PHILADELPHIA -- The past 12 months have seen new drugs and vaccines for indications from quitting smoking to preventing HPV. Which ones should clinicians embrace and which should they be more cautious about?
PHILADELPHIA, June 4 -- The past 12 months have seen new drugs and vaccines for indications from quitting smoking to preventing HPV. Which ones should clinicians embrace and which should they be more cautious about?
Joseph Lex, M.D., of Temple University, offered an assessment of several new products, based on a review of the clinical evidence and old-fashioned common sense, at the American Academy of Physician Assistants meeting here.
One initially promising product that should have the support of longer-term studies before it becomes more widely used, said Dr. Lex, is inhaled human insulin (Exubera), approved by the FDA in January 2006.
Although this formulation may be better tolerated and more convenient for some patients, he said, one can't help but wonder about the long-term effects of inhaling a powdered anabolic hormone into the lungs. Definite pulmonary fibrosis has not been found but changes have been noted in lung function tests that indicate impaired diffusion.
The long-term safety of this product should be confirmed by phase IV post-marketing studies before recommending it to patients, Dr. Lex advised.
On the other hand, he said, a sometimes-controversial product that clinicians can get behind is the quadrivalent HPV vaccine (Gardisil), FDA-approved in June 2006. It's indicated for girls and women ages nine to 26 for preventing cervical cancer, genital warts, and pre-cancerous conditions caused by HPV types 6, 11, 16, and 18.
The vaccine has been a political hot button, Dr. Lex noted, but one can't deny the clinical evidence, he said. As an example he offered one recent study in which 36 of 233 women in the placebo group experienced HPV-associated genital warts, compared with only four of the 235 in the treatment group, he noted.
The vaccine effectively prevents genital warts and cancer, and "I would advise patients to get it," Dr. Lex said.
Another vaccine that should be recommended, he said, is the new rotavirus vaccine (Rotateq), approved in February 2006. The pentavalent vaccine is designed to protect against rotavirus A, B, and C, the most common causes of severe diarrhea in children.
In February 2007, there were reports of 28 cases of intussusception associated with the vaccine, Dr. Lex noted. The intussusception occurred anywhere from the day of vaccination to 73 days later, he said.
These reports were especially concerning to public health officials because the previous rotavirus vaccine had been withdrawn from the market because of a link with intussusception, Dr. Lex explained. However, he said, after analyzing the data, the FDA concluded that these reports represented nothing more than the normal background rate of intussusception and were not associated with the vaccine.
"It looks like that initial scare is over and we are okay," Dr. Lex said.
Another new product with good data behind it, according to Dr. Lex, is varencline (Chantix), an anti-smoking drug that competes with nicotine for nicotine receptors, approved in May 2006.
In a study comparing the effectiveness of the drug with that of bupropion (Zyban) and placebo, 17% of the placebo group, 30% of the bupropion group, and 44% of the varencline group were still not smoking after 12 weeks, Dr. Lex said.
However, he noted, the numbers were not as good at nine months of follow-up, with 10% of the placebo group, 15% of the bupropion group, and 23% of the varencline group still not smoking.
In addition, varencline has not been compared with nicotine replacement products such as sprays, patches, or gum, he said.
The most common side effect associated with the drug is nausea, which occurred in 40% of patients in the study, Dr. Lex noted, adding that the long-term side effects of the drug are unknown.
Varencline may, however, be a promising alternative to bupropion, Dr. Lex said.