Budget impact analysis of the DiviTum TKa assay in postmenopausal women with hormone receptor positive metastatic breast cancer

Abstract

Background

DiviTum TKa, a blood-based biomarker assay developed to monitor and predict treatment response in hormone receptor positive metastatic breast cancer (HR + mBC), may decrease traditional disease monitoring assessments and avoid prolongation of futile treatments.

Objective

To estimate the diagnostic and treatment budget impact of the assay on a postmenopausal HR + HER2- mBC population in a one-million-member U.S. health plan.

Methods

We developed a budget impact model comparing inclusion and exclusion of DiviTum TKa to standard care under which DiviTum TKa (1) reduces the frequency of traditional mBC monitoring tools, and (2) predicts treatment futility in advance of radiological disease progression. Traditional disease monitoring assessment schedules were based on guidelines and expert opinions. DiviTum TKa’s impact on therapy utilization was based on published literature and expert opinion. Modeled costs included DiviTum TKa, NCCN-recommended treatments, imaging, biomarker testing, and adverse events. We calculated total and per-member per-month (PMPM) costs with a 3-year time horizon.

Results

The inclusion of 416 DiviTum TKa assays ($166,400) was largely offset by 193 fewer CT scans, 88 fewer bone scans, and 55 fewer biomarker tests over 3 years, a savings of −$128,400, resulting in a PMPM of $0.001. In scenario analyses, adding DiviTum TKa resulted in additional treatment-related cost-savings (−$465,600), resulting in a PMPM cost-savings of −$0.013, or an average savings of −$7,400 per each patient initiating first-line cyclin-dependent kinase 4/6 inhibitor plus aromatase inhibitor therapy. Expected savings approached 3× the spend on the new test. Results were most sensitive to DiviTum TKa cost, population parameters, and treatment costs.

Conclusions

Clinical use of the DiviTum TKa assay is expected to decrease traditional imaging and monitoring and may reduce the overall cost of managing mBC if it leads to clinical decisions to avoid futile therapy. Post-coverage, real-world monitoring of palliative therapies among post-menopausal mBC populations is needed to better categorize cost savings over time.

PLAIN LANGUAGE SUMMARY

What is already known about this subject

Current monitoring of therapy for hormone receptor positive metastatic breast cancer involves a combination of tumor marker testing, imaging, and other tools. Monitoring is variable in practice, and therefore relatively insensitive to evidence of tumor progression.

What this study adds

DiviTum TKa is a novel biomarker that may offer a more convenient and sensitive alternative to traditional monitoring of metastatic breast cancer. Factoring in cost offsets due to reduced monitoring and earlier discontinuation of futile therapies may be cost-saving to health plans that cover this technology.

Keywords:

• Metastatic breast cancer
• disease monitoring
• budget impact
• economic model
• disease imaging
• biomarkers
• cancer progression

JEL Classification Codes:

• C11
• C1
• C
• C15

Introduction

Metastatic breast cancer (mBC) represents a significant human and economic burden in the United States. Breast cancer is the second leading cause of cancer death among women in the United States with nearly 44,000 deaths annually¹. Among women age 50–64 and over 65 with mBC, five-year relative survival is 30.2% and 28.3%, respectively², while the total costs of mBC across all age groups and phases of care were $63.4 billion in 2015 and are expected to increase to $152.4 billion in 2030³. Recent economic studies estimate that cumulative per patient total costs for patients with mBC range from $200,000 to more than $400,000 in the initial years following diagnosis^4,5.

Advances in therapy—specifically cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) and fulvestrant—have improved progression-free and overall survival for women with mBC⁶. The benefits of new therapy options have increased the role of monitoring in disease management⁷. Current recommendations, which include a combination of carcinoembryonic antigen (CEA), cancer antigen (CA) 15-3, and CA 27.29 tumor markers and imaging, reflect the need to detect disease activity and response to treatment so that therapies can be adjusted accordingly^8–11. Monitoring itself can be burdensome and costly¹²; furthermore, there is documented variability in both the type and schedule of monitoring among patients, likely reflecting multiple factors, including clinical uncertainty regarding disease progression, interpretation of test results, and patient and physician preferences regarding monitoring and therapy selection^12,13.

Circulating thymidine kinase activity (TKa) is a potential prognostic and monitoring marker in HR + mBC patients treated with endocrine therapy alone or in combination with a CDK4/6i^14,15. DiviTum TKaⁱ is a blood-based biomarker assay for TKa that has been developed to monitor and predict treatment response in HR + HER2- mBC, a subtype that accounts for approximately 70% of breast cancer cases in the US¹⁶. Assessments of DiviTum TKa in early clinical studies suggest that it may decrease the need for traditional disease monitoring assessments on the basis of identifying good prognosis patients. Clinical studies also suggest that the test may enable identification of poor prognosis patients, and avoid prolongation of futile treatments^15,17,18. Accordingly, the purpose of this study (previously presented at ISPOR 2021¹⁹) is to estimate the projected budget impact of including DiviTum TKa on a U.S. payer formulary as a treatment option for postmenopausal women with HR + HER2- mBC.

Methods

Model overview

We developed a budget impact model in Excel (Microsoft, Redmond, WA) to estimate the costs (in 2021 US Dollars) associated with mBC disease monitoring and treatment in the United States. The model compared (1) disease monitoring before the introduction of DiviTum TKa, wherein the frequencies of CT scans, bone scans, and biomarker assays were based on current standards of care, versus (2) disease monitoring after the introduction of DiviTum TKa, with consequently reduced frequencies of CT scans, bone scans, and biomarker assays. We used a population model to estimate successive monthly patient cohorts who then entered a treatment sequence model that tracked disease progression and overall survival from first through fourth line therapy along with monitoring, treatment, and adverse event costs over a three-year time horizon. The model considered only direct medical expenditures. The estimated budget impact of DiviTum TKa was estimated as the cost of monitoring with DiviTum TKa minus the cost of monitoring without DiviTiumTKa, divided by the plan population, and divided by 36 months to derive the total cost per plan member per month (PMPM).

Population model

The population model was used to estimate the monthly number of postmenopausal women with HR + HER2- mBC who receive first-line treatment with a CDK4/6i plus an aromatase inhibitor (AI) (Figure 1). We assumed a one-million-member U.S. health plan and then applied U.S.-based population data for post-menopausal women age 50–64 and 65 and older (Table 1)²⁰. The proportion of women over age 65 enrolled in the health plan through Medicare Advantage was 30%²¹.

Figure 1. (a) Model schematic: population model. (b) Model schematic: budget impact model.

Table 1. Model parameters.

Health plan population	Base case	−25%	+25%	Source
Population size	1,000,000	750,000	1,250,000	Assumption
Proportion age ≥50–64	19.2%	14.4%	24.0%	Statista^20
Proportion female	51.4%	38.6%	64.3%	Statista^20
Proportion age ≥65	16.5%	12.4%	20.6%	Statista^20
Proportion female	55.5%	41.6%	69.4%	Statista^20
Proportion with medicare advantage	30.0%	22.5%	37.5%	Kaiser Family Foundation^21
Proportion mBC patients treated with first-line CDK4/6i + AI	39.2%	29.4%	48.9%	Goldschmidt et al.^13
Prevalence: HR+/HER2- (Luminal A) breast cancer	Base case	−25%	+25%	Source
Age-adjusted BC prevalence/100K, 50–64, females	159.0	119.3	198.8	SEER^22
Age-adjusted BC prevalence/100K, ≥65, females	260.0	195.0	325.0	SEER^22
Annual proportion who progress to metastatic BC	18.5%	13.9%	23.2%	Malmgren et al.^23
Incidence: HR+/HER2- (Luminal A) breast cancer	Base case	−25%	+25%	Source
Age-adjusted incidence/100K, age 50–64, females	185.7	139.3	232.1	SEER^24
Distant stage at diagnosis	7.4	5.6	9.3	SEER^24
Age-adjusted incidence/100K, age ≥65, females	314.5	235.9	393.1	SEER^24
Distant stage at diagnosis	14.4	10.8	18.0	SEER^24
Monitoring, before DiviTum TKa	First follow-up	Follow-up period 1	Follow-up period 2	Source
DiviTum TKa	NA	NA	NA
CT scans	12 weeks	Quarterly for 1.5 y	Quarterly for 1.5 y	NCCN^9
Bone scans	2 weeks	Quarterly for 1.5 y	Quarterly for 1.5 y	NCCN^9
Biomarkers	4 weeks	Monthly for 6 m	Quarterly for 1.5 y	NCCN^9
Monitoring, after DiviTum TKa	First follow-up	Follow-up period 1	Follow-up period 2	Source
DiviTum TKa	2 weeks	Monthly for 6 m	Quarterly for 1.5 y	Biovica Int. AB^25
Proportion progressed at first follow-up (scenario analysis)	15% (±25%)			Biovica Int. AB^25, Malorni et al.^17
Months on futile therapy avoided (scenario analysis)	1 (0–2)			Biovica Int. AB^25, Malorni et al.^17
CT scans	12 weeks	Semi-annually for 1.5 y	Semi-annually for 1.5 y	NCCN^9
Bone scans	2 weeks	Semi-annually for 1.5 y	Semi-annually for 1.5 y	NCCN^9
Biomarkers	4 weeks		Quarterly for 9 m	NCCN^9
Monitoring costs	Base case	−25%	+25%	Source
DiviTum TKa	$400.00	$300.00	$500.00
CT scans	$475.24	$356.43	$594.05	CMS^26
Bone scans	$388.07	$291.05	$485.09	CMS^26
Biomarkers	$39.77	$29.83	$49.71	CMS^26
Treatment sequence	1st line	2nd line	3rd line	Cytotoxic 4th line
Palbociclib (CDK4/6i)	91%
Ribociclib (CDK4/6i)	5%
Abemaciclib (CDK4/6i)	4%
Anastrozole (AI)	90%
Exemestane (AI)	10%
Fulvestrant		80%
Any AI		10%
Cytotoxic therapy		10%
Any AI subsequent to fulvestrant			80%	100%
Cytotoxic therapy subsequent to fulvestrant			20%	100%
Fulvestrant subsequent to any AI			80%	100%
Cytotoxic therapy subsequent to any AI			20%	100%
Cytotoxic therapy subsequent to cytotoxic therapy			100%	100%
Median progression-free survival	Base case	−25%	+25%	Source
1st-line: CDK4/6 inhibitor + aromatase inhibitor	27.6 m	20.7 m	34.5 m	PALOMA-2^10
2nd line: fulvestrant monotherapy	6.5 m	4.9 m	8.1 m	Fulvestrant PI^27
2nd-line: aromatase inhibitor monotherapy	4.8 m	3.6 m	6.0 m	Anastrozole PI^28
2nd-line: cytotoxic therapy	5.7 m	4.3 m	7.1 m	Perez et al.^29
3rd line: fulvestrant monotherapy	6.5 m	4.9 m	8.1 m	Fulvestrant PI^27
3rd-line: aromatase inhibitor monotherapy	4.8 m	3.6 m	6.0 m	Anastrozole PI^28
3rd-line: cytotoxic therapy	4.6 m	3.5 m	5.8 m	Perez et al.^29
4th-line: cytotoxic therapy	2.7 m	2.0 m	3.4 m	Perez et al.^29
Median overall survival	Base case	−25%	+25%	Source
1st-line: CDK4/6 inhibitor + aromatase inhibitor	37.5 m	28.1 m	46.9 m	PALOMA‐1^30
2nd line: fulvestrant monotherapy	26.4 m	19.8 m	33.0 m	Fulvestrant PI^27
2nd-line: aromatase inhibitor monotherapy	26.7 m	20.0 m	33.4 m	Anastrozole PI^28
2nd-line: cytotoxic therapy	18.6 m	14.0 m	23.3 m	Perez et al.^29
3rd line: fulvestrant monotherapy	26.4 m	19.8 m	33.0 m	Fulvestrant PI^27
3rd-line: aromatase inhibitor monotherapy	26.7 m	20.0 m	33.4 m	Anastrozole PI [28]
3rd-line: cytotoxic therapy	12.5 m	9.4 m	15.6 m	Perez et al.^29
4th-line: cytotoxic therapy	9.7 m	7.3 m	12.1 m	Perez et al.^29
Treatment costs	Base case	−25%	+25%	Source
Palbociclib 125 mg capsule	$622.47	$466.85	$778.09	Analy$ource^31
Ribociclib 200 mg tablet	$224.93	$168.70	$281.16	Analy$ource^31
Abemaciclib 150 mg tablet	$233.18	$174.89	$291.48	Analy$ource^31
Anastrozole 1 mg tablet	$0.14	$0.11	$0.18	Analy$ource^31
Exemestane 25 mg tablet	$1.88	$1.41	$2.35	Analy$ource^31
Fulvestrant 250 mg/5 mL syringe	$162.50	$121.88	$203.13	Analy$ource^31
Abraxane (Paclitaxel) 100 mg vial	$1,512.02	$1,134.02	$1,890.03	Analy$ource^31
Adverse events	CDK4/6i + AI	Cytotoxic therapy	Cost/AE	Source
Anemia	6%	9%	$8,116	PALOMA‐1^30, Perez et al.^29, CMS^32
Diarrhea	4%	0%	$7,331	PALOMA‐1^30, Perez et al.^29, CMS^32
Fatigue	7%	0%	$7,011	PALOMA‐1^30, Perez et al.^29, CMS^32
Leukopenia	18%	0%	$10,871	PALOMA‐1^30, Perez et al.^29, CMS^32
Nausea	2%	2%	$11,139	PALOMA‐1^30, Perez et al.^29, CMS^32
Neuropathy	0%	9%	$7,331	PALOMA‐1^30, Perez et al.^29, CMS^32
Neutropenia	59%	15%	$6,000	PALOMA‐1^30, Perez et al.^29, CMS^32
Thrombocytopenia	4%	1%	$7,198	PALOMA‐1^30, Perez et al.^29, CMS^32

We then estimated the number of prevalent cases of nonmetastatic HR+/HER2- (Luminal A) breast cancer in the two age groups using data from the Surveillance, Epidemiology, and End Results (SEER) Program²²; the proportion of these nonmetastatic cases that progressed to mBC (18.5%) was derived from Malmgren et al., who conducted a retrospective cohort study of BC patients from 1990 to 2010 with follow up through 2015 of de novo mBC patients (stage IV at diagnosis) and recurrent mBC patients with subsequent distant metastatic recurrence (stage I-III initial diagnosis)²³. The age-based incidence of de novo mBC cases was also obtained from SEER²⁴. Lastly, we estimated the total number of mBC cases who go on to receive first-line treatment with CDK4/6i + AI (the target population) from Goldschmidt et al., who examined 64 community oncologists’ medical records to describe contemporary treatment patterns for mBC among postmenopausal women in a real-world setting.

Cancer monitoring

Monitoring frequencies before the introduction of DiviTum TKa were based on NCCN guidelines and expert opinion⁹. These included CT scans for all patients administered at diagnosis, 12 weeks, then quarterly for three years; bone scans administered to 50% of patients at diagnosis and 2 weeks, and then quarterly for three years; and biomarker testing administered to 50% of patients at diagnosis, at 4 weeks, then monthly for six months and quarterly for 1.5 years (Table 1).

The DiviTum TKa testing schedule was based on the manufacturer’s recommendation and clinical opinion²⁵. This schedule assumed all patients received DiviTum TKa at mBC diagnosis and two weeks after diagnosis, then monthly for six months, then quarterly for 1.5 years. Reductions in the NCCN guideline-based disease monitoring frequencies after the introduction of DiviTum TKa were based on clinical opinion, as follows: CT scans administered at diagnosis, 12 weeks, then semi-annually for 1.5 years; bone scans administered at diagnosis and 2 weeks, and then semi-annually for 1.5 years; and biomarker testing (including annual declines in the number of tested patients) administered at diagnosis, at 4 weeks, then monthly for 3 months and quarterly for 9 months, with this last estimate representing an average across variable standards of care.

Treatment

Treatment choices were modeled on NCCN-recommended treatments for HR + HER2- mBC patients⁹. All patients derived from the population model entered the treatment sequence model via first-line treatment with CDK4/6i + AI. Patients who progressed after first-line treatment could then receive second-line treatment with either fulvestrant, aromatase inhibitors, or cytotoxic therapy. In the third line, cytotoxic-naïve patients could receive treatment among fulvestrant or aromatase inhibitors (if naïve), or additional cytotoxic therapy. Once patients began cytotoxic therapy, they were assumed to be ineligible for anything other than additional cytotoxic therapy.

We modeled treatment-associated progression-free and overall survival using transition probabilities derived from an exponential fit to the respective median survivals, obtained from the treatment regimens’ clinical trials. The transition probabilities were used in a Markov model framework to move each monthly cohort entering the model from first-line treatment to fourth-line treatment and/or death.

Costs

We based the unit cost of DiviTum TKa, CT scans, bone scans, and biomarker testing on internal estimates for DiviTum TKa cost and Centers for Medicare & Medicaid Services (CMS) Healthcare Common Procedural Coding System (HCPCS) codes (Table 1)²⁶. We used the wholesale acquisition cost per drug, obtained from Analy$ource.com, an online drug pricing database³¹. The cost per adverse event was derived from the 2021 CMS Final Rule and Correction Notice Tables³².

Sensitivity and scenario analyses

We evaluated the uncertainty of all model inputs on the PMPM using one-way sensitivity analysis, in which one parameter at a time is varied to its low and high value while keeping all other parameters constant; larger resultant PMPM ranges indicate parameters with the greatest impact on results. In a scenario analysis, we explored DiviTum TKa’s impact on therapy utilization based on published literature and expert opinion^17,25; in this scenario, DiviTum TKa predicted treatment futility and led to therapy changes an average of one month in advance of radiological disease progression-driven changes in 15% of patients at first follow-up, and these patients immediately transitioned from first-line treatment to second-line treatment.

Results

Population model

In a health plan with 1,000,000 members, we estimated 228 prevalent (i.e. previously diagnosed) HR+/HER2- (Luminal A) BC patients per year. Of this cohort, 42 progressed to mBC, and 17 initiated treatment with CDK4/6i + AI. We further estimated 270 incident (newly diagnosed) women with HR+/HER2- (Luminal A) BC per year, of whom 11 had metastatic disease at diagnosis and 4 initiated treatment with CDK4/6i + AI. In total, approximately 21 women per year (1.7 per month) would initiate treatment with CDK4/6i + AI (Table 2).

Table 2. Population model results.

Population flow	Age 50–64	Age ≥65	Total
Female plan members	98,688	27,473	126,161
Prevalent HR+/HER2- (Luminal A) BC	157	71	228
# Progress to metastatic BC	29	13	42
# Treated with CDK4/6i + AI	11	5	17
Incident HR+/HER2- (Luminal A) BC	183	86	270
# Metastatic BC at diagnosis	7	4	11
# Treated with CDK4/6i + AI	3	2	4
New patients per month			2

Before DiviTum TKa approval

Total treatment and adverse event costs were $13.7 million (including $13.3 million for first-line treatment with CDK4/6i + AI) and $530,500, respectively (Table 3). Before the addition of DiviTum TKa, patients received 423 CT scans, 194 bone scans, and 208 biomarker tests over three years, for $201,000, $75,400, and $8,300, respectively. In one year, on average, individual patients received 4.8 CT scans, 2.4 bone scans, and 4.3 biomarker tests. The total three-year cost of monitoring before the addition of DiviTum TKa was $284,700. The overall three-year cost of monitoring, treatment, and adverse events before the addition of DiviTum TKa was $14.5 million.

Table 3. Budget impact model results.

	Before DiviTum TKa	After DiviTum TKa	Difference	Difference PMPM
Base case
Total cost	$14,518,998	$14,556,984	$37,986	$0.001
Monitoring	$284,680	$322,666	$37,986	$0.001
Treatment	$13,703,867	$13,703,867	$0	$0.000
Adverse events	$530,451	$530,451	$0	$0.000
Treatment futility avoidance scenario
Total cost	$14,518,998	$14,053,431	-$465,567	-$0.013
Monitoring	$284,680	$311,179	$26,500	$0.001
Treatment	$13,703,867	$13,209,240	-$494,627	-$0.014
Adverse events	$530,451	$533,013	$2,561	$0.000

After DiviTum TKa approval

Treatment and adverse event costs were equivalent after the addition of 416 DiviTum TKa assays, however, we estimated this led to 193 fewer CT scans, 88 fewer bone scans, and 55 fewer biomarker tests over three years. In one year, on average, individual patients received 8.5 DiviTum TKa assays, 2.8 CT scans, 1.4 bone scans, and 3.0 biomarker assays. The total cost of DiviTum TKa testing over three years was $166,400, while the costs of CT scans, bone scans, and biomarker tests were $109,100 (Δ -$91,900), $41,200 (Δ -$34,300), and $6,100, (Δ -$2,200), respectively (Figure 2(A)). The total cost of monitoring after the addition of DiviTum TKa was $322,700 (Δ $38,000), resulting in an overall three-year PMPM of $0.001.

Figure 2. (a) Base case monitoring cost results. (b) Monitoring cost, treatment futility avoidance scenario.

Scenario analysis

In the scenario analysis accounting for reduced time spent on futile first-line therapy after the addition of DiviTum TKa, meantime on treatment with CDK4/6i + AI therapy was 28 months without DiviTum TKa testing; with DiviTum TKa, 27 months; this led to treatment-related cost savings due to avoidance of time on futile therapy. Treatment costs decreased to $13.2 million (Δ -$494,600) and adverse event costs increased to $533,000 (Δ $2,600, due to increased use of cytotoxic therapy in later lines of treatment). The total cost of DiviTum TKa testing over three years was $161,700, while the costs of CT scans, bone scans, and biomarker tests were $104,300 (Δ -$96,700), $39,300, (Δ -$36,200), and $5,900, (Δ -$2,400), respectively. The total cost of monitoring after the addition of DiviTum TKa was $311,200 (Δ $26,500; Figure 2(B)). The overall three-year cost of monitoring plus treatment and adverse events, factoring in reduced time on futile first-line therapy after the addition of DiviTum TKa, was $14.1 million (Δ -$465,600), resulting in a PMPM cost-savings of -$0.013 (Figure 3(B)).

Figure 3. (a) Treatment & adverse event cost, treatment futility avoidance scenario. (b) Total cost, treatment futility avoidance scenario.

Sensitivity analysis

In one-way sensitivity analysis for the base case, the PMPM was most sensitive to the cost of DiviTum TKa testing, the cost of CT scans, the proportion treated with first-line CDK4/6i + AI, and the annual proportion of prevalent BC patients who progress to mBC (Figure 4(a)). For the reduced time on futile therapy scenario, PMPM results were most sensitive to the reduction of time on futile therapy, the proportion of patients predicted by DiviTum TKa to progress early, the cost of the CDK4/6i palbociclib, the proportion treated with first-line CDK4/6i + AI, and the annual proportion of prevalent BC patients who progress to mBC (Figure 4(b)).

Figure 4. (a) One-way sensitivity analysis, base case. (b) One-way sensitivity analysis, treatment futility avoidance scenario.

Discussion

In this budget impact analysis, the use of DiviTum TKa reduced the use of a substantial proportion of traditional monitoring tools such that the budget impact on a health plan with 1,000,000 members was minimal ($0.001 PMPM). The more impactful potential clinical value of the DiviTum TKa assay, however, is identifying women for whom lack of response to a costly CDK 4/6i was detected and acted upon earlier than standard monitoring. In such situations, the DiviTum TKa can be cost-saving to plans under adherence scenarios that are expected by clinical experts.

We focus the base estimate on monitoring only because it is a more likely—and therefore more conservative—estimate of the costs of management with the novel assay. While it is possible that DiviTum TKa will prove useful in detecting treatment failure/futility earlier than traditional monitoring, it is likely that such savings will be realized after clinicians gain experience with the assay over time. It is also possible that early changes to therapy in patients with tumors resistant to CDK 4/6i + AI therapy could lead to improved clinical outcomes, which is a hypothesis that should be tested in future clinical studies.

In the monitoring-only scenario, the cost of CT scans was an important factor influencing the budget impact. Reimbursements for CT scans can be somewhat higher for commercial insurers versus Medicare. Thus, a plan serving primarily commercially-insured patients may realize modest cost savings with changes to monitoring alone. Furthermore, the addition of DiviTum TKa may help refine current clinical guidelines’ nonspecificity as to the recommended frequency of imaging exams. When considering the expanded scenario that includes futile therapies, the price of CDK4/6is is the most influential factor impacting the overall budget. The average sales price of albociclib, ribociclib, and abemaciclib have increased 5–10% per year since they were introduced³³. Further price increases will increase the potential savings afforded by DiviTum TKa.

Limitations

We note the limitations of our analysis. Because clinicians have not yet had experience with DiviTum TKa beyond clinical trials, the assumptions made in this model must be viewed as preliminary. Also, to our knowledge, there are no universal fixed patterns of mBC monitoring, therefore the cost offsets estimated in this analysis are specific to the assumptions about real-world use. Lastly, we restricted the available treatment pathway in our model due to limited pathway data and to focus our findings on the impacts of HR + HER2- mBC monitoring. Further, the focus was on a single treatment pathway only: those initiating first-line treatment with CDK4/6i + AI therapy, which amounts to 21 patients per year within a 1 million-member plan. Following approval and commercial introduction of DiviTum TKa, future research on practice patterns and costs in this population will be necessary to validate the analysis.

Conclusions

The inclusion of DiviTum TKa reduced the use of a substantial proportion of traditional monitoring. If the use of DiviTum TKa can also predict lack of benefit from costly CDK4/6i therapy and clinicians act on that information in a timely fashion, this can result in substantial cost savings to patients and health plans. In this scenario, net savings on adding a new test to care could be three times the cost of the new test itself. Following approval and commercial introduction of DiviTum TKa, future research on practice patterns will be necessary to validate our analysis.

Transparency

Declaration of funding

This work was funded by Biovica International AB.

Declaration of financial/other interests

JJC, GFG, and SDR are paid consultants of Biovica International AB; RAD is a full time employee of Biovica International AB. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

JJC, GFG, RAD, and SDR all contributed to analysis and manuscript writing.

Acknowledgements

None stated

Previous presentations

This work was previously presented as a digital poster at ISPOR 2021.

Notes

i DiviTum TKa is a registered trademark of Biovica AB, Uppsala, Sweden.