[BLOG]: Diagnostics as aids for specialty drug treatment

Fikry, MDFDA’s recent pre-market approvals of 2 new pharmaceutical drug therapies for non-small cell lung cancer (NCSLC) -- and simultaneous approval of 2 new tests used in connection with those therapies -- have cast a spotlight on the value of diagnostic laboratory tests as aids in realizing the potential of precision medicine. This PD-L1 class of NSCLC drugs belong to a new generation of pharmaceuticals for conditions ranging from high cholesterol levels to hepatitis C infection that harness insights into genetics and genomics to help address unmet health needs.

But the relatively high list prices of some “specialty pharmaceuticals” have prompted debate about how to appropriately value drug R&D and pricing. Within this heated environment, the significance of lab diagnostics not just in promoting accurate disease diagnosis but also to help facilitate treatment selection, monitoring and even drug development is often lost.

Related:Why new lung cancer drug approval is important

Consider the new direct acting antiviral therapies for hepatitis C viral infection. These treatments have cure rates of 95% or higher, but can run more than $80,000 for a 12-week course of treatment. Hepatitis C infection can run amok in the body for decades, promoting the development of liver fibrosis or cirrhosis and other adverse conditions before symptoms appear. As many as 3 of the 4 people with hepatitis C in the United States don’t know it, despite the wide availability of blood tests to screen for infection. Clearly, the value of these powerful new hepatitis C therapies on individual and public health is directly tied to the availability of relatively inexpensive lab tests. But when was the last time you read a news article about a new agent for hepatitis C that also highlighted the critical role of diagnostics in making its use possible?

NEXT: FDA clears companion diagnostics for patient management

Laboratory diagnostics are essential tools of physician practice, informing many medical decisions. They are also comparatively cost-effective, representing only about 3% of the nation’s overall healthcare costs. As the explosion of knowledge in molecular biology brings new insights, physicians will increasingly rely on companion and other types of lab diagnostics that consider genetic, proteomic, or other markers in connection with drug treatment strategies.

Since the 1998 introduction of the first companion diagnostic (for HER2-positive metastatic breast cancer patients), the FDA has cleared or approved more than 20 companion diagnostics to help guide patient management. These tests are not limited to oncology; there are companion diagnostics to complement therapies for a number of disease states, including cystic fibrosis, human immunodeficiency virus (HIV), severe growth deficiency and others. Many other lab tests are not companion diagnostics as defined by FDA, but may be used by physicians to help guide patient selection and monitoring in connection with drug therapies.

Related:Breast cancer drug research roundup from ASCO

Laboratories can also play an important role in the uptake of new drug therapies. A laboratory that performs a test service based on an IVD companion diagnostic may enjoy closer relationships with physicians than the corresponding drug and test product manufacturers. That’s because laboratories have medical experts on staff who advise physicians directly on test selection and interpretation. Depending on its reach and expertise, a laboratory may be well positioned to educate clinicians as well as health plans about the value of companion diagnostics in connection with their associated therapies in ways that the pharmaceutical company or in vitro diagnostic manufacturer could never do alone.  

Put simply, lab tests are necessary adjuncts to the use and monitoring of many widely used therapies, and this symbiotic relationship is only likely to tighten over time. Given that prescription drug spending is currently increasing more rapidly than healthcare spending in general, healthcare decision makers will be even more pressed than in the past to answer question about how to balance innovation with “pharmaco-economics": How can we better align policymaker, regulator and payer considerations so that companion diagnostics that support patient selection are seamlessly reimbursed? How can high R&D costs be controlled without suppressing innovation and development into new drugs? And most importantly, because health plans often require substantial cost sharing for the drugs, how can we ensure that these therapeutic innovations are made available in a manner that encourages, not discourages, patient use?

Read next: Drugs in Perspective: Zykadia (ceritinib)

RWhatever the answers are, one thing is certain: diagnostic lab tests, and the laboratories that provide them, are essential partners to fulfilling precision medicine and delivering better outcomes for patients.

Christopher Fikry, MD, is general manager, oncology, for Quest Diagnostics, a provider of diagnostic information services. Quest provides 115 laboratory test services with pharmacogenomic applications, including more than 20 FDA-cleared or approved companion diagnostics.