Debate on the conservative and aggressive treatment options for the optimal management of indolent non-Hodgkin's lymphoma

Radioimmunotherapy for non-Hodgkin's lymphoma: a review for radiation oncologists

PURPOSE

The aim of this study was to review advances in radioimmunotherapy (RIT) for non-Hodgkin's lymphoma (NHL) and to discuss the role of the radiation oncologist in administering this important new form of biologically targeted radiotherapy.

METHODS AND MATERIALS

A review of articles and abstracts on the clinical efficacy, safety, and radiation safety of yttrium Y 90 (90Y) ibritumomab tiuxetan (Zevalin) and iodine I 131 tositumomab (Bexxar) was performed.

RESULTS

The clinical efficacy of RIT in NHL has been shown in numerous clinical trials of 90Y ibritumomab tiuxetan and 131I tositumomab. Both agents have produced significant responses in patients with low-grade, follicular, or transformed NHL, including patients with disease that had not responded or had responded poorly to previous chemotherapy or immunotherapy. Reversible toxicities such as neutropenia, thrombocytopenia, and anemia are the most common adverse events with both agents.

CONCLUSIONS

Radioimmunotherapy is safe and effective in many patients with B-cell NHL. 90Y ibritumomab tiuxetan and 131I tositumomab can produce clinically meaningful and durable responses even in patients in whom chemotherapy has failed. Treatment with RIT requires a multispecialty approach and close communication between the radiation oncologist and other members of the treatment team. The radiation oncologist plays an important role in treating patients with RIT and monitoring them for responses and adverse events after treatment.

Synthesis of Nα-(1-Phenyl-2-mercaptoethyl) Amino Acids, New Building Blocks for Ligation and Cyclization at Non-Cysteine Sites: Scope and Limitations in Peptide Synthesis

A new and convenient method for the synthesis and incorporation of N(alpha)-(1-phenyl-2-mercaptoethyl)-derivatized amino acids applicable to chemical ligation at non-cysteine sites is presented. N(alpha)-Auxiliary derivatives of glycine and alanine were easily prepared using reductive amination approaches. Several strategies for the incorporation of these derivatives into peptide chains were investigated: coupling without protection, with acid-labile protection, with base-labile protection, and via a novel protection strategy using the thiazolidine derivative. All amino acid derivatives were successfully coupled to various peptide resins, and with the exception of those incorporating Boc-protected derivatives, all resins yielded the desired peptide fragments. However, the coupling of the two alanine derivative diastereomers generated some epimerization. Finally, N-terminal auxiliary glycine and alanine peptides were cyclized, and the corresponding native circular peptides were obtained upon successful removal of the auxiliary.

Marine natural products and related compounds in clinical and advanced preclinical trials

The marine environment has proven to be a very rich source of extremely potent compounds that have demonstrated significant activities in antitumor, antiinflammatory, analgesia, immunomodulation, allergy, and anti-viral assays. Although the case can and has been made that the nucleosides such as Ara-A and Ara-C are derived from knowledge gained from investigations of bioactive marine nucleosides, no drug directly from marine sources (whether isolated or by total synthesis) has yet made it to the commercial sector in any disease. However, as shown in this review, there are now significant numbers of very interesting molecules that have come from marine sources, or have been synthesized as a result of knowledge gained from a prototypical compound, that are either in or approaching Phase II/III clinical trials in cancer, analgesia, allergy, and cognitive diseases. A substantial number of other potential agents are following in their wake in preclinical trials in these and in other diseases.

Antineoplastic Agents. 520. Isolation and Structure of Irciniastatins A and B from the Indo-Pacific Marine Sponge Ircinia ramosa

The Indo-Pacific marine sponge Ircinia ramosa has been found to contain two powerful (GI50 from 0.001 to <0.0001 microg/mL) murine and human cancer cell growth inhibitors. Both were isolated (10(-3)-10(-4)% yields) by cancer cell line bioassay-guided techniques and named irciniastatins A (1) and B (2). Structural elucidation by a combination of spectral analyses, primarily high resolution mass and 2D-NMR (principally APT, HMQC, HMBC, and ROESY) spectroscopy, revealed the unusual structures 1 and 2.