Nektar Therapeutics R&D day was held yesterday in New York. During the event, Nektar scientists unveiled three preclinical programs underway at the company, and commented some of their clinical research programs in the area of small molecule PEGylation and pulmonary delivery.

Nektar's pulmonary antibiotics

An innovative nebulizer system for ventilated patients with hospital acquired pneumonia is being tested for NKTR-061 and NKTR-063. This pulmonary antibiotic platform would represent an opportunity to reduce costs associated with hospitalized patients. NKTR-061 (inhaled amikacin) is being developed under an agreement signed with Bayer Schering Pharma in August, 2007. The product is in phase 2 clinical trials for the treatment of Gram-negative pneumonia, and it is expected to advance into phase 3 trials in 2008. NKTR-063 (inhaled vancomycin) is in preclinical development for evaluation of the treatment of Gram-positive pneumonia, and a pharmacokinetic study is to be initiated in 2008.

Nektar's small drug PEGylation technology

The intellectual property of Nektar in this area is strong with 55 US issued patents and 490 patent applications filed worldwide. The company's small molecule PEGylation technology platform is comprised of two different approaches, either utilizing large MW PEGs (NKTR-102 and NKTR-105) or small MW PEGs (NKTR-118 and NKTR-125).

NKTR-118 (oral PEG-naxolol) is in phase 1 clinical trials to treat serious gastrointestinal side effects of opioid usage, including opioid-induced constipation. Naxolol is an antagonist of opioid mu-receptors. Its PEGylation reduces blood brain barrier penetration and preserves the central analgesic effect of opioids. A phase 2, dose escalation trial for NKTR-118 is to commence next week. NKTR-125 (oral PEG-diphenhydramine) is a new preclinical development program designed to treat allergy symptoms. PEGylation of the antihistaminic also reduces its entrance into the central nervous system, consequently prevents drowsiness.

The company's lead oncolytic candidate under development for the treatment of refractory solid tumors is NKTR-102 (PEG-irinotecan). PEGylation of irinotecan appears to improve its pharmacokinetic profile. Another PEGylated oncolytic candidate is NKTR-105 (PEG-docetaxel), which is in early preclinical development.

Source: Nektar Therapeutics