Introduction: The choice of initial therapy in follicular lymphoma can be a key determinant in future therapy, as irreversible toxicities with first line regimens can impact the patient's ability to tolerate future treatment. Minimizing drug exposure will result in less frequent occurrence of significant adverse events and associated treatment costs. In the era of COVID-19 pandemic, there is additional benefit to minimizing the number of patient visits and hospital admissions. Limited information exists related to the outcomes and associated costs of existing treatment sequences. Additionally, treatment administration at different types of clinical sites results in varied reimbursement models, making informed evaluation of clinical and financial evidence challenging.
Methods: The current study applies a budget impact model methodology in order to describe the associated impact of treatment selection and sequencing on outcomes and costs in the treatment of relapsed or refractory low-grade follicular lymphoma in first line therapy followed by Consolidation and also in first line therapy to second line therapy. Key model inputs included: Number of treatment cycles, number of days a treatment was received, duration of response (DOR), rate of side effects and associated costs, and total treatment costs, including drugs, medical treatment, laboratory testing and adverse event costs.
Treatment outcomes were based on the published literature that summarized the overall response rate, median DOR, and toxicity. Treatment regimen costs were evaluated based on payer pricing, Wholesale Acquisition Cost (WAC), Average Selling Price (ASP) and Average Wholesale Price (AWP) and modified to adjust for weight-based dosing and negotiate payer reimbursement rates. Associated medical costs for medical treatment and supportive care were estimated using current Medicare fee schedule rates.
Included were seven options for first line therapy of follicular lymphoma from 2020 NCCN Guidelines - (Bendamustine + rituximab (BR); Bendamustine + Obinutuzumab (OB); CHOP rituximab (RCHOP); CHOP + Obinutuzumab (OCHOP); CVP+ rituximab (RCVP); CVP + Obinutuzumab (OCVP); Lenalidomide + rituximab (R2)), followed by three for Consolidation (Rituximab maintenance (RM); Obinutuzumab maintenance (O); Radioimmunotherapy (RIT with 90 Y-ibritumomab tiuxetan (Y90-IT, Zevalin)) and three Second Line therapy options (RIT; Lenalidomide only; Lenalidomide + Obinutuzumab (LO)).
Results: The treatment sequence of first line BR followed by Consolidation with RIT Y90 (Zevalin) had the longest predicted DOR (2586 days). The associated treatment sequence costs were $212,485 for BR followed by Y90-IT, compared with $233, 388 for BR followed by rituximab maintenance, which had a predicted DOR of 2478 days. The predicted DOR for treatment sequences starting with OCHOP, OCVP and RCHOP and followed by RIT with Y90-IT was approximately 1000 days less than BR followed by Y90-IT for a cost difference of $4,421, $12,914 and $25,826, respectively. The treatment sequence of first line BR followed by Second Line RIT Y90-IT had the second longest predicted DOR of 2586 days at costs of $212,485, compared to 2778 days for BR followed by LO, at a total sequence costs of $796,695.
Conclusion: The use of Y90-IT in Consolidation or Second Line treatment demonstrated desired patient outcomes at one of the lowest cost profiles. Additionally, Y90-IT administration can be completed in only two clinic visits, reducing patient travel and contact, improving safety in an era of COVID-19 precautionary measures and reducing cost.
Figure 1. Duration of Response and Total Sequence Costs for Twelve First Line to Consolidation and First Line to Second Line Treatment Regimens.
Disclosures
McBride: Merck: Speakers Bureau; Coherus BioSciences: Consultancy, Speakers Bureau; Pfizer: Consultancy; Bristol-Myers Squibb: Consultancy; MorphoSys: Consultancy; Sandoz: Consultancy.
KRAS mutation in secondary malignant histiocytosis arising from low grade follicular lymphoma