Ipilimumab: unleashing the power of the immune system through CTLA-4 blockade

Malignant melanoma is rising faster in incidence than any other malignancy. Long-term remission or "cure" is rare and is almost exclusively limited to therapies that stimulate an immune antitumor response. Ipilimumab is a novel targeted human immunostimulatory monoclonal antibody that blocks cytotoxic T-lymphocyte antigen4 (CTLA-4), an immune-inhibitory site expressed on activated T cells. Ipilimumab is well tolerated as an outpatient infusion therapy. Multiple studies have confirmed significant antimelanoma activity. A randomized trial has documented a survival benefit when ipilimumab was compared to a gp-100 vaccine only arm. The unique mechanism of action of ipilimumab makes assessment of response by conventional criteria difficult. Benefit from ipilimumab can occur after what would be considered progression with World Health Oganization (WHO) or Response Evaluation Criteria in Solid Tumors (RECIST) criteria. New immune response criteria have been proposed. Therapeutic responses peak between 12 and 24 weeks, with slow responses continuing up to and beyond 12 months. The major drug- related adverse side effects (10%-15% grade 3 or above) are immune-related and consist most commonly of rash, colitis, hypophysitis, thyroiditis, and hepatitis. Colonic perforation can occur and patients with diarrhea have to be monitored carefully with strict adherence to treatment algorithms. Algorithms for the treatment of other adverse side effects have been developed. The treatment of immune-related side effects with immunosuppressive agents, such as corticosteroids, does not appear to impair antitumor response. With proper monitoring and management of side effects, ipilimumab is an extremely safe drug to administer. The benefits of ipilimumab will most certainly extend to other malignancies in the near future.

Ipilimumab efficacy and safety in patients with advanced melanoma: a retrospective analysis of HLA subtype from four trials

Ipilimumab is a fully human, monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4 to potentiate an antitumor T-cell response. This agent improved overall survival in a phase III trial in previously treated patients with advanced melanoma. Because the mechanism of action for ipilimumab is thought to be HLA independent, most trials enrolled patients without regard to HLA subtype. However, enrollment in the phase III trial was restricted to class-I HLA-A*0201-positive patients because two of the three arms contained an HLA-A*0201-restricted gp100 vaccine. HLA typing was also performed prospectively in several phase II trials and was available for 93.5% of patients. In this retrospective analysis, pooled efficacy and safety data are presented according to HLA-A*0201 status and dose from pretreated patients randomized to 0.3, 3, or 10 mg/kg ipilimumab in four phase II trials. Median overall survival (OS) was similar for the 187 HLA-A*0201-positive [9.3 months, 95% CI (confidence interval) 7.4-11.5] and 266 HLA-A*0201-negative patients [11.4 months, 95% CI 9.3-15.1] randomized to ipilimumab at all doses across the four phase II trials. These data are comparable to the OS for the 137 HLA-A*0201-positive patients randomized to ipilimumab in the phase III study [10.1 months, 95% CI 8.0-13.8]. Ipilimumab-induced adverse events and immune-related adverse events (skin, gastrointestinal, hepatic, other) also occurred at similar frequencies among patients in the phase II and III trials, regardless of HLA-A*0201 status. These findings support the hypothesis that ipilimumab-treated patients with advanced melanoma have similar outcomes regardless of their HLA-A*0201 status.

Abstract C230: MPC-6827 is safely combined with temozolomide for the treatment of patients with metastatic melanoma

Purpose: MPC-6827 (4-arylaminoquinazoline) is a microtubule destabilizing agent with in vitro cytotoxic and in vivo vascular disrupting characteristics. We determined the dose-limiting toxicity (DLT) and the most tolerable doses of MPC-6827 in combination with daily administration of temozolomide.

Experimental Design: Metastatic melanoma patients were treated weekly with a 2-hour intravenous infusion of MPC-6827 for 6 or 3 consecutive weeks during 8- or 4-week cycles, respectively. Temozolomide was administered orally either at 75 mg/m2 daily during the first 6 weeks of an 8-week cycle or at 85 mg/m2 daily during the first 3 weeks of a 4-week cycle. Therapy was repeated every 56 days in the 8-week cycle and every 28 days in the 4-week cycle. Three pre-selected doses of MPC-6827 were tested: 2.1, 2.7, and 3.3 mg/m2. Patients in the 2.1 mg/m2 dose level were treated at 8-week cycles. Due to the inconveniences of 8-week cycles, patients enrolled in the 2.7 and 3.3 mg/m2 dose levels were treated at 4-week cycles. Patients were observed for DLTs during the first cycle. Plasma samples were obtained at various timepoints after MPC-6827 infusion to evaluate concentrations of MPC-6827 and temozolomide. A conventional “3+3” design was used for dose escalation.

Results: Twenty-two patients (median age, 59 years; range, 35–81; median number of prior therapies,2; range 1–5) with stage IV melanoma (3 M1b, 19 M1c) were enrolled, two patients are still receiving therapy. Twenty patients (91 %) had an ECOG score 0–1 and ten (45%) patients had brain metastases. Eight patients (36%) received temozolomide/dacarbazine therapy previously. Four patients (18%) experienced a grade 3 or greater MPC-6827-related SAE, which include an increased Troponin I level (n=1), cerebral hemorrhage (n=2), and cerebral infarction associated with a brain metastasis (n=1). One of the cerebral hemorrhages was deemed a DLT. Median MPC-6827 half-life ranged from 2.9–4.0 hours. Cmax and AUC increased proportionally with dose. The highest dose tested was 3.3 mg/m2 once weekly with temozolomide 85 mg/m2 daily for 3 weeks of a 4-week cycle. Employing modified RECIST criteria, two patients achieved partial response (durations of 6 and 4 months). Another nine patients achieved stable disease (duration range: 1 – 6 months).

Conclusion: The combination of MPC-6827 and temozolomide is safe and well tolerated in patients with refractory metastatic melanoma, including brain metastases. Responses are durable. A dose reduction of MPC-6827 is not required when combined with temozolomide. Incidences of cerebral hemorrhage, deep venous thrombosis and/or pulmonary emboli were similar to those in previous reports.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C230.

Guidelines for the evaluation of immune therapy activity in solid tumors: immune-related response criteria

PURPOSE

Immunotherapeutic agents produce antitumor effects by inducing cancer-specific immune responses or by modifying native immune processes. Resulting clinical response patterns extend beyond those of cytotoxic agents and can manifest after an initial increase in tumor burden or the appearance of new lesions (progressive disease). Response Evaluation Criteria in Solid Tumors or WHO criteria, designed to detect early effects of cytotoxic agents, may not provide a complete assessment of immunotherapeutic agents. Novel criteria for the evaluation of antitumor responses with immunotherapeutic agents are required.

EXPERIMENTAL DESIGN

The phase II clinical trial program with ipilimumab, an antibody that blocks CTL antigen-4, represents the most comprehensive data set available to date for an immunotherapeutic agent. Novel immune therapy response criteria proposed, based on the shared experience from community workshops and several investigators, were evaluated using data from ipilimumab phase II clinical trials in patients with advanced melanoma.

RESULTS

Ipilimumab monotherapy resulted in four distinct response patterns: (a) shrinkage in baseline lesions, without new lesions; (b) durable stable disease (in some patients followed by a slow, steady decline in total tumor burden); (c) response after an increase in total tumor burden; and (d) response in the presence of new lesions. All patterns were associated with favorable survival.

CONCLUSION

Systematic criteria, designated immune-related response criteria, were defined in an attempt to capture additional response patterns observed with immune therapy in advanced melanoma beyond those described by Response Evaluation Criteria in Solid Tumors or WHO criteria. Further prospective evaluations of the immune-related response criteria, particularly their association with overall survival, are warranted.

Guidelines for the evaluation of immune therapy activity in solid tumors: immune-related response criteria

PURPOSE

Immunotherapeutic agents produce antitumor effects by inducing cancer-specific immune responses or by modifying native immune processes. Resulting clinical response patterns extend beyond those of cytotoxic agents and can manifest after an initial increase in tumor burden or the appearance of new lesions (progressive disease). Response Evaluation Criteria in Solid Tumors or WHO criteria, designed to detect early effects of cytotoxic agents, may not provide a complete assessment of immunotherapeutic agents. Novel criteria for the evaluation of antitumor responses with immunotherapeutic agents are required.

EXPERIMENTAL DESIGN

The phase II clinical trial program with ipilimumab, an antibody that blocks CTL antigen-4, represents the most comprehensive data set available to date for an immunotherapeutic agent. Novel immune therapy response criteria proposed, based on the shared experience from community workshops and several investigators, were evaluated using data from ipilimumab phase II clinical trials in patients with advanced melanoma.

RESULTS

Ipilimumab monotherapy resulted in four distinct response patterns: (a) shrinkage in baseline lesions, without new lesions; (b) durable stable disease (in some patients followed by a slow, steady decline in total tumor burden); (c) response after an increase in total tumor burden; and (d) response in the presence of new lesions. All patterns were associated with favorable survival.

CONCLUSION

Systematic criteria, designated immune-related response criteria, were defined in an attempt to capture additional response patterns observed with immune therapy in advanced melanoma beyond those described by Response Evaluation Criteria in Solid Tumors or WHO criteria. Further prospective evaluations of the immune-related response criteria, particularly their association with overall survival, are warranted.

A randomized, double-blind, placebo-controlled, phase II study comparing the tolerability and efficacy of ipilimumab administered with or without prophylactic budesonide in patients with unresectable stage III or IV melanoma

PURPOSE

Diarrhea (with or without colitis) is an immune-related adverse event (irAE) associated with ipilimumab. A randomized, double-blind, placebo-controlled, multicenter, multinational phase II trial was conducted to determine whether prophylactic budesonide (Entocort EC), a nonabsorbed oral steroid, reduced the rate of grade >or=2 diarrhea in ipilimumab-treated patients with advanced melanoma.

EXPERIMENTAL DESIGN

Previously treated and treatment-naïve patients (N = 115) with unresectable stage III or IV melanoma received open-label ipilimumab (10 mg/kg every 3 weeks for four doses) with daily blinded budesonide (group A) or placebo (group B) through week 16. The first scheduled tumor evaluation was at week 12; eligible patients received maintenance treatment starting at week 24. Diarrhea was assessed using Common Terminology Criteria for Adverse Events (CTCAE) 3.0. Patients kept a diary describing their bowel habits.

RESULTS

Budesonide did not affect the rate of grade >or=2 diarrhea, which occurred in 32.7% and 35.0% of patients in groups A and B, respectively. There were no bowel perforations or treatment-related deaths. Best overall response rates were 12.1% in group A and 15.8% in group B, with a median overall survival of 17.7 and 19.3 months, respectively. Within each group, the disease control rate was higher in patients with grade 3 to 4 irAEs than in patients with grade 0 to 2 irAEs, although many patients with grade 1 to 2 irAEs experienced clinical benefit. Novel patterns of response to ipilimumab were observed.

CONCLUSIONS

Ipilimumab shows activity in advanced melanoma, with encouraging survival and manageable adverse events. Budesonide should not be used prophylactically for grade >or=2 diarrhea associated with ipilimumab therapy.

Pharmacokinetics (PK) of CR011-vcMMAE, an antibody-drug conjugate (ADC), in a phase (Ph) I study of patients (pts) with advanced melanoma

9063

Background: CR011-vcMMAE, an ADC of fully-human monoclonal anti-GPNMB antibody (Ab) with monomethylauristatin E (MMAE), is in Ph I/II trials in pts with melanoma and breast cancer. We report PK and toxicity data from a Ph I study in melanoma pts treated every (q) 3 weeks (w), qw, or 2 of 3w. Methods: Enzyme-linked immunosorbent assays were used to measure ADC, total Ab (TA), soluble GPNMB (sGPNMB), and anti-ADC Ab in pt samples. Free MMAE was measured by liquid chromatography/mass spectrometry. Results: Initially, 32 pts were treated in 9 cohorts of 0.03 to 2.63 mg/kg iv q3w using standard 3+3 dose escalation. Noncompartmental PK analysis showed dose-proportional TA, ADC and free MMAE levels. As previously reported, maximum tolerated dose (MTD) was 1.88 mg/kg iv q3w; dose limiting toxicity (DLT) was rash. At MTD (n=15), terminal phase half life (T½) of TA was 41 ± 25h and T½ of ADC was 29 ± 13h. Mean maximum plasma concentrations of free MMAE was 1.3–2.9% of TA concentration across all doses. Mean sGPNMB at baseline was 12 ng/ml (range 1.3–32 ng/ml), corresponding to 0.024 % of TA concentration at MTD. Anti-ADC Ab were detectible in 8/240 (3.3%) samples (n=54). Based on the T½, two additional dose schedules (qw and 2 out of 3w) were initiated (n=14). Pts received 0.75 mg/kg (n=3) and 1.0 mg/kg (n=5) in the qw schedule and 1.25 mg/kg (n=3) and 1.5 mg/kg (n=3) in 2 of 3w. The most common adverse events (AEs) were rash (n=6), pruritus (n=5) and fatigue (n=4). 1 DLT (Gr 3 rash) was observed at 1.0 mg/kg qw. Enrollment is ongoing in both schedules. Conclusions: The relatively short T½ of CR011-vcMMAE (∼40h) does not appear to be due to immunogenicity or sGPNMB-mediated clearance. Preliminary data suggest that weekly dosing is tolerated at higher per-cycle cumulative doses than the q3w schedule.

[Table: see text]

Nab-paclitaxel and bevacizumab as first-line therapy in patients with unresectable stage III and IV melanoma

9061^

Background: Nab-paclitaxel (Abraxane) increases intra-tumoral concentrations of paclitaxel and has efficacy superior to that of paclitaxel for the treatment of metastatic breast cancer (J Clin Oncol 2005:23:7794–7803). Nab-paclitaxel demonstrated single agent activity in metastatic melanoma. (ASCO 2005:7558) Bevacizumab is a monoclonal antibody that targets VEGF resulting in inhibition of tumor angiogenesis and enhances tumor response to paclitaxel. (NEJM 2007:357:2666–2676) Methods: Eligible were chemotherapy-naïve patients with unresectable stage III or IV melanoma, ECOG performance status of 0–1, and adequate organ function. The treatment regimen was given in a 28-day cycle in which nab-paclitaxel 150 mg/m2 was administered on days 1, 8, and 15 and bevacizumab 10mg/kg on days 1 and 15 until disease progression or dose limiting toxicity. Response assessments were made by RECIST criteria every 2 cycles. Results: Forty-one patients have been treated since 08/15/07. Over 50% of the patients had stage IV, MIc disease. The median duration of follow-up for progression-free survival from start of protocol treatment is 5.3 months. Progression-free survival at 4 months is 83%,(95%CI:69%-97%). Median progression free survival is 6.25 months (95%CI: 5.63–9.41). The median duration of follow-up for survival is 4.7 months. Three patients have died and 38 patients remain alive. The 6 month survival rate is 91% (95%CI:79%-100%).The 12 month survival rate is 83% (95% CI:65%-100%). The median duration of overall survival has not been reached yet. Dose modifying toxicities consisted primarily of neutropenia, neuropathy, and hypertension. Conclusions: Early experience suggests that nab-paclitaxel and bevacizumab is an effective and well-tolerated regimen as first-line therapy in patients with metastatic melanoma. The study is ongoing with an accrual target of 50 patients.

[Table: see text]

ASCO Conflict of Interest Policy and Exceptions

In compliance with the guidelines established by the ASCO Conflict of Interest Policy (J Clin Oncol. 2006 Jan 20;24[3]:519–521) and the Accreditation Council for Continuing Medical Education (ACCME), ASCO strives to promote balance, independence, objectivity, and scientific rigor through disclosure of financial and other interests, and identification and management of potential conflicts. According to the ASCO Conflict of Interest Policy, the following financial and other relationships must be disclosed: employment or leadership position, consultant or advisory role, stock ownership, honoraria, research funding, expert testimony, and other remuneration (J Clin Oncol. 2006 Jan 20;24[3]:520). The ASCO Conflict of Interest Policy disclosure requirements apply to all authors who submit abstracts to the Annual Meeting.

For clinical trials that began accrual on or after April 29, 2004, ASCO's Policy places some restrictions on the financial relationships of principal investigators (J Clin Oncol. 2006 Jan 20;24[3]:521). If a principal investigator holds any restricted relationships, his or her abstract will be ineligible for placement in the 2009 Annual Meeting unless the ASCO Ethics Committee grants an exception. Among the circumstances that might justify an exception are that the principal investigator (1) is a widely acknowledged expert in a particular therapeutic area; (2) is the inventor of a unique technology or treatment being evaluated in the clinical trial; or (3) is involved in international clinical oncology research and has acted consistently with recognized international standards of ethics in the conduct of clinical research. NIH-sponsored trials are exempt from the Policy restrictions. Abstracts for which authors requested and have been granted an exception in accordance with ASCO's Policy are designated with a caret symbol (^) in the Annual Meeting Proceedings.

For more information about the ASCO Conflict of Interest Policy and the exceptions process, please visit www.asco.org/conflictofinterest .

Association of baseline and on-study tumor biopsy markers with clinical activity in patients (pts) with advanced melanoma treated with ipilimumab

9008

Background: Ipilimumab is a fully human monoclonal antibody to cytotoxic T-lymphocyte antigen-4. Identifying predictive markers may help select advanced melanoma pts most likely to benefit from ipilimumab therapy. Biomarkers in the tumor microenvironment are thought to be more relevant for predicting response than those in the peripheral blood. Methods: We examined tumor biopsy markers in a Phase II study CA184004 (ipilimumab 3 and 10 mg/kg). Ipilimumab was administered every 3 weeks (Q3W) x 4; eligible pts could receive ipilimumab Q12W starting Wk 24. Pre- and post-treatment (Wk 4) tumor biopsies were performed for hematoxylin and eosin analysis of tumor-infiltrating lymphocytes (TILs); immunohistochemistry of FOXP3 and indoleamine 2,3-dioxygenase (IDO); and mRNA expression profile analysis. Response was assessed with modified World Health Organization criteria. Associations between tumor biomarkers and clinical activity (complete response, partial response, or stable disease ≥ 24 wks) were assessed. Results: Ipilimumab 3 or 10 mg/kg was administered to 40 and 42 pts, respectively. In tumor biopsies, clinical activity was associated with high expression of FOXP3 (P = 0.014) and IDO (P = 0.012) at baseline and an increase from baseline in TILs (Wk 4) (P = 0.005) ( Table ). Tumor mRNA profiling identified genes with significant changes from baseline in expression, or with baseline expression levels that may be associated with clinical activity. These included various immune response genes and known melanoma antigens. Conclusions: Biomarkers in the tumor microenvironment have been demonstrated to be associated with clinical activity in pts treated with ipilimumab.

[Table: see text]

[Table: see text]

Efficacy of ipilimumab 10 mg/kg in advanced melanoma patients (pts) with good and poor prognostic factors

9036

Background: Ipilimumab is a fully human monoclonal antibody against cytotoxic T-lymphocyte antigen-4. In total, ∼50% of metastatic melanoma pts treated with 10 mg/kg ipilimumab are alive at 1 year (Wolchok et al. CRI-CVC annual meeting 2008. Oral presentation), and identifying prognostic factors may help select pts most likely to benefit from treatment. Factors predictive of poorer prognosis in melanoma include advanced stage of disease (ie, M1c), age 60+, gender (male), elevated baseline lactate dehydrogenase (LDH) levels, and lack of a prior response to therapy. In this pooled analysis, potential prognostic factors in pts with advanced melanoma treated with ipilimumab 10 mg/kg in 2 phase II studies (CA184–008, N=155 and -022, N=72) were explored. Methods: Ipilimumab 10 mg/kg was given every 3 weeks (Q3W) × 4 (induction); eligible pts could continue to receive ipilimumab Q12W starting at week (Wk) 24 (maintenance). Response was based on modified World Health Organization criteria. Each variable was analyzed separately. Results: Disease control rate (complete/partial response [CR/PR] and stable disease) seems not to be associated with age (<65 yrs: 25.2%; ≥65 yrs: 32.9%), gender (male: 22.6%; female: 34.0%), M stage (M0: 33.3%; M1a: 41.0%; M1b: 26.4%; M1c: 23.6%), response to prior systemic therapy (yes: 32.5%; no: 26.7%), prior immunotherapy (yes: 21.6%; no: 35.3%), LDH >upper normal limit (UNL) (yes: 25.9%; no: 29.7%), or LDH >2×UNL (yes: 15.9%; no: 30.6%). Best overall response rate (CR or PR) was not associated with age (<65 yrs: 7.3%; ≥65 yrs: 7.9%), gender (male: 4.0%; female: 11.7%), M stage (M0: 8.3%; M1a: 15.4%; M1b: 5.7%; M1c: 5.7%), response to prior systemic therapy (yes: 12.5%; no: 6.4%), prior immunotherapy (yes: 3.2%; no: 12.7%), LDH >UNL (yes: 8.6%; no: 6.3%), or LDH >2×UNL (yes: 4.5%; no: 8.2%). Overall survival was not associated with age (median OS: <65 yrs: 11.6 mo; ≥65 yrs: 7.59 mo), M stage (median OS: M0: 21.9 mo; M1a: 15.7 mo; M1b: 15.4 mo; M1c: 6.6 mo), or response to prior systemic therapy (median OS: yes: 11.6 mo; no: 10.7 mo). Conclusions: Ipilimumab demonstrates clinical activity independent of negative prognostic factors, and may even benefit those pts with the worst prognosis.

[Table: see text]

Association between immune-related adverse events (irAEs) and disease control or overall survival in patients (pts) with advanced melanoma treated with 10 mg/kg ipilimumab in three phase II clinical trials

9034

Background: The monoclonal antibody ipilimumab targets cytotoxic T-lymphocyte antigen-4. The most common AEs associated with ipilimumab are irAEs, and both antitumor and irAE responses likely reflect its immune-mediated mechanism of action. In this report, a potential association between disease control (DC) or overall survival (OS) and irAEs in patients (pts) with advanced melanoma treated with 10 mg/kg ipilimumab in 3 Phase II clinical trials was explored. Methods: Across 3 Phase II studies (CA184008, 022, and 007), ipilimumab (10 mg/kg) was given every 3 weeks (Q3W) x 4 (induction); eligible pts could continue to receive ipilimumab Q12W starting at week (wk) 24 (maintenance). In study 022, pts were randomized to 0.3, 3, and 10 mg/kg groups, whereas study 008 was a single-arm trial of ipilimumab 10 mg/kg. In study 007, ipilimumab 10 mg/kg was administered either with placebo or daily prophylactic budesonide. Disease control (CR/PR/SD) was evaluated using modified World Health Organization (mWHO) and immune- related response criteria (Hodi FS, et al. J Clin Oncol 26: 2008 (May 20 suppl; abstr 3008). Association between DC and grade 0/1 vs. grade ≥2 irAEs was examined (studies 007, 008, and 022). Association between OS and irAEs which developed within 12 wks of ipilimumab treatment was also explored using landmark analyses from Day 81 (studies 008 and 022). Results: Across the 3 phase II studies, the rate of DC by mWHO in pts with grade 0/1 irAEs was 20–24% and in pts with grade ≥2 irAEs was 34–43%. The number of pts with DC was higher among those who experienced an irAE compared with those who did not, but DC was not statistically significantly associated with grade 0/1 vs grade ≥2 irAEs. For pts who lived up to Day 81 in studies 008 and 022, median OS (95% CI) from Day 81 was 14.8 mo (10.0–21.7) for any irAE and 8.21 mo (5.29–13.7) for no irAE within 12 weeks; median OS was 13.6 mo (5.78-NR) for any grade ≥2 irAE and 11.3 mo (7.95–15.8) for no grade ≥2 irAE within 12 weeks. Conclusions: DC and survival benefits with ipilimumab are observed among pts that develop an irAE and among pts that do not develop an irAE. Thus, pts who do not experience an irAE may still demonstrate clinical benefit with ipilimumab.

[Table: see text]

Evaluation of the effect of systemic corticosteroids for the treatment of immune-related adverse events (irAEs) on the development or maintenance of ipilimumab clinical activity

9037

Background: Ipilimumab, a fully human monoclonal antibody that inhibits cytotoxic T-lymphocyte antigen-4, has clinical activity at 10 mg/kg in patients (pts) with advanced melanoma. Most grade 3/4 immune-related adverse events (irAEs) associated with ipilimumab can be managed with systemic corticosteroids following established treatment guidelines. However, little has been reported about the effects of corticosteroids used to treat irAEs on ipilimumab antitumor responses. Methods: Across 3 phase II studies with 10 mg/kg ipilimumab monotherapy in advanced melanoma (CA184008, 022, and 007; N=283), 83 pts (29.3%) achieved disease control [complete/partial responses (CR/PR), or stable disease (SD) ≥12 weeks] and 43/83 (52%) received steroids for treatment of irAEs. The pts' ability to develop and maintain disease control in the presence and absence of steroids was analyzed. Disease control was assessed by modified World Health Organization (mWHO) criteria and novel immune-related response criteria (irRC) (Hodi FS, et al. J Clin Oncol 26: 2008 [May 20 suppl; abstr 3008]). The range of follow-up was 5.7–6.3 months. Results: Of 117 pts who received steroids prior to response assessment, 26 pts achieved CR or PR, or maintained SD without disease progression by mWHO, and the remaining 91 pts had PD. Of 166 pts who either never received steroids or received them after response assessment, 31 achieved a CR, PR, or SD (by mWHO). Further, of 26 pts with CR/PR by mWHO, 14 received subsequent steroids and 11 maintained a response, while of 12 pts who received no subsequent steroids, 9 maintained a response. Similar results were obtained if irRC were used (see table ). Conclusions: Systemic corticosteroids for treatment of irAEs do not appear to impact the development or maintenance of ipilimumab clinical activity in advanced melanoma.

[Table: see text]

[Table: see text]