Chemex Pharmaceuticals Inc. is working on a new formulation of itscompound to treat photo-damaged skin after a pilot study showedCHX-100 caused unacceptable dermal side effects, the Fort Lee,N.J., company said Tuesday.CHX-100 (masoprocol cream) was tested in three concentrationsagainst a vehicle on 64 patients in a double-blinded study. The once-a-day treatment for up to 12 weeks showed masoprocol creamresulted in improvement in all three drug groups, while the vehiclegroup did not improve."Even though we got efficacy in all three groups, the side effectswere there," which Chemex chief financial officer Len Stigliano saidincluded redness and irritation. "Since people would use this for thelong term, you don't want to see any side effects, or at least minimaleffects."We want to reformulate it to see if we can minimize the irritationand then do another pilot study or an irritation study," Stigliano toldBioWorld. He said new studies are expected to begin in the firstquarter of 1995.Chemex's stock (NASDAQ:CHMX) was down 3 cents Tuesday,closing at 63 cents per share. The company has about 8.6 millionshares outstanding.The drug's active ingredient is an extract from the creosote bush,which grows abundantly in the Southwest, and is what the companywas founded on. Masoprocol also is the main ingredient in Chemex'scompound Actinex, which is being marketed by joint venture partnerBlock Drug Co. Inc., of Jersey City, N.J., for treating premalignantskin lesions."When we did a Phase II for Actinex, a lot of clinicians said weshould look at it for photo-damaged skin," Stigliano said, "becausewhen [patients were] done with treatment, their skin looked brandnew."The one clear thing we showed is that it works. Nobody has a drugfor this now, so there's obviously a huge potential market."Stigliano said masoprocol cream, which was cited in AmericanIndian folklore for its therapeutic value, "is fairly high up on ourpriority list, only because it clearly has activity and seems to havepotential in other uses."Chemex is contemplating its use in an acne indication, he said, and"we played with masoprocol systemically as an anti-tumor agent. Wehaven't gotten too far with that," Stigliano said, because of the costsassociated with cancer studies.The pilot study for photo-damaged skin was the equivalent of aPhase I/II study. Concentrations were .25, 1 and 2.5 percentmasoprocol cream. Stigliano said Chemex thought it would see moreirritation in the 2.5 percent formulation.The company said a new, stable formulation of masoprocol creamhas been developed, and will be tested to see if it can reduce dermalside effects.Actinex contains 10 percent masoprocol cream. Chemex filed a newdrug application with the FDA in September for Amlexanox to treataphthous ulcers, or canker sores. It also has compounds in earlystage clinical studies, or nearly in the clinic, for atopic dermatitis andpsoriasis.Stigliano said the company has about $2 million in cash, andannounced in July that it would need to seek equity financing orsome sort of merger agreement. n

-- Jim Shrine

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