Weighing value in HER2+ breast cancer treatment

Targeted treatments of HER2-positive breast cancers have dramatically prolonged many patients’ lives. But treatment outcomes in clinical trial settings don’t always translate into comparable real-world clinical value, noted Sunil Verma, MD, MSEd, FRCP(C), at the American Society of Clinical Oncology (ASCO) Annual Meeting 2016 in Chicago.

VermaVerma, who is professor and head of the department of oncology, and medical director of the Tom Baker Cancer Centre at the University of Calgary, in Alberta, Canada, chaired a June 6 session, “Updates and Controversies in HER2-Positive Breast Cancer.

“There’s a disconnect,” said Verma. “We have nearly doubled overall survival for metastatic HER2-positive breast cancer-a substantial record. … The question is, what is the value of these treatments?”

Assessing treatment value

Assessing treatments’ value for complex and evolving diseases like breast cancer can be a daunting challenge. A treatment’s value hinges on clinical costs and benefits to the patient, in terms of survival impacts, toxicities, and quality-of-life.

New tools such as ASCO’s 2015 Value Framework can help make sense of such considerations in the context of drug acquisition costs.

One important component of value is cost-effectiveness, or the relative costs and outcomes of different treatments: Does a given agent achieve a clinical goal as well as another treatment option, but at a lower cost?

Healthcare economists use different measures of cost effectiveness, like Incremental Cost Effectiveness Ratio (ICER) or Quality Adjusted Life Year (QALY), a measure of patient life expectancy and quality of life.

The cost-effectiveness picture for HER2-positive breast cancer treatments is pretty clear for trastuzumab (Herceptin, Genentech), Verma said.

Studies from the U.S., Canada, U.K., Australia and Europe all show that adjuvant trastuzumab (Herceptin, Genentech) for HER2-positive breast cancer is cost-effective, Verma noted. (But that may not be true in certain developing countries; less than 10% of low- and middle-income countries have access to anti-HER2 therapies, he noted.)

“Trastuzumab in adjuvant settings is clearly cost-effective across the board,” Verma said. “First-line trastuzumab? Again-it’s quite consistent.”

Still, he said, the cost-effectiveness picture is less clear for newer targeted therapies.

Next: New tools help assess value

New tools help assess value

Cost-effectiveness is just one value-related consideration, of course.  

ASCO’s new 2015 Value Framework, developed by ASCO’s Value in Cancer Care Task Force, includes weighted measures of a drug’s likely disease-control benefits and toxicities for patients, expressed as a “Net Health Benefit” score.

Points are awarded or deducted for a drug’s clinical benefit (net improvement in disease-free, progression-free, and overall survival, for example), the incidence of toxicities, and symptoms control.

“Points are combined to get a net health benefit score, which is then juxtaposed against direct cost of treatment,” Verma explained.

The newest update to the Value Framework was released May 31, 2016; it now includes all-grades side effects instead of only higher-grade toxicities. User-friendly software interfaces will bring this value-assessment tool into the clinic and help inform doctors’ and patients’ discussions and decisions, Verma said.

The framework provides bar graphs depicting head-to-head comparisons of different treatment options’ clinical benefits, toxicities, Net Health Benefit scores, and drug-acquisition costs (but importantly, not the relative or downstream financial costs of pursuing a particular treatment).

Cost-effectiveness data needs to be brought into the equation, said Verma.

“And value-based assessment tools don’t yet emphasize and consider patient’s values, choices, or preferences,” he cautioned. “Biosimilar equivalence studies are not considered-and I don’t think they consider the overall budget impacts of these therapies, at all.”

Tools may incorporate such factors down the road. Value-assessment tools are heuristics-decision-making aids. The value for a particular drug at a particular place and time depend on institutional variables, cost factors, and patient populations.

“I think we really need to start considering values, to get more bang for our buck in clinical settings,” Verma said.