Reece, Donna

Abstract Introduction: In multiple myeloma, randomized trials of maintenance therapy using thalidomide or lenalidomide following autologous transplant (ASCT) demonstrated prolonged progression-free survival (PFS), but overall survival benefit was inconsistent. The MY.10 trial (n=332) demonstrated improved PFS with thalidomide-prednisone maintenance therapy, but quality of life was inferior and overall survival was not improved. As a randomized trial with a no-treatment control arm and biospecimen collection, MY.10 provides a unique opportunity to identify predictors of benefit from therapy that could be used to personalize treatment. Immunomodulatory drug action is mediated in part through binding to cereblon (CRBN) and downregulation of IRF4. Candidate single nucleotide polymorphisms (SNPs) were selected from the CRBN/IRF4 pathway and other genes previously associated with myeloma prognosis, drug response and toxicity from literature review. The aim of this study was to investigate associations between candidate SNPs and benefit from immunomodulatory compound-based maintenance therapy, as well as prognostic impact. Methods: Genomic DNA was extracted from samples preserved in Trizol¨. SNPs were genotyped using TaqMan¨ genotyping assays on the ViiA7 qPCR platform. Analysis was performed on 187 patients with available samples and clinical data (86 in treatment arm; 101 in observation arm). Cox regression models were performed using SAS clinical 2.0 for prognostic impact of a single SNP on PFS, assessed with and without adjusted covariates (age, stage, performance status and response to ASCT). In treatment benefit analysis, PFS was modeled with genotype, treatment assignment and their interaction term. Results: SNPs with significant prognostic impact for PFS in all 187 patients were found in CRBN (rs1672753) (HR 0.59, 95%CI 0.4-0.86; p=0.006) and the following SNPs which had been found to be prognostic in prior studies were validated: CYP1A1 (rs1048943) (HR 1.98, 95%CI 1.19-3.27; p=0.008), CYP1B1 (rs1056836) (HR 0.72, 95%CI 0.52-0.99; p=0.043), and trend toward significance for SNP in CYP1A2 (rs2069514) (HR 2.02, 95%CI 0.98-4.15; p=0.057). Of these, only the CYP1A1 SNP was found to be possibly predictive of greater benefit from maintenance therapy. A SNP in ABCA1 (rs363717), previously associated with thalidomide-induced neuropathy,‎ was prognostic in this study (HR 1.44, 95%CI 1.03-2.02; p=0.033) but not predictive of treatment benefit. Table 1 lists SNPs associated with a differential level of benefit from maintenance therapy, including SNPs in FAM179a and ICAM1 that were possibly associated with harm from maintenance therapy. Table 1. SNPs and treatment interaction with significant impact on PFS. HR represent hazard ratio of treatment versus observation for a given genotype group. Asterisk Indicates trend toward significance. Wildtype Heterozygote & mutant p-value interaction Gene dbSNP ID SNP HR 95% CI HR 95% CI FAM179A rs1053667 T>C 0.46 0.33, 0.66 2.28 0.78, 6.65 0.003 ICAM1 rs1799969 G>A 0.51 0.36, 0.73 1.75 0.83, 3.70 0.007 CASP3 rs1049216 A>G 0.82 0.54, 1.25 0.41 0.25, 0.69 0.029 IRF4 rs12203592 C>T 0.69 0.47, 1.02 0.38 0.21, 0.69 0.062* CYP1A1 rs1048943 A>G 0.62 0.44, 0.87 0.11 0.02, 0.52 0.079* Conclusion: Previously identified SNPs in drug metabolism and drug efflux genes were validated to be prognostic in this cohort. The prognostic but not predictive significance of a SNP in CRBN suggests a possible role for CRBN in multiple myeloma disease biology independent of immunomodulatory therapy. SNPs predictive of differing degrees of benefit from immunomodulatory maintenance were found in genes involved in immunomodulatory activation, drug action and cell adhesion mediated drug resistance; SNPs in FAM179A and ICAM1 were possibly associated with harm from thalidomide maintenance and could potentially be used to identify patients unsuitable for immunomodulatory maintenance therapy. These results may be applicable to lenalidomide and pomalidomide, since immunomodulatory compounds exhibit similar chemical structures and mechanisms of action. Validation of these SNPs in prospective clinical trials involving other immunomodulatory can test this hypothesis. Further studies are needed to confirm our findings. Disclosures Off Label Use: thalidomide and prednisone maintenance for multiple myeloma. Bahlis:Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Consultancy; Johnson & Johnson: Speakers Bureau; Johnson & Johnson: Consultancy; Johnson & Johnson: Research Funding. Song:Celgene Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. White:Celgene Canada: Honoraria, Research Funding. Chen:Celgene: Consultancy, Honoraria, Research Funding. Seftel:Celgene: Honoraria, Research Funding. Howsen-Jan:Celgene: Honoraria, Research Funding. Reece:Amgen: Honoraria; Bristol-Myers Squibb: Research Funding; Merck: Research Funding; Novartis: Honoraria, Research Funding; Onyx: Consultancy; Millennium Takeda: Research Funding; Lundbeck: Honoraria; Otsuka: Research Funding; Janssen-Cilag: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Shepherd:Celgene: Honoraria, Research Funding. Chen:Celgene: Honoraria, Research Funding. Djurfeldt:Celgene: Research Funding. Reiman:Soricimed Biopharma Inc: Consultancy, Other: Scientific Advisory Board for Soricimed.

Abstract Abstract 1874 Poster Board I-899 Lenalidomide (Revlimid®) and dexamethasone is an effective regimen in relapsed/refractory multiple myeloma (MM) patients (pts), with an overall response rate of 60.6% and median time to progression (TTP) of 13.4 months (Dimopoulos MA, et al, Leukemia 2009 Jul 23 [Epub ahead of print]). Oral cyclophosphamide and prednisone is an older regimen with excellent patient tolerance, and we sought to enhance the efficacy of lenalidomide by adding oral cyclophosphamide and prednisone in this phase I-II trial. The CPR regimen consisted of cyclophosphamide on days 1, 8 and 15; lenalidomide on days 1–21; and prednisone 100 mg every other day in a 28 day cycle. ASA 81 mg/day was given to all pts as DVT prophylaxis. Three dose levels were evaluated using a 3 by 3 dose escalation design. Between 11/2007–07/2009, 31 pts with relapsed/refractory MM who had not previously received lenalidomide were entered onto study. Median age was 61 (40–78) years and 61% were male. Immunoglobulin subtype was IgG in 19 pts (61%), IgA in 8 pts (26%) and light chain only in 4 pts (13%). Median number of prior regimens was 2 (1–5) and 28 pts had undergone previous ASCT, including double transplants in 6 pts. Prior therapy included thalidomide in 9 (29%) and bortezomib in 15 (48%). FISH cytogenetics were available in 13 pts; one had 13q deletion but none had t(4;14) or p53 deletion. At the time of protocol entry, median β 2-microglobulin level was 246 (92–767) nm/L, albumin 39 (34–48) g/L, creatinine 83 (50–126) μmol/L, platelet count 230 (75–337) × 109/L and ANC 2.5 (1.1–6.1) x 109/L. Protocol treatment is summarized in Table 1. Dose limiting toxicity was not observed during cycle 1 at any dose level. Grade 3–4 toxicities included thrombocytopenia in 5 pts (16%) and neutropenia in 9 pts (29%). These were managed with dose reduction and/or growth factor support. Four episodes of febrile neutropenia occurred. Other grade 3–4 non-hematologic toxicities included abdominal pain/bacteremia in 1 pt in cohort 1; hypokalemia in 1 pt in cohort 2; and DVT in 2 pts, dizziness in 2 pts and fatigue in 1 pt in cohort 3. Using the International uniform response criteria (Durie BG, et al, Leukemia 2006; 20:1467–1473), the best response was documented at a median of 6 (1–5) cycles and included the following: dose level 1 (1 CR, 2 PR); dose level 2 (1 VGPR, 2 PR); dose level 3 (5 CR, 9 VGPR, 9 PR, 1 MR and 1 stable disease). At a median follow-up (F/U) of 12 (8–21) months, 20 pts remain on study, 2 have withdrawn and 9 pts have progressed at a median of 9 (4–13) months; only 1 one has died (due to MM). We conclude: 1) the combination of full doses of the agents in CPR can be given in a 28 day cycle with minimal toxicity; 2) the overall response rate (CR + VGPR + PR) in 31 pts to date is 93%; 3) at a median F/U of 1 year, only 9 pts (29%) have progressed; 4) longer follow-up is required to assess the TTP and survival of the CPR regimen. Disclosures: Reece: Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Off Label Use: Lenalidomide in combination with drugs other than dexamethasone. Anglin:Celgene: Honoraria. Chen:Celgene: Honoraria, Research Funding. Kukreti:Celgene: Honoraria. Mikhael:Celgene: Honoraria. Trudel:Celgene: Honoraria.

Abstract Abstract 2403 Immunoglobulin light chain amyloidosis (AL) is a monoclonal plasma cell disorder characterized by the accumulation of monoclonal light chain fragments that have undergone a conformational transformation and deposit as amyloid fibrils in different tissues. High-dose melphalan (HDM) with autologous hematopoietic stem-cell transplant (ASCT) is increasingly used to treat patients (pts) with AL Amyloidosis. However, transplant-related mortality (TRM) is high, ranging between 13% to 43%. The survival benefit of HDM has been attributed to a patient-selection bias. Recently, a randomized clinical trial by Jaccard A et al, showed longer survival in the group assigned to receive melphalan plus dexamethasone (Mel/Dex) than in the group assigned to receive HDM. The present is a retrospective study aiming to define which pts with AL are most likely to benefit from HDM. Patients and Methods We retrospectively reviewed the medical records of all the pts included in the Princess Margaret Hospital Amyloidosis Database who underwent ASCT from January 2004 to March 2010 to determine: a) TRM, b) Hematological response (HR) and Organ response (OR) and c) Overall survival (OS). We included transplanted pts who had received no more than two previous courses of any chemotherapy regimen who did not have concurrent myeloma, and who had an Eastern Cooperative Oncology Group (ECOG) performance-status score of 2 or better. As part of the ASCT the stem cells were obtained from the peripheral blood with granulocyte colony-stimulating factor (G-CSF) alone (5 μ g/kg subcutaneously, twice daily). Pts then received HDM, 200 mg/m2 given intravenously on day 0, and stem cells were infused on day 1. The HDM was reduced to 140 mg/m2 for pts 65 years of age or older and for those with an important decrease of the ejection fraction, a calculated creatinine clearance of less than 30 ml per minute, or severe liver disease. HR and OR was assessed using 2004 Amyloidosis Consensus Response Criteria (Gertz, M et al, 2004). For statistical evaluation, HR was defined as observing complete or partial remission (CR or PR); stable disease (SD) or progression was considered as no HR. All statistical tests were 2-sided X2 t test and P values less than .05 were considered to be statistically significant. Results Seventy seven pts were evaluated with a median age of 56 years (33-74). Clinical characteristics are seen in Table 1. Only 18/77 pts (23%) received induction therapy: Dexamethasone alone n=9, Cyclophosphamide and Prednisone n=2, Mel/Dex n=4, VAD n=2 and Melphalan and Prednisone n=1. TRM observed was 12% mainly due to congestive heart failure and sepsis. Complete HR was achieved in 38 cases (49%) and OR was seen in 59%. Among the most common complications to ASCT, febrile neutropenia was reported in 67%, transient renal impairment in 10% and congestive heart failure in 3%. Median OS was significantly lower for patients with B-type natriuretic peptide (BNP) >300 pg/ml (17.7 vs 64.46 months) (p0.0004), Troponin I >0.07 ng/ml (19.25 vs 97.4 months) (p0.00001) and those who achieved a complete HR (115 vs 88 months) (p0.0345). Multivariate Cox regression analysis showed that BNP>300 pg/ml and Troponin I >0.07 ng/ml (normal <0.07) were the most important factors to predict OS for patients with AL who underwent ASCT (p0.0002 and 0.04 respectively). Conclusions Based on this study of 77 patients, clinical selection is the most important factor to better improve outcomes for HDM in AL. Patients with BNP>300 pg/ml and/or abnormal levels of Troponin I (>0.07) should not be considered eligible for transplants due to a high degree of mortality. Our series showed a CR rate of 49% which is higher than 33% reported by Palladini et al with Mel/Dex. Stringent case selection may be the most important factor in decreasing mortality rate associated to ASCT leading to better outcomes. Table 1. Clinical Characteristics of patients with AL Amyloidosis undergoing ASCT (at initial diagnosis) Clinical Characteristics N Median Range % Age (years) 77 57 33–74 Hemoglobin (g/L) 77 138 104–182 Creatinine (μ mol/L) 77 129 37–700 **BNP (pg/ml) 44 180 10–1670 ***BMPC (%)– 77 7 1–30 24 Hr Proteinuria (g/d) 77 5.5 0–24.9 Intraventricular Septal Distance (mm) 77 13 9–23 Kappa/lambda ratio 53 4.4 0.001–71.2 Kidney Involvement 71 Heart Involvement 52 Liver involvement 23 GI involvement 10 3 or more organs involved by AL 16 ** B-Type Natriuretic Peptide *** BMPC: Bone marrow plasma cells Disclosures: Stewart: Millennium: Consultancy; Celgene: Honoraria. Reece: Celgene: Honoraria, Research Funding. Chen: Celgene Corporation: Consultancy, Honoraria, Research Funding. Kukreti: Celgene: Honoraria.

Abstract Abstract 2876 Poster Board II-852 Multiple myeloma (MM) patients (pts) are immunosuppressed given the underlying disease, previous treatments and myelosuppression seen on lenalidomide (Revlimid, Rev). We evaluated the infectious complications seen on Celgene's Expanded Access Rev program at Princess Margaret Hospital. We have treated 75 pts who had progressed after at least one prior therapy as part of a national study in Canada. At entry, pts were required to have a neutrophil count of ≥1.0 ×109/L. The median age was 61 yrs (range 35-79); 52% were males. Prior therapy included stem cell transplant in 65, thalidomide in 54 and bortezomib in 24. Number of lines of prior therapy were as follows: 24 (one), 29 (two), 16 (three), 8 (four) and one (five). Neupogen was used liberally (63%) after a patient had a dose delay on trial due to neutropenia. Patients were treated with full dose lenalidomide at entry onto clinical trial and were maintained on full dosing unless platelet counts were <30×109/L or ANC was <1.0×109/L. No other dose adjustments were made for renal dysfunction. Results: There were 32 pts (43%) who had a clinically evident infection; the majority (91%) was on prophylactic antibiotics (septra/ciprofloxacin) at the time. There were two deaths due to infection and 23 pts (72%) required hospitalization (range 2-27 days). The majority of infections occurred within the first 4 cycles of treatment (26 pts) and seemed to occur more in pts with several lines of prior therapy – 7/24 (29%) with 1 prior therapy, 14/29 (48%) with 2, 9/16 (56%) with 3 and 2/8 (25%) with 4 prior therapies. Sixteen were neutropenic of which 7 had febrile neutropenia (9%). The types of infections were: respiratory in 14 (1 with pneumocystis pneumonia), cellulitis in 4, herpes simplex and herpes zoster in 2 pts each. These included streptococcus pneumoniae (1), staphylococcus aureus (3), respiratory syncitial virus (1) and mycobacterium chelonae (1). Rev was held during the infection in 23 pts (72%). Conclusions: 1) Infections are frequent in this patient population (43%) and often lead to hospitalization (72%); respiratory infections accounted for a large majority (43%). 2) Early aggressive growth factor support and broader antibiotic prophylaxis may be of benefit especially in heavily pretreated patients. 3) Dose reduction of Rev in the context of serious infections should be further evaluated. Disclosures: Kukreti: Celgene: Honoraria. Trudel:Celgene: Honoraria, Speakers Bureau; Ortho Biotech: Honoraria. Chen:Celgene: Honoraria.

Abstract Btz (VELCADE®) is approved for patients (pts) with relapsed MM. This study characterized PK/PD of btz at 2 doses (1.0, 1.3mg/m2) after single- and multiple-dose administration, and evaluated their relationship. 24 pts with relapsed MM and creatinine clearance ≥50mL/min were randomized to btz 1.0 (n=12) or 1.3mg/m2 (n=12) on D 1, 4, 8 and 11 of a 21-D cycle (C). Pts could continue therapy for ≥8 Cs if beneficial. PK/PD samples were drawn at multiple time points on D1 and D11 of C1 and C3 over 48h. Plasma concentrations of btz were similar following administration of 1.0 and 1.3mg/m2; differences in mean plasma Cmax and AUC values were within the degree of intersubject variability (Table). There was a decrease in clearance and an increase in terminal half-life of btz on D11 vs D1 of C1.The volume of distribution of btz suggests extensive peripheral tissue distribution. After single or repeat administration, mean maximum percent inhibition of 20S proteasome activity (vs baseline) in whole blood was 70–84% and 73–83% for the 1.0 and 1.3mg/m2 doses, respectively. The percentage of pts who had >90% inhibition was greater in subsequent doses vs first dose. Reversibility of 20S proteasome inhibition in whole blood was demonstrated. PK/PD modeling revealed an exposure-response relationship, with Emax and EC50 values consistent across study days. These results confirm btz is a potent inhibitor of the 20S proteasome. The efficacy of single-agent btz has been explored and validated in the pivotal phase 2 SUMMIT and phase 3 APEX trials at 1.3mg/m2, and explored in the phase 2 CREST trial at 1.0mg/m2. Complete safety and efficacy data by dose will be presented. Mean±SD PK parameters of btz in plasma 1.0mg/m2 1.3mg/m2 1.0mg/m2 1.3mg/m2 D1/C1 (n=11) D11/C1 (n=12) an=5;bn=11;cn=10;dn=7;en=11;fn=9 Tmax (h) 0.13±0.13 0.11±0.06 0.07±0.03 0.20±0.29 Cmax (ng/mL) 56.7±36.3 112±122 106.2±46.7 88.6±47.6 AUC48h(ng·h/mL) 26.5±12.4 34.6±19.8 82.8±35.9b 82.4±28.6b AUClast (ng·h/mL) 22.6±12.6 31.5±18.6 137±106 122.2±67.4 CL (L/h) 102.1±48.1 111.6±73.6 23.2±17.8 28.0±19.8 Vβ (L) 1976±2498a 2015±2974d 1659±752c 2415±1711 t1/2λz(h) 30.7±44.8a 11.5±12.7d 78.9±50.9c 75.6±49.9 D1/C3 (n=12) D11/C3 (n=12) Tmax (h) 0.12±0.12 0.10±0.05 0.16±0.17 0.10±0.05 Cmax (ng/mL) 66.5±42.6 120.3±70.7 83.9±69.3 114.9±98.3 AUC48h(ng·h/mL) 66.4±24.1 79.4±24.5b 101.6±58.2b 85.2±18.7f AUClast (ng·h/mL) 74.8±35.8 86.0±27.6 227±181 160.7±67.1 CL (L/h) 32.2±19.0 32.1±15.4 15.1±13.9 18.2±9.2 Vβ (L) 1852±951d 2059±1231 3294±2993e 2505±1641 t1/2λz (h) 39.9±14.4d 49.1±34.6 193±169e 108.6±64.8

Abstract Abstract 1217 Poster Board I-239 Background Single autologous stem cell transplant (ASCT) is considered the standard of care after induction therapy for younger multiple myeloma (MM) patients (pts). However, it is not curative and virtually all patients will ultimately relapse. As more options are available to treat relapsed disease, the role of a second ASCT as salvage therapy is unclear. Method Retrospective review of all MM pts who received a 2nd ASCT as salvage therapy at Princess Margaret Hospital. Results Between February 1997 and July 2009, 79 MM pts received a second ASCT for relapsed MM at our institution. Median age was 60 yrs (range 39-72) at second transplant. 48 pts (61%) were male. Immunoglobulin subtype included IgG (42), IgA (21), light chain (11), nonsecretory (3), IgM(1) and IgD (1). Transplant conditioning regimen for first transplant was high dose melphalan (MEL) 140-200 mg/m2 in 67, busulphan and cyclophosphamide in 1, and combinations of MEL with etoposide (E) or TBI in the rest. 2nd ASCT conditioning consisted of MEL alone in 76, the remaining 3 had MEL with either TBI or E. The median time to relapse after the first transplant was 2.72 years (0.81-8.26), with a median interval between transplants of 3.61 years (1.63-9.59). Response to first transplant in 78 evaluable patients was 13 CR/nCR (17%), 56 PR/VGPR (72%), 9 MR/SD (12%). Nineteen pts received maintenance therapy between transplants. Two transplant-related deaths occurred following 2nd ASCT. In 73 evaluable patients, response to second transplant was 11 CR/nCR (15%), 57 PR (78%), 6 MR/SD (8%). After 2nd ASCT, with median follow up 5.92 years (71 months), median progression-free survival (PFS) was 18.5 months and median overall survival (OS) was 4.4 years. Long term progression-free status based on the progression-free interval after 1st ASCT is summarized Table 1. PFS based on progression free interval after 1st ASCT is outlined in Figure 1. Conclusions 2nd ASCT is a feasible and safe salvage therapy in relapsed MM patients. It is effective in providing a median progression free survival of 18.5 months and median overall survival of 4.4 years (52.8 months) after 2nd ASCT. This is comparable if not better than modern salvage chemotherapies. The longer the disease free interval after 1st ASCT the more effective 2nd ASCT is at extending both progression free survival and overall survival. It is reasonable, therefore, to consider a 2nd ASCT if the time to progression is greater than 2 years after first ASCT. Disclosures Chen: Celgene: Honoraria, Research Funding; Ortho Biotech: Honoraria. Trudel:Celgene: Honoraria, Speakers Bureau; Ortho Biotech: Honoraria. Kukreti:Celgene: Honoraria.

Abstract Background: Lenalidomide (Revlimid®) in combination with dexamethasone was approved in the US on June 29, 2006 for the treatment of subjects with multiple myeloma who had received at least one prior therapy. On February 28, 2005 based upon a positive interim analysis of two pivotal placebo-controlled Phase III studies, an independent Data Safety Monitoring Board recommended the studies be unblinded and all subjects in both studies be given access to lenalidomide. In April 2005, the FDA in association with myeloma patient advocacy groups requested Celgene establish an expanded access program to make lenalidomide plus dexamethasone available to subjects with relapsed or refractory multiple myeloma while the treatment was awaiting approval. Aim: To provide lenalidomide to multiple myeloma subjects with a high likelihood of benefit and to obtain additional safety data. Methods: Subjects with relapsed or refractory multiple myeloma that received at least 1 prior therapy were eligible. Subjects received 25 mg lenalidomide plus high-dose dexamethasone in 4-week cycles until disease progression was documented, study drug was discontinued, or lenalidomide became commercially available for this indication. Results: Between September 8, 2005 and July 25, 2006, approximately 1400 subjects in the US and Canada were enrolled into the study. A data snapshot taken March 17, 2006 demonstrated that 746 subjects had been enrolled, median age was 63 years, 60% were male, and 66.5% had Stage III disease. Median time on study was 7.1 weeks (0.1–24.4) and median daily dose was 20.5 mg. At least one Grade 3 or 4 adverse event was reported in 261 (35%) of the 746 subjects. Most commonly reported Grade 3–4 events were neutropenia (7.9% of subjects), thrombocytopenia (6.0%), fatigue (3.6%), anemia (3.5%), pneumonia (3.1%) and hyperglycemia (2.0%). These most commonly reported Grade 3–4 adverse events were the same as those found in the previous pivotal studies, however, their frequencies of occurrence were lower in the current study probably due to ongoing data collection and differences in study maturity. Likewise, the most commonly reported adverse events (all grades) were the same as those reported in the two previous pivotal studies. Conclusion: Preliminary data from this expanded access program in over 1400 subjects with multiple myeloma are consistent with results from two earlier Phase III pivotal studies. The EAP of lenalidomide plus dexamethasone in multiple myeloma represents a model of how government, advocacy groups, healthcare providers and industry can work together to quickly provide treatment to subjects in need while a clearly active treatment regimen is awaiting approval.

Abstract The t[4;14] simultaneously deregulates fibroblast growth factor receptor 3 (FGFR3) and MMSET in 15% of patients (pts) with Multiple Myeloma (MM). Although oncogenic, FGFR3 expression is lost in ~25% of t[4;14] pts on gene expression profiling while MMSET is always retained. The t[4;14] is highly associated with poor prognosis, furthermore FGFR3 kinase inhibitors are in Phase I trials, thus detection of t[4;14] pts is increasingly important. The Multiple Myeloma Research Consortium (MMRC) therefore evaluated 4 competing methodologies for the diagnostic detection of t[4;14]. Bone marrow (BM) samples were collected in uniform fashion from 85 pts. FGFR3 immunocytochemistry (ICC) and flow cytometry (FC) were performed at the retrieval site, while split samples were shipped to the MMRC tissue bank and processed under GLP conditions. Processed samples were analyzed by cIg-FISH and quantitative IgH-MMSET RT-PCR (QPCR) on unsorted BM and blood. Of 60 samples with sufficient plasma cells for analysis, 8 were FISH +ve [13.3%]. Low % BM plasma cells prevented successful FISH in 25% of samples reflecting large volume harvests and hemodilution. Analysis was conducted in a blinded fashion. With FISH as the gold standard for detection of t[4;14] the sensitivity and specificity of the other diagnostic tests are: BM QPCR is most sensitive (7 of 8 FISH positive detected) and specific (42/43 negatives correctly identified). QPCR on peripheral blood is ongoing. FC is more sensitive to the detection of FGFR3 protein than ICC. Correlation between FC and ICC was only 0.46. Interestingly, 6 of 7 evaluable pts here and 13/14 (92%) in an expanded analysis of FISH +ve patients also expressed the FGFR3 protein. Given the discrepancy between this finding and previously reported loss of FGFR3 expression in 25% of pts we further explored t[4;14] stability. Clonal selection/heterogeneity was determined by the % plasma cells in each pt. with an unbalanced translocation (loss of one der chromosome). In 42 t[4;14] pts, 13 (31%) had a balanced translocation(>75% of cells with a double fusion), 14 (33%) had an unbalanced translocation (>75% cells with only one signal), and 15 (36%) had a chimeric picture. This heterogeneous pattern is suggestive of an evolution towards an unbalanced translocation. Despite this survival did not differ between pts with balanced or unbalanced translocation. Conclusions: These results indicate that the t[4;14] is highly heterogeneous with respect to balanced versus unbalanced translocations, which likely evolve over time. For detection, cIg-FISH continues to be the gold standard diagnostic methodology but may be limited by low plasma cell numbers in dilute BM or during MM remission. QPCR and FC appear most sensitive and specific for presence of t[4;14] and FGFR3 protein expression respectively. Surprisingly (given prior evidence of loss of FGFR3 expression in 25% of pts) 92% of t[4;14] pts in this series expressed FGFR3 protein. # Analyzed % Positive Sensitivity Specificity FISH 60 13 - - QPCR 65 14 87.5 97.6 Flow 82 15 85.7 91 ICC 85 15 62.5 92

Abstract Abstract 4055 Introduction: Approximately 15% of patients (pts) with multiple myeloma (MM) exhibit a t(4;14) translocation that results in constitutive activation of the receptor tyrosine kinase (RTK) fibroblast growth factor receptor 3 (FGFR3) in the absence of ligand. This translocation has been strongly linked with a poor prognosis and short survival compared with pts without this translocation. Dovitinib (TKI258) is an RTK inhibitor that has demonstrated in vitro inhibitory activity against FGFR (including FGFR3), vascular endothelial growth factor receptor (VEGFR), and platelet-derived growth factor receptor (PDGFR), with IC50values of approximately 10 nM. Tumor growth inhibition was observed in xenograft tumor models of MM treated with dovitinib. This study was designed to evaluate the efficacy and safety of dovitinib in pts with relapsed or refractory MM that is either t(4;14) positive or negative. Patients and Methods: Adult pts who had received at least 2 prior antimyeloma regimens and who had relapsed or were refractory to their last treatment regimen were enrolled in this multicenter, open-label, 2-stage, phase 2 trial. Pts were evaluated for t(4;14) status at the baseline visit and classified according to the result into either a t(4;14)-positive or a t(4;14)-negative group. Dovitinib was administered at a dose of 500 mg/day on a 5-days-on/2-days-off schedule. Response was characterized as per the International Myeloma Working Group (IMWG) criteria. The primary endpoint was extended overall response rate as defined by the rate of pts with best overall response of complete response, very good partial response, partial response, or minor response. Secondary endpoints included safety, overall response rate, progression-free survival, and pharmacokinetics. After disease progression, pts had the option to continue treatment with the addition of low-dose dexamethasone (40 mg every 7 days) with M-protein levels at the time of progression considered as the new baseline. Results: A total of 43 pts were enrolled in this study; 26 pts were t(4;14) negative, 13 were t(4;14) positive, and 4 pts had unknown/indeterminate t(4;14) status. Median age was 63 years. Most pts (86%; n = 37) had received ≥ 3 prior lines of therapy. No objective responses were observed in either group of pts. Due to the apparent lack of efficacy, the study did not proceed to stage 2. The following observations are based on the preliminary data. In the t(4;14)-negative group, median duration of exposure to the study drug was 4.0 weeks, and 9 of the 26 pts (35%) had stable disease, 13 (50.0%) had progressive disease, and 4 (15%) were not evaluable. Due to slow enrollment and lack of efficacy among the earlier enrolled t(4;14)-positive pts, enrollment for the t(4;14)-positive group was closed prematurely. Among the 13 enrolled t(4;14)-positive pts, median duration of exposure to the study drug was 8.7 weeks. Best responses were stable disease for 8 pts (62%), disease progression for 3 pts (23%), and unknown for 2 pts (15%). Among both groups, the most common adverse events of any grade, regardless of study drug, were nausea (67%), diarrhea (58%), vomiting (51%), fatigue (47%), thrombocytopenia (33%), and anemia (28%). Most of the nonhematologic events were mild. The most common grade 3/4 adverse events were thrombocytopenia (26%) and anemia (23%). The principal reasons for discontinuation of dovitinib monotherapy were disease progression (72%) and adverse events (19%). Six pts continued on the dovitinib plus dexamethasone regimen; 1 pt is ongoing, and 5 pts discontinued due to disease progression (n = 4) and adverse events (n = 1). Conclusion: Dovitinib was found to have no or minimal single-agent activity in relapsed/refractory myeloma irrespective of t(4;14) status. Although the patient numbers are small, the rate of patients with stable disease during study treatment who may have had a clinical benefit was higher in the t(4;14)-positive group, suggesting that this subgroup may be a candidate to explore combination treatment of dovitinib with other agents, such as proteasome inhibitors. Gastrointestinal toxicity, while mostly mild, remains a challenge, and timely monitoring and supportive care during dovitinib treatment may alleviate these symptoms. Dovitinib may be a promising agent for combination therapies to improve prognosis of patients with t(4;14)-positive MM. Disclosures: Scheid: Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Reece:Millennium Pharmaceuticals: Research Funding; Otsuka: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Spencer:Celgene: Honoraria; Janssen: Honoraria, Speakers Bureau; Novartis: Honoraria. Callander:Millennium Pharmaceuticals: Research Funding. Sonneveld:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Honoraria, Research Funding. Kalimi:Novartis Pharmaceuticals: Employment. Cai:Novartis: Employment. Shi:Novartis: Employment, Equity Ownership. Scott:Novartis: Employment. Stewart:Millennium Pharmaceuticals: Consultancy, Honoraria, Research Funding; Onyx: Consultancy; Celgene: Consultancy.