Conley, Christopher J.

Background. Hemophagocytic lymphohistiocytosis (HLH) was originally described in pediatric patients presenting with fever, hepatosplenomegaly, and blood cell abnormalities. Later, HLH was recognized to occur in adults, often associated with hematologic malignancies or serious infections. Conclusion. Patients presenting with HLH are critically ill, and rapid diagnosis is key. In adults, the search for the trigger must begin promptly as time to diagnosis effects survival. The underlying trigger in our patients was Histoplasma capsulatum infection, which is rare in the southwestern United States. Prompt diagnosis led to recovery in one patient, while the other did not survive.

Abstract Purpose: Clear cell renal cell carcinoma (ccRCC) is frequently associated with inactivation of the von Hippel–Lindau tumor suppressor, resulting in activation of HIF-1α and HIF-2α. The current paradigm, established using mechanistic cell-based studies, supports a tumor promoting role for HIF-2α, and a tumor suppressor role for HIF-1α. However, few studies have comprehensively examined the clinical relevance of this paradigm. Furthermore, the hypoxia-associated factor (HAF), which regulates the HIFs, has not been comprehensively evaluated in ccRCC. Experimental Design: To assess the involvement of HAF/HIFs in ccRCC, we analyzed their relationship to tumor grade/stage/outcome using tissue from 380 patients, and validated these associations using tissue from 72 additional patients and a further 57 patients treated with antiangiogenic therapy for associations with response. Further characterization was performed using single-cell mRNA sequencing (scRNA-seq), RNA-in situ hybridization (RNA-ISH), and IHC. Results: HIF-1α was primarily expressed in tumor-associated macrophages (TAMs), whereas HIF-2α and HAF were expressed primarily in tumor cells. TAM-associated HIF-1α was significantly associated with high tumor grade and increased metastasis and was independently associated with decreased overall survival. Furthermore, elevated TAM HIF-1α was significantly associated with resistance to antiangiogenic therapy. In contrast, high HAF or HIF-2α were associated with low grade, decreased metastasis, and increased overall survival. scRNA-seq, RNA-ISH, and Western blotting confirmed the expression of HIF-1α in M2-polarized CD163-expressing TAMs. Conclusions: These findings highlight a potential role of TAM HIF-1α in ccRCC progression and support the reevaluation of HIF-1α as a therapeutic target and marker of disease progression.

Abstract Abstract 2741 Background: The novel agent lenalidomide (LEN) has shown significant single-agent activity in patients with relapsed lymphoma through anti-proliferative and immunomodulatory mechanisms. In combination LEN may synergistically improve the efficacy of rituximab. However, there is limited data on the efficacy and safety of LEN in multi-drug combination regimens for treatment-naïve patients. We designed a phase II single arm trial to evaluate tumor response, toxicity (AE) and survival with a combination of LEN, rituximab, cyclophosphamide (CTX) and dexamethasone (DEX) (LR-CD) in symptomatic untreated patients with indolent B-cell lymphoma. (NCT00784927). Methods: Eligibility required age ≥18, ECOG PS ≤2, confirmed diagnosis of indolent B-cell lymphoma (FL1–2, SLL, MZL or LPL/WM), measurable nodes ≥2cm or IgM ≥400mg/dL (LPL/WM), ANC ≥1400/mm3, platelets ≥100,000/mm3, creatinine ≤2mg/dL, and signed informed consent. Only patients needing therapy were considered eligible. Treatment consisted of IV rituximab 375mg/m2 D1, oral LEN 20mg D1–21, CTX 250mg/m2 D1, 8, 15, DEX 40mg D1, 8, 15, 22 and ASA 325 mg daily in a 28 day cycle. Treatment continued 2 cycles beyond best response up to a maximum of 12 cycles. Toxicity was assessed by NCI CTCAE v3.0. Results: Thirty-one patients have enrolled at Mayo Clinic with 28 evaluable for toxicity and response (1 deemed ineligible, 1 withdrew before treatment, 1 treatment violation). Four patients continue on study at this time. Patient characteristics: median age 68.5(43–83), 71% male, stage IV 86%, FL 28%, MZL 25%, LPL/WM 39%, and SLL 4%. Median number of cycles given was 6 and 71% completed the study per protocol. The best overall response is 89% with 32% CR and 57% PR. In subgroup analysis, the response rates for LPL/WM was 91% (all PR) and for FL 88% (CR 63%, PR 25%). The most common grade ≥3 AEs were neutropenia (35.7%), leukopenia (17.8%), anemia (14.3%) and thrombosis (14.3%). The LPL/WM subgroup experienced more grade ≥3 anemia (36%) compared to the group as a whole. Patients (57%) required at least one dose reduction of LEN (n =10), CTX (n = 9) or DEX (n = 7). At a median f/u of 14.5 (1.8–36.5) months 86% are progression free (fig. 1) and the OS is 96% (fig. 2). One death unrelated to treatment occurred 7.7 months after completing 12 cycles of treatment. Conclusion: Lenalidomide can be safely combined with other active agents and in the combination LR-CD produces high response rates in symptomatic patients with indolent B-cell lymphoma. The regimen is well tolerated with manageable toxicities which are similar to that seen with single agent LEN. The encouraging results seen in patients with LPL/WM have led to expansion of this cohort for additional study. Disclosures: Reeder: Celgene: Research Funding. Off Label Use: lenalidomide use in non-Hodgkin lymphoma. Stewart:Celgene: Consultancy, Honoraria.

Abstract Purpose We previously reported an interaction with warfarin anticoagulation when initiating treatment with direct-acting antiviral agents for hepatitis C infection. A decreased warfarin sensitivity led to subtherapeutic anticoagulation. To study this interaction further, we expanded our research to include patients treated with the combination of elbasvir and grazoprevir concurrent with warfarin anticoagulation and investigated changes in warfarin sensitivity during and after treatment. Methods Using electronic health records of the Veterans Health Administration, patients starting treatment with elbasvir–grazoprevir for hepatitis C infection concurrent with warfarin anticoagulation were identified. Inclusion required stable warfarin anticoagulation prior to 12 weeks of treatment with elbasvir–grazoprevir. A warfarin sensitivity index (WSI) was calculated at the start and end of treatment and 12 weeks after treatment. The primary endpoint was the difference in WSI from pre- to end-treatment. The secondary endpoint was the WSI difference from pretreatment to 12 weeks posttreatment. Changes in International Normalized Ratio, warfarin doses, and time in therapeutic range were measured. Results In the final sample of 43 patients, the mean WSI decreased during treatment from 0.53 to 0.40, or 25.2%. After treatment, the mean WSI rose to 0.51. Although the mean weekly warfarin dose increased from 40.3 to 44.6 mg during treatment, the mean International Normalized Ratio decreased from 2.40 to 1.96, recovering to 2.59 after treatment. The time spent in therapeutic range decreased from 74.1% before treatment to 39.8% during treatment and back to 64.9% 12 weeks posttreatment. Conclusion When elbasvir–grazoprevir was added to stable warfarin anticoagulation, warfarin sensitivity decreased significantly during treatment and returned to baseline after treatment.

AbstractPatients with indolent non‐Hodgkin lymphoma (NHL) have multiple treatment options yet there is no consensus as to the best initial therapy. Lenalidomide, an immunomodulatory agent, has single agent activity in relapsed lymphoma. This trial was conducted to assess feasibility, efficacy, and safety of adding lenalidomide to rituximab, cyclophosphamide, and dexamethasone (LR‐CD) in untreated indolent NHL patients requiring therapy. This was a single institution phase II trial. Treatment consisted of IV rituximab 375 mg/m2 day 1; oral lenalidomide 20 mg days 1–21; cyclophosphamide 250 mg/m2 days 1, 8, and 15; and dexamethasone 40 mg days 1, 8, 15, and 22 of a 28‐day cycle. Treatment continued 2 cycles beyond best response for a maximum of 12 cycles without rituximab maintenance. Thirty‐three patients were treated. Median age was 68 (43–83 years). 39% had stage IV disease. Histologic subtypes included 8 follicular lymphoma (FL), 7 marginal zone lymphoma (MZL) (1 splenic, 2 extranodal, and 4 nodal), 15 Waldenström's macroglobulinemia (WM), 1 lymphoplasmacytic lymphoma, 1 small lymphocytic lymphoma, and 1 low‐grade B‐cell lymphoma with plasmacytic differentiation (unable to be classified better as MZL or LPL). Hematologic toxicity was the most common adverse event. Median time of follow‐up was 23.4 months (range 1.8–50.9). The overall response rate was 87.9%, with 30.3% complete response. The median duration of response was 38.7 months. The median progression free survival was 39.7 months, while median overall survival (OS) has not yet been reached. Lenalidomide can be safely added to a simple regimen of rituximab, oral cyclophosphamide, and dexamethasone and is an effective combination as initial therapy for low‐grade B‐cell NHL.