Pharmacokinetics of quinacrine in the treatment of prion disease

BACKGROUND: Prion diseases are caused by the accumulation of an aberrantly folded isoform of the prion protein, designated PrP(Sc). In a cell-based assay, quinacrine inhibits the conversion of normal host prion protein (PrP(C)) to PrP(Sc )at a half-maximal concentration of 300 nM. While these data suggest that quinacrine may be beneficial in the treatment of prion disease, its penetration into brain tissue has not been extensively studied. If quinacrine penetrates brain tissue in concentrations exceeding that demonstrated for in vitro inhibition of PrP(Sc), it may be useful in the treatment of prion disease. METHODS: Oral quinacrine at doses of 37.5 mg/kg/D and 75 mg/kg/D was administered to mice for 4 consecutive weeks. Plasma and tissue (brain, liver, spleen) samples were taken over 8 weeks: 4 weeks with treatment, and 4 weeks after treatment ended. RESULTS: Quinacrine was demonstrated to penetrate rapidly into brain tissue, achieving concentrations up to 1500 ng/g, which is several-fold greater than that demonstrated to inhibit formation of PrP(Sc )in cell culture. Particularly extensive distribution was observed in spleen (maximum of 100 μg/g) and liver (maximum of 400 μg/g) tissue. CONCLUSIONS: The documented extensive brain tissue penetration is encouraging suggesting quinacrine might be useful in the treatment of prion disease. However, further clarification of the distribution of both intracellular and extracellular unbound quinacrine is needed. The relative importance of free quinacrine in these compartments upon the conversion of normal host prion protein (PrP(C)) to PrP(Sc )will be critical toward its potential benefit

Safety and efficacy of cryopreserved autologous tumor infiltrating lymphocyte therapy (LN-144, lifileucel) in advanced metastatic melanoma patients who progressed on multiple prior therapies including anti-PD-1

2518 Background: Treatment options are limited for patients with advanced melanoma who have progressed on checkpoint inhibitors and targeted therapies such as BRAF/MEK inhibitors (if BRAF-V600E mutated). Adoptive cell therapy utilizing tumor-infiltrating lymphocytes (TIL) has shown antitumor efficacy with durable long-term responses in heavily pretreated melanoma patients. Safety and efficacy of lifileucel (LN-144), a centrally manufactured autologous TIL therapy are presented. Methods: C-144-01 is a global Phase 2 open-label, multicenter study of the efficacy and safety of lifileucel in patients with unresectable metastatic melanoma. We report on Cohort 2 (N = 55) patients who received cryopreserved lifileucel. Tumors resected at local institutions were processed in central GMP facilities for TIL production in a 22-day process. Final TIL infusion product was cryopreserved and shipped to sites. Patients received one week of cyclophosphamide/fludarabine preconditioning lymphodepletion, a single lifileucel infusion, followed by up to 6 doses of IL-2. Results: In 55 patients with Stage IIIC/IV unresectable melanoma, 3.1 mean prior therapies (anti-PD1 100%; anti-CTLA-4 80%; BRAF/MEK inhibitor 24%), high baseline tumor burden (110 mm mean target lesion sum of diameters), ORR was 38% (2 CR, 18 PR, 1 uPR). Of 21 responders, 4 have progressed to date with median follow up of 7.4 months. Overall disease control was 76%. Improved responses in some patients were observed with longer follow up. Most (54) patients progressed on prior anti-PD1 and those with PD-L1 negative status (TPS < 5%) were among responders. Mean cells infused was 28 x10 9 . Median IL-2 doses administered was 6.0. Adverse events resolved to baseline, 2 weeks post TIL infusion, a potentially important benefit of one-time TIL therapy. Conclusions: Lifileucel treatment results in 38% ORR in heavily pretreated metastatic melanoma patients with high baseline disease burden who received prior anti-PD1 and BRAF/MEK inhibitor if BRAF mutated. Based on these data, a new Cohort 4 in C-144-01 has been initiated to support lifileucel registration. Clinical trial information: NCT02360579

Trastuzumab Deruxtecan in Previously Treated HER2-Low Advanced Breast Cancer

Copyright © 2022 Massachusetts Medical Society.BACKGROUND: Among breast cancers without human epidermal growth factor receptor 2 (HER2) amplification, overexpression, or both, a large proportion express low levels of HER2 that may be targetable. Currently available HER2-directed therapies have been ineffective in patients with these &quot;HER2-low&quot; cancers. METHODS: We conducted a phase 3 trial involving patients with HER2-low metastatic breast cancer who had received one or two previous lines of chemotherapy. (Low expression of HER2 was defined as a score of 1+ on immunohistochemical [IHC] analysis or as an IHC score of 2+ and negative results on in situ hybridization.) Patients were randomly assigned in a 2:1 ratio to receive trastuzumab deruxtecan or the physician&apos;s choice of chemotherapy. The primary end point was progression-free survival in the hormone receptor-positive cohort. The key secondary end points were progression-free survival among all patients and overall survival in the hormone receptor-positive cohort and among all patients. RESULTS: Of 557 patients who underwent randomization, 494 (88.7%) had hormone receptor-positive disease and 63 (11.3%) had hormone receptor-negative disease. In the hormone receptor-positive cohort, the median progression-free survival was 10.1 months in the trastuzumab deruxtecan group and 5.4 months in the physician&apos;s choice group (hazard ratio for disease progression or death, 0.51; P&lt;0.001), and overall survival was 23.9 months and 17.5 months, respectively (hazard ratio for death, 0.64; P = 0.003). Among all patients, the median progression-free survival was 9.9 months in the trastuzumab deruxtecan group and 5.1 months in the physician&apos;s choice group (hazard ratio for disease progression or death, 0.50; P&lt;0.001), and overall survival was 23.4 months and 16.8 months, respectively (hazard ratio for death, 0.64; P = 0.001). Adverse events of grade 3 or higher occurred in 52.6% of the patients who received trastuzumab deruxtecan and 67.4% of those who received the physician&apos;s choice of chemotherapy. Adjudicated, drug-related interstitial lung disease or pneumonitis occurred in 12.1% of the patients who received trastuzumab deruxtecan; 0.8% had grade 5 events. CONCLUSIONS: In this trial involving patients with HER2-low metastatic breast cancer, trastuzumab deruxtecan resulted in significantly longer progression-free and overall survival than the physician&apos;s choice of chemotherapy. (Funded by Daiichi Sankyo and AstraZeneca; DESTINY-Breast04 ClinicalTrials.gov number, NCT03734029.).N