Roschewski, Mark

Introduction Frontline therapy for pts with follicular lymphoma (FL) is not based on the molecular profile of the tumor. The PI3K pathway is central to FL biology, but the molecular profile of tumors most sensitive to PI3K inhibition (PI3Ki) is unknown. Copanlisib inhibits both PI3Kα and δ isoforms, and we hypothesized that most pts with treatment naïve FL will have PI3Ki-sensitive tumors and durable complete responses (CRs) may be achievable with short durations of targeted therapy. A gene expression profiling (GEP) predictor utilizes a combination of the expression of 45 selected informative genes and an additional 19 housekeeping genes to identify FL pts at high-risk for early progression within 24 months (Wright et al. ASH Annual Meeting2022). We also hypothesized that copanlisib would induce durable CRs in high-risk pts by the GEP assay. Here, we report a preliminary analysis of an ongoing “window of opportunity” study of copanlisib followed by response-adapted copanlisib and rituximab in treatment-naïve pts with FL (NCT03789240). Methods Pts with untreated grade 1-2, 3A FL, ≥stage 2 are eligible if systemic therapy is indicated: symptoms, progressive lymphadenopathy, or organ compromise. Prior radiation is permitted. Eligibility includes age ≥18 and adequate organ function unless due to lymphoma. HIV, CMV, Hep B or C, and autoimmune conditions are excluded. Pts first receive copanlisib 60mg on days 1, 8, and 15 of a 28-day “window of opportunity” to explore the activity of copanlisib. Following the window, pts receive 6 cycles of copanlisib 60mg on days 1, 8, and 15 of a 28-day cycle along with rituximab 375mg weekly x 4 then on day 1 of each cycle and response is assessed with FDG-PET and CT scans. Pts without response after C6 are taken off study and those with a partial response (PR) can continue for an additional 6 cycles and then stop therapy. Pts who achieve a CR after 6 cycles stop therapy. No maintenance is given. Supportive care includesPCP prophylaxis. The primary endpoint is the CR rate with secondary endpoints of safety, duration of CR, and PFS. Exploratory objectives include identification of a predictive signature of PI3Ki response and the response rate in high-risk pts identified by the GEP assay. Results Twenty-eight pts have enrolled. Median age was 56y (range, 24-80). Seventeen (61%) and 12 (43%) pts had high-risk FLIPI and FLIPI-2 scores ≥3, respectively; 6 (21%) pts had Grade 3A FL, and 17 (61%) pts met two or more GELF criteria. After copanlisib monotherapy in the window, 27 (96%) pts had tumor reductions by CT with a median change of -38% (-62% to +16%) (Figure 1). Among 22 pts who completed 6 cycles, 21 (96%) responded, including 9 (41%) pts with PR and 12 (55%) pts with CR. Of 9 pts with PR who received an additional 6 cycles of therapy, only 1 (11%) converted to a CR bringing the overall CR rate to 59% (13/22 pts). After a median follow-up of 25.8 months, the 2-year PFS was 43.2% (95% CI, 20.7-64.0%). The median duration of CR was 29.7 months (95% CI, 6.3 months - not estimable) with 8 (62%) CRs ongoing (Figure 2). Toxicity was evaluated in 28 pts across 220 cycles. Most common were rash (64%), mucositis (50%), and nausea/vomiting (50%), all G1-2 except 1 (4%) pt with G3 mucositis. The most common ≥G3 toxicities were neutropenia and infections in 5 (18%) pts each. ≥G3 neutropenia occurred in 10 (5%) cycles, responded to therapy interruption and/or growth factors, and did not require dose reduction. Two (8%) pts had copanlisib dose reduced, 1 (4%) each due to rash and mucositis. Therapy was prematurely discontinued in 5 pts: 3 due to COVID-19, 1 for hepatotoxicity that resolved, and 1 due to infusion reaction to rituximab. Nine of 24 (38%) pts were poor risk by the GEP assay. Complete responses were observed in 71%, 67%, and 57% of pts categorized as high-risk by FLIPI, FLIPI-2, and GEP assay, respectively. The CR rate was not affected by bulky disease (any LN >7cm; p=1.00), high-risk FLIPI (p=0.19), high-risk FLIPI-2 (p=0.67), poor-risk GEP (p=1.00), or metabolic tumor volume (p=0.33). Conclusion Nearly all pts with treatment naïve FL have PI3Ki-responsive tumors, and the combination of copanlisib with rituximab achieved a CR rate of 59% at the end of induction therapy. The median duration of CR is nearly 30 months, including ongoing remissions without maintenance. CRs were observed in pts deemed high-risk by the GEP assay and FLIPI score. The safety profile is excellent, with mostly G1-2 toxicities manageable with supportive care.

e19063 Background: Constitutive activation of the JAK-STAT pathway has been reported in lymphomas, suggesting that targeting this pathway could show clinical benefit. Ruxolitinib phosphate, an oral JAK inhibitor represents a potential therapeutic agent for high grade lymphomas. This study is designed to investigate benefits of ruxolitinib in patients with relapsed or refractory PTCL and DLBCL Methods: Patients with relapsed/refractory DLBCL and aggressive T cell lymphomas who were ineligible for, or relapsed after, stem cell transplantation were eligible. Patients received ruxolitinib, at a dose of 10mg or 5mg BID, with gradual escalation to 25mg BID. Weekly hematological assessments were done during the first cycle, CT scans were done after every two cycles. Descriptive statistics for response to therapy were collected. Progression free survival (PFS), Overall survival (OS) curves were plotted using Kaplan-Meier method, comparisons between groups were made using the log rank test. Primary outcome of the study was to assess the overall response rate (ORR). Secondary objectives were to determine PFS, OS, duration of response and safety. Relationship between responses to oral ruxolitnib and gene expression profiling was explored. Results: Of the 60 patients enrolled, 25 patients had PTCL, 32 DLBCL, 3 pending path review. Median age was 62 yrs., 56.6% had stage IV disease. Median number of cycles received was 2 (min 1, max 60). At the time of evaluation, 76% patients had progressed on therapy. The median follow-up of patients was 3.7 months (min 0.9; max 61.4). Data for 41 patients was available for evaluation of response. Complete response (CR) was noted in 1 patient with PTCL. Partial response (PR) was noted in 1, stable disease (SD) in 4 patients. Among the responders, a PTCL patient with SD had a sustained response for 60 months, a patient with PR had a response duration of 31 months. The median OS and PFS were 5.9 and 1.8 months. PFS was 2.2 months in patients with PTCL and 1.8 months in DLBCL. Median OS was 5 months in patients with DLBCL, 6.9 months in PTCL. The estimated 6 month PFS and OS were 17% (95%CI: 9%, 28%) , 49% (95%CI: 35%, 62%). There was no difference in PFS or OS between PTCL and DLBCL (p = 0.42, p = 0.94). Grade 3 or higher adverse events were seen in 62%. Anemia was seen in 20%, thrombocytopenia in 8%, infections in 6%. Conclusions: Ruxolitinib can produce responses in some patients with relapsed/refractory NHL, particularly in patients with PTCL. It may play a role in combination therapies in future. Clinical trial information: NCT01431209.