Cenicriviroc, a dual CCR2 and CCR5 antagonist leads to a reduction in plasma fibrotic biomarkers in persons living with HIV on antiretroviral therapy

Background: Chronic HIV is associated with increased inflammation and tissue fibrosis despite suppressive antiretroviral therapy (ART). Monocytes and macrophages have been implicated in the pathogenesis of fibrosis, facilitated by chemokine receptor interactions.Methods: We assessed systemic fibrotic biomarkers (transforming growth factor beta-1 [TGF-β1], thrombospondin-1 [TSP-1], C-terminal pro-peptide of collagen type I [CICP], and IL-11) in banked plasma from a previously published 24-week open-label trial of cenicriviroc (CVC), a dual CCR2/CCR5 antagonist, among persons living with HIV (PLWH) on stable ART with undetectable plasma HIV RNA (<50 copies/mL). Fibrotic markers were assessed by ELISA and Luminex. Untreated HIV-seronegative individuals (n = 6) of similar age and demographics served as a comparator group.Results: Median age of PLWH was 55 years. At baseline, PLWH had higher median TGF-β1 (2.11 vs 1.62 ng/mL, p = 0.01), TSP-1 (236.74 vs 83.29 ng/mL, p < 0.0001), and CICP (200.46 vs 111.28 ng/mL, p = 0.01), but lower IL-11 (36.00 vs 53.74 pg/mL, p = 0.01) compared to HIV-uninfected individuals. Over 24 weeks, median TGF-β1 (-0.74 ng/mL, p = 0.006), TSP-1 (-52.12 ng/mL, p < 0.0001), and CICP (-28.12 ng/mL, p < 0.0001) decreased and IL-11 (28.98 pg/mL, p < 0.0001) increased in PLWH. At week 24, TGF-β1, CICP, and IL-11 were similar between the two groups (p > 0.05), while TSP-1 remained elevated in PLWH (p = 0.009) compared to controls.Conclusions: PLWH had higher levels of the plasma fibrotic markers TGF-β1, TSP-1, and CICP. After 24 weeks of CVC, fibrotic markers generally returned to levels comparable to HIV-uninfected controls. Dual CCR2 and CCR5 blockade may ameliorate the detrimental fibrotic events that persist in treated HIV.

Pharmacokinetics and safety of weekly dapsone and dapsone plus pyrimethamine for prevention of pneumocystis pneumonia

The safety and pharmacokinetics of weekly dapsone and weekly dapsone plus pyrimethamine were examined in adult patients with human immunodeficiency virus infection who were at risk for pneumocystis pneumonia because of a prior episode or a CD4+ T-cell count less than 250 cells per mm3. Groups of patients received 100, 200, and 300 mg of dapsone as a single weekly dose. The maximum tolerated dose of weekly dapsone was established as 200 mg per week in patients receiving at least 500 mg of zidovudine concomitantly. This dose of dapsone was then found to be well tolerated when combined with pyrimethamine at 25 mg. Further patients were randomized to dapsone at 200 mg or dapsone at 200 mg plus pyrimethamine at 25 mg once weekly. Twenty-six patients each were followed for a median of 33 weeks on dapsone alone and 45 weeks on the combination. Seven patients in each group withdrew because of toxicity. Five patients receiving dapsone developed documented pneumocystis pneumonia, while four and two patients receiving dapsone plus pyrimethamine developed documented and presumptive pneumocystis pneumonia, respectively. To evaluate the tolerability of a higher dose of pyrimethamine, 11 patients had their regimen changed to dapsone at 200 mg plus pyrimethamine at 75 mg, which was well tolerated by 10 of the patients for a median period of 11 weeks. The pharmacokinetics of dapsone and pyrimethamine were examined by using a population pharmacokinetic model. Decreases in the apparent volume of the peripheral compartment were observed when multiple-dose regimens of dapsone were compared with single-dose dapsone and when multiple-dose regimens of dapsone with pyrimethamine were compared with multiple-dose dapsone alone. When administered weekly, dapsone at 200 mg and dapsone at 200 mg with pyrimethamine at 25 mg are both well-tolerated regimens. This preliminary study suggests that the efficacy of these regimens in preventing pneumocystis pneumonia, however, may be less than that of trimethoprim-sulfamethoxazole.

Salvage trial of trimetrexate-leucovorin for the treatment of cerebral toxoplasmosis in patients with AIDS

The clinical efficacy of trimetrexate, a dihydrofolate reductase inhibitor with potent in vitro antitoxoplasma activity, was assessed in 9 sulfonamide-intolerant patients with AIDS and biopsy-proven cerebral toxoplasmosis. The 9 patients were treated for 28-149 days with trimetrexate (30-280 mg/m2/day) plus leucovorin (20-90 mg/m2 every 6 h). Radiographic responses were documented in 8 patients, and clinical responses in 5 patients. Despite continued therapy, all patients deteriorated clinically and radiographically within 13-109 days of their initial improvement. Trimetrexate at very high doses for extended periods was not associated with serious toxicity. Trimetrexate alone had dramatic but transient activity in sulfonamide-intolerant patients and thus is not adequate as single-agent therapy for AIDS-associated toxoplasmosis.

Trimetrexate-leucovorin dosage evaluation study for treatment of Pneumocystis carinii pneumonia

To determine the maximal tolerable dosage of trimetrexate for treatment of pneumocystis pneumonia, 25 patients were treated each day with 45 mg/m2 of trimetrexate and 80 mg/m2 of leucovorin; 10 received 60 mg/m2 and 80 mg/m2; 12 received 60 mg/m2 and 160 mg/m2; and 6 received 90 mg/m2 and 160 mg/m2, respectively. Leucovorin was increased twofold and trimetrexate reduced by 50% or suspended briefly for various levels of neutropenia and thrombocytopenia until blood counts increased. Dosage-modifying hematologic toxicity occurred in 12 (46%), 8 (80%), 9 (75%), and 4 (67%) patients with the respective groups. Cytopenias were in each case reversible and other toxicities were well tolerated. All survivors but one were able to receive a full 21 doses of trimetrexate. Twenty-four (92%), 10 (100%), 7 (58%), and 4 (80%) of patients in the respective groups survived. Thus, the 45 mg/m2/day dosage of trimetrexate with 80 mg/m2/day of leucovorin resulted in the least dosage-modifying toxicity and excellent efficacy. This combination should be selected for studies to compare trimetrexate with other therapies for pneumocystis pneumonia.

Treatment of Pneumocystis carinii pneumonia with trimetrexate in acquired immunodeficiency syndrome (AIDS)

In vitro studies have shown that trimetrexate, a lipid-soluble analogue of methotrexate, is 1500 times more potent than trimethoprim as an inhibitor of dihydrofolate reductase from Pneumocystis carinii. Furthermore, trimetrexate is readily taken up by P carinii, while performed folates such as leucovorin are not. These observations suggest that the combination of trimetrexate plus leucovorin, which can specifically protect mammalian host tissues from the toxic effects of the antifolate, may be useful in the treatment of pneumocystis pneumonia. This concept was tested in a clinical study of 49 patients with acquired immunodeficiency syndrome (AIDS) and P carinii pneumonia who were treated for 21 days with trimetrexate and leucovorin. Patients were divided into three groups: 16 patients who were unable to tolerate or had failed both pentamidine isethionate and trimethoprim-sulfamethoxazole therapy were treated with trimetrexate plus leucovorin (Group I); 16 patients who were unable to tolerate sulfonamide therapy were treated with trimetrexate with leucovorin as initial therapy (Group II); and 17 patients in whom trimetrexate with leucovorin plus sulfadiazine was used as initial therapy (Group III). Response and survival rates were 69% and 69% in Group I; 63% and 88%, respectively, in Group II; and 71% and 76%, respectively, in Group III. Toxicity was minimal. The results indicate that trimetrexate with leucovorin is safe and effective for initial therapy in AIDS patients with P carinii pneumonia and in those intolerant or unresponsive to standard therapies.

Trimetrexate for the treatment of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome

Preclinical studies have demonstrated that trimetrexate is a potent inhibitor of dihydrofolate reductase from Pneumocystis carinii. On the basis of this evidence, this lipid-soluble antifolate was used as an antipneumocystis agent in 49 patients with the acquired immunodeficiency syndrome (AIDS) and pneumocystis pneumonia. Simultaneous treatment with the reduced folate leucovorin was used as a specific antidote to protect host tissues from the toxic effects of the antifolate without affecting the antipneumocystis action of trimetrexate. Patients were assigned to three groups and treated for 21 days: in Group I, trimetrexate with leucovorin was used as salvage therapy in patients in whom standard treatments (both pentamidine isethionate and trimethoprim-sulfamethoxazole) could not be tolerated or had failed (16 patients); in Group II, trimetrexate with leucovorin was used as initial therapy in patients with a history of sulfonamide inefficacy or intolerance (16 patients); and in Group III, trimetrexate with leucovorin plus sulfadiazine was used as initial therapy (17 patients). The response and survival rates were, respectively, 69 percent and 69 percent in Group I; 63 percent and 88 percent in Group II; and 71 percent and 77 percent in Group III. Trimetrexate therapy had minimal toxicity; transient neutropenia or thrombocytopenia occurred in 12 patients and mild elevation of serum aminotransferases in 4. We conclude that the combination of trimetrexate and leucovorin is safe and effective for the initial treatment of pneumocystis pneumonia in patients with AIDS and for the treatment of patients with intolerance or lack of response to standard therapies.