An alternative to triptans—the first in 20 Years
Merck's Maxalt (rizatriptan) is the current US standard of care for migraines. But the company will capture an even bigger
piece of the acute migraine market if its telcagepant (MK0974) is approved. An antagonist of the calcitonin gene-related peptide (CGRP) receptor, it stands to be the first approval
in a new class of migraine drugs in nearly 20 years—since the first tryptamine (or triptan) drug was approved in 1991.
The drug offers an alternative, but still needs to prove itself in the real world. "It looks like Merck's new drug lacks the
cardiovascular toxicities of the triptans," says Barbara Ryan, pharma analyst at Deutsche Bank. "It doesn't look like there
is anything dramatic to report in the efficacy department. It's just a question of how much better it will be than triptans,
and what kind of market share it will get in the current climate when everyone is focused on costs and the triptans are going
A Phase III study published in the Lancet in November compared telcagepant with AstraZeneca's triptan, Zomig (zolmitriptan).
In the study telcagepant showed effectiveness similar to zolmitriptan's but with fewer side effects. An accompanying editorial
said the result "marks a new era in migraine therapy."
CGRP receptor antagonists inhibit the transmission of pain signals in the brainstem by blocking the release of CGRP. Merck
is developing other CGRP antagonists as back-up compounds to telcagepant. "There is clearly a market here," Ryan says. "The
new drug may work for the people who don't respond or can't tolerate the triptans."
Merck expects to file an NDA in this indication in 2009.
Acute coronary syndrome/stroke
The Generation X of anticoagulants
Two new factor Xa inhibitors with potent anticoagulant properties are leading candidates to make an impact on heart-attack
and stroke prevention.
"This is a big market with a huge unmet need, and these are oral therapies," says Barbara Ryan. "So there is a lot of room
for efficacious drugs. The question is how efficacious and safe are they going to be?"
Factor Xa is a catalyst for the proteolysis reaction that converts prothrombin to thrombin and stimulates blood clotting.
Inhibiting this reaction stops harmful blood clots. It is thought that Factor Xa drugs will require less monitoring than traditional
anticoagulants and thus will be useful in indications such as atrial fibrillation.