Erminia Fontana

Brostallicin: a new concept in minor groove DNA binder development.

Brostallicin is a bromoacryloyl derivative of distamycin A, which has shown very promising preclinical activity against a variety of human tumors both in vitro and in vivo. The drug has a limited toxicity towards bone marrow precursor cells in vitro resulting in a therapeutic index much higher than those achieved with other distamycin A derivatives. It retains activity against cancer cells resistant to alkylating agents, topoisomerase I inhibitors and cells with mismatch repair deficiency. Brostallicin has a peculiar mechanism of action involving activation upon binding to glutathione (GSH) catalyzed by glutathione-S-transferase (GST). As a consequence, cells expressing relatively high GST/GSH levels are more susceptible to treatment with brostallicin. Considering that increased levels of GST/GSH are often found in human tumors, this could represent an advantage for the drug in the clinic. Initial clinical studies indicate the tolerability of the drug and allow the determination of the optimal dose for subsequent studies. Some partial response were obtained in these initial phase I studies. Altogether, the results suggest brostallicin to be a new promising anticancer agent with a new mechanism of action. It also raises the possibility to use it in combination with other anticancer drugs currently used.

A phase I dose-escalation and pharmacokinetic study of brostallicin (PNU-166196A), a novel DNA minor groove binder, in adult patients with advanced solid tumors.

Purpose: This study was performed to determine the maximum tolerated dose, dose-limiting toxicities, and pharmacokinetics of brostallicin, a nonalkylating DNA minor groove binder and a synthetic derivative of distamycin A, given as a weekly i.v. infusion. Experimental Design: Using an accelerated dose escalation design, patients with advanced solid tumor malignancies were treated with brostallicin administered as a 10-min i.v. infusion on days 1, 8, and 15 of a 28-day cycle. The starting dose of brostallicin was 0.3 mg/m2/week. To study the pharmacokinetic behavior of brostallicin, serial blood samples were obtained before and after the first and last infusions during cycle 1, and in cycles 2 and 4 in a limited number of patients. Results: Fourteen patients received 32 complete cycles of brostallicin. Dose-limiting toxicity was febrile neutropenia and was observed in 3 of 5 patients treated at 4.8 mg/m2/week. The maximum tolerated dose and recommended Phase II dose was 2.4 mg/m2/week. The mean ± SD terminal half-life at the maximum tolerated dose was 4.6 ± 4.1 h. There was moderate distribution of brostallicin into tissues, and the clearance was ∼20% of the hepatic blood flow. The area under the concentration time curve0-∞ of brostallicin increased in a dose-linear fashion. No significant relationship was observed between any plasma pharmacokinetic parameter and clinical toxicities. There were no objective responses during the trial, but 5 patients had stable disease after two cycles of treatment. Conclusions: The dose-limiting toxicity of weekly brostallicin was neutropenia. Systemic exposure increases linearly with dose. The recommended dose for Phase II studies is 2.4 mg/m2 on days 1, 8, and 15 of a 28-day cycle.

Synthesis of exemestane labelled with 13C

The synthesis of exemestane Aromasin, an irreversible steroidal aromatase inhibitor, specifically labelled with (13)C is reported. The preparation of [(13)C(3)]exemestane was achieved according to an eight-step procedure starting from the commercially available testosterone.

Carbon-14 labelled tribendimidine, a broad-spectrum anthelmintic drug.

The preparation of [(14) C]tribendimidine, a broad-spectrum anthelmintic agent related to amidantel, and its use during excretion and metabolism studies in the rat are described in this paper.

Synthesis of tritium labelled thymic humoral factor γ2 (THF‐γ2, thymoctonan)

The synthesis of the title compound labelled with tritium in the proline residue is reported. A five-step sequence starting from the commercially available [ 3 H]proline 1 afforded [ 3 H]THF-γ2 with a radiochemical purity ≥97% and a high specific activity (>3.7 TBq/mmol). The overall radiochemical yield was about 15% from 1.

Synthesis of [17-14C] nicergoline

The synthesis of 1,6-dimethyl-8β-(5-bromonicotinoyl-[14C]oxymethyl)-10α-methoxy-ergoline ([17-14C] nicergoline) is reported. A five-step route starting from the addition of potassium [14C] cyanide 2 to 1,6-dimethyl-8β-chloro-10α-methoxy-ergoline 1 yielded the expected [17-14C] nicergoline, 97% radiochemically pure, with a specific activity of 2.23 GBq/mmol. The overall radiochemical yield was about 10% from 2.

Synthesis of carbon‐14 labelled 1‐[4‐methyl‐3‐mxo‐4‐AZA‐5α‐androstane‐17β‐carbonyl]‐1,3‐diisopropylurea (turosteride), a new 5α‐reductase inhibitor

The synthesis in eight steps of the title compound from the commercially available[20- 14 C]pregnenolone 1 is described. The expected 1-[4-methyl-3-oxo-4-aza-5α-androstane-17β-[ 14 C]carbonyl]-1,3-diisopropylurea ([ 14 C]FCE 26073) was obtained with a radiochemical purity higher than 97% and a specific activity of 2.03 GBq/mmol. An overall radiochemical yield of 21% was achieved from 1