ALBERT

Description: Abstract 3034 Background: The combination of lenalidomide (R), bortezomib (V), and dexamethasone (D) (RVD) in newly diagnosed MM patients is well tolerated and associated with a very high overall response rate. The goal of the current trial is to improve on the CR rate compared with RVD by adding a novel targeted agent. Preclinical studies have demonstrated that vorinostat (Vor), an HDAC inhibitor, is synergistic with bortezomib, immunomodulatory (IMiD®) compounds and dexamethasone. Clinical studies in the relapsed setting using either bortezomib or lenalidomide with vorinostat have yielded promising results with manageable toxicity. The aim of this study is to determine the tolerability and preliminary efficacy of the combination of RVD with vorinostat in newly diagnosed patients with symptomatic MM. Methods: Patients (Pts) received the current standard RVD regimen (lenalidomide 25 mg days 1–14, bortezomib 1.3 mg/m2 days 1, 4, 8, 11 and dexamethasone 20/10 mg PO [cycles 1–4/5-8] days 1, 2, 4, 5, 8, 9, 11, 12 for up to 8 21 day cycles) combined with oral vorinostat (Vor), provided by Merck and Co. Inc., at 100, 200, 300 or 400 mg daily days 1 – 14 of each cycle. Pts were assigned to one of the four dosing cohorts according to the Bayesian Escalation with Overdose Control (EWOC) algorithm. DLT (≥ G3 non hematologic toxicity, G4 hematologic toxicities defined as G4 thrombocytopenia of any duration; failure of recovery of ANC to ≥1,000/μL or platelets to ≥50,000/μL within 14 days of the last treatment; or inability to receive Day 1 dose for Cycle 2 due to continued drug-related toxicity from cycle 1) was determined in the first cycle of therapy. Toxicities were assessed and graded for all cycles using the NCI CTCAE v 3.0. Responses were assessed by modified EBMT and Uniform criteria. Pts with PR or better could proceed to autologous transplant after ≥ 4 cycles. Results: Eleven pts (median age 54, 82% men, 54.5% ISS Stage II/III) have been enrolled to date with n=4 pts each in cohorts 1 (Vor 100mg) and 2 (Vor 200mg), and 3 pts in cohort 3 (Vor 300 mg). One patient has completed 8 cycles, 1 pt completed 4 cycles and proceeded to transplant, 6 pts remain on study treatment and 3 pts have discontinued therapy (1 for significant peripheral neuropathy {grade 3}, 1 for patient choice unrelated to toxicity and 1 for non adherence). Two DLTs have occurred: syncope (cohort 1) and asymptomatic grade 3 elevation of ALT (cohort 2) with none in cohort 3.The episode of syncope was not related to cardiac arrhythmia. One study related SAE has occurred (syncope). One other episode of grade 3 elevation of ALT occurred in a pt in cycle 3 in cohort 1. Both episodes of increased ALT resolved and patients remained on study with dose modification. One patient developed grade 3 diarrhea in cohort 1. No patients have developed a grade 4 toxicity. Treatment emergent peripheral neuropathy occurred in 6 patients (4 grade 1, 1 grade 2 and 1 grade 3). No episodes of study related grade 3 fatigue, nausea, or vomiting have occurred. The MTD has not been reached. Eight patients are evaluable for response. All have responded to study therapy with 3 CRs, 1 VGPR and 4 PRs. Three patients went on to stem cell collection after 4 cycles and all collected an adequate dose for transplant of 〉5 ×106 CD34+ cells/kg. Conclusion: The combination of RVD with vorinostat has been generally well tolerated to date. No unexpected toxicity has been noted with side effects commensurate with prior experience with each of the drugs and no additive toxicity seen to date. While asymptomatic elevation of ALT has been seen and will require ongoing monitoring, grade 3 ALT elevation was a DLT in the original RVD study and related to dexamethasone, so may not be related to the addition of vorinostat. Early efficacy data is promising with 50% of patients achieving a VGPR or higher. Accrual is ongoing to determine the MTD. Disclosures: Kaufman: Celgene, Millenium: Consultancy; Celgene, Merck: Research Funding. Off Label Use: Use of lenalidomide as upfront therapy. Use of vorinostat as upfront therapy. Shah:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium Pharmaceuticals, Inc.: Research Funding; Novartis: Research Funding. Heffner:Millenium: Consultancy, Honoraria, Research Funding. Richardson:Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees. Orlowski:Celgene: Consultancy, Research Funding; Millenium: Consultancy, Research Funding. Lonial:Millennium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Speakers Bureau.

Description: Background: Preclinical work from our group and others has demonstrated that the combination of a farnesyl transferase inhibitor (FTI) and the proteasome inhibitor bortezomib results in enhanced plasma cell apoptosis and is associated with AKT activation (David, Blood 2005). More recently, further preclinical data suggests that the mechanism responsible for this profound synergy is due to inhibition of HDAC6 with a resultant inhibition of both the proteasome and aggresome pathway (David ASH 2007). Based upon these observations, with the MMRC we initiated a phase I trial combining the FTI tipifarnib with bortezomib to clinically evaluate the efficacy of this combination. Methods: Patients with relapsed or refractory myeloma were treated with bortezomib at 1.0 mg/m2 given on days 1,4,8, and 11 in conjunction with escalating doses of tipifarnib (100–400mg/BID) given on days 2–15 every 21 days. Dose escalation was accomplished using an adaptive phase I design (Escalation With Overdose Control (EWOC)). Eligibility criteria included a serum creatinine of 500, and platelets 〉25. If dose escalation is able to proceed to 400mg of tipifarnib with 1.0 mg/m2, the tipifarnib dose escalation will restart with bortezomib given at 1.3 mg/m2. Results: Sixteen patients have been enrolled to date into respective tipifarnib dose levels 100 mg(n=6),200mg (n=5) and 300mg (n=5). Median age for the enrolled patients is 59 (range 43–76) and median time from myeloma diagnosis was 4.7 years. 15/16 patients had received prior high dose therapy. The average number of prior therapies was 4.5, and of the16 patients, 8 were refractory to prior bortezomib (relapsed on therapy or within 6 months) 4 were bortezomib naïve, and 4 were previously exposed to bortezomib but not known to be refractory. Among these patients with advanced myeloma and refractory disease, stabilization of disease or better was seen among 7/16 patients with 2 of the 7 achieving an MR. Of note, among the patients achieving clinical benefit, 1 patient had a stable M-protein, but experienced an 80% reduction in circulating plasma cells while on therapy, and another has had a 75% reduction in the free light chain assay. The most common drug related side effects were was Gr2 diarrhea (23.5%). Hematologic toxicities were difficult to ascertain as patients had advanced myeloma and many were entered onto study with platelet counts between 25 and 50. Additional grade 3 toxicities included renal insufficiency (related to progression), pneumonia and altered mental status which were all considered unrelated to study drug, but were associated with progression of disease. There were no Grade 3 –5 drug related toxicities. There were no cardiac events or DVT, and 1 patient experienced grade 2 peripheral neuropathy who did not have pre existing PN at baseline. Conclusions: The combination of bortezomib and tipifarnib is supported by preclinical rationale and has produced stable disease or better among a group of patients with refractory and advanced myeloma. To date the optimal dose of both tipifarnib and bortezomib have yet to be defined, and additional patients will be enrolled to define the MTD for tipifarnib with 1.0mg/m2 of bortezomib, followed by escalation of tipifarnib with 1.3mg/m2 of bortezomib. Correlative studies evaluating the effect of the combination on HDAC6 and plasma cell apoptosis will be presented.

Description: Key Points Lenalidomide-bortezomib-dexamethasone resulted in partial response or better in nearly two-thirds of relapsed/refractory myeloma patients. The regimen had substantial activity despite high rates of prior bortezomib/thalidomide and regardless of poor prognostic characteristics.

Description: Abstract 1218 Poster Board I-240 Background The combination of lenalidomide (Len, Revlimid®), bortezomib (Bz, Velcade®), and dexamethasone (dex; RVD) has shown excellent efficacy in relapsed/refractory multiple myeloma (MM) patients, with overall response rates (ORR; ≥partial response [PR]) of 69%, including 26% complete/near complete responses (CR/nCR), and manageable toxicities (Anderson et al. ASCO 2009). The phase I portion of the study (Richardson et al. IMW 2009) found the maximum tolerated dose (MTD) of this combination in newly diagnosed MM patients to be Len 25 mg/day, Bz 1.3 mg/m2, and dex 20 mg. In all phase I patients, the ORR was 100%, including 31% CR, 9% nCR, and 75% 3very good PR (VGPR). Results reported here are for patients treated in the phase II portion of the study. Methods Patients were treated with Len 25 mg/day (days 1–14), Bz 1.3 mg/m2 (days 1, 4, 8, 11), and dex 20 mg (cycles 1–4) and 10 mg (cycles 5–8) on the day of and day after Bz for up to eight 21-day cycles. Patients received prophylactic anticoagulants. Responses were assessed by modified EBMT and Uniform criteria to include nCR and VGPR. Patients with at least PR could proceed to ASCT after 34 cycles; responding patients who did not go on to ASCT could continue therapy at their physician's discretion. Patients with 3grade 2 peripheral neuropathy (PNY) by CTCAE v3 were excluded. Thirty five patients were enrolled in the phase II portion of this study and were evaluable for both efficacy and safety. Results Median age was 59 years (range 22-86), 54% were men, 34% / 54% / 11% were ISS Stage I / II / III, and 57% / 31% had IgG / IgA MM, respectively. Patients received a median of 8 cycles of Bz and dex and 11 cycles of Len; 11 (31%) patients remain on therapy. Among the 24 patients who have gone off therapy, 5 (21%) completed treatment per protocol, 8 (33%) proceeded to ASCT, 3 (13%) had progressive disease (all during cycle 14 or later), 1 (4%) withdrew due to toxicities, 1 (4%) received non-protocol therapy, and the remaining (n=6; 25%) withdrew consent or stopped treatment due to physician decision. All patients (100%) had a best confirmed pre-ASCT response of 3PR, with 54% CR/nCR and 69% 3VGPR (Table). Response rates in the 31 and 24 patients who completed 4 and 8 cycles, respectively, are shown in the Table. Among the 24 patients without CR at cycle 4, response improved between cycles 4 and 8 in 16 (67%) patients. Fifteen of the 35 (43%) patients were mobilized for ASCT, with a median stem cell yield of 4.4 × 106 (2.3–6.6 × 106) CD34+ cells/kg. After median follow-up of 19.3 months, median time to progression (TTP), progression-free survival (PFS), and overall survival (OS) have not been reached; the estimated 1-year TTP and PFS are 76% and the estimated OS is 100%. Treatment-emergent grade 3 and 4 adverse events that occurred in 〉1 patient included lymphopenia (n=7; 20%), hypokalemia (n=3; 9%), and fatigue and neutropenia (n=2; 6% each). Sensory PNY of any grade occurred in 27 (77%) patients, which was grade 1 (n=18; 67%) and grade 2 (n=8; 30%) in the majority of patients; only one patient had grade 3 sensory PNY. Neuropathic pain and motor PNY were reported in 10 (29%; all grade 1 and 2) and 6 (17%; 1 grade 3) patients, respectively, with no grade 3 PNY seen. Importantly, PNY was reversible with dose reduction, supportive care, and/or completion of therapy. Thrombosis/thromboembolism was reported in just 2 (6%) patients. No treatment-related mortality was seen. Conclusion These phase II results suggest that RVD is a highly effective combination, with a pre-ASCT ORR of 100% and high rates of CR/nCR, and encouraging time-to-event analyses to date. RVD was well tolerated, with limited rates of grade 3 PNY and DVT/PE despite prolonged use of Bz and Len. Data from patients treated at the MTD in phase I and the impact of adverse risk factors (including advanced stage and high-risk cytogenetics) on outcome, as well as following ASCT, will be reported at the meeting. Based upon these promising results, phase II/III studies of RVD and RVD-based combinations are either planned or ongoing. Disclosures Richardson: Keryx: Membership on an entity's Board of Directors or advisory committees; Millennium Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees; Johnson and Johnson: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Lonial:BMS: Consultancy; Gloucester: Research Funding; Millennium Pharmaceuticals, Inc.: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy. Jakubowiak:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Exelixis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Centocor Ortho Biotech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol-Myers-Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Jagannath:Merck: Consultancy, Honoraria; Millennium Pharmaceuticals, Inc.: Consultancy, Honoraria. Raje:AstraZeneca: Research Funding; Novartis: Research Funding; Celgene: Research Funding. Ghobrial:Millennium Pharmaceuticals, Inc.: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Speakers Bureau. Schlossman:Millennium Pharmaceuticals, Inc.: Speakers Bureau; Celgene: Speakers Bureau. Mazumder:Millennium Pharmaceuticals, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Munshi:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium Pharmaceuticals, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Laubach:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Vesole:Celgene: Consultancy, Equity Ownership. Rosenblatt:Celgene: Research Funding. Doss:Millennium Pharmaceuticals, Inc.: Speakers Bureau; Celgene: Speakers Bureau. Mitsiades:Millennium Pharmaceuticals, Inc.: Consultancy; Novartis Pharmaceuticals: Consultancy; Bristol-Myers Squibb: Consultancy; Merck & Co.: Consultancy; Kosan Pharmaceuticals: Consultancy; Pharmion: Consultancy; Amgen Pharmaceuticals: Research Funding; AVEO Pharma: Research Funding; EMD Serono: Research Funding; Sunesis Pharmaceuticals: Research Funding; PharmaMar: Licensing royalties. Hideshima:Biotest AG: Consultancy. Knight:Celgene: Employment, Equity Ownership. Esseltine:Millennium Pharmaceuticals, Inc.: Employment, Equity Ownership. Anderson:Millennium Pharmaceuticals, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding.

Description: Bortezomib, a proteasome inhibitor with efficacy in multiple myeloma, is associated with thrombocytopenia, the cause and kinetics of which are different from those of standard cytotoxic agents. We assessed the frequency, kinetics, and mechanism of thrombocytopenia following treatment with bortezomib 1.3 mg/m2 in 228 patients with relapsed and/or refractory myeloma in 2 phase 2 trials. The mean platelet count decreased by approximately 60% during treatment but recovered rapidly between treatments in a cyclic fashion. Among responders, the pretreatment platelet count increased significantly during subsequent cycles of therapy. The mean percent reduction in platelets was independent of baseline platelet count, M-protein concentration, and marrow plasmacytosis. Plasma thrombopoietin levels inversely correlated with platelet count. Murine studies demonstrated a reduction in peripheral platelet count following a single bortezomib dose without negative effects on megakaryocytic cellularity, ploidy, or morphology. These data suggest that bortezomib-induced thrombocytopenia is due to a reversible effect on megakaryocytic function rather than a direct cytotoxic effect on megakaryocytes or their progenitors. The exact mechanism underlying bortezomib-induced thrombocytopenia remains unknown but it is unlikely to be related to marrow injury or decreased thrombopoietin production.

Description: Abstract 3851 Poster Board III-787 Background Preclinical work from our group and others has demonstrated that the combination of a farnesyl transferase inhibitor (FTI) and the proteasome inhibitor bortezomib results in enhanced plasma cell apoptosis and is associated with AKT activation (David, Blood 2005). Sequence of bortezomib followed by a FTI synergistically inhibited cell growth compared to concurrent treatment. More recently, further preclinical data suggests that the mechanism responsible for this profound synergy is due to inhibition of HDAC6 with a resultant inhibition of both the proteasome and aggresome pathway (David ASH 2007). Based upon these observations, with the MMRC, we initiated a phase I trial combining the FTI tipifarnib with bortezomib to clinically evaluate the efficacy of this combination. Methods Patients with relapsed or refractory myeloma were treated with bortezomib at 1.0 mg/m2 or 1.3mg/m2 given on days 1,4,8, and 11 in conjunction with escalating doses of tipifarnib (100-400mg PO BID) given on days 2-15 every 21 days, respectively. Dose escalation was accomplished using an adaptive phase I design (Escalation With Overdose Control (EWOC)). Eligibility criteria included a serum creatinine of 500, and platelets 〉25. Results Twenty-six patients have been enrolled to date: bortezomib 1.0 mg/m2 with tipifarnib 100 mg (n=6), 200mg (n=5), 300mg (n=7), 400mg (n=2) and bortezomib 1.3mg/m2 with tipifarnib 300mg (n=6), 400mg to be enrolled. Median age is 63 (range 42-77). 19/26 patients had received prior high dose therapy. The average number of prior therapies was 4, and, of the 26 patients, 10 were refractory to bortezomib (relapsed on therapy or within 6 months) 11 were bortezomib naïve, and 5 were previously exposed to bortezomib but not refractory. Among these patients with advanced myeloma and refractory disease, 50% had stabilization of disease or better. Maximum number of cycles received was 10. Of note, among the patients achieving clinical benefit, 1 had a stable M-protein, but experienced an 80% reduction in circulating plasma cells while on therapy, and another has had a 75% reduction in the free light chain assay. The most common drug-related toxicities were GI (17.0%) with nausea/vomiting occurring most frequently. Hematologic toxicities were difficult to ascertain as patients had advanced myeloma and many entered with platelet counts of 25-50. Additional grade 3 toxicities included renal insufficiency (related to PD), pneumonia and altered mental status which were all considered due to disease progression. There were no Grade 3- 5 non-hematologic drug related toxicities. There were no cardiac events or DVT, and 1 patient experienced grade 2 peripheral neuropathy who did not have pre- existing PN at baseline. Conclusions The combination of bortezomib and tipifarnib is supported by preclinical rationale and has produced stable disease or better among a group of patients with refractory and advanced myeloma. To date the optimal doses of both tipifarnib and bortezomib have yet to be defined, and additional patients will be enrolled to define the MTD by escalation of tipifarnib to 400 with 1.3mg/m2 of bortezomib. Correlative studies evaluating the effect of the combination on HDAC6 and plasma cell apoptosis will be presented. Disclosures: Lonial: Celgene: Consultancy; Millennium: Consultancy, Research Funding; BMS: Consultancy; Novartis: Consultancy; Gloucester: Research Funding. Kaufman:Millennium : Consultancy; Celgene: Consultancy, Research Funding; Genzyme: Consultancy; Merck: Research Funding.

Description: Abstract 3803 Background: The MMRC is a non-profit, disease-focused consortium founded in 2004 comprised of 13 North American centers with expertise in multiple myeloma (MM). The MMRC Inc. (Norwalk, CT), MMRC's member institutions, and several pharmaceutical partners work closely to speed early development of new treatment options for MM patients. In December 2007, MMRC headquarters staff implemented multiple project management (PM) business solutions to address trial barriers that delay activation of our phase I-II clinical trials and established trial metric benchmarks considered attainable at our member institutions. In November 2009, we reported initial data1 on trial activation: MMRC trials initiated between Sep08-Jul09 (n=5) demonstrated a 38% decrease in mean time to first patient dosed (FPFD), compared with the Early Group trials (EG) initiated before PM solutions (Jun06-Sept08; n=7 trials). These results also confirmed improvement over published metrics from Dilts et al 2,3. We present additional data on time to FPFD and now enrollment, to assess impact of the MMRC PM resources and processes on trial efficiency. Methods: Twenty-one (21) trials conducted within the MMRC from May 2006 to June 2010 had sufficient trial data for review. Data were collected by MMRC-funded project managers at the clinical centers using a web-based clinical trial management system (CTMS). FPFD was defined as the time from the member institutions' receipt of the final protocol (FP) from the trial sponsor, to the time the first patient was dosed on the trial at any participating MMRC member institution. With respect to enrollment, pre-study enrollment commitment (EC) established between MMRC and the study sponsor was defined as the total number of subjects committed to receive at least one dose of study drug across all participating MMRC centers on a trial; baseline enrollment timeline (BET) was prospectively defined as the target time period to attain EC. Results: Mean time to FPFD was 181 calendar days for the early group trials (EG, n=7) and 122 days for the recent group (RG) trials (n=14, Sep08 – Jun10), representing a 32% reduction of time to FPFD in the RG. Additionally, time from final protocol to first patient dosed at all MMRC centers on a trial decreased 18% from a mean of 7.7 months (EG) to 6.3 months (RG). With respect to MMRC trial enrollment, data was available for 16/21 trials (5 EG and 11 RG). 2 EG trials were missing data and 3 RG trials were still enrolling as of June 2010. The mean MMRC pre-study EC was 39 subjects per trial (n=16 trials; 626 enrollment target); the mean actual MMRC enrollment was 49 subjects per trial (n=16; 783 enrolled through Jun 29, 2010) representing a 25% increase in actual versus committed enrollment. Two trials did not meet MMRC EC: MMRC investigators discontinued their involvement in these trials at approximately 30% target EC due to trial complexity or low patient enrollment. 14/16 evaluable trials (88%) met their EC; 11/16 trials met EC within BET (69%) of which 8/16 trials (50%) reached EC 34% faster than their BET (representing a mean reduction of 4.5 months). The overall pre-study mean BET for 16 trials was 13.1 months. MMRC's actual mean enrollment timeline was 11.3 months for the group of 14 evaluable trials representing improvement over the original BET by a mean of 1.9 months (14%). We believe FP to FPFD is a more meaningful metric beyond that of first patient consented. Moreover, we believe that if all participating trial centers focus their efforts on dosing the first patient and within a targeted timeframe, it may improve our research efforts overall. Conclusion: Development of drugs in the clinical setting has become time and resource intensive. Activating and enrolling trials promptly is a priority for drug development. The MMRC's standardization of processes and support for site-based PM resources results in improved trial metrics. MMRC member centers met or exceeded pre-specified enrollment targets in 88% of the trials analyzed to date. Ongoing monitoring of trial conduct continues to reveal areas where increased focus is needed to realize further trial efficiencies. These trial metrics and measures to improve efficiency may be applied with similar expected benefit in all oncology disciplines. Disclosures: Wear: Multiple Myeloma Research Consortium (MMRC): Employment. Richardson:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC; 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; Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees. Revta:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Vij:Multiple Myeloma Research Consortium (MMRC): Research Funding; Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Fiala:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Lonial:Bristo-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millenium Pharmaceuticals Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Francis:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Siegel:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC; Celgene: Speakers Bureau; Millennium: Speakers Bureau. Schramm:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Jakubowiak:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC, Research Funding; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Centocor Ortho-Biotech: Honoraria, Speakers Bureau; Exelixis: Honoraria, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Harvey:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Reece:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC; Celgene: Honoraria, Research Funding; Ortho Biotech: Honoraria, Research Funding; Merck: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Facet: Research Funding; Otsuka: Honoraria, Research Funding. Gul:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Jagannath:Celgene: Honoraria; Millenium: Honoraria; Orthobiotec: Honoraria; Onyx Pharma: Honoraria; Merck: Honoraria; Proteolix: Honoraria; Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. La:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Hofmeister:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Jansak:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Stewart:Millennium: Consultancy; Celgene: Honoraria; Multiple Myeloma Research Consortium: Member Institution of the MMRC. Hagerty:Mayo Clinic: Employment; Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Wolf:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC; Celgene: Speakers Bureau; Millennium: Speakers Bureau; Novartis: Speakers Bureau; Orthobiotech: Speakers Bureau. Davis:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Krishnan:Celgene: Speakers Bureau; Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Duarte:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Zimmerman:Millennium, Celgene: Speakers Bureau. Cisneros:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding; Bayer: Research Funding; Multiple Myeloma Research Consortium: Member Institution of the MMRC. Birgin:Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC. Ott:Multiple Myeloma Research Consortium (MMRC): Employment. Tasca:Multiple Myeloma Research Consortium (MMRC): Employment. Kelley:Multiple Myeloma Research Consortium (MMRC): Employment. Anderson:Millennium: Consultancy; Multiple Myeloma Research Consortium (MMRC): Member Institution of the MMRC; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy; Merck: Consultancy; Bristol-Myers Squibb: Consultancy; Acetylon: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Giusti:Multiple Myeloma Research Consortium (MMRC): Employment.

Description: Abstract 3879 Poster Board III-815 Introduction Preclinical and clinical studies have demonstrated the central importance of the PI3K/AKT axis in malignant cell survival and proliferation, yet few therapeutic options have been available. SF1126 is a conjugate comprised of the well-characterized PI3K inhibitor SF1101 (LY294002) attached to a vascular-targeting tetra-peptide (SF1174) designed to bind to RGD-recognizing integrin receptors expressed on endothelial and tumor cells resulting in angiogenesis inhibition and direct antitumor effect. SF1126 has recently demonstrated reversal of resistance mediated through the PI3K/PTEN pathway in trastuzumab-resistant HER2-over-expressing breast cancer cell lines. From the parallel solid tumor study (ASCO 2009), SF1126 was well tolerated, inhibited the PI3K pathway selectively in tumor tissue, and resulted in stable disease in a heavily pretreated population. The rationale for using SF1126 in myeloma is based upon a body of work from Durden et al. (ASH 2007) and David et al. (ASH 2008) demonstrating in vivo and in vitro activity in human myeloma cell lines and xenograft models. These studies demonstrated SF1126 has activity at 5-10uM and combines safely and with enhanced efficacy with dexamethasone, melphalan, and bortezomib. Methods Patients were eligible if they had relapsed or refractory myeloma with at least 2 prior lines of therapy. Dose escalation using Bayesian methodology [Escalation With Overdose Control (EWOC)] incorporated information from the solid tumor trial along with information from this trial. In addition to standard measures of efficacy, a novel assay assessing in vivo PI3K inhibition was evaluated. Briefly, we have developed a protocol for multiparameter flow cytometry analysis of intracellular phosphoepitopes for monitoring pharmacodynamic (PD) molecular targets of SF1126 in study subject's myeloma cells. The aims are to determine: 1) constitutive activation of AKT (by comparing to ex vivo LY294002 treatment) 2) AKT activation in response to IGF-1 (a microenvironment stimulus) 3) inhibition of basal activation and/or inhibition of IGF-1 potentiated response following SF1126 treatment and 4) correlation of this analysis to SF1126 dose and patient response. Subjects undergo serial bone marrow (BM) sampling on day 0 and day 1 (4 hrs after dosing) of cycles 1 and 2. Results To date, a total of 7 patients have been treated with escalating doses ranging from 90 to 1110 mg/m2. Most patients were male (6), median age was 63 (50-69) and median number of prior treatments was 8 (3-10). All had documented refractory disease with bone marrow aspirates showing plasma cell percentages of 30-90%. No grade 4 drug-related toxicities have been noted to date. Approximately one-third of patients experienced grade 2 nausea/vomiting. Constitutional symptoms included fatigue and loss of appetite. Although preclinical studies demonstrated a rise in blood glucose one hour post infusion, this was not seen in any patients receiving drug. The dose limiting toxicity is still undefined. Median number of cycles is 1 (0.4-2.5), with one patient achieving stable disease (urinary protein stabilized following rapid rise prior to study initiation). All patients were taken off study due to progression. In vivo inhibitory effects of SF1126 on the pathway were demonstrated in bone marrow samples. PK data demonstrates similar PK to what has been seen in the solid tumor trial: a) SF1126 is rapidly cleared post-infusion; b) PK of active hydrolysis product (LY294002/SF1101) shows t1/2 ∼1.1-1.5 hrs; c) dose proportional Cmax and AUC(0-t); d) AUC values at doses ≥ 140 mg/m2 exceed those found effective in mouse xenograft studies. Conclusion The PI3K inhibitor SF1126 resulted in similar PK to that seen in solid tumor patients and in vivo studies demonstrated that PI3K activity in the plasma cell compartment of the bone marrow had suppression of this key pathway following SF1126. Completion of the study at the current dose (1110mg/m2) and planning for a future trial combining SF1126 with other active agents in myeloma is currently ongoing. Additional PK/PD and clinical data from this trial will be available. Disclosures: Lonial: Millennium: Consultancy, Research Funding; Celgene: Consultancy; BMS: Consultancy; Novartis: Consultancy; Gloucester: Research Funding. Jagannath:Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria; Merck: Honoraria. Garlich:Semafore Pharmaceuticals: Employment, Equity Ownership, Research Funding. Trudel:Celgene: Honoraria, Speakers Bureau; Ortho Biotech: Honoraria.