Abstract 5537: Histone deacetylase 11 (HDAC11) regulates B cell lymphopoiesis and potentiates plasma cell survival in multiple myeloma

Initially studied mainly for its role as a regulator of neural cell differentiation and development, expression of HDAC11 was once thought to be restricted exclusively to brain, kidney and testes. Hence, our recent discovery that HDAC11 acts as an important modulator of antigen presentation and T cell activation, downregulating IL-10 transcription via interactions with the IL-10 promoter at the chromatin level, exposes a previously unknown capacity and tissue specificity for this enzyme. Transgenic mice harboring an eGFP reporter construct driven by the HDAC11 promoter (Tg-HDAC11-eGFP) (Heinz, N Nat. Rev. Neuroscience 2001) clearly illustrate the dynamic changes in HDAC11 gene expression in hematopoietic cell lineages, additionally unveiling an important role for HDAC11 in B cell lymphopoiesis and plasma cell biology. While common lymphoid progenitors appear to be devoid of HDAC11 transcriptional activation as indicated by minimal detectable eGFP expression, eGFP intensity markedly increases in the B-1 stage of differentiation in the periphery. Interestingly, examination of both the bone marrow (BM) and peripheral blood (PB) plasma cell compartment demonstrates an increase in expression of eGFP/HDAC11 mRNA at the steady-state, and these results are consistent with HDAC11 expression measured in PB from healthy human subjects. Furthermore, mice globally deficient in HDAC11 expression (HDAC11KO mice) exhibit a 50% decrease in plasma cells in both the bone marrow and peripheral blood plasma cell compartments relative to wild-type mice. The concordance of HDAC11 expression and plasma cell differentiation leads us to hypothesize that HDAC11 may also be critical to malignant plasma cell survival. A comparison of normal bone marrow and malignant plasma cells isolated from multiple myeloma patient samples reveals a significantly higher level of HDAC11 expression associated with malignancy. Similar results are observed in 8 of 12 myeloma cell lines suggesting that HDAC11 expression may provide a distinct survival advantage to malignant plasma cells. Further stratification of patients into “newly diagnosed” and “proteasome inhibitor resistant” categories defines a positive correlation between HDAC11 expression and refractory disease. Treatment of the myeloma cell lines with Quisinostat, a second-generation HDAC inhibitor with enhanced selectivity for HDAC 1, 2, 4, 10 and 11 induces growth retardation at low nanomolar concentrations. Future studies will entail direct targeting of HDAC11 in myeloma cell lines and patient specimens to determine the contribution of HDAC11 to Quinsinostat activity. Taken together, we have unveiled a previously unknown role for HDAC11 in plasma cell differentiation and survival. The demonstration of HDAC11 overexpression in primary human myeloma cells provides a framework for therapeutics targeting this HDAC in multiple myeloma.

Citation Format: Eva Sahakian, Jason Brayer, John Powers, Mark Meads, Susan Deng, Allison Distler, Melissa Alsina, Taiga Nishihori, Rachid Baz, Alejandro Villagra, Javier Pinilla-Ibarz, Eduardo Sotomayor, Kenneth Shain. Histone deacetylase 11 (HDAC11) regulates B cell lymphopoiesis and potentiates plasma cell survival in multiple myeloma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5537. doi:10.1158/1538-7445.AM2014-5537

Lenalidomide maintenance for high-risk multiple myeloma after allogeneic hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (alloHCT) with reduced-intensity conditioning is an appealing option for patients with high-risk multiple myeloma (MM). However, progression after alloHCT remains a challenge. Maintenance therapy after alloHCT may offer additional disease control and allow time for a graft-versus-myeloma effect. The primary objective of this clinical trial was to determine the tolerability and safety profile of maintenance lenalidomide (LEN) given on days 1 to 21 of 28 days cycles, with intrapatient dose escalation during 12 months/cycles after alloHCT. Thirty alloHCT recipients (median age, 54 years) with high-risk MM were enrolled at 8 centers between 2009 and 2012. The median time from alloHCT to LEN initiation was 96 days (range, 66 to 171 days). Eleven patients (37%) completed maintenance and 10 mg daily was the most commonly delivered dose (44%). Most common reasons for discontinuation were acute graft-versus-host disease (GVHD) (37%) and disease progression (37%). Cumulative incidence of grades III to IV acute GVHD from time of initiation of LEN was 17%. Outcomes at 18 months after initiation of maintenance were MM progression, 28%; transplantation-related mortality, 11%; and progression-free and overall survival, 63% and 78%, respectively. The use of LEN after alloHCT is feasible at lower doses, although it is associated with a 38% incidence of acute GVHD. Survival outcomes observed in this high-risk MM population warrant further study of this approach.

Comparison of 1-day vs 2-day dosing of high-dose melphalan followed by autologous hematopoietic cell transplantation in patients with multiple myeloma

High-dose melphalan at 200 mg/m(2) can be administered in 1 day or over 2 consecutive days before autologous hematopoietic cell transplantation (HCT) for multiple myeloma (MM). Limited data exist on the comparison of the two dosing schedules. A retrospective study of 278 consecutive MM patients receiving high-dose melphalan from January 2010 to December 2012 was conducted. Objectives were to compare the length of hospitalization, toxicity profile, response rates, PFS and OS. One hundred and eighty five patients received 2-day dosing and 93 received 1-day dosing. The two end points of the 95% confidence interval (CI) for the difference did not exceed the preselected margin, therefore the length of hospitalization was considered equivalent. No significant differences were found for response rates, PFS and OS.  The toxicity profile was similar with the exception of more frequent ⩾grade 3 oral mucositis in the 2-day group (13.5% vs 5.4%; odds ratio 3.07 (95% CI:1.11-8.48); P=0.03). High-dose melphalan, given either in 1 day or over 2 days, produced comparable treatment outcomes except for increased grade 3/4 mucositis in the 2-day regimen. One-day dosing could shorten the hospital stay by 1 day and may allow better resource utilization.

Phase II study of pegylated liposomal doxorubicin, low-dose dexamethasone, and lenalidomide in patients with newly diagnosed multiple myeloma

Our previous phase I/II trial of pegylated liposomal doxorubicin (PLD), low-dose dexamethasone, and lenalidomide in patients with relapsed and refractory myeloma showed an overall response rate of 75%, with 29% achieving ≥ VGPR. Here, we investigated this combination (PLD 30 or 40 mg/m(2) intravenously, day 1; dexamethasone 40 mg orally, days 1-4; lenalidomide 25 mg orally, days 1-21; administered every 28 days) in a phase II study in patients with newly diagnosed symptomatic multiple myeloma to determine its efficacy and tolerability (ClinicalTrials.gov NCT00617591). At best response, patients could proceed with high-dose melphalan or with maintenance lenalidomide and dexamethasone. In 57 patients, we found that the overall response rate and rate of very good partial response and better on intent-to-treat, our primary endpoints, were 77.2% and 42.1%, respectively, with responses per the International Myeloma Working Group. Median progression-free survival was 28 months (95% CI 18.1-34.8), with 1- and 2-year overall survival rates of 98.1 and 79.6%. During induction, grade 3/4 toxicities were neutropenia (49.1%), anemia (15.8%), thrombocytopenia (7%), fatigue (14%), febrile neutropenia (8.8%), and venous thromboembolic events (8.8%). During maintenance, grade 3/4 toxicities were mainly hematologic. We found this combination to be active in patients with newly diagnosed myeloma, with results comparable to other lenalidomide-based induction strategies without proteasome inhibition. In addition, maintenance therapy with lenalidomide was well tolerated.

Immunotherapy strategies for multiple myeloma: the present and the future

Growing knowledge of the complexities of the immune system have led to a better understanding of how it can be harnessed for the purpose of anticancer therapy. Moreover, recent success with immunotherapies for solid tumors, combined with novel therapeutic strategies against myeloma, heighten excitement at the prospect of improving clinical outcomes for myeloma by improving antitumor immunity. Increased understanding of myeloma tumor-associated antigens, availability of more potent vaccines, expanded immune-modulating therapies, development of agents that block immune-suppressive pathways, increased sophistication of adoptive cell therapy techniques and capitalization upon standard autologous transplant are all important standalone or combination strategies that might ultimately improve prognosis of patients with multiple myeloma.

New treatments for human papillomavirus infection

Human papillomavirus infection is very common. In this article, we review the latest developments in the treatment of lesions caused by this virus, with a particular focus on anogenital warts. Sinecatechins and new imiquimod formulations are among the most significant new developments. Others include photodynamic therapy and intralesional immunotherapy, but there is insufficient evidence to recommend their routine use. Finally, while therapeutic vaccines and inhibitory molecules appear to hold great promise, they are still in the early phases of investigation. More studies are needed, and these should have similar designs, larger samples, and sufficiently long follow-up periods to enable the direct comparison of the short-term and long-term effectiveness of different treatment options.

Outcomes of patients with solitary plasmacytomas (SP) in the era of PET imaging and serum-free light chain (sFLC) testing: A single institution experience

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Background: SP can occur in bone (SPB) or in extramedullary sites (EMP) and generally accounts for ~ 3-5% of plasma cell dyscrasias. Up to 50% of SPB and 15% of EMP will progress to multiple myeloma (MM). We evaluated the utility and prognostic significance of positron emission tomography (PET) imaging and SFLC ratio (sFLCr). Methods: We retrospectively reviewed electronic medical records of patients with SP evaluated at Moffitt Cancer Center between 1990-2012. The diagnosis of SP was per IMWG criteria (BJH 2003, 121:749) (biopsy proven single site, negative skeletal survey, bone marrow biopsy with no more than 10% plasma cells). Initial and post therapy sFLCr as well as PET findings were correlated with progression to symptomatic MM (PFS). Radiation therapy (XRT) was at the discretion of the treating physician. Results: 135 patients were identified and 91 (67%) were males. The median age was 58 years (range 20-82). Consistent with prior reports, the PFS of the entire cohort was 43 months (95% CI 17.8-70). 23 patients had PET prior to progression. All patients had uptake in the primary lesion (except 4 who had resection of the primary). 8 patients had additional PET findings in other bony structure (PET+), and 15 did not (PET-). 2 and 6 of the PET- and PET+ patients progressed (median PFS Not reached (NR) vs. 8.1 months, p=0.021) respectively. Of the 49 patients with available sFLC data, 32 had an abnormal ratio (17 progressed) and 17 patients had a normal ratio (2 progressed). Abnormal baseline sFLCr was associated with progression (median PFS 19 months vs NR, p=0.012). Post XRT, 44 patients had an available sFLCr, of which 23 had an abnormal ratio and 21 a normal ratio. A persistent serum/urine m spike after XRT was associated with progression to MM (median PFS 20.8 months vs NR, p<0.0001). However, the association between Post XRT sFLCr and progression to MM was not statistically significant (median PFS 19 vs 43 months (abnormal vs normal ratio) p=0.2). Conclusions: PET imaging and sFLC are predictors of outcomes in SP and their routine inclusion in the diagnostic work up of patients with SP will result in a stage migration where patients outcomes are improved compared to historical controls.

Final results from the phase Ib/II study (PX-171-006) of carfilzomib, lenalidomide, and low-dose dexamethasone (CRd) in patients with relapsed or progressive multiple myeloma

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Background: Carfilzomib (CFZ) is approved in the US as single-agent treatment for patients with multiple myeloma (MM) who have progressed after bortezomib (BTZ) and an IMiD and are refractory to last line of treatment. We previously reported interim data from PX-171-006 (NCT00603447), a Ph 1b/2 study of CRd in relapsed or progressive MM (Wang et al. ASCO 2011). Herein we report final results. Methods: Patients (1–3 prior treatments) received CRd in 28-day (D) cycles—CFZ IV on D1, 2, 8, 9, 15, 16, lenalidomide (LEN) PO D1–21, and dexamethasone (dex) wkly. In phase 1, CFZ (15–27 mg/m2) and LEN (10–25 mg) doses were escalated to determine the maximum tolerated dose (MTD) with a maximum planned dose (MPD) of CFZ 20 mg/m2 D1, 2 of Cycle 1 and 27 mg/m2 thereafter, LEN 25 mg/d, and dex 40 mg/wk, followed by phase 2 expansion at MTD/MPD. Endpoints included IMWG overall response rate (ORR), duration of response (DOR), progression-free survival (PFS), and safety. Results: A total of 84 patients were enrolled since June 2008. Overall, prior treatment included BTZ (77%/18% refractory) and LEN (70%/35% refractory); 20% had high-risk cytogenetics/FISH. MTD was not reached in Ph 1, supporting expansion at the MPD (n=52, 23% BTZ refractory and 42% LEN refractory). As of Nov 2012 (median follow-up 24.4 mo): ORR was 69% overall and 76.9% at MPD with very good partial response in 36.9% and 38.5% and stringent complete response in 3.6% and 3.8%, respectively; median DOR was 18.8 (95% CI 9.7–41.5) and 22.1 mo (95% CI 9.5–NE) respectively; median PFS was 11.8 (95% CI 7.6–20.7) and 15.4 mo (95% CI 7.9–NE), respectively. Seven responders at MPD pursued other therapy and were censored for PFS.A median of 8.5 (range 1−46) CFZ cycles were started; 4% required CFZ dose reductions; 15% discontinued CFZ due to adverse events (AEs). Grade 3/4 AEs were generally consistent with earlier studies in advanced MM that used similar doses of single-agent CFZ; grade 3/4 peripheral neuropathy was 1%. Conclusions: CRd was well tolerated, providing robust and durable responses in this pt population where 35% were LEN refractory. This combination is being further evaluated in several ongoing phase 2/3 trials. Clinical trial information: NCT00603447.

Clinical response by baseline characteristics in patients (pts) with relapsed and bortezomib (BTZ)-refractory multiple myeloma treated with panobinostat (PAN), BTZ, and dexamethasone (DEX; PANORAMA 2)

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Background: In PANORAMA 2, PAN + BTZ + DEX recaptured responses in heavily pretreated pts with BTZ-refractory MM; overall response rate (ORR), clinical benefit rate (CBR), and progression-free survival (PFS) were 34.5%, 52.7%, and 5.4 months, respectively. Here, we evaluate clinical response per baseline characteristics. Methods: Response was based on European Group of Blood and Marrow Transplantation 1998 criteria. High-risk cytogenetics was defined as del(17p), t(4;14), or t(14;16). Quality of life (QoL) was measured with Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACT/GOG-Ntx) v4.0 scale. Results: Response rate trended higher in pts whose prior BTZ therapy was not their last line of therapy (Table). Although no trend in response rate was noted, PFS appeared longer in pts progressing within 60 days of their last BTZ-containing regimen than in those progressing on their last BTZ-containing regimen. In the 14 pts with high-risk cytogenetics, ORR was 42.9% and CBR was 71.4%. The mean FACT/GOG-Ntx subscale did not exhibit a clinically meaningful change from baseline (mean ± standard deviation [SD], 114.2 ± 21.1; n = 41) to cycle 9 day 1 (day 169; 104.2 ± 15.4; n = 16) as determined by 50% SD threshold for minimally important difference. Other QoL parameters were similarly unchanged. Conclusions: PAN + BTZ + DEX demonstrated activity regardless of baseline demographics in heavily pretreated pts with BTZ-refractory MM. Clinical trial information: NCT01083602. [Table: see text]

Evaluation of spot urine protein to creatinine ratio and 24-hour urine protein quantification for proteinuria in patients with plasma cell dyscrasia

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Background: Though cumbersome, a 24-hour urine collection remains crucial for diagnosis and monitoring in plasma cell dyscrasias (PCD). Nephrology guidelines recommend replacement of 24-hour urine collection with spot urine protein/creatinine (Pr/Cr) ratio for proteinuria. Only limited data exist on accuracy of spot urine Pr/Cr ratio in PCD. Methods: From 04/2012 to 01/2013, a total of 67 PCD patients were prospectively enrolled. Oliguria or dialysis were considered ineligible. Spot urine was collected on the day of 24-hour urine collection. Spot urine Pr/Cr ratios were compared to 24-hour urine on (1) total protein and (2) monoclonal protein (M-spike). Results: Fifty-two of 67 patients were evaluable (missing samples in 9; no Pr/Cr ratios in 4; protein below the level of detection in 2). A median age was 66 (range, 36 - 82), 62% were male, and 81% were Caucasian. Primary diagnoses were myeloma (n=47), amyloidosis (n=2), plasmacytoma (n=2), and MGUS (n=1). Comorbidities included hypertension (58%), chronic kidney disease (27%), diabetes (19%), and congestive heart failure (2%). A median serum creatinine was 0.9 mg/dL (range, 0.5 - 5.1). A median spot urine Pr/Cr ratio was 140 mg/g creatinine (range, 32 - 21,447), a median 24-hour urine protein was 130 mg (range, 31 - 15,092: n=49), and a median urine M-spike was 1.9 mg (range, 0 - 8,099). Most spot urine samples were collected in the morning (65%). There were strong correlations between (1) spot urine Pr/Cr ratio and 24-hour total urine protein (Spearman correlation coefficient=0.91, p < 0.0001), and (2) spot urine Pr/Cr ratio and 24-hour urine M-spike (Spearman correlation coefficient=0.73, p < 0.0001). The timing of spot urine sample collection had no significant effect (p = 0.274 by Wilcoxon rank-sum test). Conclusions: Spot urine Pr/Cr ratio strongly correlates with proteinuria measured in 24-hour urine collection and may predict the quantity of urine M-spike in non-oliguric PCD population. Spot urine Pr/Cr ratio may be useful as a monitoring tool for estimation of proteinuria. The study is ongoing and updated result will be provided.

Phase II study of CD4+-guided pentostatin lymphodepletion and pharmacokinetically targeted busulfan as conditioning for hematopoietic cell allografting

One limitation of reduced-intensity preparative regimens is potential for graft failure. We have developed a regimen that targets CD4(+) lymphodepletion to ensure early and durable engraftment. The primary endpoint was achievement of ≥50% CD3(+) donor chimerism by day +28. Forty-two patients (median age, 53 years; range, 29 to 73 years) received pentostatin 4 mg/m(2) i.v. on days -28, -21, and -14 when the CD4(+) cell count was >100 cells/μL and on days -4 and -3 regardless of CD4(+) level. Rituximab 375 mg/m(2) was administered to patients with CD20(+) malignancies on days -21, -14, -7, +1, and +8. Busulfan 200 mg/m(2) i.v. was administered on days -4 and -2 at a dose to target a cumulative AUC dose of 16,000 (±10%) μmol·min/L. Graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus plus methotrexate in 86% of patients. Donors were matched-related (47%), matched unrelated (43%), or mismatched unrelated (10%). Chronic lymphocytic leukemia (45%) and follicular non-Hodgkin lymphoma (14%) were the most common diagnoses. Disease status at initiation of the preparative regimen was complete remission in 22%, partial response in 55%, and stable/progression in 24%. The median percent CD4(+) cell count decrease from baseline (day -28) was 52% to day -21, 66% to day -14, 62% to day -7, and 91% to day 0. At day +28, all 42 patients (100%) had ≥50% CD3(+) donor chimerism. No patient experienced graft failure. Overall response rate was 82% (complete remisson, 67%). The day +100 cumulative incidence of grade II-IV acute GVHD was 59% (grade III-IV acute GVHD, 19%), and the 2 year cumulative incidence of chronic GVHD was 69% (moderate/severe, 58%). Nonrelapse mortality was 2% at day +100 and 17% at 2 years. Two-year PFS was 55%, and OS was 68%. This regimen ensures durable engraftment, is effective against persistent disease, and results in relatively low mortality from causes other than relapse.

Allogeneic hematopoietic cell transplantation for consolidation of VGPR or CR for newly diagnosed multiple myeloma

Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative approach in patients with multiple myeloma, but its use for consolidation of first remission has not yet been fully explored. Twenty-two myeloma patients with very good partial response (VGPR) or CR received allogeneic peripheral blood grafts as consolidation from HLA-matched donors between 2007 and 2012. Conditioning regimens were fludarabine (30 mg/m(2) i.v. if with bortezomib and 40 mg/m(2) i.v. when without bortezomib, × 4 days) plus melphalan (70 mg/m(2) intravenously × 2 days) with (n=13) or without (n=9) bortezomib (1.3 mg/m(2)). The cumulative incidence of grades II - IV acute GVHD at day 100 was 45% (95% CI: 24-65%) and moderate-to-severe chronic GVHD at 2 years was 46% (95% CI: 19-69%). With a median follow-up of 18 (range, 2-61) months, the 2-year PFS estimate is 74.8% (95% CI: 45-90%), which compares favorably with the 52% (95% CI: 35-66%) after autologous HCT for similar patients (a median follow-up of 30 (range, 9-55) months). We are conducting a phase 2 study to assess the efficacy of allogeneic HCT as post-remission therapy.

Phase Ib dose-escalation study (PX-171-006) of carfilzomib, lenalidomide, and low-dose dexamethasone in relapsed or progressive multiple myeloma

PURPOSE

Carfilzomib, a selective proteasome inhibitor, has shown safety and efficacy in relapsed and/or refractory multiple myeloma. This phase I study in patients with relapsed or progressive multiple myeloma assessed the safety and tolerability of escalating doses of carfilzomib in combination with lenalidomide and low-dose dexamethasone (CRd) to identify the dose for a phase II expansion study.

EXPERIMENTAL DESIGN

Patients with multiple myeloma who relapsed after 1 to 3 prior regimens enrolled into dose-escalation cohorts. CRd was administered on 28-day dosing cycles: carfilzomib 15 to 27 mg/m(2) on days 1, 2, 8, 9, 15, and 16; lenalidomide 10 to 25 mg on days 1 to 21; and dexamethasone 40 mg weekly.

RESULTS

Forty patients enrolled in six cohorts. Prior treatment included bortezomib (75%) and lenalidomide (70%); 20% and 36% were refractory overall. The maximum tolerated dose was not identified, and the highest dose combination tested was recommended for the phase II study. The most common toxicities of any grade were fatigue (62.5%), neutropenia (55.5%), and diarrhea (52.5%). Grade 3/4 toxicities included neutropenia (42.5%), thrombocytopenia (32.5%), and lymphopenia (27.5%), with no grade 3/4 neuropathy reported. Proteasome inhibition 1-hour after dose was more than 80% in cycles 1 and 2. Among all patients, the overall response rate was 62.5%, the clinical benefit response rate was 75.0%, and the median duration of response and progression-free survival were 11.8 and 10.2 months, respectively.

CONCLUSION

The maximum planned CRd dose, carfilzomib 27 mg/m(2), lenalidomide 25 mg, and dexamethasone 40 mg, was recommended for further study, with promising safety and efficacy.