Real-world use of supportive medications to prevent and manage key adverse events during first-line (1L) treatment of metastatic pancreatic adenocarcinoma (mPDAC) with FOLFIRINOX (FFX), FFX without 5FU bolus, and gemcitabine+nab-paclitaxel (GnP).

695 Background: 1L treatment of mPDAC with FFX or GnP typically requires supportive care to alleviate toxic effects. Two of the most common adverse events are neutropenia, which may be treated with granulocyte colony-stimulating factor (G-CSF), and diarrhea, often treated with atropine and/or loperamide. Medications may be administered as prophylaxis (PPx) or to manage symptoms as they occur. Other methods to improve tolerability include modifying regimens with lower doses or omitted components, such as removing the 5FU bolus from FFX (FFXnb). This study examines PPx vs non-PPx G-CSF, atropine, and loperamide during 1L treatment with FFX, FFXnb, and GnP. Methods: This retrospective observational study utilized Optum Market Clarity claims + EHR linked data. Inclusion criteria were: adult patients (pts) diagnosed with mPDAC between January 1, 2015 and May 31, 2023; initiated treatment (index date) with 1L FFX, FFXnb, or GnP -14 to +90 days from diagnosis; no evidence of other cancers in 6 months pre-index continuous enrollment; at least one EHR record post-index. G-CSF PPx was defined as administration/fill within 7 days of the start of a treatment, inclusive. PPx with atropine or loperamide was defined as administration/fill the day before or day of a treatment; all other use was categorized “non-PPx”. Pts may appear in both PPx and non-PPx categories. Results: Rates of overall use, PPx, and non-PPx for each medication of interest are shown (Table). The overall G-CSF use rate was >3.5 times higher for FFX and FFXnb vs GnP. While ≥70% of FFX/FFXnb pts received PPx, non-PPx still occurred in more than 1 in 8 pts. One-fifth of FFX and FFXnb pts received atropine at any time, vs. just 6% of GnP pts. Atropine PPx was less common than non-PPx for FFX/FFXnb and was rare in GnP pts. Similar to the other medications, loperamide was observed more for FFX and FFXnb vs. GnP, but was the least common of the medications, used by <10% of pts in any regimen. PPx and non-PPx use were similar. Use of the three medications was similar between FFX and FFXnb. Conclusions: In a RW cohort of 1L mPDAC pts, G-CSF and antidiarrheal use was more common in FFX and FFXnb than GnP pts. Most FFX and FFXnb pts received PPx G-CSF, reflecting clinician efforts to manage the high risk of neutropenia with these regimens. Non-PPx G-CSF still occurred in 14–18% of pts. FFXnb had similar rates of concomitant medications as FFX, indicating that removing the 5FU bolus may have minor impact on the need for some supportive medications. Concomitant medication use. Medication 1L FFX(n=511) 1L FFXnb(n=583) 1L GnP(n=958) G-CSF % treated overall 77% 71% 20% % PPx 76% 70% 17% % non-PPx 18% 14% 9% Atropine % treated overall 20% 20% 6% % PPx 11% 9% 2% % non-PPx 15% 16% 5% Loperamide % treated overall 7% 9% 3% % PPx 4% 5% 1% % non-PPx 4% 6% 2%