Chemically Programmed Bispecific Antibodies in Diabody Format.

Chemically programmed bispecific antibodies (biAbs) endow target cell-binding small molecules with the ability to recruit and activate effector cells of the immune system. Here we report a platform of chemically programmed biAbs aimed at redirecting cytotoxic T cells to eliminate cancer cells. Two different antibody technologies were merged together to make a novel chemically programmed biAb. This was achieved by combining the humanized anti-hapten monoclonal antibody (mAb) h38C2 with the humanized anti-human CD3 mAb v9 in a clinically investigated diabody format known as Dual-Affinity Re-Targeting (DART). We show that h38C2 × v9 DARTs can readily be equipped with tumor-targeting hapten-derivatized small molecules without causing a systemic response harming healthy tissues. As a proof of concept, we chemically programmed h38C2 × v9 with hapten-folate and demonstrated its selectivity and potency against folate receptor 1 (FOLR1)-expressing ovarian cancer cells in vitro and in vivo Unlike conventional biAbs, chemically programmed biAbs in DART format are highly modular with broad utility in terms of both target and effector cell engagement. Most importantly, they provide tumor-targeting compounds access to the power of cancer immunotherapy.

Porphyria cutanea tarda in a child following multi-agent chemotherapy.

Porphyria cutanea tarda (PCT) is a blistering skin disorder that occurs most commonly in middle-aged individuals. It is caused by decreased uroporphyrinogen decarboxylase (UROD) activity, which results in elevated levels of uroporphyrinogen. Occurrence remains very rare in children with some sources quoting as few as 50 reports of childhood cases.1 The literature reports occasional cases of PCT onset with various drugs, including barbiturates, estrogens, griseofulvin, rifampicin, sulfonamides, imatinib, methotrexate, tamoxifen, and cyclophosphamide, however its incidence in childhood is uncommon.2-6 We present a case of new-onset PCT in an eight year-old following treatment of pre-B cell acute lymphoblastic leukemia with multi-agent chemotherapy.

Samarium iodide-mediated Reformatsky reactions for the stereoselective preparation of ß-hydroxy-γ-amino acids: synthesis of isostatine and dolaisoleucine.

The synthesis of ß-hydroxy-γ-amino acids via SmI(2)-mediated Reformatsky reactions of α-chloroacetyloxazolidinones with aminoaldehydes is reported. Diastereoselective coupling is demonstrated to depend on the absolute configuration of the Evans chiral auxiliary employed in the reaction, allowing erythro or threo products to be obtained selectively. The potential utility of the methodology is exemplified by the facile synthesis of biologically relevant N-Boc-isostatine (2b) and N-Boc-dolaisoleucine (3c).

Aliphatic C-H to C-C conversion: synthesis of (-)-cameroonan-7α-ol.

In the course of a synthesis of the tricyclic sesquiterpene (-)-cameroonan-7α-ol from the acyclic (+)-citronellal, seven aliphatic C-H bonds were converted to C-C bonds, and three rings and four new stereogenic centers were established.

Effect of in-office samples on dermatologists' prescribing habits: a retrospective review.

The relationship between physicians and pharmaceutical companies has caused the medical community to question the degree to which pharmaceutical interactions and incentives can influence physicians' prescribing habits. Our study aimed to analyze whether a change in institutional policy that restricted the availability of in-office samples for patients resulted in any measurable change in the prescribing habits of faculty physicians in the Department of Dermatology and Cutaneous Surgery at the University of South Florida (USF)(Tampa, Florida). Medical records were retrospectively reviewed for common dermatology diagnoses-acne vulgaris, atopic dermatitis, onychomycosis, psoriasis, and rosacea-before and after the pharmaceutical policy changes, and the prescribed medications were recorded. These medications were then categorized as brand name, generic, and over-the-counter (OTC). Statistical analysis using a mixed effects ordinal logistic regression model accounting for baseline patient characteristics was conducted to determine if a difference in prescribing habits occurred.

Conventional and Chemically Programmed Asymmetric Bispecific Antibodies Targeting Folate Receptor 1.

T-cell engaging bispecific antibodies (biAbs) can mediate potent and specific tumor cell eradication in liquid cancers. Substantial effort has been invested in expanding this concept to solid cancers. To explore their utility in the treatment of ovarian cancer, we built a set of asymmetric biAbs in IgG1-like format that bind CD3 on T cells with a conventional scFv arm and folate receptor 1 (FOLR1) on ovarian cancer cells with a conventional or a chemically programmed Fab arm. For avidity engineering, we also built an asymmetric biAb format with a tandem Fab arm. We show that both conventional and chemically programmed CD3 × FOLR1 biAbs exert specific in vitro and in vivo cytotoxicity toward FOLR1-expressing ovarian cancer cells by recruiting and activating T cells. While the conventional T-cell engaging biAb was curative in an aggressive mouse model of human ovarian cancer, the potency of the chemically programmed biAb was significantly boosted by avidity engineering. Both conventional and chemically programmed CD3 × FOLR1 biAbs warrant further investigation for ovarian cancer immunotherapy.

A single-arm, open-label efficacy and tolerability study of diclofenac sodium 3% gel for the treatment of actinic keratosis of the upper and lower lip.

OBJECTIVES AND METHODS: This study is an evaluation of patients diagnosed with actinic keratosis (AK) lesions of the upper and lower lip (both cutaneous and mucosal surfaces), with at least one lesion on the vermilion (mucosal) lip. Patients were treated twice daily with a topical application of diclofenac sodium 3% gel (Solaraze Gel, Doak Dermatologics) for a period of 90 days with a follow-up assessment at 30 days post-treatment. The presence or absence of target and new lesions was assessed and quantified at the initial baseline visit and at each follow-up visit. An investigator global improvement index score assessment and an evaluation of tolerability was also performed at each follow-up visit. CONCLUSION: The application of diclofenac sodium 3% gel provides an effective approach for the treatment of AK of the lip. The cure rate reported in this study for AK of the lip was similar to that of diclofenac sodium 3% gel for AK on skin elsewhere on the body, and has a low incidence of irritation and other adverse reactions, as well as a high rate of patient satisfaction. The unique safety and tolerability profile of diclofenac sodium 3% gel would appear to lend itself well to treatment of the mucosal lip and vermilion, particularly when treatment decisions involve cosmetic appearance during and subsequent to therapy.

Stable and Potent Selenomab-Drug Conjugates.

Selenomabs are engineered monoclonal antibodies with one or more translationally incorporated selenocysteine residues. The unique reactivity of the selenol group of selenocysteine permits site-specific conjugation of drugs. Compared with other natural and unnatural amino acid and carbohydrate residues that have been used for the generation of site-specific antibody-drug conjugates, selenocysteine is particularly reactive, permitting fast, single-step, and efficient reactions under near physiological conditions. Using a tailored conjugation chemistry, we generated highly stable selenomab-drug conjugates and demonstrated their potency and selectivity in vitro and in vivo. These site-specific antibody-drug conjugates built on a selenocysteine interface revealed broad therapeutic utility in liquid and solid malignancy models.

Harnessing the fcµ receptor for potent and selective cytotoxic therapy of chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is a B-cell malignancy in need of new, effective, and safe therapies. The recently identified IgM receptor FcµR is overexpressed on malignant B cells in CLL and mediates the rapid internalization and lysosomal shuttling of IgM via its Fc fragment (Fcµ). To exploit this internalization and trafficking pathway for targeted drug delivery, we engineered an IgM-derived protein scaffold (Fcµ) and linked it with the cytotoxic agent monomethylauristatin F. This Fcµ-drug conjugate was selectively toxic for FcµR-expressing cell lines in vitro and for CLL cells but not autologous normal T cells ex vivo. Notably, the cytotoxic activity of the Fcµ-drug conjugate was maintained in CLL cells carrying a 17p deletion, which predicts resistance to standard chemotherapy. Next, we tested the possible therapeutic application of the Fcµ-drug conjugate in immunodeficient NOD/SCID/IL-2Rγ(null) (NSG) mice engrafted with peripheral blood cells from patients with leukemia. Three intravenous injections of the Fcµ-drug conjugate over a 10-day period were well tolerated and selectively killed the human CLL cells but not the coengrafted autologous human T cells. In summary, we developed a novel strategy for targeted cytotoxic therapy of CLL based on the unique properties of FcµR. FcµR-targeted drug delivery showed potent and specific therapeutic activity in CLL, thus providing proof of concept for FcµR as a valuable therapeutic target in CLL and for IgM-based antibody-drug conjugates as a new targeting platform.

Diclofenac gel in the treatment of actinic keratoses.

Actinic keratoses are areas of intraepithelial neoplasia for which treatment is necessary. Because they arise in areas of sun damage, it is desirable to treat the entire damaged field to not only treat visible lesions, but also subclinical, emerging malignancies, ie, "field therapy", 5-fluorouracil, imiquimod, and diclofenac are all treatment options, and are discussed and compared.

Potassium hydride in paraffin: a useful base for organic synthesis.

The preparation of potassium hydride as a 1:1 homogenate with paraffin, termed KH(P), is reported. KH(P), a solid at room temperature, is stable without special handling. On suspension in THF with a phosphonium salt, KH(P) rapidly generates the ylide. Wittig condensation with aromatic, aliphatic, and alpha,beta-unsaturated aldehydes proceeds with high Z selectivity. KH(P) should be a generally useful base for organic synthesis.