The MDM2 antagonist idasanutlin in patients with polycythemia vera: results from a single-arm phase 2 study.

Idasanutlin, an MDM2 antagonist, showed clinical activity and a rapid reduction in JAK2 V617F allele burden in patients with polycythemia vera (PV) in a phase 1 study. This open-label phase 2 study evaluated idasanutlin in patients with hydroxyurea (HU)-resistant/-intolerant PV, per the European LeukemiaNet criteria, and phlebotomy dependence; prior ruxolitinib exposure was permitted. Idasanutlin was administered once daily on days 1 through 5 of each 28-day cycle. The primary end point was composite response (hematocrit control and spleen volume reduction > 35%) in patients with splenomegaly and hematocrit control in patients without splenomegaly at week 32. Key secondary end points included safety, complete hematologic response (CHR), patient-reported outcomes, and molecular responses. All patients (n = 27) received idasanutlin; 16 had response assessment (week 32). Among responders with baseline splenomegaly (n = 13), 9 (69%) attained any spleen volume reduction, and 1 achieved composite response. Nine patients (56%) achieved hematocrit control, and 8 patients (50%) achieved CHR. Overall, 43% of evaluable patients (6/14) showed a ≥50% reduction in the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (week 32). Nausea (93%), diarrhea (78%), and vomiting (41%) were the most common adverse events, with grade ≥ 3 nausea or vomiting experienced by 3 patients (11%) and 1 patient (4%), respectively. Reduced JAK2 V617F allele burden occurred early (after 3 cycles), with a median reduction of 76%, and was associated with achieving CHR and hematocrit control. Overall, the idasanutlin dosing regimen showed clinical activity and rapidly reduced JAK2 allele burden in patients with HU-resistant/- intolerant PV but was associated with low-grade gastrointestinal toxicity, leading to poor long-term tolerability. This trial was registered at www.clinincaltrials.gov as #NCT03287245.

Obinutuzumab-atezolizumab-lenalidomide for the treatment of patients with relapsed/refractory follicular lymphoma: final analysis of a Phase Ib/II trial.

We evaluated the triplet regimen obinutuzumab-atezolizumab-lenalidomide (G-atezo-len) for patients with relapsed/refractory (R/R) follicular lymphoma (FL) in an open-label, multicenter phase Ib/II study (BO29562; NCT02631577). An initial 3 + 3 dose-escalation phase to define the recommended phase II dose of lenalidomide was followed by an expansion phase with G-atezo-len induction and maintenance. At final analysis, 38 patients (lenalidomide 15 mg, n = 4; 20 mg, n = 34) had completed the trial. Complete response rate for the efficacy population (lenalidomide 20 mg, n = 32) at end-of-induction was 71.9% (66.7% in double-refractory patients [refractory to rituximab and alkylator] [n = 12]; 50.0% in patients with progressive disease within 24 months of first-line therapy [n = 12]). The 36-month progression-free survival rate was 68.4%. All treated patients had ≥1 adverse event (AE; grade 3-5 AE, 32 patients [84%]; serious AE, 18 patients [47%]; AEs leading to discontinuation of any study drug, 11 patients [29%]). There were 2 fatal AEs (1 merkel carcinoma, 1 sarcomatoid carcinoma; both unrelated to any study drug). The G-atezo-len regimen is effective and tolerable in patients with R/R FL. AEs were consistent with the known safety profile of the individual drugs.

A Randomized Double-Blind Placebo-Controlled Phase IIB Trial of Curcumin in Oral Leukoplakia.

Oral leukoplakia is a potentially malignant lesion of the oral cavity, for which no effective treatment is available. We investigated the effectiveness of curcumin, a potent inhibitor of NF-κB/COX-2, molecules perturbed in oral carcinogenesis, to treat leukoplakia. Subjects with oral leukoplakia (n = 223) were randomized (1:1 ratio) to receive orally, either 3.6 g/day of curcumin (n = 111) or placebo (n = 112), for 6 months. The primary endpoint was clinical response obtained by bi-dimensional measurement of leukoplakia size at recruitment and 6 months. Histologic response, combined clinical and histologic response, durability and effect of long-term therapy for an additional six months in partial responders, safety and compliance were the secondary endpoints. Clinical response was observed in 75 (67.5%) subjects [95% confidence interval (CI), 58.4-75.6] in the curcumin and 62 (55.3%; 95% CI, 46.1-64.2) in placebo arm (P = 0.03). This response was durable, with 16 of the 18 (88.9%; 95% CI, 67.2-96.9) subjects with complete response in curcumin and 7 of 8 subjects (87.5%) in placebo arm, demonstrating no relapse after 6 months follow-up. Difference in histologic response between curcumin and placebo was not significant (HR, 0.88, 95% CI, 0.45-1.71; P = 0.71). Combined clinical and histologic response assessment indicated a significantly better response with curcumin (HR, 0.50; 95% CI, 0.27-0.92; P = 0.02). Continued therapy, in subjects with partial response at 6 months, did not yield additional benefit. The treatment did not raise any safety concerns. Treatment of oral leukoplakia with curcumin (3.6 g for six months), thus was well tolerated and demonstrated significant and durable clinical response for 6 months. Cancer Prev Res; 9(8); 683-91. ©2016 AACR.

Fluorescence and nucleic acid binding properties of bovine leukemia virus nucleocapsid protein.

We used the intrinsic fluorescence of bovine leukemia virus p12, a nucleocapsid protein with two tryptophan-containing zinc fingers (ZFs), to study its conformation and binding to single-stranded nucleic acids. Spectral emission maxima suggested solvent-exposed tryptophans. A peptide derived from ZF1 had a higher quantum yield and longer average lifetime (tau) than ZF2. BLV p12 tau and rotational correlation time were greater than ZF values, but all de-metallated sequences gave similar results. Apo p12 showed reduced fluorescence intensity, tau and loss of secondary structure. DNA-binding affinity of p12 was in the nanomolar range, and decreased 14-fold after Zn++ ejection. Nucleobase preference of BLV p12 was different from the closely related HTLV-1 but similar to HIV-1 and SIV nucleocapsids, both phylogenetically distant.