Khan, Arooj

Abstract Oral cyclophosphamide and prednisone is a convenient regimen in relapsed and refractory multiple myeloma (MM), with a partial response (PR) rate of 40% and median progression-free survival of 19 months in our retrospective analysis of patients in first or second relapse after autologous stem cell transplantation (ASCT) (Trieu Y, et al, Mayo Clin Proc2005; 80: 1582). We sought to enhance the efficacy of this regimen by adding oral lenalidomide (Revlimid®), a potent anti-myeloma agent, in a 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 patients (pts) as prophylaxis for DVT. Three dose levels were evaluated using a 3 by 3 dose escalation design. Between 11/2007–07/2008, 15 pts with relapsed/refractory MM were entered onto study. Median age was 60 (45–78) years and 60% were male. Immunoglobulin subtype was IgGκ:λ in 10:1; IgA κ:λ in 2:1 and κ light chain in 1. Median number of prior regimens was 2 (1–3) and 14 had undergone previous ASCT, including double transplants in 2 pts. Prior therapy also included thalidomide in 3 (20%) and bortezomib in 6 (40%). FISH cytogenetics were available in 9, but none had 13q deletion, t(4;14) or p53 deletion. At the time of protocol entry, median β2-microglobulin level was 222 (92–325) nm/L, albumin 38 (35–46) g/L, creatinine 78 (50–100) μmol/L, platelet count 230 (93–318) x 109/L and ANC 2.5 (1.9–9.0) x 109/L. Protocol treatment is summarized in Table 1. Dose level N Cyclophosphamide dose (mg/m2) Lenalidomide dose (mg) Prednisone dose (mg) Median # cycles given 1 3 150 15 100 9 2 3 150 25 100 6 3 6 300 25 100 4 3 (expanded) 3 300 25 100 1 Dose limiting toxicity was not observed during cycle 1 at any of the dose levels and the maximum tolerated dose of this regimen has not yet been reached at the highest dose level planned; all pts remain on active therapy. Grade 3/4 thrombocytopenia was seen in 1 pt (cohort 2) and neutropenia in 4 pts (1 in cohort 1, 1 in cohort 2 and 2 in cohort 3) and were managed with dose reduction and/or growth factor support. No episodes of febrile neutropenia occurred in any pt. Only 1 pt experienced varicella zoster; routine antiviral prophylaxis was not used. Other grade 3/4 non-hematologic toxicities were uncommon and included abdominal pain/bacteremia in 1 pt in cohort 1, hypokalemia in 1 pt in cohort 2, and DVT in 1 pt in cohort 3. Mild grade 1/2 constipation (47%), muscle cramps (33%) and fatigue (33%) were also noted. To date, best response includes the following: dose level 1 (1 near complete remission [nCR], 2 PR); dose level 2 (3 PR); dose level 3 (4 PR, 2 minimal response [MR]); expanded cohort 3 (1 MR, 2 too early). 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 (nCR + PR + MR) in 13 evaluable pts to date is 87%; 3) no pts have progressed in this preliminary analysis; 4) longer follow-up is required to assess the long-term efficacy of this regimen.

Abstract Abstract 3055 Lenalidomide (Revlimid®) and dexamethasone is an effective regimen for relapsed/refractory (rel/ref) multiple myeloma (MM) patients (pts) with an overall response rate of 60% and median time to progression of 13.4 months (Dimopoulos ME, et al. Leukemia 2009; 23: 2147-52). We combined lenalidomide with the alkylating agent combination of cyclophosphamide and prednisone—an older regimen with minimal cumulative myelosuppression and good activity as second or third line therapy (Trieu Y, et al, Mayo Clin Proc 2005; 80: 1582). The CPR regimen consisted of cyclophosphamide (CY) on days 1, 8, and 15, lenalidomide on days 1–21 and prednisone 100 mg q 2 days in a 28-day cycle. ASA 81 mg/day was given as DVT prophylaxis. Three dose levels were evaluated using a 3 × 3 dose escalation design. Thirty-two pts were entered between 11/2007-06/2009; median age was 64 (42-80) yrs, 60% were male, and immunoglobulin isotype was IgG in 19 (62%), IgA in 8 (25%) and light chain in 4 (13%) pts. Median β2-microglobulin level was 257 (92-767) nm/L, albumin 39 (34-48) g/L, creatinine 83 (50-126) μmol/L, platelet count 355 (75-479) × 109/L and ANC 2.5 (1.1-6.1) × 109/L. The median number of prior regimens was 2 (1-5). Prior therapy included: ASCT (single in 91%; double in 19%), thalidomide (28%) and bortezomib (50%). FISH cytogenetics were available in 13 pts; 1 had del 13q but none had t(4;14) or del p53. Table 1 summarizes protocol treatment delivered. Table 1. Dose level N Cyclophosphamide dose (mg/m2) Lenalidomide dose (mg) Prednisone dose (mg) Median # cycles given 1 3 150 15 100 12 (12–34+) 2 3 150 25 100 10 (9–23) 3 26 300 25 100 17 (5–28+) 1–3 (All) 32 150–300 15–25 100 19 (5–34+) Dose limiting toxicity was not observed during cycle 1 at any dose level. Grade 3–4 toxicities during the trial included: thrombocytopenia in 7 (22%) and neutropenia in 9 (29%), managed with dose reduction and/or growth factors; five episodes of febrile neutropenia occurred, all at dose level 3. In cohort 3, other grade 3–4 non-hematologic toxicities included 1 episode each of abdominal pain/bacteremia, hypokalemia, fatigue, sick sinus syndrome, cardiac amyloidosis, perforated diverticulum and 2 episodes of DVT. Two heavily pretreated pts developed 2° MDS, including 1 previously treated for lymphoma, 43 and 190 mos after the diagnosis of MM. The best response using modified EBMT criteria was documented at a median of 7 (1-26) cycles and included the following: dose level 1 (1 CR, 2 PR); dose level 2 (1 VGPR, 2 PR); dose level 3 (4 CR, 14 VGPR, 11 PR, 1 MR and 1 stable disease). At a median F/U of 16 (5-34) months, 13 pts remain on study and 18 have progressed at a median of 10 (2-23) mos; 1 was lost to F/U and 9 have died of progressive MM. The 1-year actuarial OS and PFS rates are 93% (95% CI 76–98%) and 78% (95% CI 60–89%), respectively. We conclude: 1) the combination of full doses of the agents in CPR can be given in a 28 day cycle with an acceptable safety profile; 2) the objective response rate (CR + PR + MR) in all 32 pts to date is 94%; 3) the 1-year OS of 93% and PFS of 78% compare favorably with other 3-drug combinations in rel/ref MM pts; 4) further evaluation of this regimen in newly diagnosed pts would be of interest. Disclosures: Reece: Celgene: Honoraria, Research Funding. Off Label Use: Combination of lenalidomide and cyclophosphamide and prednisone in relapsed and refractory myeloma patients. Chen:Celgene Corporation: Consultancy, Honoraria, Research Funding. Kukreti:Celgene: Honoraria.

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.