novel therapies. Disclosures: Gertz: Celgene: Honoraria. Lacy:Celgene: Research Funding. Dispenzieri:Binding site: Honoraria; Celgene: Research Funding. Kyle:Millennium: Consultancy; Binding Site: Honoraria. Kumar:Millennium Pharmaceuticals, Inc.: Research Funding; Celgene: Consultancy, Research Funding; Genzyme: Research Funding; Novartis: Research Funding; Merck: Consultancy, Honoraria.

Abstract Abstract 2992 Background: Patients with myeloma receiving initial therapy with lenalidomide-based regimens can have difficulty collecting adequate stem cells for an autologous transplant. Stem cell collection in these patients can be significantly enhanced by addition of the CXCR-4 antagonist plerixafor to the mobilization regimen. Plerixafor is typically given subcutaneously (SQ), with collection approximately 11 hours after injection to obtain maximum yield. Intravenous administration can potentially allow more rapid and predictable mobilization compared to the SQ route. We designed this trial to prospectively assess the efficacy of intravenous plerixafor administration in patients undergoing lenalidomide therapy. Patients and methods: Patients who were receiving initial therapy with a lenalidomide-based regimen and were undergoing stem cell collection within 12 months of their myeloma diagnosis were enrolled. Patients received GCSF at 10 μg/kg/day for 4 days followed by addition of plerixafor at 0.24 mg/kg/dose starting on day 5. Plerixafor was administered intravenously early morning (6–7 am) followed by apheresis beginning 4–5 hours later. Plerixafor was administered for a maximum of 4 days; but patients could continue apheresis beyond the 4th day at treating physician discretion. The aims of the study were to determine the proportion of patients reaching a stem cell yield of at least 3 million CD34 cells/kg by second day of apheresis, the safety and tolerability of intravenously administered plerixafor, and the overall rate of failure to mobilize (defined as less than 2.5 million CD34 cells/kg in 4 collections). Results: Thirty-seven patients were accrued between December 2009 – April 2011, and 36 were eligible for analysis. The median age was 61 years (range; 28–73); 61% were male. The median time from start of initial therapy to enrollment was 4.6 months (range; 2.6 to 11.1) and the median cycles of lenalidomide were 4 (range; 3–11). Thirty-four (94%) of the patients achieved at least 3 million CD34 cells/kg within 2 days of apheresis. The median CD34 cells/kg after 1 day of collection was 3.9 million (range; 0.7 to 9.2) and after two days of collection was 7.02 million (range: 1.1–16.5). Two patients failed the mobilization (<2.5 million CD34 cells/kg). There were no grade 3 or 4 non-hematological adverse events and one patient experienced grade 4 thrombocytopenia. The most common grade 1 or 2 adverse events seen were gastrointestinal, namely nausea, diarrhea and abdominal pain or bloating. Grade 1 dizziness was reported in 8 patients. Overall, the infusion was well tolerated. Conclusion: Intravenously administered plerixafor is an effective strategy for mobilization in this patient group with low rate of failure to mobilize. It is well tolerated with toxicity comparable to the SQ administration. It also offers flexibility in patient scheduling with a convenient schedule for early morning infusion followed by apheresis later in the day. Disclosures: Kumar: Merck: Consultancy, Honoraria; Celgene: Consultancy, Research Funding; Millennium Pharmaceuticals, Inc.: Research Funding; Genzyme: Research Funding; Novartis: Research Funding. Off Label Use: Use of the investigational agent MLN9708 for the treatment of previously untreated multiple myeloma. Lacy:Celgene: Research Funding.

Abstract Background Acquired factor X (FX) deficiency is associated with immunoglobulin light chain (AL) amyloidosis and may be accompanied by hemorrhage. There are limited data on the effects of autologous stem cell transplant (ASCT) on FX deficiency. We reviewed hemorrhagic complications and the effect of high dose melphalan (HDM) and ASCT on FX levels in AL amyloidosis patients with FX deficiency. Methods We conducted a retrospective chart review of patients with AL amyloid with FX levels below 60%, not on chronic anti-coagulation who underwent HDM/ASCT at the Mayo Clinic, Rochester, MN between 1995 and 2011. Results Forty-one of 358 patients (11%) met our study criteria. Median pre-ASCT FX was 45% (range: 2%, 59%). The most common bleeding complication was central line associated n=15 (37%) followed by gastrointestinal n=10 (24%) and genitourinary n=9 (22%). The most frequent and severe bleeding complications occurred in patients with FX levels less than 10%. Four patients required emergent splenectomy owing to splenic rupture; one of these patients died from hemorrhagic shock. Periprocedural prophylaxis included activated recombinant Factor VII (rFVIIa) infusions, fresh frozen plasma (FFP) infusions and platelet transfusions. rFVIIa was efficacious in controlling bleeding during splenectomy (n=5) and, in conjunction with arterial embolization, for retroperitoneal bleed (n=1). Elective splenectomy for FX deficiency (n=1) resulted in only transient improvement in FX level. No relationship between the degree of pre-ASCT FX deficiency and other laboratory values (alkaline phosphatase, AST, total bilirubin, serum albumin, total serum protein, serum creatinine, total urine protein, beta2 microglobulin, troponin T) was found. Post-ASCT FX levels were determined in seventeen patients. In four of these patients, post-ASCT FX levels were determined in the acute/subacute phase of ASCT before steady state FX levels could be achieved; the median change in FX for these patients was -6.5% (range: -19%, 3%). In the remaining thirteen patients, who were between 99 and 1920 days from ASCT, FX improved by median 26% (range: -15%, 92%). Overall post-ASCT FX increased in twelve of thirteen (92%) patients. The improvement in FX correlated with improvement in the degree of proteinuria (p = 0.04) and showed a trend towards significant correlation with improvement in serum alkaline phosphatase (p = 0.06). Conclusions Hemorrhagic complications are most frequent and severe for FX levels below 10%. rFVIIa infusions, FFP and platelets were effective prophylactic agents. In the single patient who underwent elective splenectomy, a transient improvement in FX level was seen. Splenectomy was otherwise reserved for patients with splenic rupture/hematoma. Post-ASCT FX levels increased in twelve (92.3%) of the remaining thirteen patients; five of the patients (38.5%) were no longer FX deficient after ASCT. The degree of improvement in FX levels was correlated with improvement in markers of renal or hepatic involvement by amyloid. Disclosures: Kumar: Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Onyx: Consultancy, Research Funding.

Abstract Background Pomalidomide (POM) is the newest Immunomodulatory agent (IMiDs) that has shown clinical efficacy in relapsed multiple myeloma (MM) refractory to lenalidomide (LEN) and thalidomide (THAL). Studies of MM cell microenvironment suggest that tumor subclones compete for dominance during changes in drug therapy. It was previously observed that a minor clonal population increased in prominence of MM cells after 1 year of treatment with LEN. We examined whether the patients having THAL or LEN as the most recent prior-line therapy affects response to POM. Methods We studied 208 patients enrolled in a phase II trial of POM / dexamethasone between November 2007 and March 2012 at Mayo Clinic, Rochester. We reviewed the immediate prior-line therapy before enrollment in our trial. Comparison of treatment duration of POM and response rates were conducted between patients who had either THAL or LEN as latest prior-line therapy, and patients who were treated with non-IMiDs immediate before enrollment in POM trial. Treatment duration of POM was estimated using Kaplan Meier method and the survival curves were compared using log-rank test. We used univariate Cox proportional hazard models to estimate the prognostic impact of different variables. Results The median age of patients was 63 (range from 32 to 88). 68 % were males. 80 patients (38.5%) had THAL or LEN immediate prior to POM. Median prior-line therapies were 3. Patients who received THAL or LEN immediately prior to POM had a lower response rate than those who had non-IMiDs as latest therapy (29% vs 44%, p 0.04) and shorter median duration of POM treatment (5.7 months vs 7.3 months, p 0.02). In 190 (91%) patients who were previously treated with LEN and THAL at any time, median time between the end of LEN or THAL treatment and the initiation of POM was higher for POM responders than non-responders (10 months vs 3 months, p 0.0008). Patients responded to POM had a shorter duration of prior LEN or THAL treatment compared to non-responders (9 months vs 15 months, p 0.001). Conclusion THAL or LEN as an immediate prior-line therapy to POM is associated with a lower response rate and shorter effective treatment duration. Longer interval between prior immunomodulatory compounds and POM, and shorter exposure to previous immunomodulatory compounds are associated with better POM treatment response. Disclosures: Gertz: Celgene: Honoraria. Kumar:Merck: Consultancy, Honoraria; Celgene: Consultancy, Research Funding; Millennium: The Takeda Oncology Company: Research Funding; Novartis: Research Funding; Genzyme: Research Funding. Lacy:Celgene Corporation: Research Funding.

Abstract Background Multiple myeloma (MM) is uncommon in patients below 40 years of age. Between 1960 and 1992 when stem cell transplantation (SCT) was rarely performed and novel agents were unavailable, overall survival (OS) was reported to be 54 months in the Mayo Clinic series of patients with MM below forty years of age. The impact of novel agents or SCT in this population is unclear. Herein, we report the outcomes of patients under 40 years of age who were evaluated over a span of more than five decades with a focus on the periods contemporaneous with the introduction of SCT and novel agents, the major therapeutic milestones in the management of MM. Methods We analyzed the medical records of patients with MM under 40 years of age who were evaluated at Mayo Clinic, Rochester, MN between 1/1/1960 and 12/31/2011. SCT and novel agents were utilized infrequently prior to the years 1990 and 2000, respectively. Patients were therefore divided into three cohorts by the year of diagnosis of MM: Group A (1960 -1979), Group B (1980 to 1999) and Group C (2000 –2011) to assess the impact of major therapeutic advances (i.e. Increased utilization of SCT and novel agents compared to conventional chemotherapy). OS was calculated by the Kaplan -Meier method. Results Out of 8063 unique MM patients seen at our institution during this period, 174 (2%) patients were under 40 years of age at diagnosis. The median age at diagnosis was 36 years (range: 19-39). The estimated median follow-up of the entire cohort was 179 months (95% CI: 149-196 months). The median OS of the entire cohort was 76 months (95% CI: 45-80 months) from diagnosis. The median OS of patients in Groups A (n=29, 17%), B (n=93, 53%), and C (n=52, 30% ) was 44 months (95% CI: 20- 76), 79 months (95% CI: 46-97), and 92 months (95% CI: 42-NR), respectively (p=0.005). No significant OS difference was noted between Groups B and C (Figure). Sixty-six (38%) patients underwent at least one SCT (autologous: 56 patients and allogeneic 10 patients). The utilization of SCT increased over the three time periods from Group A 0%, Group B 39% and Group C 58% (p<0.001). Of 153 patients in whom front-line therapy-related data were available 118 (77%) received conventional and 35(23%) received novel agents. The median OS of patients who underwent transplantation (n=66) was 93 months compared to 46 months for those who did not (n=108, p=.01). In the 66 patients who underwent SCT, the median OS was 93 months for conventional agents-based induction (95% CI: 73-143) versus 97 months (95% CI: 41-187) for novel agent based induction (p=.4). Sixty-eight (40%) patients received novel agents at some point during the course of their disease [bortezomib 35 (54%), thalidomide 44 (67%), lenalidomide 47 (71%) and pomalidomide 7(11%)]. The median survival of these patients was 131 (95% CI: 88-161) months versus to 46 (CI: 37-74) months for those (n=106) receiving conventional agents only (p=0.0002). Conclusions OS of patients with MM under 40 years of age in the pre-transplant era (Group A) was significantly shorter than that of patients diagnosed in the era of SCT (Group B) and SCT plus novel agents (Group C). Although improvement of survival outcomes is evident with utilization of novel agents, similar outcomes of Groups B and C indicate lack of incremental benefit over SCT with utilization of novel agents. Maximal survival gain coincides with the introduction of SCT in this unique patient cohort. Disclosures: Kumar: Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Onyx: Consultancy, Research Funding.

Abstract Abstract 2942 Background: Pomalidomide (pom) is a distinct immunomodulatory (IMid) drug with high response rates in relapsed MM, including patients previously treated with thalidomide, bortezomib and lenalidomide. However, its duration of response and long term outcome is unknown. We evaluated the long term outcomes of the first Mayo Clinic cohort of pts treated with Pom. Methods: Pts with relapsed/refractory myeloma with 1–3 prior therapies were enrolled. Pom 2 mg/d was given orally continuously on 28 day cycle with weekly dexamethasone 40 mg. All pts received DVT prophylaxis with aspirin, heparin or warfarin. Results: 60 pts with relapsed MM were enrolled from Nov 2007-Aug 2008. Median age was 65.5; 36 were male. Median time from diagnosis was 45.6 mo (9.–-192.5). Nineteen (32%) were high-risk according to mSMART (msmart.org), and 78% were ISS Stage 2/3. Prior therapies included transplant (65%), bortezomib (33%), thalidomide (47%), lenalidomide (35%) [previous IMiD 60%] and radiation (38%). Toxicities at least possibly attributed to Pom included G3/4 anemia (5/0%), leukopenia (17/3%) and thrombocytopenia (3/0%). G3/4/5 non-hematological toxicities occurred in 30 (50%) and included fatigue (18/0/0%), pneumonia (8/2/2%), hyperglycemia (5/0/0%) and constipation (5/0/0%). Only one pt had grade 3 neuropathy. Treatment adjustment for occurred in 30 pts (50%) for pom (mostly for neutropenia) and 35 pts (58%) for dex. A median of 11.5 cycles were administered. With median follow up of 30.1 months (mo), overall response was seen in 39 (65%) [4 sCR, 5 CR, 16 VGPR, 14 PR]. Median time to first reponse (≥PR) was 1.7 mo (0.8–14.8). Median duration of response (in responders of ≥PR) was 21.3 mo. Median PFS was 13 mo and the 2 year OS rate was 76%. Standard risk pts had median PFS of 18.4 mo and 2 year OS rate was 85%; high risk pts had median PFS of 9.2 mo and 2 year OS rate was 57%. (Figure 1) Conclusions: Pom/dex is highly effective and well tolerated in relapsed MM, with a response rate of 65% even in pts with multiple prior therapies, including other IMiDs, bortezomib and transplant. The response is also durable, with median duration in excess of 21 months. Pom/dex provides long term benefit with median PFS 13 months and 2 year OS rate of 76%. Disclosures: Kumar: Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees. Stewart:Celgene Corporation: Consultancy, Research Funding; Millenium: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Onyx: Consultancy, Research Funding. Fonseca:Consulting :Genzyme, Medtronic, BMS, Amgen, Otsuka, Celgene, Intellikine, Lilly Research Support: Cylene, Onyz, Celgene: Consultancy, Research Funding. Lacy:Celgene: Research Funding.

Abstract Abstract 4120 Introduction: Autologous stem cell transplantation (ASCT) remains an effective treatment for immunoglobulin light chain (AL) amyloidosis but its high treatment related mortality is a concern. The development of acute renal failure can strongly affect the survival of these patients. This study looks at the impact of the timing of dialysis initiation on the overall survival (OS). Methods: AL patients who underwent ASCT from 3/96 to 1/10 were selected. Patients were placed into 4 groups: I - never dialyzed, II - initiated dialysis prior to ASCT, III - dialysis began within 30 days of ASCT and IV - dialysis was started after 30 days of ASCT. Results: Four hundred and ten patients were selected for study and 75 (18.3%) received dialysis. Baseline characteristics are listed in Table 1. In univariate analysis, serum creatinine (Scr) and b-2 microglobulin (b2m) were associated with dialysis post-ASCT. Both became non-significant in the multivariate model suggesting they are co-dependent. Dialysis had a strong influence on survival, p < 0.001 (Fig 1). This was most evident when dialysis was started after ASCT (group III (p = 0.003) and IV (p = 0.004)), but not before (II, p = 0.19).To explore the interactions of dialysis with cardiac biomarkers in their relationship with OS, cardiac troponins T (cTnT) and N terminal-pro-brain natriuretic peptide (NT-pro-BNP) were analyzed with timing of dialysis in a proportional hazard model. Timing of dialysis (p < 0.001), cTnT (p = 0.03) and NT-pro-BNP (p = 0.03) all were associated with OS. Using Receiver Operator Characteristic (ROC) curves, best cut points were chosen for cTnT (0.01 ng/ml) and NT-pro-BNP (1350 pg/ml) for survival. When treated as categorical variables, the proportional hazard model found that only NT-pro-BNP (p = 0.002) and timing of dialysis (p < 0.001) were independent predictors of OS but cTnT had loss its significance (p = 0.07). Using Kaplan Meier method, dialysis was a significant risk factor in patients with low cTnT and both high and low NT-pro-BNP (p < 0.001) but not in patients with elevated cTnT (p = 0.25). Discussion: The timing of acute renal failure strongly affects the OS of AL patients undergoing ASCT. In our study, patients who started dialysis prior to ASCT did not have an inferior OS compared to patients who never needed dialysis. On the other hand, starting dialysis after ASCT significantly shortened OS. The timing of dialysis was an independent predictor of OS even when combined with cardiac biomarkers. NT-pro-BNP appears to be the stronger marker when timing of dialysis is considered in the multivariate analysis. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: Multiple myeloma (MM) is a heterogeneous disease with very divergent outcomes that are dictated in a large part by specific cytogenetic abnormalities, as well as other prognostic factors such as the proliferative rate of marrow plasma cells. Prognostic systems incorporating these factors have shown clinical utility in identifying high-risk patients, and are increasingly being utilized for treatment decision-making. However, the prognostic relevance of these factors may change with the application of novel therapies. The objective of this study was to determine the impact of risk-stratification (incorporating plasma cell metaphase cytogenetics, interphase fluorescent in-situ hybridization (FISH) and the slide-based plasma cell labeling index (PCLI)) in a cohort of patients with newly diagnosed MM treated initially with lenalidomide + dexamethasone (Rev-Dex). Methods: From March 2004 to November 2007, 100 consecutive patients treated with Rev (25mg/day) on days 1 through 21 of a 4-week cycle in combination with dexamethasone as initial therapy for newly diagnosed myeloma, were identified. High-risk MM was defined as presence of any one or more of the following: hypodiploidy, monoallelic loss of chromosome 13 or its long arm (by metaphase cytogenetics only), deletion of p53 (locus 17p13) or PCLI ≥ 3% or immunoglobulin heavy chain (IgH) translocations, t(4;14) (p16.3;q32) or t(14;16)(q32;q23) on FISH. PFS and OS survival estimates were created using the Kaplan Meier method, and compared by log-rank tests. Results: The median estimated follow-up of the entire cohort (N=100) was 36 months. The median PFS was 31 months; the median OS has not been reached. The 2- and 3-year OS estimates were 93% and 83%, respectively. 16% patients were deemed high-risk by at least one of the 3 tests (cytogenetics, FISH or PCLI). Response rates (PR or better) were 81% versus 89% in the high-risk and standard risk groups, respectively, P=NS; corresponding values for CR plus VGPR rates were 38% and 45% respectively. The median PFS was 18.5 months in high-risk patients compared to 37 months in the standard-risk patients (n=84), P<0.001(Figure). Corresponding values for TTP were 18.5 months and 36.5 months, respectively, P=<0.001. OS was not statistically significant between the two groups; 92% 2-year OS was noted in both the groups. Overall, 95 patients had at least one of the 3 tests to determine risk, while 55 patients could be adequately stratified based on the availability of all the 3 tests, or at least one test result that led to their inclusion in the high-risk category. The significant difference in PFS persisted even when the analysis was restricted to the 55 patients classified using this stringent criterion; 18.5 months vs. 36.5 months in the high-risk and standard- risk groups respectively; P<0.001. In a separate analysis, patients who underwent SCT before the disease progression were censored on the date of SCT to negate its effect, and PFS was still inferior in the high-risk group (p=0.002). Conclusion: The TTP and PFS of high-risk MM patients are inferior to that of the standard-risk patients treated with Rev-Dex, indicating that the current genetic and proliferation-based risk-stratification model remains prognostic with novel therapy. However, the TTP, PFS, and OS obtained in high-risk patients treated with Rev-Dex in this study is comparable to overall results in all myeloma patients reported in recent phase III trials. In addition, no significant impact of high-risk features on OS is apparent so far. Longer follow-up is needed to determine the impact of risk stratification on the OS of patients treated with Rev-Dex. Figure Figure

Abstract Abstract 4867 Introduction Both multiple myeloma (MM) and (AL) amyloidosis are clonal plasma cell proliferative disorders. While AL rarely “progresses” to MM, probably due to the shorter survival of AL patients, patients with MM have been reported to develop overt AL at a higher frequency. We conducted this study to identify and describe the clinical features, diagnosis, treatment patterns and response, and outcome among patients diagnosed with AL following an initial diagnosis of MM. Patients and Methods Of the 354 patients identified from a prospectively maintained database who carried a diagnosis of both MM and AL during the interval between January 1990 and December 2008, 44 patients had a histologic diagnosis of AL, at least 6 months after the diagnosis of MM. The organ involvement and treatment response (organ and hematologic) for AL as well as MM response to treatment were assessed according to conventional criteria. Results The median age at diagnosis of MM and AL was 63 years (range, 42-82) and 68 years (range, 45-86), respectively; 27 (61%) were males. The median time to AL diagnosis after MM diagnosis was 41 months (range, 7.6-134). The estimated median follow up from diagnosis of MM and AL is 15.5 years and 10 years, respectively and 39 (89%) patients have died. The median overall survival (OS) from diagnosis of MM and AL was 68.6 months and 9.1 months, respectively. At the time of AL diagnosis, 33 (75%) patients had developed typical features suggestive of AL [heart failure (12), paresthesias (11), nephrotic range proteinuria (9), elevated alkaline phosphatase and hepatomegaly (2), fatigue (7), weight loss (5), macroglossia (4) and periorbital ecchymoses (1)]; while others developed atypical features (3) (7%) or had an incidental finding of AL (8) (18%) [autopsy (2), unexplained cytopenia (2), mild proteinuria (1) and no symptoms (3)]. Cumulatively, amyloid deposits were revealed by biopsy of: bone marrow (23) (52%), subcutaneous abdominal fat (17) (39%), organ (10) (23%) and carpal tunnel tissue (6) (14%). Organ involvement, treatment response and hematologic status of MM at AL diagnosis were assessed for the evaluable patients. None, 1 and >1 organ involvement occurred in 5 (11%), 28 (64%) and 9 (20%) patients, respectively at AL diagnosis or follow up; while AL as the cause of neuropathy was questionable in 2. The organs involved were: heart (14, including 8 with >1 organ involvement), nerves (11), kidney (10), soft tissue (6), lung (5), GI (1) and liver (1). The hematologic status of MM at AL diagnosis included SD (22), progression (10), PR (3), VGPR (3) and not evaluable (6). The subsequent hematologic and organ response did not differ significantly among those who had a treatment change or started (20) (45%) compared with those who did not have a treatment change (20) (45%) at AL diagnosis [excluding those lost to follow up (2) or diagnosed at autopsy (2)]; although more patients (8/10) who had biochemically progressive MM belonged to the former group. The best hematologic response to treatment(s) after AL diagnosis (28) (64%) was: SD (17), PR (3), VGPR (6), CR (1), and progression (1); and not evaluable in others. The organ response (excluding patients with carpal tunnel surgery) to treatment(s) (18) (41%) was: progression (11), stable (4) and organ improvement (3). More patients with an improved (2/3) and stable (1/4) organ response had hematologic PR or better than those with progression (0/11) of organ disease. Five (11%) patients were alive at last follow up; and had either isolated kidney (3) and soft tissue (macroglossia) (1) or no organ involvement (1). All patients with an organ improvement, and 2/5 patients alive, had received PBSCT after AL diagnosis. Fewer patients with >1 organ involvement (1/9) underwent PBSCT compared with those without organ involvement (2/5); and achieved (0) PR versus (3) VGPR (to any treatment), respectively. Only 1/8 patient with an incidental discovery of AL developed symptomatic (cardiac) AL after 108 months of MM diagnosis and died; the remaining are either alive (1) or died from MM and its complications (3), infection (1), or were diagnosed at autopsy (2). Conclusion The recognition of AL (especially cardiac and multiorgan involvement) is critical in MM patients in order to determine prognosis and influence treatment. A high index of suspicion is required for the prompt recognition of AL to ensure timely institution of therapy with a goal of achieving hematologic and organ response. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 4228 Background Peripheral blood stem cells (PBSC) are the preferred graft type for autologous stem cell transplantation (ASCT) and mobilization is typically done using growth factor (GF) alone or a combination of chemotherapy (CTX) and GF. The success of mobilization is influenced by several factors such as prior therapy, mobilization strategy, underlying disease, among others. Patients (Pts) failing to mobilize successfully often have GF dose increased and if unsuccessful, mobilization is reattempted with chemotherapy + GF or G-CSF (Granulocyte Colony-Stimulating factor) + GM-CSF (Granulocyte–Macrophage Colony-Stimulating factor). More recently, plerixafor, a CXCR4 inhibitor, has been found to enhance G-CSF based collection allowing potential early intervention in poor mobilizers. However, this approach requires valid cut-points for peripheral CD34 counts (pCD34) for cost efficient use. Methods We studied 656 first time, G-CSF based PBSC mobilizers with Non-Hodgkin Lymphoma (562; 86%), or Hodgkin's Disease (94; 14%). Salvage attempts were excluded, as were first attempts using CTX+GCSF, plerixafor or GF combinations. Sensitivity-specificity analysis (Receiver operating characteristic) was used to define ideal cut-points for predefined outcomes. We used a CD34 yield of 2 million/kg as the minimum required collection and 5 million/kg as the ideal collection for the current analysis. Our current practice is to initiate collection at a pCD34 of 10/uL. Results We first determined the best day 1 pCD34 cutoff for being able to collect at least 2 million/kg PBSC to be 9/uL. Among those with ≥9/uL, only 6.6 % failed to collect at least 2 million compared to 55% among the rest (P < 0.001). These numbers were 6.3% and 50% respectively using the traditional cutoff of 10/uL. We then examined how the pCD34 on day 2 predicted collection, among those failing to reach the current threshold of 10/uL. Among this group, a pCD34 on day 2 of 9.1/uL was the best cutoff to predict a collection of 2 million/kg. Among those with >=9.1/uL, only 22% failed to collect at least 2 million compared to 79% among the rest (P < 0.001). Among those with day 1 pCD34 < 10, 49% achieved a count of 9.1/uL on day 2. We then examined what pCD34 on day 1 can best predict a pCD34 ≥ 9.1 on day 2 and found this to be 5.2/uL. Among those with day 1 pCD34 ≥ 5.2/uL, 79% reached day 2 pCD34 ≥ 9.1 compared to 24% among the rest (P < 0.001). We then determined cutoffs based on ideal targets using only those patients achieving pCD34 count > 10/uL by day 2, since these patients would have started collection without any change in the mobilization technique. We used a maximum of 5 collections to achieve the goal as being ideal, taking into account the most commonly used practice of collecting during weekdays. We examined cutoffs for a target of 5 million/kg for one transplant. The best day 1 or day 2 pCD34 predicting a 5 million/kg yield in 5 collections was 17/uL. Among those with day 1or 2 pCD34 ≥ 17/uL, 4% failed to reach 5 million in ≤ 5 days compared to 96% among the rest (P < 0.001). Conclusions This study provides an estimate of optimal pCD34 count thresholds for early identification of patients with lymphoma at high risk of collection failure. It is reasonable to use the first or second day pCD34 count, since a substantial proportion of patients will achieve the threshold value by day 2 and these patients appear to have similar outcome as those reaching the threshold by day 1. Based on the results here, interventions such as addition of plerixafor can be considered if pCD34 count is < 6/uL on day 1 or < 10/uL by day 2, to achieve the minimum collection of 2 million/kg. However, in order to achieve the ideal targets, a higher threshold should be considered and the recommendation based on the current study would be 17/uL for a target of 5 million. Such a target-adapted strategy may be more appropriate. Disclosures: Kumar: Celgene,Genzyme,Millenium,Novartis,Bayer,: Honoraria, Research Funding. Gertz:Genzyme: Research Funding. Micallef:Genzyme: Research Funding.