Spectrum Pharmaceuticals Inc. has announced that its double-blinded, randomized, placebo-controlled, multi-centre, dose-ranging phase 2 trial with ozarelix in patients suffering from benign prostatic hypertrophy (BPH) met the primary endpoint.

The results were highly statistically significant (p<0.0001) in improving clinical symptoms of BPH as measured by the international prostate symptom score (IPSS), the standard method of assessing BPH symptoms and the primary endpoint of the study. Other efficacy endpoints of the study, such as urine flow, residual urine volume, and quality of life were also met. In addition, the drug had an excellent safety profile. The trial was conducted in Europe in collaboration with Spectrum Pharmaceutical's partner AEterna Zentaris Inc.

"We are encouraged by the safety and efficacy results demonstrated in the phase 2 trial of our proprietary drug, ozarelix, and we plan to move the drug into phase 3 as expeditiously as possible," stated Rajesh C. Shrotriya, MD, chairman, president and CEO of Spectrum Pharmaceuticals. "We are currently preparing an information package, which we expect to present to the FDA by the beginning of 2007, when we will determine the next steps in this drug's development. The BPH market is a significant market, with current annual sales of more than $4 billion worldwide. We believe ozarelix might represent an improved therapeutic option in this unsatisfied market."

In this study, 144 patients with symptomatic moderate to severe BPH were randomized to placebo or different doses of ozarelix given intramuscularly at day 1 and day 15.

While the primary efficacy endpoint was achieved at all dosage regimens, the best results were obtained with the 15 mg dose of ozarelix, in terms of decrease of the IPSS score. Using the 15 mg dose, the observed mean decrease in the IPSS score at weeks 12, 20 and 28 was 8.6, 9.4 and 8.7, respectively (mean: 47 per cent decrease from baseline). This improvement in the IPSS represents a highly statistically significant difference versus baseline (p<0.001) as well as versus placebo (p<0.0001). Furthermore, this long lasting effect, which was still present at the end of the 28-week observation period, was seen at all dosage regimens. A moderate and transient decrease in serum testosterone was observed in the initial 2-4 weeks, which rapidly returned to normal levels and did not result in any adverse effect on sexual function as measured by the IIEF (International Index of Erectile Function) score.

"The most common symptoms of BPH include a weak and interrupted urine stream and frequent and urgent urination. In severe cases, BPH can cause urinary track infections, incontinence, and kidney failure," stated Luigi Lenaz MD, chief scientific officer of Spectrum Pharmaceuticals. "Drugs currently used to treat BPH may take six months or longer to take effect, however, in this trial ozarelix had a rapid and pronounced effect. We believe this excellent efficacy of ozarelix is related to its unique mechanism of action which includes the inhibition of intra-tissue growth factors in the prostate gland."

Ozarelix also achieved improved secondary endpoint parameters such as urine flow, residual urinary volume, and quality of life. The results of the trial demonstrated the excellent safety profile of ozarelix in all doses administered, where patients had no drug related serious side effects. In particular, the erectile function as measured by the IIEF was not affected at any dose regimen.