Capecitabine: fulfilling the promise of oral chemotherapy

Prodrug Rewards in Medicinal Chemistry: An Advance and Challenges Approach for Drug Designing

This article emphasizes the importance of prodrugs and their diverse spectrum of effects in the field of developing novel drugs for a variety of biological applications. Prodrugs are chemicals that are supplied inactively, but then go through enzymatic and chemical transformation in vivo to release the active parent medication that can have the desired pharmacological effect. By adding an inactive chemical moiety, prodrugs are improved in a number of ways that contribute to their potency and durability. For the purpose of illustrating the usefulness of the prodrug approach, this review covers examples of prodrugs that have been made available or are now undergoing human trials. Additionally, it included lists of the most common functional groups, carrier linkers, and reactive chemicals that can be used to create prodrugs. The current study also provides a brief introduction, several chemical methods and modifications for creating prodrugs and mutual prodrugs, as well as an explanation of recent advancements and difficulties in the field of prodrug design. The primary chemical carriers employed in the creation of prodrugs, such as esters, amides, imides, NH-acidic carriers, amines, alcohols, carbonyl, carboxylic, and azo-linkages, are also discussed. This review also discusses glycosidic and triglyceride mutually activated prodrugs, which aim to deliver the drugs after bioconversion at the intended site of action. The article also discusses the extensive chemistry and wide variety of applications of recently approved prodrugs, such as antibacterial, anti-inflammatory, cardiovascular, antiplatelet, antihypertensive, atherosclerotic, antiviral, etc. In order to illustrate the prodrug and mutual drug concept's various applications and highlight its many triumphs in overcoming the formulation and delivery of problematic pharmaceuticals, this work represents a thorough guide that includes the synthetic moiety for the reader.

Current diagnostic and clinical issues of screening for dihydropyrimidine dehydrogenase deficiency

Fluoropyrimidine drugs (FP) are the backbone of many chemotherapy protocols for treating solid tumours. The rate-limiting step of fluoropyrimidine catabolism is dihydropyrimidine dehydrogenase (DPD), and deficiency in DPD activity can result in severe and even fatal toxicity. In this review, we survey the evidence-based pharmacogenetics and therapeutic recommendations regarding DPYD (the gene encoding DPD) genotyping and DPD phenotyping to prevent toxicity and optimize dosing adaptation before FP administration. The French experience of mandatory DPD-deficiency screening prior to initiating FP is discussed.

Locally Advanced Breast Cancer in the Elderly: Curettage Mastectomy

Aims and background

Locally advanced breast tumor represents 5–20% of new cases diagnosed every year. The purpose of this study was to report our experience and to compare it with the literature.

Methods

From 1998 to 2003 at the Molinette Hospital in the Turin University Third Division of General Surgery, there were 34 cases of breast cancer in older women (between 70 and 94 years of age), 14 of which (41.18%) were locally advanced breast tumor. We evaluated the type of surgical intervention and anesthesia used, muscular invasion, the presence of receptors positive to estrogens and progesterone, the operative mortality, the percentage of local-regional recurrence, and relapses after a period of time.

Results

Among the patients with locally advanced breast tumor, 21.43% (3/14) were at stage MIA and 78.57% (11/14) at stage IIIB. In 14.29% (2/14) of the cases, Patey's radical mastectomy was performed, in 57.14% (8/14) Halsted's radical mastectomy, and in 28.57% (4/14) a simple mastectomy with the removal of the fascia of the major pectoral muscle. Three (21.43%) patients underwent a second intervention for local-regional disease. None of the patients had distant metastasis in the first 2 years after the operation. Mortality after 2 years was 23.1% (3/13). None of the patients who underwent surgery had adjuvant therapy, usually because it was refused by the patients themselves or their families. All the negative and positive hormone receptor patients received tamoxifen.

Conclusions

Locally advanced breast tumors are frequent in elderly women. In the past, there has been a tendency to surgical under-treatment. As regards locally advanced breast tumor, curettage operations represent the only possibility to improve the quality of life of the elderly. These should be performed after carefully evaluating a series of variables in the general and local condition of the patient, the aggressiveness of the intervention and the life expectancy.

Capecitabine for the oral treatment of metastatic breast cancer

Women with metastatic breast cancer require tailored chemotherapy that improves outcomes without compromising quality of life. Capecitabine, a pro-drug of 5-fluorouracil, is an oral fluoropyrimidine carbamate that is sequentially activated in a three-step process. This results in the preferential production of 5-fluorouracil in tumors rather than in normal surrounding tissue, improving the tolerability and efficacy of 5-fluorouracil. In combination with docetaxel, capecitabine is the first agent that has shown superior activity to single-agent docetaxel, and it is a particularly appropriate option for younger, fitter patients with rapidly progressing disease and/or visceral metastases. However, for older patients and those with comorbidities and/or after progression to taxanes, single-agent capecitabine may be the best option. Its role in earlier disease stages (adjuvant therapy) is being investigated.

Satraplatin: an orally available platinum analog for the treatment of cancer

Satraplatin is a novel, orally bioavailable, platinum anticancer drug. Platinum analogs form the mainstay of treatment for a number of cancers, including lung, ovarian, colorectal and head and neck cancer. A disadvantage of the currently marketed platinum analogs is that they must all be administered via intravenous infusion. In addition, their utility is often limited by toxicity, particularly neurotoxicity, ototoxicity and renal toxicity. Satraplatin has preclinical antitumor activity comparable with that of cisplatin and, clinically, has a more manageable side-effect profile. Satraplatin is active in lung, ovarian and prostate cancer, and appears to have good efficacy in combination with radiation for lung and head and neck cancer. Preclinical data suggest it may also be effective for the treatment of certain cisplatin-refractory tumors. A large, randomized Phase III trial is currently evaluating satraplatin in combination with prednisone for the treatment of patients with hormone-refractory prostate cancer whose disease has progressed following prior systemic therapy. Positive results from this trial would support regulatory approval for satraplatin for this indication. The availability of an active oral platinum agent, such as satraplatin, with few of the serious toxicities associated with traditional intravenous platinum compounds makes satraplatin an alternative to other platinum agents and a new treatment option in the oncologist's armamentarium.

Trastuzumab-based combination therapy for breast cancer

Trastuzumab, a humanised monoclonal antibody directed against the extracellular domain of HER-2, has been shown to be active against HER-2-overexpressing metastatic breast cancer, either as single agent or when used in combination with chemotherapy. In preclinical models, trastuzumab has shown additive and even synergistic anti-tumour activity with the most active chemotherapeutic agents used in the treatment of breast cancer. In a large, randomised, Phase III trial, the combination of trastuzumab plus chemotherapy was shown to improve response rate and survival. The high incidence of cardiotoxicity seen with the combination of trastuzumab plus anthracycline drugs prompted carrying out of several clinical studies combining trastuzumab with other chemotherapeutic agents, including docetaxel, vinorelbine, platinum salts, gemcitabine and capecitabine. This article summarises the available data on trastuzumab-based combinations for breast cancer.

Prodrug research: futile or fertile?

The objective of this Commentary is to help clarify and illustrate what prodrugs are, what they are not, which benefits they can offer, and what their limits are. To this end, a number of criteria of classification and evaluation are presented. This is followed by a discussion of the pharmaceutical, pharmacokinetic and pharmacodynamic objectives of prodrug research. Recent examples (e.g. oseltamivir, bambuterol, capecitabine, clopidogrel and tirapazamine) are discussed in a biochemical perspective to illustrate these objectives and to demonstrate some of the therapeutic benefits afforded by successful prodrugs. Attention is also called to the fact that the in vitro and in vivo behavior of prodrug candidates may differ from that of the parent drug in ways that go beyond the original pharmaceutical, pharmacokinetic or pharmacodynamic objective being pursued. We conclude that prodrugs offer a viable strategy to disentangle pharmacodynamic and pharmacokinetic optimization.