British Biotech plc's positive new findings on its noveloral anti-cancer drug marimastat were announcedThursday just weeks before the company is set to recievea cash infusion of 47 million.
While the company emphasized that the findings weretentative, Phase II trials of BB 2516, an oral matrixmetalloproteinase (MMP) inhibitor, now namedmarimastat, showed a reduction or no increase in cancerantigens in 33 percent of patients with four commoncancers. An additional 26 percent of the 94 patientsshowed a reduction in the rate of increase in cancerantigens.
The findings showed that marimastat is the first in thisclass of drugs to show significant clinical results, saidHenrik Rasmussen, vice president for clinical research forNorth America. "We are well ahead of the field."
He expects marimastat to be used in combination withcytotoxic drugs rather than compete with the standardtherapies.
Shares of the Oxford, England company (LSE:BBG),which had increased in price even before theannouncement was made, closed Friday at 16.75 after ahigh of 20 on Thursday when the news was released.
Beginning Dec. 11, 1995, the holders of 9 million stockwarrants, purchased at a discounted price of 5.25, willbe able to convert their warrants to shares, providing thecompany with a cash infusion of over 47 million inJanuary. The stock, boosted by the positive news, had torise above 5.25 in order for the warrants to beexercised.
Marimastat is a broad spectrum agent with potentinhibitory action against the known classes of MMP,enzymes implicated in breaking down tissues whichsurround malignant tumors, an important factor in cancergrowth and spread. Marimastat therapy prevents tissuebreakdown and contains malignancy, according to thecompany.
British Biotech, which is now enrolling patients for aPhase III trials that will begin next year, expects the drugto used in colorectal, ovarian, pancreatic and prostaticcancers. Rasmussen said the drug's current dose of 25, 50and 75 milligrams twice a day is well above the optimaldose and that subsequent patients will receive doses of 5-10 milligrams twice a day.
Marimastat reduced cancer-specific antigens, surrogatemarkers of tumor progressions. The levels remainedsuppressed in 43 percent of patients after four weeks oftherapy, according to British Biotech. Surrogate markersused in the Phase II study include CA125 antigen forovarian cancer, CEA for gastrointestinal malignancies,and PSA or prostate specific antigen for prostatic cancer.
Only four of the 117 patients in the antigen trialsdiscontinued treatment due to side effects, particularlypain and tenderness in the joints.
While the drug had effect in each of the four cancer types,it showed higher activity in ovarian cancer. Thisdifference will be assessed in subsequent trials,Rasmussen said.
Patients involved in the Phase II trial had inoperablecancers and were not being treated with other regimens.
Other Phase II trials will address marimastat's ability tostabilize lung cancer and its effect in bone cancer patientswith primary breast or prostatic cancer and patients withgastric cancer and melanoma. An injectable version ofmarimastat, called batimastat, was placed on hold earlierthis year because of side effects attributable to themanufacturing process. (See BioWorld Today, Feb. 20,1995, p. 1.)
British Biotech has an agreement with London-basedGlaxo Wellcome plc to collaborate on an oral arthritisdrug that is related to marimastat. Glaxo paid BritishBiotech $4.7 million up front and will financedevelopment costs. (See BioWorld Today, Sept. 28,1995, p. 1.)
This is the second round of promising clinicaldevelopments from the company. In September BritishBiotech released results that showed lexipafant had astatistically significant improvement of organ functioninpatients with acute pancreatitis. (See BioWorld Today,Sept. 15, 1995, p. 1.) n
-- Michele L. Robinson Washington Editor
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