BiDil — the only drug indicated for use in patients of a specific, self-reported race — can lower the cost of treatment for heart failure, according to a cost-effectiveness study published this week.
The study, printed in the current issue of the American Heart Association journal Circulation, helps promote the uniquely indicated drug, and may add to the relatively small amount of information currently available on the cost effectiveness of pharmacogenomic therapies.
Although BiDil substitutes self-reported race for the molecular diagnostics that are used to identify responders in most personalized therapies, an ongoing investigation into molecular markers of BiDil response is underway, and the cost-effectiveness study highlights many of the factors important to the cost of the treatment as a potential pharmacogenomic agent.
"It's really very easy" to expect that patient groups selected on the basis of a biomarker, rather than self-reported race, would experience similar cost savings "because there is really a large reduction in hospitalization — at least a 30-percent reduction, and we know that in heart failure, 75 percent of the cost is related to" hospitalization of all patients, Jalal Ghali, a researcher involved in the study, and associate chief of the Cardiology Section and director of the Heart Failure Program in Cardiovascular Clinical Research at the Louisiana Health Sciences Center in Shreveport, La., told Pharmacogenomics Reporter this week. Since such a large fraction of heart failure-related costs can be attributed to hospitalization, which is the major cost reduced by BiDil therapy, it is reasonable to assume that responding patients may see cost reductions regardless of race.
"It's really very easy" to expect that patient groups selected on the basis of a biomarker, rather than self-reported race, would experience similar cost savings.
However, the cost-effectiveness study data pertains only to black patients, who have different rates of certain health conditions, such as diabetes, than the general US population. This might make it difficult to generalize the results of the analysis across a broader population. In addition, NitroMed, the manufacturer of BiDil, has no data suggesting that the study results provide insight into the cost effectiveness of the heart-failure therapy on populations selected through the use of biomarkers, Michael Sabolinski, NitroMed's senior vice president for clinical development and regulatory affairs, told Pharmacogenomics Reporter this week. Sabolinski is one of the Circulation paper's eight co-authors.
Nevertheless, David Veenstra, a research associate professor in the Department of Pharmacy at the University of Washington in Seattle familiar with pharmacogenomic cost-effectiveness issues, said that if a genetic test can more accurately identify responders and non-responders than self-reported ethnicity there is a good chance that it will be more cost effective — assuming a low cost for the test and a similar drug cost.
The BiDil cost-effectiveness study shows that treatment with the drug is a "dominant" strategy, reducing costs and improving outcomes compared to a reference case, Sabolinski said.
The reference case is a standard established by the US Public Health Service Panel on Cost Effectiveness on Health and Medicine. The panel defines appropriate methodology, which it describes as "conservative assumptions about duration of survival and treatment effect," Sabolinski said. The only thing considered in the current model are direct healthcare costs; it excludes factors such as quality of life and the ability to work, he added.
The company clearly hopes the research will further bolster BiDil's position in the marketplace and its standing in the eyes of insurers. "I think that it's very important with regard to understanding the economics and cost to the medical system, to various payors, to formulary committees, and from the medical perspective, you always want to help people and save money," Sabolinski said.
NitroMed launched NitroMed with tier III insurance reimbursement, which involves a $30 to $50 patient copay "across the board" according to Sondra Newman, NitroMed's director of investor relations. Tier II reimbursement requires a $20 to $30 copay. The company will not disclose the number of carriers reimbursing for the drug in either category, but NitroMed believes it will "meet or exceed" its 35-percent tier II goal by mid-January, said Newman.
Liana Moussatos, who covers NitroMed for Pacific Growth Equities, appears to agree. She wrote in a PacGrowth news summary this week that "this peer-reviewed publication could help to accelerate reimbursement progress." Total November prescriptions of BiDil grew 35 percent over October, and continued to grow into this month as prescriptions for hydralazine, one of the two compounds composing the drug, have plateaued since its launch, Moussatos wrote this week in a separate analysis.
Over the course of about 13 months, "when you look at all healthcare costs, it saves approximately $1,700," said Sabolinski. He and colleagues calculated costs based on the use of healthcare services observed in the African-American Heart Failure Trial, or AHeFT, the clinical trial that eventually resulted in approval of the drug by the US Food and Drug Administration in June.
When the costs of heart-failure healthcare are taken into account, including the cost of the drug, "you're looking at care in the BiDil-treated group of approximately $8,600 per patient [per year], and in the placebo plus best-care group, you had a cost of $9,100," per year, said Sabolinski. "When you look at all healthcare-related costs, [including drug costs], they are approximately $18,000 in the BiDil plus-best-care group, and $19,700 in the placebo plus best-care group," he said. Total healthcare costs include the costs associated with concomitant diseases and other conditions.
The costs of heart failure-related healthcare is driven by the number of hospitalizations and the length of each stay, and savings associated with BiDil treatment are due to "a large reduction of hospitalizations," according to the Circulation paper. Assuming that patients receive no further benefit after the end of the trial, the researchers calculated the cost effectiveness of BiDil to be $16,600 per life-year at two years after enrollment, $37,100 per life-year at five years, and $41,800 per life-year over a lifetime.
Moving Toward PGx Status
The study's findings come at a time when researchers at the University of Pittsburgh Medical Center have associated a particular variant of the endothelial nitric oxide, or eNOS, gene with BiDil response in the Genetic Risk Assessment in Heart Failure trial. "We really need to look for a biomarker, because it seems to me that we're withholding the drug from many patients who would benefit from it, and the only reason we're not using it is because of skin color," said Ghali, the LSU Health Sciences Center Heart Failure Program director.
The company is funding the GRAHF trail in hopes that the drug's indications can be widened to include members of other racial categories who carry particular genetic markers, a list which may include more than just eNOS, Dennis McNamara, leader of the GRAHF study and director of the Heart Failure/Transplantation Program and an associate professor of medicine at the University of Pittsburgh Medical Center, said last month.
In an uncommon situation for pharmacogenomics, should eNOS prove effective in identifying patients likely to respond to BiDil, rather than relying on patient-reported ethnicity, the drug's market would probably expand. Although the results so far suggest this is the case, "I wish our data clearly suggested it was going to be that simple — I don't know that it is," McNamara said.
It is generally assumed that there are quite few cost-effectiveness studies dealing with pharmacogenomics. However, given the limited number of examples of real pharmacogenomic therapies, Veenstra said this is understandable. "People say there aren't any, or that there are few, but the reason that there are few economic studies is that there are few clinical applications at this point."
— Chris Womack ([email protected])