Final results of phase II trial of doxorubicin HCl liposome injection followed by bexarotene in advanced cutaneous T-cell lymphoma

BACKGROUND

High response rates for doxorubicin HCl liposome injection (DLI) in cutaneous T-cell lymphoma (CTCL) have been reported with vague criteria until recently. Approximately 50% of CTCL patients respond to bexarotene (Bex).

PATIENTS AND METHODS

A phase II trial was carried out to clarify the true overall response rate (ORR) for DLI and to assess the role of sequential Bex. Patients were treated with DLI 20 mg/m(2) i.v. every 2 weeks for 16 weeks (8 doses) followed by 16 weeks with Bex 300 mg/m(2) orally. Response assessments were carried out after 16 (DLI) and 32 weeks (Bex). Skin responses were measured by the modified Severity-Weighted Assessment Tool (mSWAT) and the Composite Assessment of Index Lesion Severity (CA).

RESULTS

Thirty-seven patients were treated: stage IV (22, 8 with Sézary syndrome), IIB (10), earlier stage refractory to skin-directed therapies or radiation therapy (5). For 34 assessable patients: ORR 14/34 [41%: partial response (PR) 12, clinical complete response (CCR) 2]. Maximum responses were all seen after 16 weeks DLI. Median progression-free survival (PFS) was 5 months. There were 22 deaths: 21 of disease and 1 of heart failure. Twenty-seven grade 3 and 5 grade 4 toxic events were observed.

CONCLUSION(S)

With strict criteria, DLI ORR is among the highest reported for single agents in CTCL. Sequential Bex did not increase the response rate or duration.

Vorinostat in combination with bexarotene in advanced cutaneous T-cell lymphoma: A phase I study

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Background: Vorinostat, a histone deacetylase inhibitor, is registered for the treatment of advanced cutaneous T-cell lymphoma (CTCL) in the US. Preclinical studies suggest that vorinostat may enhance the activity of chemotherapeutic or biological anticancer agents in a variety of cancers. This Phase I, multicenter, open-label study systematically evaluated vorinostat combined with the retinoid bexarotene in patients (pts) with advanced CTCL. Methods: Eligible pts were aged ≥18 years with stage ≥IB progressive, persistent, or recurrent CTCL refractory to ≥1 systemic therapy. Primary objective was to determine the maximum tolerated dose (MTD). Phase Ia Part I: dose escalation of vorinostat (200–400 mg/day) and bexarotene (150–300 mg/m2/day); Part II: fixed vorinostat dose (400 mg/day) with bexarotene dose escalation (150–450 mg/day). Cycles were repeated every 28 days for ≤6 cycles. Clinical activity and safety of the combination was also assessed. Results: 23 pts received ≥1 dose of study medication. Three pts in dose level (DL) 2 experienced dose-limiting toxicities (DLTs) ( Table ). No DLTs were observed in the first cycle of DL 2a and 2b. The MTD (Part I) was vorinostat 200 mg/day plus bexarotene 300 mg/m2/day. The Part II MTD was not reached as the study was discontinued early due to low enrollment; no DLTs were observed at DL 6 or 7. The most common drug-related adverse events (DRAEs) were hypothyroidism (35%), fatigue (30%), and hypertriglyceridemia (30%). No Grade 4 or 5 DRAEs were reported and 4 pts had serious DRAEs (Grade ≤3). Eighteen pts have discontinued: 5 due to AEs, 5 due to progressive disease, and 8 withdrew consent. Of 22 pts evaluable for efficacy, 4 (18%) had an objective response, and 7 (32%) derived clinical benefit (pruritis relief). Conclusions: These preliminary data suggest that the vorinostat/bexarotene combination is feasible in pts with advanced CTCL; however, the dosage of either drug must be reduced to avoid unacceptable side effects.

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Bexarotene is effective and safe for treatment of refractory advanced-stage cutaneous T-cell lymphoma: multinational phase II-III trial results

PURPOSE

Cutaneous T-cell lymphomas (CTCL) are malignancies of T cells appearing as skin lesions and are responsive to retinoid therapy. Safety and efficacy of a novel RXR-selective retinoid (rexinoid) bexarotene (Targretin, LGD1069; Ligand Pharmaceuticals Inc, San Diego, CA) was evaluated as a single-agent oral therapy administered once daily in an open-label study in patients with refractory advanced-stage CTCL.

PATIENTS AND METHODS

Ninety-four patients with biopsy-confirmed CTCL in advanced stages (IIB-IVB) were enrolled at 26 centers. Fifty-six patients received an initial dose of 300 mg/m2/d oral bexarotene and 38 started at more than 300 mg/m2/d.

RESULTS

Clinical complete and partial responses were reported by Primary End point Classification for the study in 45% (25 of 56) of patients enrolled at 300 mg/m2/d dosing. At more than 300 mg/m2/d, 55% (21 of 38) of patients responded, including 13% (five of 38) clinical complete. For the 300 mg/m2/d initial dose group, the rate of relapse after response was 36% and the projected median duration of response was 299 days. Improvements were also seen in overall body-surface area involvement, median index lesion surface area, adenopathy, cutaneous tumors, pruritus, and CTCL-specific quality of life. The most frequent drug-related adverse events included hypertriglyceridemia (associated rarely with pancreatitis), hypercholesterolemia, hypothyroidism, and headache.

CONCLUSION

Bexarotene is the first in a novel class of pharmacologic agents, the RXR-selective retinoids, or rexinoids. Bexarotene is orally administered, safe, and generally well tolerated with reversible side effects, and is effective for the treatment of advanced, refractory CTCL.

Mycosis fungoides metastasizing to the brain parenchyma: case report

OBJECTIVE AND IMPORTANCE

Mycosis fungoides is a rare T-cell lymphoma of the skin that can, in one-half to three-quarters of patients suffering from this disease, involve the viscera in late stages of the disease. Although autopsy series performed more than 2 decades ago showed that the incidence of metastatic mycosis fungoides to the central nervous system is approximately one of seven, a total of only several dozen cases have been reported to date. As compared to meningeal involvement, intraparenchymal metastases are even rarer. We describe a biopsy-proven case of intraparenchymal central nervous system mycosis fungoides in a patient with nonprogressive skin involvement and no detectable visceral involvement, and we present a review of the relevant literature.

CLINICAL PRESENTATION

A 68-year-old man, 3 years after the diagnosis of his skin disease, developed fatigue, confusion, and frontal lobe signs without the presence of cerebriform cells in the peripheral blood or any other clinical evidence of visceral involvement. Magnetic resonance imaging revealed a diffuse area of increased T2-weighted signal involving the white matter of both cerebral hemispheres as well as a focal area of T2 abnormality along the body of the corpus callosum. The radiological differential diagnosis was either leukodystrophy caused by chemotherapy, progressive multifocal leukoencephalopathy, or glioma with associated white matter changes.

INTERVENTION

A stereotactic serial brain biopsy revealed diffuse perivascular infiltrates of atypical lymphocytes, as well as several large cells with cerebriform nuclei consistent with mycosis fungoides. The cells were immunoreactive for LCA, MT1, UCHL1, and CD3.

CONCLUSION

We stress the importance of including mycosis fungoides as part of the differential diagnosis for a brain lesion in patients with cutaneous T-cell lymphoma, because treatments do exist, and we conclude that a serial stereotactic biopsy may be necessary to provide a definitive diagnosis.

Large-cell variants of mantle cell lymphoma: cytologic characteristics and p53 anomalies may predict poor outcome

Large-cell variants are uncommon in mantle cell lymphoma (MCL). Here we describe the pathologic and clinical findings in five patients with large-cell lymphoma related to MCL (L-MCL), and compare them to a group of classic small-cell MCL (s-MCL) cases. Histologically, the MC origin of the large cells was evinced by their association with a small mantle cell component in the same tissue, or their distribution in a classic mantle zone pattern, or their development in a patient with previous s-MCL. The large cells were either pleomorphic mantle cells (case 1) or transformed blast-like cells (case 2-5). The median nuclear diameter, median nuclear area and proliferation index of L-MCLs and s-MCLs, were statistically different. Immunophenotypic characterization of four specimens of L-MCL and 10 of s-MCLs with a large panel of antibodies showed the classic findings of MCL, i.e. the IgM+ D+/-, CD5+, CD10-, CD23- phenotype in all cases except two (one CD5- and one CD23+), and the association with a loose follicular dendritic cell network. Two of four L-MCLs and 5/10 s-MCLs demonstrated rearrangements of the bcl-1 gene by Southern blot or by polymerase chain reaction (PCR); 2/4 L-MCLs and 1/9 s-MCLs had p53 mutations on single-strand conformation polymorphism analysis; none of the 14 specimens showed rearrangement of bcl-2 by PCR or bcl-6 and c-myc by Southern blot. All patients with 'transformed' histology (versus 37% of all others) died of lymphoma; their survival (15-18 months; median 17) was much shorter than that of all the others (28-117+ months; median 43) (P=0.0035). All three patients with p53 anomalies, two of whom had tumours with transformed histology, died of their disease in a short time (15, 18 and 28 months). In contrast, the presence of bcl-1 rearrangements did not have prognostic implications. This study documents the existence of large-cell variants of MCL and the poor prognosis associated with the 'transformed' cytologic type and/or p53 abnormalities.

Role of leuCAM integrins and complement in platelet-monocyte rosette formation induced by immune complexes of human immunodeficiency virus-type 1-immune thrombocytopenic purpura patients

Patients with human immunodeficiency virus-type 1-immune thrombocytopenic purpura (HIV-1-ITP) have elevated polyethylene glycol (PEG)-precipitable immune complexes (ICs) composed of IgG, IgM, and complement that are threefold to sevenfold higher than in healthy control subjects. These complexes contain anti-F (ab')2 as well as anti-idiotype antibodies versus anti-HIV-1gp120. Because anti-F (ab')2 and anti-idiotype antibodies correlate with thrombocytopenia (r = .83 [J Clin Invest 77:1756, 1986] and r = .90 [J Clin Invest 89:356, 1992], respectively) we studied the binding of ICs to platelets and monocytes as well as their role in platelet-monocyte rosette formation. ICs bind to platelets in a saturation-dependent manner (optimum at 10 micrograms/mL; 0.5% of serum conc). Binding to platelets could not be inhibited with platelet saturating concentrations of aggregated IgG or with monoclonal antibody (MoAb) IV.3 versus FcR gamma II. Platelet binding could be inhibited with Fab anti-C3, anti-Clq, or anti-C4 by 57%, 40%, and 46% respectively, not with control Fab (P < .001). Monocytes from HIV-1-ITP patients form rosettes with normal platelets 16.8 +/- 5.2 rosettes/100 monocytes compared with 4.8 +/- 0.8 control monocytes plus normal platelets (P = .009). Gel-washed HIV-1-ITP platelets formed 19 +/- 2.0 rosettes with U937 cells compared to 6.3 +/- 1.0 for normal platelets (P = 0.001). Arming of U937 cells with HIV-1-ITP ICs (5 micrograms/mL) formed 36.7 +/- 2.5 rosettes compared with 10.6 +/- 1.2 for control ICs (P < .01). Rosetting of armed U937 cells could be inhibited with MoAbs versus the alpha chains of CD11a (LFA-1), 11b (Mac-1), or 11c (p150,95) by 67%, 70%, and 61%, respectively (P < .007), whereas binding of ICs to U937 cells was unaffected. Isotype-matched control as well as MoAbs versus antigens on U937 cells (CD13, CD33) or the anti-FcR gamma II receptor had no effect. However, Fab fragments of polyclonal anti-C3 inhibited rosette formation by 78% (P < .01); control Fab had no effect. Thus, platelet-monocyte rosette formation is not Fc dependent. It is complement receptor dependent and requires the cooperation of all three leuCAM integrins.

Easy bruising, thrombocytopenia, and elevated platelet immunoglobulin G in Graves' disease and Hashimoto's thyroiditis

Platelet IgG levels, count, and function and easy bruising or bleeding were studied in 25 patients with Graves' disease and 12 with Hashimoto's thyroiditis (normal value for platelet IgG 10.7 +/- 4.5 ng [SD]/10(6) platelets). Eight of 22 patients with Graves' disease and normal platelet counts had elevated platelet IgG averaging 38 +/- 4.0 ng (SEM) (range, 24 to 60). Four of 10 patients with Hashimoto's thyroiditis and normal platelet counts ahd elevated platelet IgG averaging 45 +/- 7.2 ng (range, 27 to 66). Five patients with thrombocytopenia had platelet counts averaging 53000 +/- 12000/microL (SEM) and elevated platelet IgG averaging 154 +/- 40 ng (range, 27 to 300). Twelve of 15 patients with a history of easy bruising or bleeding had elevated platelet IgG compared to five of 22 without easy bruising (p < 0.001). Four of six with elevated platelet IgG had one or more abnormal in-vitro platelet aggregation measurements (particularly with epinephrine) compared to none of six with normal platelet IgG levels (p = 0.03). We conclude that elevated platelet IgG is associated with easy bruising and thrombocytopenia in about half of patients with Graves' disease or Hashimoto's thyroiditis.

Heavy-chain subclass of round antiplatelet IgG in autoimmune thrombocytopenic purpura

The gamma heavy-chain subclass of bound antiplatelet antibody was examined in six patients with autoimmune thrombocytopenic purpura (ATP) by a solid-phase radioimmunoassay. Monospecific antisera for gamma G1, gamma G2, gamma G3, and gamma G4 subclasses were employed in a "sandwich" technique, utilizing the binding of 126I-staphylococcal protein A. We have previously reported that serum antiplatelet antibody was restricted to be gamma G3 subclass in ATP. In contrast, all 4 IgG subclasses were found bound to platelets of ATP patients in the same distribution as that present in normal serum. It is suggested that the differences noted between serum antiplatelet IgG and platelet-bound IgG may represent different mechanisms of platelet injury.

A solid-phase radioimmunoassay for bound anti-platelet antibody: studies on 45 patients with autoimmune platelet disorders

A highly sensitive, solid-phase radioimmunoassay has been developed for detecting platelet-bound immunoglobulin, which employs 125I-staphylococcal protein A. The assay detects platelet IgG at the picogram level, which is 10- to 50-fold more sensitive than currently available procedures. It is relatively simple and can be performed on frozen extracts from as little as 2 X 10(5) platelets. Washed platelets are frozen, thawed, sonicated, and centrifuged at 20,000 X g. The supernatant, which contains 7S IgG, is applied in serial dilution to the wells of a plastic microliter plate capable of adsorbing protein. Commercial rabbit anti-human IgG is added and then "sandwiched" to 125I-staphylococcal protein A. The wells are removed from the plate and assayed for radioactivity. Thirty-two of 35 thrombocytopenic patients (92%) with ATP had platelet IgG values greater than those of controls by 2 S.D. and averaged 150 +/- 145 (S.D.) ng/10(6) platelets; 11 healthy controls, 11.4 +/- 7.4 ng; five "thrombocytopenic" controls, 9.7 +/- 13 ng. The platelet count (X) correlated inversely with IgG/platelet (Y) according to the equation: Log Y = -0.66 log X + 4.8; r = -0.71, p less than 0.001. Elevated platelet IgG levels were also found in 5 ATP patients in "apparent remission"; two of four had evidence for compensated thrombocytolysis (increased megathrombocytes). Elevated platelet IgG levels were also found in six patients with thrombocytopenia secondary to lymphoproliferative disorders.

A Solid Phase Radio-Immuno Assay for Platelet-Bound IgG Employing 125-I protein Extraction of 7S IgG and Identification of Its Subclasses

Studies on bound anti-platelet Ab have not differentiated Ab from Ag-Ab complexes. A sensitive solid phase radio-immuno assay has been developed for IgG, which detects picogram IgG. Washed platelets are frozen, thawed, sonicated and centrifuged at 20,000 g. The supernatant is applied in serial dilution to a series of plastic wells, capable of adsorbing protein. After incubation, the wells are washed with 1% BSA in PBS, pH 7.2. Commercial rabbit anti-human IgG in 1% BSA-PBS (or specific anti-human IgG subclass) is then applied. Unbound anti-IgG is washed away and the wells treated with 125-I staphprotein A (10,000 cpm/well; 2x107 cpm/μgm). Unbound protein A is washed away and the wells assayed for radioactivity. Twenty-six of 28 thrombocytopenic patients (92%) with autoimmune thrombocytopenic purpura had IgG greater than 2 SD of controls and averaged autoimmune thrombocytopenic purpura had IgG greater than 2 SD of controls and averaged, 172±155 (SD) ng/106 platelets; 11 healthy controls, 12.3±4.9 ng; 5 ‘thrombocytopenic controls, ‘8.2±5.7 ng. The platelet count (X) correlated inversely with IgG/platelet (Y) according to the equation: log Y=-0.61 log X + 4.4; r=0.64. P<0.00l. Sucrose gradient analysis, employing 7S and 19S marker proteins, revealed platelet ‘extract IgG’ activity migrating as 7S protein, not as Ag-Ab complex. Three patients were tested for IgG subclasses: γG1, γG2, γG3 and γG4. These averaged 75±9.7, 13±6.1, 9.7±4.2 and 2.3±1.3% of total bound IgG. We conclude that a 7S immunoglobulin can be extracted from platelets which is IgG and contains all 4 IgG subclasses at a distribution found in normal plasma.