Selpercatinib Shows Minimal Payer Budget Impact for RET-Altered Solid Tumors

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Minimal impact on payer budgets were observed when selpercatinib (Retivmo) treatment was added as a tumor-agnostic treatment option for patients with RET-altered solid tumors, according to research presented in a poster during the International Society for Pharmacoeconomics and Outcomes (iSPOR) 2023 Meeting.¹

Selpercatinib is a highly selective and potent RET kinase inhibitor that was initially approved by the FDA for the treatment of patients with RET fusion-positive non–small cell lung cancer. Selpercatinib was also granted accelerated approval for adult patients who have locally advanced or metastatic RET fusion-positive solid tumors who have either received or progressed on previous systemic treatment, or have no appropriate treatment alternatives.

Findings from the phase 1/2 LIBRETTO-001 trial (NCT03157128) supported these approvals, as the study showed an overall response rate of 44% in 41 efficacy evaluable patients (95% CI, 28%-60%), including a 4.9% complete response rate and a 39% partial response rate. The median duration of response was 24.5 months (95% CI, 9.2-not estimable).^2,3

Investigators developed an integrated budget impact analysis (iBIM) to estimate the number of patients who are eligible for single treatment with selpercatinib and to evaluate the potential impact on third-party payers’ formulary budgets of introducing selpercatinib for RET-altered solid tumors as a single treatment in the United States.¹

This iBIM for selpercatinib included 19 solid tumor types that reported potential RET-alterations across tumor types and restricted to solid tumors. The patient population for all tumor types were determined individually before results were integrated.

Looking at the characteristics of the model, payers were commercial and Medicare, there were 1,000,000 plan members, and 100% of patients were tested for RET alterations. The first costing approach consisted of micro-costing for proxy comparator, which was a tumor-specific single treatment or regimen selected to be a representative comparator for each disease. Another RET inhibitor, pralsetinib (Gavreto), was included as a comparator per its approved indications from the FDA. The other comparator costing approach was published literature-based.

Selpercatinib had a 65% market share assumption in year 1, 70% in year 2, and 75% in year 3. Other model characteristics included the cost of drugs and administration, dosing regimens, single treatment-related costs, such as monitoring, supportive care, and administration costs, and adverse event (AE) related costs.

The one-way sensitivity analysis (OWSA) was performed for both commercial and Medicare perspectives at years 1, 2, and 3. This assessed the uncertainty that was associated with model parameters and key assumptions.

In scenario 1, the assumed RET testing rate was 50%, and scenario 2 was the gastrointestinal tumor specific (GI-specific) scenario which included the evaluation of pancreatic cancer colorectal cancer, gastric cancer, small intestine cancer, and cholangiocarcinoma.

The conceptual approach utilized in the study serves as a proof of concept for developing BIMs for tumor-agnostic indications in the future.

Across both perspectives and years, most OWSA identified drug costs, incidence of RET, and single treatment duration as significant drivers of incremental costs. For both RET-testing at 50% and GI-specific scenarios, there were a low number of patients treated.

For 50% RET testing, 5.84 million were eligible for single treatment, and 3.79 million in year 1, 4.09 million in year 2, and 4.38 million in year 3 were selpercatinib treated for commercial payers vs 27.91 for single treatment, and 18.14, 19.54, and 20.93 for selpercatinib who were Medicare payers. In the GI-specific scenarios, 1.94 vs 8.49 million were commercial vs Medicare payers eligible for single treatment, and 1.26 million vs 5.52 at year 1, 1.36 vs 5.94 at year 2, and 1.46 vs 6.37 at year 3 were eligible for selpercatinib.

Findings showed that the number of patients with RET-altered solid tumors who were eligible for single treatment in third-party United States payer plans was low. Per million, the number of patients treated with selpercatinib across all 19 tumor-types who were commercial payers were 7.59 at year 1, 8.17 at year 2, and 8.76 at year 3. For Medicare, the subsequent numbers were 36.29 (year 1), 39.08 (year 2), and 41.87 (year 3).

Incremental PMPM estimates for years 1, 2, and 3 for commercial payers ranged from $0.073–$0.213 and for Medicare payers, ranged from $0.371–$1.053 in the proxy comparator method. This suggests minimal impact of selpercatinib addition on payer budgets. In both perspectives, findings based on the published literature costing for comparators were similar.

Overall, these findings demonstrated minimal impact on payer budgets after the addition of selpercatinib treatment but should be interpreted with caution as there is uncertainty associated with several assumptions and parameters.

REFERENCES
1.Bhandari NR, Cinfio F,Gilligan AM, et al. Integrated budget impact analysis of introducing selpercatinib as a tumor-agnostic treatment option for patients with RET-altered solid tumors in the united states. Presented at: 2023 International Society for Pharmacoeconomics and Outcomes Research; May 7-10, 2023. Boston, MA.

2. FDA approves selpercatinib for locally advanced or metastatic RET fusion-positive non-small cell lung cancer. News release. FDA. September 21, 2022. Accessed May 8, 2023. https://bit.ly/3DFyvq0

3. FDA approves selpercatinib for locally advanced or metastatic RET fusion-positive solid tumors. News release. FDA. September 21, 2022. Accessed May 8, 2023. https://bit.ly/3f8Wzr7