Sphinx Pharmaceuticals Corp. announced that a preliminaryanalysis of Phase II clinical trials on its topical ointment fortreating psoriasis suggested that the drug, called Kynac, doeshave a beneficial pharmacological effect on psoriatic lesions,but not enough to be considered clinically meaningful.
As a result, the Durham, N.C., company is conducting further,separate clinical analyses to determine whether it needs toreformulate the drug, which acts by inhibiting protein kinase C(PKC), or to go with a more potent PKC inhibitor in its researchpipeline to end up with a compound that will provide greaterclinical benefits.
The theory behind using PKC inhibitors to treat inflammatoryand proliferative disorders such as psoriasis and eczema is thatthey interfere with the key intracellular enzymes that act toregulate cellular processes.
In the trials, each of the 30 patients served as his own control,with one lesion going untreated, one receiving vehicle and onereceiving Kynac twice daily for a period of four to six weeks,explained Clayton Duncan, Sphinx's president and chiefexecutive officer.
As expected for emollients, the ointment vehicle alone showedsignificant improvement of psoriatic skin lesions over theuntreated controls. And Kynac also improved the lesions -- interms of redness, scaling and thickness -- compared with theuntreated controls. "We clearly saw the effects taking placetoward the end of the study, and it got better after six weeks,"Duncan told BioWorld. Still, there wasn't enough of an effect tobe "clinically important," he added.
The company now intends to determine the pharmacologicaleffect and extent of Kynac's skin penetration through ahistopathological analysis of punch biopsies of treated lesions,Clayton explained. The two-week study will begin shortly inthe United Kingdom.
Also on tap is an occluded study to determine if it's possible toincrease the skin penetration. In this approach the treatedlesion is covered for four to six hours, a method that "quiteoften increases penetration two- to threefold," Clayton toldBioWorld.
Meanwhile, Sphinx still intends to initiate Phase II trials ofKynac (in the current formulation) for treating eczema thisyear, either late in the second quarter or early in the third,Clayton said.
And Sphinx is also developing the PKC inhibitor formulated asan emulsion and called Kynacyte as an adjunct tochemotherapy. Sphinx submitted an investigational new drug(IND) application to FDA in late December 1992 to testKynacyte's ability to enhance the efficacy of chemotherapeuticdrugs, including doxorubicin and cisplatin, in treating solidtumors. The Phase I trials are slated to examine Kynacyte aloneor in conjunction with doxorubicin in 20 to 30 cancer patientswith one of several solid tumors. Patient enrollment has not yetbegun, Clayton told BioWorld.
Sphinx has approximately 12.6 million shares outstanding, fullydiluted, and had $57 million cash on hand at the end ofcalendar 1992. Its stock (NASDAQ:SPHX) closed Friday up 25cents a share to $4.75.
-- Jennifer Van Brunt Senior Editor
(c) 1997 American Health Consultants. All rights reserved.