The key thought is that human trials are successful, not test tube, not small mammals but human:
The initial study, conducted by AFB Parexel in Berlin involved single
administrations of drug or placebo to a total of 48 healthy young adult
volunteers, ranging in age from 18 to 35.
The second trial, at the same clinical site in Berlin, involved 30 healthy
elderly volunteers, aged 65 to 76, each of whom was administered a single oral
dose of drug or placebo. In this double-blinded trial, AMPALEX was again found
to be safe and well-tolerated. The elderly volunteers were also given the same
nonsense syllable memory test that had been given to the young volunteers in the
first study. In the absence of drug, the elderly volunteers' memory was
substantially worse than that of the young volunteers. In the presence of drug,
a statistically significant positive effect on memory performance was observed.
Several of the elderly volunteers receiving the highest dosage of AMPALEX scored
at or above the average score achieved by the young volunteers in the earlier
study.
The third study, at the Karolinska Hospital in Stockholm, Sweden, involved
administration of CX516 to healthy young adults under double-blind, placebo-
controlled conditions. This five-day study involved administration of placebo on
days 1, 4 and 5 and drug on days 2 and 3, with psychological testing conducted
on each day. AMPALEX was safe and well-tolerated by all volunteers receiving
drug, with no adverse events reported. Statistically significant improvements in
performance on several measures of learning and memory were noted in the group
that received CX516.
On the basis of these encouraging results, Cortex initiated a Phase I/IIa study
in patients experiencing deficits of memory and cognition due to Alzheimer's
disease. The double-blind, placebo-controlled dose escalation study, which is
being conducted at the National Institutes of Health in Bethesda, Maryland,
involves administration of CX516 to an eventual total of 16 to 20 patients for
up to 28 consecutive days. |
