Dynamics of mutations in patients with essential thrombocythemia treated with imetelstat.

In a phase-2 study, the telomerase inhibitor imetelstat induced rapid hematologic responses in all patients with essential thrombocythemia who were refractory or intolerant to prior therapies. Significant molecular responses were achieved within 3-6 months in 81% of patients with phenotypic driver mutations in JAK2, CALR and MPL. Here, we investigated the dynamics of additional somatic mutations in response to imetelstat. At study entry, 50% of patients carried 1-5 additional mutations in the genes ASXL1, CBL, DNMT3A, EZH2, IDH1, SF3B1, TET2, TP53 and U2AF1. Three patients with baseline mutations also had late-emerging mutations in TP53, IDH1 and TET2. Most clones with additional mutations were responsive to imetelstat and decreased with the driver mutation, including the poor prognostic ASXL1, EZH2 and U2AF1 mutations while SF3B1 and TP53 mutations were associated with poorer molecular response. Overall, phenotypic driver mutation response was significantly deeper in patients without additional mutations (P = 0.04) and correlated with longer duration of response. In conclusion, this detailed molecular analysis of highly pretreated and partly resistant patients with essential thrombocythemia reveals a high individual patient complexity. Moreover, imetelstat demonstrates potential to inhibit efficiently co-incident mutations occurring in neoplastic clones in patients with essential thrombocythemia. (ClinicalTrials.gov number, NCT01243073. N Engl J Med 2015; 373:920-928, DOI: 10.1056/NEJMoa1503479.).

Telomerase Inhibitor Imetelstat in Patients with Essential Thrombocythemia.

BACKGROUND: Imetelstat, a 13-mer oligonucleotide that is covalently modified with lipid extensions, competitively inhibits telomerase enzymatic activity. It has been shown to inhibit megakaryocytic proliferation in vitro in cells obtained from patients with essential thrombocythemia. In this phase 2 study, we investigated whether imetelstat could elicit hematologic and molecular responses in patients with essential thrombocythemia who had not had a response to or who had had unacceptable side effects from prior therapies. METHODS: A total of 18 patients in two sequential cohorts received an initial dose of 7.5 or 9.4 mg of imetelstat per kilogram of body weight intravenously once a week until attainment of a platelet count of approximately 250,000 to 300,000 per cubic millimeter. The primary end point was the best hematologic response. RESULTS: Imetelstat induced hematologic responses in all 18 patients, and 16 patients (89%) had a complete hematologic response. At the time of the primary analysis, 10 patients were still receiving treatment, with a median follow-up of 17 months (range, 7 to 32 [ongoing]). Molecular responses were seen in 7 of 8 patients who were positive for the JAK2 V617F mutation (88%; 95% confidence interval, 47 to 100). CALR and MPL mutant allele burdens were also reduced by 15 to 66%. The most common adverse events during treatment were mild to moderate in severity; neutropenia of grade 3 or higher occurred in 4 of the 18 patients (22%) and anemia, headache, and syncope of grade 3 or higher each occurred in 2 patients (11%). All the patients had at least one abnormal liver-function value; all persistent elevations were grade 1 or 2 in severity. CONCLUSIONS: Rapid and durable hematologic and molecular responses were observed in patients with essential thrombocythemia who received imetelstat. (Funded by Geron; ClinicalTrials.gov number, NCT01243073.).

Brentuximab vedotin demonstrates objective responses in a phase 2 study of relapsed/refractory DLBCL with variable CD30 expression.

Several non-Hodgkin lymphoma (NHL) subtypes, including diffuse large B-cell lymphoma (DLBCL), variably express CD30. This phase 2, open-label study evaluated the efficacy of brentuximab vedotin, an anti-CD30 antibody-drug conjugate, in relapsed/refractory CD30(+) NHL. This planned subset analysis of B-cell NHLs includes 49 patients with DLBCL and 19 with other B-cell NHLs. Objective response rate was 44% for DLBCL, including 8 (17%) complete remissions (CRs) with a median duration of 16.6 months thus far (range, 2.7 to 22.7+ months). There was no statistical correlation between response and level of CD30 expression; however, all responding patients had quantifiable CD30 by computer-assisted assessment of immunohistochemistry. DLBCL patients were generally refractory to first-line (76%) and most recent therapies (82%), and 44% of these refractory patients responded (15% CRs). Patients with other B-cell lymphomas also responded: 1 CR, 2 partial responses (PRs) of 6 with gray zone, 1 CR of 6 with primary mediastinal B-cell, and 1 CR of 3 with posttransplant lymphoproliferative disorder. Adverse events were consistent with known toxicities. The combination of brentuximab vedotin with rituximab was generally well tolerated and had activity similar to brentuximab vedotin alone. Overall, significant activity with brentuximab vedotin was observed in relapsed/refractory DLBCL, and responses occurred across a range of CD30 expression. This study was registered at www.clinicaltrials.gov as #NCT01421667.

Ofatumumab in combination with ICE or DHAP chemotherapy in relapsed or refractory intermediate grade B-cell lymphoma.

Standard treatment of transplant-eligible patients with relapsed diffuse large B-cell lymphoma (DLBCL) consists of rituximab and platinum-based chemotherapy, either ifosfamide, carboplatin, and etoposide (ICE) or dexamethasone, cytarabine, and cisplatin (DHAP), with autologous transplant consolidation for those with chemosensitive disease. Nonetheless, outcomes are suboptimal for patients failing rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). We performed a multi-center phase II trial investigating the safety and efficacy of ofatumumab, a monoclonal antibody against CD20, combined with ICE or DHAP second-line therapy in patients with relapsed or refractory DLBCL, grade 3b follicular lymphoma, or transformed follicular lymphoma. Sixty-one patients were treated with either ofatumumab-ICE (35) or ofatumumab-DHAP (26). The overall response rate (ORR) was 61%, and the complete response (CR) rate was 37%. In patients with 2 or 3 adverse risk factors according to the second-line, age-adjusted, international prognostic index, the ORR was 59% and CR 31%, and in patients with early-relapsing or primary refractory disease, the ORR was 55% and CR 30%. Toxicity was largely hematologic, and stem cell mobilization was successful in 43 of 45 patients. Substitution of ofatumumab for rituximab in standard second-line regimens following failure of R-CHOP is a promising approach. This trial was registered at www.clinicaltrials.gov as NCT00823719.

Biochemical Diagnosis of Acute Hepatic Porphyria: Updated Expert Recommendations for Primary Care Physicians.

Acute hepatic porphyria (AHP) is a group of rare, metabolic diseases where patients can experience acute neurovisceral attacks, chronic symptoms, and long-term complications. Diagnostic biochemical testing is widely available and effective, but a substantial time from symptom onset to diagnosis often delays treatment and increases morbidity. A panel of laboratory scientists and clinical AHP specialists collaborated to produce recommendations on how to enhance biochemical diagnosis of AHP in the USA. AHP should be considered in the differential diagnosis of unexplained abdominal pain, the most common symptom, soon after excluding common causes. Measurement of porphobilinogen (PBG) and porphyrins in a random urine sample, with results normalized to creatinine, is recommended as an effective and cost-efficient initial test for AHP. Delta-aminolevulinic acid testing may be included but is not essential. The optimal time to collect a urine sample is during an attack. Substantial PBG elevation confirms an AHP diagnosis and allows for prompt treatment initiation. Additional testing can determine AHP subtype and identify at-risk family members. Increased awareness of AHP and correct diagnostic methods will reduce diagnostic delay and improve patient outcomes.

Clinical Utility of a Blood-based Protein Assay on Diagnostic Colonoscopy Referrals for Elevated-risk Colorectal Cancer Patients in Primary Care.

BACKGROUND: Colonoscopies are effective in finding early stage colorectal cancer (CRC), which when found in a timely manner, dramatically improve survival rates. A significant number of at-risk patients are still not screened. We investigated the utility of a blood-based protein assay to assess for CRC in patients with elevated risk on the quality of preventive care delivered by board-certified primary care physicians (PCPs) in the United States. METHODS: We report on the results of a 3-part, longitudinal, randomized controlled trial. Part 1 assessed physicians' ability to identify simulated patients at risk for CRC and found PCPs missed colonoscopy referrals for high-risk patients ~40% of the time. Part 2 randomized PCPs into control and intervention arms and demonstrated that a novel blood-based protein assay increased referral rates for a diagnostic colonoscopy when caring for simulated patients. Part 3, reported herein, compares real-world colonoscopy rates of actual patients cared for by control versus intervention physicians. Part 3 was executed to confirm whether the use of the assay demonstrated the same utility in their real world, high-risk patients as found in part 2 using simulated patients. RESULTS: In the simulations, physicians with access to the assay were significantly more likely to order diagnostic colonoscopies. Similarly, in real-world practice, patients were also more likely to be referred for a diagnostic colonoscopy (odds ratio, 4.57; 95% confidence interval, 1.19-17.57). CONCLUSIONS: An increase in CRC risk, as indicated by the assay in simulated and real-life patients, was associated with a higher likelihood of appropriate patients being referred to diagnostic colonoscopy.

High-dose versus standard chemotherapy in metastatic breast cancer: comparison of Cancer and Leukemia Group B trials with data from the Autologous Blood and Marrow Transplant Registry.

PURPOSE: To assess survival of patients with metastatic breast cancer treated with high-dose chemotherapy (HDC) versus standard-dose chemotherapy (SDC). PATIENTS AND METHODS: SDC in four Cancer and Leukemia Group B (CALGB) trials was compared with hematopoietic stem-cell support in patients from the Autologous Blood and Marrow Transplant Registry. Cox proportional hazard regression incorporated potentially confounding effects. A total of 1,509 women were enrolled onto CALGB trials, and 1,188 women received HDC. No significant survival differences existed by CALGB trial or HDC regimen. Consideration was restricted to candidates for both SDC and HDC. The resulting sample included 635 SDC and 441 HDC patients. The outcome of interest was overall survival. RESULTS: The HDC group displayed better performance status. The SDC group had slightly better survival in first year after treatment. The HDC group had lower hazard of death from years 1 to 4 and had somewhat higher probability of 5-year survival (adjusted probabilities [95% confidence intervals], 23% [17% to 29%] v 15% [11% to 19%], P =.03). CONCLUSION: After controlling for known prognostic factors in this nonrandomized analysis of two large independent data sets, women receiving HDC versus SDC for metastatic breast cancer have a similar short-term probability of survival, and might have a modestly higher long-term probability of survival.

A Phase I Trial of the Anti-KIR Antibody IPH2101 and Lenalidomide in Patients with Relapsed/Refractory Multiple Myeloma.

PURPOSE: Natural killer (NK) cells may play an important role in the immune response to multiple myeloma; however, multiple myeloma cells express killer immunoglobulin-like receptor (KIR) ligands to prevent NK cell cytotoxicity. Lenalidomide can expand and activate NK cells in parallel with its direct effects against multiple myeloma; however, dexamethasone may impair these favorable immunomodulatory properties. IPH2101, a first-in-class antiinhibitory KIR antibody, has acceptable safety and tolerability in multiple myeloma as a single agent. The present work sought to characterize lenalidomide and IPH2101 as a novel, steroid-sparing, dual immune therapy for multiple myeloma. EXPERIMENTAL DESIGN: A phase I trial enrolled 15 patients in three cohorts. Lenalidomide was administered per os at 10 mg on cohort 1 and 25 mg on cohorts 2 and 3 days 1 to 21 on a 28-day cycle with IPH2101 given intravenously on day 1 of each cycle at 0.2 mg/kg in cohort 1, 1 mg/kg in cohort 2, and 2 mg/kg in cohort 3. No corticosteroids were utilized. The primary endpoint was safety, and secondary endpoints included clinical activity, pharmacokinetics (PK), and pharmacodynamics (PD). RESULTS: The biologic endpoint of full KIR occupancy was achieved across the IPH2101 dosing interval. PD and PK of IPH2101 with lenalidomide were similar to data from a prior single-agent IPH2101 trial. Five serious adverse events (SAE) were reported. Five objective responses occurred. No autoimmunity was seen. CONCLUSIONS: These findings suggest that lenalidomide in combination with antiinhibitory KIR therapy warrants further investigation in multiple myeloma as a steroid-sparing, dual immune therapy. This trial was registered at www.clinicaltrials.gov (reference: NCT01217203).

Pegfilgrastim appears equivalent to daily dosing of filgrastim to treat neutropenia after autologous peripheral blood stem cell transplantation in patients with non-Hodgkin lymphoma.

BACKGROUND: Filgrastim decreases the time to neutrophil recovery after autologous peripheral blood stem cell transplantation (PBSCT). We hypothesized that single-dose pegfilgrastim would mimic multiple daily doses of filgrastim, resulting in an equivalent shortening of post-PBSCT neutropenia. PATIENTS AND METHODS: Patients who were eligible for PBSCT and aged >or= 18 years were identified before high-dose chemotherapy, after the harvesting and cryopreservation of peripheral blood progenitor cells (ie, > 2.5 x 10(6) CD34-positive cells/kg). Eligible patients received either standard carmustine/etoposide/cytarabine/melphalan (BEAM) or carmustine/etoposide/cytarabine/cyclophosphamide (BEAC) high-dose chemotherapy. Before high-dose chemotherapy, patients were randomly assigned to receive pegfilgrastim 6 mg on day 1 (arm A) or weight-based, dose-adjusted filgrastim beginning on day 1 (arm B) after transplantation until neutrophil engraftment. RESULTS: One-hundred and one patients were enrolled between April 2003 and April 2007. Three patients were not treated. Demographics were well-balanced in terms of stage at diagnosis, Eastern Cooperative Oncology Group performance status, histology, and lines of previous therapy. Results (arm A/arm B) pertained to mean doses received (1.0/12.6), mean absolute neutrophil count recovery days (9.3/9.8), red blood cell transfusions (1.7/1.9), red blood cell transfusion units (3.1/3.8), platelet transfusions (3.1/2.8), positive blood culture rate (18%/29.2%), febrile neutropenia (FN; 18%/16.7%), and duration of FN (days; 7.1/6.9). Transplantation-related mortality and grade 3 or 4 adverse events were comparable between arms. CONCLUSION: Pegfilgrastim after PBSCT appears equivalent to multiple daily doses of filgrastim. This approach might be considered in lieu of filgrastim, thus obviating the need for multiple daily injections.