Walia, Rajat

Abstract Rationale This Registry was designed to prospectively evaluate the efficacy of extracorporeal photopheresis (ECP) to arrest the rate of FEV1 decline (FEV1 decline) and prolong survival in lung allograft recipients with Bronchiolitis Obliterans refractory to standard of care therapy. Methods After IRB approval, 258 lung transplant recipients were enrolled from 20 US lung transplant centers. Subjects were assigned to ECP treatment (ECPRx) (i.e., 24 procedures over 6 months) at or a few months after enrollment based on spirometric criteria. Maintenance ECPRx (mECP) was at the discretion of managing clinicians. Rate of FEV1 decline in mL/month (FEV1 decline) was compared between 6 months prior to and 6 & 12 months after ECPRx initiation using linear mixed effects models. Time 0 for survival was set as the start of ECPRx for generation of Kaplan-Meier curves. Hazard Ratios (HR) with 95% confidence intervals (lower-upper) were generated using Cox Proportional Hazards Regression to characterize significant (p < 0.05) independent associations of mECP and/or any other covariates (i.e., demographic, operative, enrollment site, spirometric ) and survival. Results An 89% (78%-96%) decrease in the FEV1 decline was observed 12 months after ECPRx initiation in 191 participants assigned to ECPRx. FEV1 decline (-164 mL/month: 144-185) was greater (p < 0.001) in participants who expired within six months of Time 0 (n = 28) vs participants (-111 mL/month: 101-120) who died six months after Time 0 (n = 77). Of 159 participants who survived for at least six months after ECPRx initiation, 40 participants without mECP, who had up to 24 ECPRx (ECPRx: n = 19), had a lower survival HR: 2.43(1.75-3.4) (p < 0.001) relative to 119 participants who received mECP (ECPRx: n = 86)(see Figure). The response to ECPRx (% Change in FEV1 decline prior to and 6 months after 1st ECP) was similar between subcohorts (No mECP: -81 decrease vs mECP: -85%, p = 0.3). The association of mECP persisted after multivariate adjustment HR 1.8 (1.8-2.7)(p = 0.002) using significant covariates: FEV1 HR 0.37 (0.3-0.5), FEV1 decline HR 0.001 (0.001-0.04), Male Gender HR 2.4 (1.7-3.4); Reflux Disease HR 1.8 (1.2-2.8); Coronary Disease HR 1.8 (1.2-2.7). Conclusions This analysis indicates that mECP is independently associated with enhanced survival most likely due to attenuation of relapse six months after ECP initiation based on similar initial response to ECPRx. A risk-adjusted, control cohort is being pursued to facilitate submission of a scientifically rigorous petition to CMS to expand the ECP National Coverage Decision to include BOS predicated on CMS 2024 scientific guidelines. This abstract is funded by: Therakos Inc

Background. The spirometric response to standard-of-care (SOC) immunosuppressive therapy for the management of bronchiolitis obliterans syndrome (BOS) has been sparsely reported in the literature. Data from a Medicare-approved Registry were analyzed to characterize the effectiveness/durability of a wide range of SOC interventions to manage the decline of lung function and to validate the study spirometric criteria for initiation of rescue therapy. Methods. Lung transplant recipients with refractory BOS at 21 US collaborating centers were enrolled in the Registry. Data included both nonspirometric (eg, demographic, Immunosuppressive Regimens for management of BOS) and spirometric parameters (ie, forced expiratory volume in 1 s [FEV 1 ] measurements and derived indices). The utility of study FEV 1 criteria for treatment (ie, statistically significant rate of FEV 1 decline >30 mL/mo) was evaluated by comparing the spirometric course between participants who met or did not meet this criterion. Results. Only 21% of participants treated with SOC therapy had >50% decrease (76 ± 25% decrease) in the rate of FEV 1 decline. Although 51% of participants had a partial response (rate of FEV 1 decline decreased on average 71%), 49% of participants had a substantial increase (mean increase 224%). The FEV 1 criterion for treatment was able to identify 19% of participants (48/258) who achieved durable stabilization (ie, nonsignificant rate of FEV 1 <30 mL/mo) with SOC therapy. Conclusions. Patients with BOS have a widely variable response to SOC therapy. Our findings support the use of FEV 1 rate of decline to assess response to SOC therapy and to ensure appropriate assignment of participants with refractory BOS to rescue therapy treatment cohorts.

BACKGROUND. We developed a prospective, multicenter “registry” to evaluate the effect of extracorporeal photopheresis for lung transplant recipients who develop chronic lung allograft dysfunction (CLAD) with the bronchiolitis obliterans syndrome (BOS) phenotype (CLAD/BOS) and who are refractory to conventional standard-of-care therapy. METHODS. Data from 258 lung transplant recipients enrolled in the Registry between April 2015 and April 2022 were included in this analysis. All recorded parameters (eg, demographics), including forced expiratory volume in 1 s (FEV1) measurements and indices (FEV1% baseline, FEV1 rate of decline) at several time periods, were included in multivariate linear/logistic and Kaplan-Meier analyses to evaluate potential associations with survival. RESULTS. Mortality at 6 and 12 mo after CLAD/BOS diagnosis was 5% and 14%, whereas mortality at 6 and 12 mo after enrollment was 15% and 26%, respectively. The primary cause of death in the cohort was respiratory failure or graft failure (74%). Rate of FEV1 decline (log) at enrollment was independently associated with survival (log days) from CLAD/BOS diagnosis and enrollment (r = 0.55 and r = 0.3, respectively). The rates of FEV1 decline among survivors were lower (–77 ± 89 mL/mo) compared with nonsurvivors (–148 ± 155 mL/mo) at 6 mo after enrollment (P = 0.0001). CONCLUSIONS. The rate of FEV1 decline quantified using at least 5 FEV1 measurements is a robust surrogate outcome. We plan to use these findings to revise our randomized controlled trial to facilitate risk adjustment using FEV1 rate of decline strata at enrollment and as a scientifically valid surrogate for outcome.