Assessment of Variation in State Regulation of Generic Drug and Interchangeable Biologic Substitutions

Generic orphan drug substitution: a critical analysis of global practices and Saudi Arabia's perspective

In an era of cost pressure, substituting generic drugs represents one of the main cost-containment strategies of healthcare systems. Despite the obvious financial benefits, in a minority of cases, substitution may require caution or even be contraindicated. In most jurisdictions, to obtain approval, the bioequivalence of generic products with the brand-name equivalent needs to be shown via bioavailability studies in healthy subjects. Rare diseases, defined as medical conditions with a low prevalence, are a group of heterogenous diseases that are typically severe, disabling, progressive, degenerative, and life-threatening or chronically debilitating, and disproportionally affect the very young and elderly. Despite these unique features of rare diseases, generic bioequivalence studies are typically carried out with single doses and exclude children or the elderly. Furthermore, the excipients and manufacturing processes for generic/biosimilar products can differ from the brand products which may affect the shelf-life of the product, its appearance, smell, taste, bioavailability, safety and potency. This may result in approval of generics/biosimilars which are not bioequivalent/comparable in their target population or that meet bioequivalence but not therapeutic equivalence criteria. Another concern relates to the interchangeability of generics and biosimilars which cannot be guaranteed due to the phenomenon of biocreep. This review summarizes potential concerns with generic substitution of orphan drugs and discusses potentially problematic cases including narrow therapeutic index drugs or critical conditions where therapeutic failure could lead to serious complications or even death. Finally, we put forward the need for refining regulatory frameworks, with emphasis on Saudi Arabia, for generic substitution and recent efforts toward this direction.

Availability and Cost of Expensive and Common Generic Prescription Drugs: A Cross-sectional Analysis of Direct-to-Consumer Pharmacies

BACKGROUND

Direct-to-consumer (DTC) pharmacies sell generic prescription drugs, often at lower prices than traditional retail pharmacies; however, not all drugs are available, and prices vary.

OBJECTIVE

To determine the availability and cost of generic drugs at DTC pharmacies.

DESIGN

Cross-sectional study.

SETTING

Five national DTC pharmacies in April and May 2023.

PARTICIPANTS

Each qualifying form of 100 generic drugs with the highest cost-per-patient (expensive) and the 50 generic drugs with the highest number of patients (common) in Medicare Part D in 2020 MAIN MEASURES: Availability of these drugs and the lowest DTC pharmacy price for a standardized drug strength and supply (e.g., 30 pills), compared to GoodRx retail pharmacy prices.

KEY RESULTS

Of the 118 expensive generic dosage forms, 94 (80%) were available at 1 or more DTC pharmacies; out of 52 common generic dosage forms, 51 (98%) were available (p < 0.001). Of the 88 expensive generics available in comparable quantities and strengths across pharmacies, 42 (47%) had the lowest cost at Amazon, 23 (26%) at Mark Cuban Cost Plus Drug Company, 13 (14%) at Health Warehouse, and 12 (13%) at Costco; for 51 common generic formulations, 16 (31%) had the lowest cost at Costco, 14 (27%) at Amazon, 10 (20%) at Walmart, 6 (12%) at Health Warehouse, and 5 (10%) at Mark Cuban Cost Plus Drug Company. For the 77 expensive generics with available GoodRx retail pharmacy prices, the median cost savings at DTC pharmacies were $231 (95% CI, $129-$792) or 76% (IQR, 53-91%); for 51 common generics, savings were $19 (95% CI, $10-$34) or 75% (IQR, 67-83%).

CONCLUSIONS

Many of the most expensive generic drugs are unavailable at direct-to-consumer pharmacies. Meanwhile, less expensive, commonly used generics are widely available, but drug prices vary by pharmacy and savings are modest, requiring patients to shop around for the lowest cost.

Comparative Effectiveness and Safety of Generic Versus Brand-Name Fluticasone-Salmeterol to Treat Chronic Obstructive Pulmonary Disease

BACKGROUND

In 2019, the U.S. Food and Drug Administration (FDA) approved the first generic maintenance inhaler for asthma and chronic obstructive pulmonary disease (COPD). The inhaler, Wixela Inhub (fluticasone-salmeterol; Viatris), is a substitutable version of the dry powder inhaler Advair Diskus (fluticasone-salmeterol; GlaxoSmithKline). When approving complex generic products like inhalers, the FDA applies a special "weight-of-evidence" approach. In this case, manufacturers were required to perform a randomized controlled trial in patients with asthma but not COPD, although the product received approval for both indications.

OBJECTIVE

To compare the effectiveness and safety of generic (Wixela Inhub) and brand-name (Advair Diskus) fluticasone-salmeterol among patients with COPD treated in routine care.

DESIGN

A 1:1 propensity score-matched cohort study.

SETTING

A large, longitudinal health care database.

PATIENTS

Adults older than 40 years with a diagnosis of COPD.

MEASUREMENTS

Incidence of first moderate or severe COPD exacerbation (effectiveness outcome) and incidence of first pneumonia hospitalization (safety outcome) in the 365 days after cohort entry.

RESULTS

Among 45 369 patients (27 305 Advair Diskus users and 18 064 Wixela Inhub users), 10 012 matched pairs were identified for the primary analysis. Compared with Advair Diskus use, Wixela Inhub use was associated with a nearly identical incidence of first moderate or severe COPD exacerbation (hazard ratio [HR], 0.97 [95% CI, 0.90 to 1.04]) and first pneumonia hospitalization (HR, 0.99 [CI, 0.86 to 1.15]).

LIMITATIONS

Follow-up times were short, reflecting real-world clinical practice. The possibility of residual confounding cannot be completely excluded.

CONCLUSION

Use of generic and brand-name fluticasone-salmeterol was associated with similar outcomes among patients with COPD treated in routine practice.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute.

Using Multiple Authorized Generics to Maintain High Prices: The Example of Entacapone

OBJECTIVES

Brand-name drug manufacturers can market or license authorized generics (AGs), which are the same product sold under a generic name. By contrast, independent generics (IGs) are made by other manufacturers. The brand-name manufacturer of entacapone, a treatment for Parkinson's disease, established 4 AGs before IGs emerged. We used this case study to understand how AGs can affect the length of brand-name exclusivity and robustness of generic competition.

METHODS

Using public Food and Drug Administration and court records, we identified the regulatory and legal history for generic entacapone products marketed through 2021. We used Medicare Part D data to estimate trends in use, prices, and spending on entacapone products from 2011 to 2020, comparing actual spending with projected spending if IG competition had begun after expiration of the key patent protecting entacapone (October 2013) and prices had fallen consistent with levels observed for other generic drugs.

RESULTS

From 2012 to 2014, 3 potential entacapone IG manufacturers instead launched AG versions after settlement agreements with the brand-name manufacturer; the brand-name manufacturer additionally introduced its own AG. Four different IG versions were marketed beginning in 2015. From 2011 to 2020, average Medicare prices declined by 62%, less than the projected 74% to 92% price decline expected for a drug with 8 generics. Over this period, Medicare spent $1.1 billion on entacapone products, which could have been reduced by an estimated $137 to $449 million through typical IG competition.

CONCLUSIONS

The case of entacapone demonstrates how licensing multiple AGs in place of IG competition can increase spending. Government regulators should more rigorously monitor AGs to prevent such strategies.

Patient Out-of-Pocket Costs Following the Availability of Biosimilar Versions of Infliximab

After market exclusivity ends for biologic drugs, biosimilars-follow-on versions made by other manufacturers-can compete with lower prices. Biosimilars have modestly reduced prescription drug spending for US payers, but it is unclear whether patients have directly experienced any savings. In this study we assessed whether availability of biosimilar infliximab was associated with lower out-of-pocket (OOP) costs, using claims from a national data set of commercially insured patients from 2014 to 2018. We used two-part models, adjusting for patient demographics, clinical characteristics, insurance plan type, and calendar month. Compared with the reference biologic, there was no difference in the percentage of biosimilar claims with OOP costs (30.1% vs. 30.8%; adjusted odds ratio (aOR) 0.98, 95% confidence interval (CI), 0.84-1.15, P = 0.84) or the average nonzero OOP cost (median $378 vs. $538, adjusted mean ratio (aMR) 0.97, 95% CI, 0.80-1.18, P = 0.77). The percentage of claims with OOP costs was lower after biosimilar competition (30.7% vs. 35.0%, aOR 0.96, 95% CI, 0.94-0.99, P = 0.003), but average nonzero costs increased (median $534 vs. $520, aMR 1.04, 95% CI, 1.01-1.07, P = 0.004). Thus, early biosimilar infliximab competition did not improve affordability for patients. Policymakers need to better assure that competition in the biosimilar market translates to lower costs for patients using these medications.

Estimating Savings Opportunities From Therapeutic Substitutions of High-Cost Generic Medications

IMPORTANCE

Use of generics is generally understood as a cost-saving practice. However, pharmacy benefit managers have an incentive to place higher-priced generic drugs on insurers' drug formularies to profit by creating a large difference between the price negotiated with pharmacies and the price paid by insurers (what is known as spread pricing).

OBJECTIVE

To examine price differentials and savings potential between high-cost generics and corresponding therapeutic alternatives of same clinical value and lower cost.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional analysis examined the top 1000 generics in Colorado's all-payer claims database (CO-APCD) in 2019. High-cost generics and lower-cost generic therapeutic alternatives of same clinical value constituted the study sample. Data were analyzed from January 2019 to December 2019.

EXPOSURES

Generic drug prices measured by transaction prices, average wholesale price (AWP), and national drug acquisition average cost (NADAC).

MAIN OUTCOMES AND MEASURES

Price differentials between the high-cost generics and the corresponding therapeutic alternatives. Levels of discounts and savings that could be achieved if the high-cost generics had been substituted by their therapeutic alternatives.

RESULTS

This cross-sectional study of the top 1000 CO-APCD generics identified 45 high-cost products that had lower-cost therapeutic alternatives of same clinical value. Overall, high-cost generics were 15.6 times more expensive than their therapeutic alternatives (median values). If the lower-cost alternatives had been used, total spending would have been reduced from $7.5 million to $873 711, resulting in 88.3% savings. Most substitutions (28 of 45 [62.2]%) involved different dosage forms or different strengths of the same drug and provided mean (SD) discounts of 94.9% (3.8%) and 77.1% (19.9%), respectively.

CONCLUSIONS AND RELEVANCE

In this study, replacing high-cost generics with lower-cost alternatives of same clinical value would produce savings of nearly 90%. Plan sponsors should be aware that some generics are associated with higher spending and should periodically review the specific products driving their generic drug spending. Substitution of high-cost generics may provide a simple pathway to offer the same therapeutic benefit at lower cost to patients and insurers.

State Laws and Generic Substitution in the Year After New Generic Competition

OBJECTIVES

Substitution of brand-name drugs with less expensive, equally effective interchangeable generics is an important strategy for promoting adherence and controlling prescription drug spending. US state laws govern generic substitution, but there is variability among states in how these laws are designed. We aimed to determine how different features of state laws regulating generic substitution are associated with use of generic drugs.

METHODS

Using national claims databases, we studied individuals with commercial insurance or Medicare Advantage plans who newly initiated one of 34 prescription drugs during the year after new generic competition (2017-2018) to determine any association between generic use and 3 different features of state laws. We used multivariable logistic regression to adjust for demographic and clinical characteristics.

RESULTS

Of 502 763 individuals who initiated one of the drugs, 409 856 (81.6%) received a generic version. Those in states requiring patient consent or notification had lower use of generics (81.1% vs 82.9%; adjusted odds ratio 0.89; 95% confidence interval 0.87-0.91; P &lt; .001). By contrast, mandating versus permitting generic substitution and protecting pharmacists from liability did not appear to have significant effects.

CONCLUSIONS

In this study of commercially insured and Medicare Advantage patients, patients in states requiring consent or notification for pharmacists to substitute Food and Drug Administration-certified interchangeable generics had lower use of generics. Laws in 39 states plus the District of Columbia could be amended to improve use of inexpensive and equally effective generic drugs.

Indication-Specific Generic Uptake of Imatinib Demonstrates the Impact of Skinny Labeling

PURPOSE

Generic competition can be delayed if brand-name manufacturers obtain additional patents on supplemental uses. The US Food and Drug Administration allows generic drug manufacturers to market versions with skinny labels that exclude patent-protected indications. This study assessed whether use of generic versions of imatinib varied between indications included and excluded from the skinny labels.

METHODS

In this cross-sectional study, we identified adult patients covered by commercial insurance or Medicare Advantage plans who initiated imatinib from February 2016 (first generic availability) to September 2020. Generic versions were introduced with skinny labels that included indications covering treatment of chronic myelogenous leukemia (CML) but excluded treatment of gastrointestinal stromal tumors (GISTs) because of remaining patent protections. Logistic regression was used to determine whether use of generic versus brand-name imatinib differed between patients with a diagnosis of CML or GIST, adjusting for demographics, insurance type, prior use of brand-name drugs, and calendar month.

RESULTS

Among 2,000 initiators, 934 (47%) had CML and 686 (34%) had GIST. Within 3 years after generics entered the market, more than 90% of initiators in both groups used generic imatinib. Initiation of generic imatinib was slightly lower among patients with GIST than among patients with CML (85% v 88%; adjusted odds ratio 0.56; 95% CI, 0.39 to 0.80; P ≤ .001).

CONCLUSION

Generic versions of imatinib were dispensed frequently for indications both included (CML) and excluded (GIST) from the skinny labeling, although patients with GIST were slightly less likely to receive a generic version. The skinny labeling pathway allowed generics to enter the market before patent protection for treating patients with GIST expired, facilitating lower drug prices.

Utilization of Generic Cardiovascular Drugs in Medicare's Part D Program

BACKGROUND

Generic medications cost less than brand-name medications and are similarly effective, but brand-name medications are still prescribed. We evaluated patterns in generic cardiovascular medication fills and estimated the potential cost savings with increased substitution of generic for brand-name medications.

METHODS

This was a cross-sectional study of cardiovascular therapies using the Medicare Part D database of prescription medications in 2017. We evaluated drug fill patterns for therapies with available brand-name and generic options. We determined the generic substitution ratio and estimated the potential savings with increased generic substitution at the national, state, and clinician level. We compared states with laws related to mandatory pharmacist generic substitution and patient consent for substitution.

RESULTS

Of ≈$22.9 billion spent on cardiovascular drugs in Medicare Part D prescription programs in 2017, ≈$11.0 billion was spent on medications with both brand-name and generic options. Although only 2.4% of medication fills were for the brand-name choice, they made up 21.2% of total spending. Accounting for estimated brand-name rebates, generic substitution for these medications would save $641 million, including $135 million in costs shouldered by patients. Furthermore, the minority of clinicians with the lowest generic utilization was responsible for a large proportion of the potential cost savings.

CONCLUSIONS

There are substantial potential cost savings from substituting brand-name medications with generic medications. These savings would be primarily driven by lower use of brand-name therapies by the minority of clinicians who prescribe them at increased rates.

Evolving Perceptions, Utilization, and Real-World Implementation Experiences of Oncology Monoclonal Antibody Biosimilars in the USA: Perspectives from Both Payers and Physicians

BACKGROUND

The adoption of oncology biosimilars has been slow in the USA, which may be attributed in part to stakeholder perceptions and lack of operational guidance that supports favorable access to biosimilars.

OBJECTIVE

Our objective was to understand the real-world implementation experiences with oncology biosimilars of US payers and healthcare professionals (HCPs) as their experience with biosimilars has evolved.

METHODS

In-depth qualitative interviews with payers (n = 20) and HCPs (n = 17 physicians, n = 3 practice managers) were conducted. Payers included managed care organizations (MCOs), integrated delivery networks, and pharmacy benefit managers (PBMs). Physicians were affiliated with a healthcare network or were community based, specialized in hematology/oncology, and had prescribed oncology biosimilars. Audio transcripts of the interviews were coded using MaxQDA software to enable descriptive analysis of the qualitative data.

RESULTS

Over 80.0% of physicians perceived the efficacy and safety of biosimilars to be highly comparable to that of originators. Up to 87.5% of physicians reported using biosimilars in > 50% of their treatment-naïve patients and were comfortable using biosimilars in all approved indications. To encourage utilization, 75.0% of MCOs/PBMs preferred biosimilars over originators in treatment-naïve patients and implementation via step therapy. Physician involvement in choosing biosimilars was minimal, which was largely dependent on practice protocols or insurance preferences. The major factor influencing payers' coverage decisions and biosimilar adoption was potential cost savings.

CONCLUSIONS

US payers and physicians who have experience with biosimilars have favorable views of oncology biosimilars, particularly for treatment-naïve patients. A framework for integrating biosimilars into oncology practice is developing, primarily driven by insurance coverage, contracting, and cost benefits.

Diabetes Drugs: List Price Increases Were Not Always Reflected In Net Price; Impact Of Brand Competition Unclear

List prices for brand-name drugs have risen steeply, often despite the introduction of competition from other brand-name drugs in the same therapeutic class. List prices, however, do not reflect any rebates that manufacturers provide payers. To understand how net prices (after rebates and other discounts) respond to competition, we compared changes in inflation-adjusted, revenue-weighted mean list and net prices of a one-month supply of three classes of diabetes drugs: glucagon-like peptide 1 (GLP1) agonists, dipeptidyl peptidase 4 (DPP4) inhibitors, and sodium glucose cotransporter 2 (SGLT2) inhibitors. These drug classes each had several brand-name products enter the market between 2005 and 2017. The annualized change in list price over this period was $75 (15 percent) for GLP1 agonists, $22 (8 percent) for DPP4 inhibitors, and $41 (11 percent) for SGLT2 inhibitors. In contrast, the annualized change in net price was $38 (10 percent) for GLP1 agonists, -$3 (-2 percent) for DPP4 inhibitors, and -$17 (-9 percent) for SGLT2 inhibitors, suggesting a variable impact of brand-name competition on net prices.

The First 2 Years of Biosimilar Epoetin for Cancer and Chemotherapy-Induced Anemia in the U.S.: A Review from the Southern Network on Adverse Reactions

Biosimilars are biologic drug products that are highly similar to reference products in analytic features, pharmacokinetics and pharmacodynamics, immunogenicity, safety, and efficacy. Biosimilar epoetin received Food and Drug Administration (FDA) approval in 2018. The manufacturer received an FDA nonapproval letter in 2017, despite receiving a favorable review by FDA's Oncologic Drugs Advisory Committee (ODAC) and an FDA nonapproval letter in 2015 for an earlier formulation. We discuss the 2018 FDA approval, the 2017 FDA ODAC Committee review, and the FDA complete response letters in 2015 and 2017; review concepts of litigation, naming, labeling, substitution, interchangeability, and pharmacovigilance; review European and U.S. oncology experiences with biosimilar epoetin; and review the safety of erythropoiesis-stimulating agents. In 2020, policy statements from AETNA, United Health Care, and Humana indicated that new epoetin oncology starts must be for biosimilar epoetin unless medical need for other epoetins is documented. Empirical studies report that as of 2012, reference epoetin use decreased from 40%-60% of all patients with cancer with chemotherapy-induced anemia to <5% of such patients because of safety concerns. Between 2018 and 2020, biosimilar epoetin use varied, increasing to 81% among one private insurer's patients covered by Medicare whose cancer care is administered with Oncology Analytics and to 41% with the same private insurer's patients with cancer covered by commercial health insurance and administered by the private insurer, to 0% in several Veterans Administration Hospitals, increasing to 100% in one large county hospital in California, and with yet-to-be-reported data from most oncology settings. We conclude that biosimilar epoetin appears to have overcome some barriers since 2015, although current uptake in the U.S. is variable. Pricing and safety considerations for all erythropoiesis-stimulating agents are primary determinants of biosimilar epoetin oncology uptake. IMPLICATIONS FOR PRACTICE: Few oncologists understand substitution and interchangeability of biosimilars with reference drugs. Epoetin biosimilar is new to the market, and physician and patient understanding is limited. The development of epoetin biosimilar is not familiar to oncologists.