The drug candidate, PA-457, is the first in a new class of HIV drugs called maturation inhibitors. In granting fast track status for the form of PA-457 that is currently being tested in human clinical trials, the FDA noted that this is a drug to treat a serious or life-threatening condition with an unmet medical need.
Developers of fast tracked products have greater access to FDA resources as well as eligibility for rolling new drug application (NDA) submissions. In addition, fast track designation may enable priority FDA review and accelerated approval.
Panacos has completed single dose (phase Ia) and multiple dose (phase Ib) studies of PA-457 in uninfected volunteers, demonstrating that the drug is well tolerated with pharmacokinetics supporting once-daily oral dosing.
Furthermore, the company recently announced positive results from a proof-of- concept phase I/II clinical trial of PA-457 in HIV-infected patients, where a single oral dose of the drug gave a significant reduction in plasma viral load from baseline.
In December 2004, Panacos initiated a phase IIa clinical trial of PA- 457. This study, being performed at multiple sites in the US, is designed to evaluate the antiviral potency of PA-457 following once-daily oral dosing for 10 days, in HIV-infected patients who are not on other antiretroviral therapy.
Results of the phase IIa clinical trial are expected in Q2, 2005 and, during the second half of 2005, Panacos intends to initiate phase IIb studies of PA-457 designed to pave the way for pivotal phase III studies beginning in 2006.
“We believe that PA-457 has great potential as a new approach to treat HIV/AIDS and are very pleased that the FDA has chosen to grant fast track status, which we believe will allow us to expedite development of this drug,” commented Dr Graham Allaway, Panacos’ COO. “PA-457 has a different mechanism of action than approved HIV drugs and as a result it potently inhibits HIV strains resistant to currently available treatments as well as wild-type virus.”