Abstract: A method of treating a hyperproliferative disorder in a subject in need of such treatment, comprising administering to said subject, in combination, a treatment effective amount of: (a) a ceramide-increasing retinoid such as fenretinide or a pharmaceutically acceptable salt thereof; and (b) at least one (and in certain embodiments at least two) compounds selected from the groups consisting of (i) a non-18 carbon chain length L-threo-sphinganine(s) or pharmaceuticeutically acceptable salt thereof, (ii) glucosylceramide or glucosyl(dihydro)ceramide synthesis inhibitor(s), and (iii) sphingomyelin or dihydrosphingomyelin synthase inhibitor(s). Preferred L-threo-sphinganines are of carbon chain length 17 carbons, 19 carbons and 20 carbons. A preferred glucosylceramide or glucosyl(dihydro)ceramide synthesis inhibitor IS D-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol. A preferred sphingomyelin or dihydrosphingomyelin synthesis inhibitor is D-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol.

Abstract: The present invention provides methods of increasing an amount of a treatment agent in the body, a cancer or tumor. The methods include administering an inhibitor of the metabolic degradation or conversion of the treatment agent to a subject undergoing treatment for a hyperproliferative disorder with said treatment agent. Methods of treating hyperproliferative disorders, tumors and cancers are also provided.

Abstract: A method to improve the effectiveness of cancer treatments by increasing the production of specific ACYL-chain dihydroceramide(s). Increase of native chain-length dihydroceramides is directly cytotoxic to human acute lymphoblastic leukemia cell line MOLT-4 ALL cells with a cytotoxic potency that is dependent upon the specific fatty acid acyl-chain length and saturation of the dihydroceramides. The combination of sphinganine and GT-11 lead to cell death in the absence of an increase of reactive oxygen species, suggesting that the ability of fenretinide to increase cytotoxic ROS is mechanistically independent of dihydroceramides increase and related cytotoxicity. Most unexpectedly, supplementing the exposure of cancer cells to a dihydroceramide-increasing anti-hyperproliferative agent(s), such as fenretinide, with specifically-chosen fatty acids can increase the cytotoxicity of the anti-hyperproliferative agent to the cancer cells to a beneficial effect.

Abstract: A method of treating a hyperproliferative disorder in a subject in need of such treatment, comprising administering to said subject, in combination, a treatment effective amount of: (a) a ceramide-increasing retinoid such as fenretinide or a pharmaceutically acceptable salt thereof; and (b) at least one (and in certain embodiments at least two) compounds selected from the groups consisting of (i) a non-18 carbon chain length L-threo-sphinganine(s) or pharmaceuticeutically acceptable salt thereof, (ii) glucosylceramide or glucosyl(dihydro)ceramide synthesis inhibitor(s), and (iii) sphingomyelin or dihydrosphingomyelin synthase inhibitor(s). Preferred L-threo-sphinganines are of carbon chain length 17 carbons, 19 carbons and 20 carbons. A preferred glucosylceramide or glucosyl(dihydro)ceramide synthesis inhibitor is D-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol. A preferred sphingomyelin or dihydrosphingomyelin synthesis inhibitor is D-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol.

Abstract: The present invention provides methods of increasing an amount of a treatment agent in the body, a cancer or tumor. The methods include administering an inhibitor of the metabolic degradation or conversion of the treatment agent to a subject undergoing treatment for a hyperproliferative disorder with said treatment agent. Methods of treating hyperproliferative disorders, tumors and cancers are also provided.

Abstract: A method of treating a hyperproliferative disorder, including a cancer, in a subject in need of such treatment, comprising administering to said subject a pharmaceutical combination containing a treatment effective amount of: (a) a vitamin A derivative (i.e., a retinoid), or a pharmaceutically acceptable salt thereof, and an inhibitor of microtubule structure or function; or (b) a combination containing fenretinide (i.e., N-(4-hydrophenyl) retinamide, 4-HPR) and ABT-751 (i.e., N-[2-[(4-hydroxyphenyl)amino]-3-pyridinyl]-4-methoxybenzenesulfonamide). Vitamin A derivatives that may be useful for this invention according to (a) include, but are not limited to, all-trans-retinoic acid, 13-cis-retinoic acid, and fenretinide. Microtubule inhibitors that may be useful for this invention according to (a) include, but are not limited to, inhibitors of the Vinca binding domain (e.g., vincristine, vinblastine, vinorelbine, and cryptophycin 52), inhibitors of the Taxane domain (e.g.