AAV9-Stathmin1 gene delivery improves disease phenotype in an intermediate mouse model of spinal muscular atrophy

Spinal muscular atrophy (SMA) is a devastating infantile genetic disorder caused by the loss of survival motor neuron (SMN) protein that leads to premature death due to loss of motor neurons and muscle atrophy. The approval of an antisense oligonucleotide therapy for SMA was an important milestone in SMA research; however, effective next-generation therapeutics will likely require combinatorial SMN-dependent therapeutics and SMN-independent disease modifiers. A recent cross-disease transcriptomic analysis identified Stathmin-1 (STMN1), a tubulin-depolymerizing protein, as a potential disease modifier across different motor neuron diseases, including SMA. Here, we investigated whether viral-based delivery of STMN1 decreased disease severity in a well-characterized SMA mouse model. Intracerebroventricular delivery of scAAV9-STMN1 in SMA mice at P2 significantly increased survival and weight gain compared to untreated SMA mice without elevating Smn levels. scAAV9-STMN1 improved important hallmarks of disease, including motor function, NMJ pathology and motor neuron cell preservation. Furthermore, scAAV9-STMN1 treatment restored microtubule networks and tubulin expression without affecting tubulin stability. Our results show that scAAV9-STMN1 treatment improves SMA pathology possibly by increasing microtubule turnover leading to restored levels of stable microtubules. Overall, these data demonstrate that STMN1 can significantly reduce the SMA phenotype independent of restoring SMN protein and highlight the importance of developing SMN-independent therapeutics for the treatment of SMA.

Abstract P2-09-08: Imprime PGG, a novel innate immune modulator, combined with pembrolizumab in a phase 2 multicenter, open label study in chemotherapy-resistant metastatic triple negative breast cancer (TNBC)

Background: CPI monotherapy provides substantial clinical benefit to patients (pts) in multiple cancers, yet response rates are limited (˜15-30%) and fails to benefit the majority. In these pts there is limited or no ongoing T cell-based immune response. Imprime PGG (Imprime), a novel beta glucan derived from Saccharomyces, may expand the clinical benefit of CPI therapy by stimulating an anti-cancer immune response. Acting as a pathogen-associated molecularpattern (PAMP), Imprime enlists innate immune functions including cytotoxic effector mechanisms, reversal of immunosuppression and cross-talk with the adaptive immune system.Imprime-mediated innate immune activation requires formation of an immune complex with naturally-occurring anti-beta glucan antibodies (ABA); sufficient ABA levels is required for complex formation. Imprime is now being studied in combination with pembrolizumab (KEYTRUDA®,Pembro), a humanized mAb against PD-1 which has been previously studied in TNBC pts.

Methods: In this study of patients who previously failed chemotherapy for metastatic TNBC, Imprime is being used in combination with Pembro in a Simon 2 stage design. Asample size of 12 evaluable pts in Stage 1 was planned.Evaluable pts received at least one dose of study treatment (tx), had measurable disease at baseline per RECIST v1.1, had at least one post-baseline scan or discontinued tx as a result of progressive disease, death, or a tx-related adverse event before the first post-baseline scan.Pts received Imprime (4 mg/kg IV days 1, 8, 15 of each 3-week cycle) + Pembro 200 mg on D1 of each cycle. Criteria to advance to Stage 2 were ≤4 grade 3/4 AEs during the first tx cycle (other than infusion reactions) and ≥1 objective response. Study primary endpoints are ORR and safety; secondary endpoints are TTR, CRR, DoR, PFS, and OS. Exploratory endpoints include ORR and PFS per irRECIST. Biopsies and blood samples are being collected to assess tx impact on immune activating events at the tumor site and in the periphery.

Results: A review of efficacy and safety data was conducted at the end of Stage 1. Thirteen pts (12 evaluable) were enrolled into Stage 1. Safety review noted 2 grade 3 adverse events that met protocol definition of Stage 1 events (1 pt: cellulitis and 1 pt: pleural infusion; both unrelated to treatment). Two events lead to 2 pts discontinuing treatment (infusion reaction and pancreatitis) and only 1 autoimmune event was observed (pancreatitis). Observed efficacy responses in the evaluable pts included 1 complete response (CR; ongoing) and 2 partial responses (PR; ongoing). Secondary efficacy endpoints have not been assessed. Early translational results support proposed MOA and analysis of Stage 1 translational data is ongoing.

Conclusion: The use of Imprime with Pembro was well tolerated and met both safety and efficacy requirements to move forward with Stage 2 of the study. No significant safety concerns were identified in Stage 1. Further investigation is thus warranted and enrollment into Stage 2 is ongoing. Updated data will be presented.

Citation Format: O'Day S, Borges V, Chmielowski B, Rao R, Abu-Khalaf M, Stopeck A, Lowe J, Mattson P, Breuer K, Gargano M, Bose N, Uhlik M, Graff J, Chisamore M, Cox J, Osterwalder B. Imprime PGG, a novel innate immune modulator, combined with pembrolizumab in a phase 2 multicenter, open label study in chemotherapy-resistant metastatic triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-09-08.

Efficacy and safety of ipilimumab in metastatic melanoma patients surviving more than 2 years following treatment in a phase III trial (MDX010-20)

BACKGROUND

In a phase III trial (ClinicalTrials.gov registration ID: NCT00094653), ipilimumab significantly improved survival versus a vaccine control in pretreated patients with metastatic melanoma. Here, we characterize outcomes of those patients who survived ≥ 2 years.

METHODS

Patients were randomized (3 : 1 : 1) to receive ipilimumab 3 mg/kg + gp100 vaccine, ipilimumab 3 mg/kg + placebo, or gp100 vaccine alone. Baseline demographic data, duration of survival, responses, and safety among patients with ≥ 2 years' survival were analyzed.

RESULTS

Among 676 randomized patients, 474 and 259 patients had at least 2 or 3 years of potential follow-up, respectively, and were eligible for analysis. Among these, 94 (20%) and 42 (16%) survived ≥ 2 and ≥ 3 years, respectively. Survival rates at 2 and 3 years were 25% (24 of 95) and 25% (13 of 53) with ipilimumab alone and 19% (54 of 284) and 15% (24 of 156) with ipilimumab plus gp100. Safety among patients with ≥ 2 years' survival was comparable with the overall study population, with the onset of new ipilimumab-related toxic effect (all grades) reported in 6 of 78 (8%) patients.

CONCLUSIONS

Ipilimumab results in survival of ≥ 2 years in one-fifth of pretreated patients with 2 years potential follow-up in a phase III trial. New onset, low-grade events starting after administration of the last dose were infrequent.

TRIAL REGISTRATION ID

NCT00094653.

Phase III randomized study of ipilimumab (IPI) plus dacarbazine (DTIC) versus DTIC alone as first-line treatment in patients with unresectable stage III or IV melanoma

LBA5

Background: IPI monotherapy (3mg/kg) improved overall survival (OS) in a phase III study of previously treated, unresectable or metastatic melanoma. Current study in 1st line metastatic melanoma evaluates combination of DTIC (a global standard of care) plus IPI. Methods: In this double-blind phase 3 study, patients (pts) with metastatic melanoma, ECOG PS 0/1, and no prior therapy for advanced disease, were randomized 1:1 to IPI (10 mg/kg) + DTIC (850 mg/m2) or placebo + DTIC (850 mg/m2) at Wks 1, 4, 7, 10 followed by DTIC q3 wks through Wk 22 (induction). Eligible pts received IPI or placebo q12 wks as maintenance. Primary endpoint was OS; 2-sided log-rank test was performed, stratified by baseline M stage and ECOG PS. Results: Of 502 pts, 56% had M1c disease, 40% elevated LDH, and 26% adjuvant therapy. 37% in IPI + DTIC and 65% in DTIC alone arms received 4 induction doses. A significant improvement in OS (HR=0.72; P=0.0009) and higher estimated 1, 2 and 3 yr survival rates were seen with IPI + DTIC (Table). 56% in IPI +DTIC (n=247) and 27% in DTIC alone (n=251) arms had grade 3/4 adverse events (AEs, regardless of attribution), including: elevated ALT (22% vs 1%); diarrhea (4% vs 0%); rash (1% vs 0%). No intestinal perforations or hypophysitis were noted. There were no drug-related deaths in IPI + DTIC and one in DTIC alone arm [gastrointestinal (GI) hemorrhage]. Conclusions: IPI (10mg/kg) + DTIC significantly improved OS in 1st line metastatic melanoma vs DTIC alone; durable survival and objective responses were noted in some pts after follow-up for up to 4yrs. Type of AEs was consistent with prior IPI studies; however, frequencies of some AEs differed with a higher transaminitis and lower diarrhea/colitis/ GI perforation rates than expected. No drug-related deaths were noted in IPI arm. OS benefit of IPI is confirmed in treatment-naive metastatic melanoma.

[Table: see text]

Phase III randomized, open-label, multicenter trial (BRIM3) comparing BRAF inhibitor vemurafenib with dacarbazine (DTIC) in patients with V600EBRAF-mutated melanoma

LBA4

Background: About 50% of melanomas have an activating V600EBRAF mutation which led to the hypothesis that inhibition of the mutated BRAF kinase may be of clinical benefit. Phase I and II trials with vemurafenib (previously PLX4032/RO5185426), an orally available inhibitor of oncogenic BRAF kinase, showed response rates (RR; CR+PR) >50% in V600EBRAF- mutated melanoma patients (pts). We conducted a phase III trial to determine if vemurafenib improved overall survival (OS) and progression-free survival (PFS) in melanoma pts with V600EBRAF mutation. Methods: Pts with previously untreated, unresectable stage IIIC or stage IV melanoma that tested positive for V600EBRAF mutation by the cobas 4800 BRAF V600 Mutation Test were randomized (1:1) to vemurafenib (960 mg po bid) or DTIC (1,000 mg/m2, IV, q3w). Randomization was stratified by PS, stage, LDH, and geographic region. Pts were assessed for tumor responses after weeks 6, 12, and then q9 weeks. Co-primary endpoints were OS and PFS on the intent-to-treat population; secondary endpoints included RR, response duration, and safety. Final analysis was planned at 196 deaths. Results: 675 pts were enrolled at 103 centers worldwide between Jan and Dec 2010. Treatment cohorts were well-balanced. At the pre-planned interim analysis (50% of deaths needed for final analysis), the hazard ratios for OS and PFS were 0.37 (95% CI 0.26 to 0.55; p<0.0001) and 0.26 (95% CI 0.20 to 0.33; p<0.0001), respectively, both in favor of vemurafenib. The confirmed RR was 48.4% and 5.5% to vemurafenib and DTIC, respectively, among the 65% of pts evaluable for RR to date. Benefit in OS, PFS, and RR was seen in all subgroups examined. Due to these data, the DTIC cohort has been allowed to cross over to vemurafenib. At the time of data analysis, 66% of vemurafenib pts and 25% DTIC pts were still on treatment. The most common toxicities of vemurafenib were: diarrhea, rash, alopecia, photosensitivity, fatigue, arthralgia, and keratoacanthoma/skin squamous cell carcinoma. Conclusions: Vemurafenib is associated with significantly improved OS and PFS compared to DTIC in pts with previously untreated, V600EBRAF-mutated metastatic melanoma.

A phase III, randomized, double-blind, multicenter study comparing monotherapy with ipilimumab or gp100 peptide vaccine and the combination in patients with previously treated, unresectable stage III or IV melanoma

4

Background: Ipilimumab, a fully human monoclonal antibody against cytotoxic T-lymphocyte antigen-4, demonstrated activity in advanced melanoma. Gp100 vaccine showed immunological and clinical responses, and enhanced clinical activity when combined with other immunotherapy. This phase III study compared efficacy and safety of ipilimumab or gp100 monotherapy and combination.

Methods: Eligible patients (HLA-A*0201+ previously treated adults with unresectable stage III/IV melanoma) were randomized 1:3:1 to ipilimumab (3 mg/kg q3w x 4 doses) + placebo (n=137), ipilimumab + gp100 (peptides 209-217[210M] and 280-288 [288V]; 1mg q3w x 4 doses; n=403), or gp100 + placebo (n=136). There was no maintenance phase. Primary endpoint was comparison of overall survival (OS) between patients who received combination versus gp100 alone; secondary endpoints were all other OS comparisons, best overall response rate (BORR), disease control rate (DCR) to W24, progression-free survival (PFS), and safety.

Results: The study demonstrated statistically significant results for all efficacy endpoints (below). Ipilimumab alone or combined with gp100 resulted in a significant improvement in OS with risk reduction of 32-34% compared to gp100. Significant differences in DCR, BORR, and PFS were observed. Adverse events with ipilimumab were consistent with prior studies: generally mild, immune-related, and medically manageable.

Conclusions: Ipilimumab is the first agent to improve median and long-term OS in a phase III study of previously treated patients with advanced melanoma. Addition of gp100 vaccine to ipilimumab did not improve outcome.

[Table: see text]

[Table: see text]

Long-term survival of patients (pts) with advanced melanoma treated with ipilimumab with or without dacarbazine

9038

Background: Ipilimumab is a fully human monoclonal antibody targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4). Here, we report updated survival of pts with advanced melanoma treated with ipilimumab in 2 completed studies. Methods: Seventy-two chemotherapy-naïve pts were randomized to receive 3 mg/kg ipilimumab every 4 weeks (Q4W) × 4 alone or with ≤6 × 5-day courses of DTIC 250 mg/m2/day (ipilimumab, n = 37; ipilimumab + DTIC, n = 35) in the multicenter, open- label Phase II study MDX010–08 (Sep 2002-Aug 2004)(Hersh E et al. J Clin Oncol 26: 2008 (May 20 suppl; abstr 9022)). In the phase I/II dose-ranging study MDX010–15, 23 pts were treated with 10 mg/kg ipilimumab every 3 weeks (Q3W) × 4 (induction) (Jun 2004- Jul 2006) (Urba W et al. J Clin Oncol 26: 2008 (May 20 suppl; abstr 3018)). No maintenance ipilimumab was administered in either study. Long-term survival was determined under a follow-up protocol (MDX010–28) from May 2007-Jan 2008. Results: Long-term data are available for 62 pts for MDX010–08 and 22 pts for MDX010–15. For MDX010–08, the median follow-up was 4.3 years (range, 4.0–4.7 years); it was 2.2 years (range, 2.0–2.4 years) for MDX010–15. Survival rates are reported in the Table . Conclusions: Ipilimumab monotherapy, administered at 3 mg/kg and without maintenance dosing, resulted in survival rates better than those observed with historical controls (Korn EJ et al. J Clin Oncol 26:527–34; 2008). Adding DTIC to ipilimumab did not suppress the effect of ipilimumab (as might have been predicted), but enhanced it still further. Consistent with previously reported response data showing that 10 mg/kg is the recommended dose (study CA184022) (Hamid O et al. J Clin Oncol 26: 2008 (May 20 suppl; abstr 9025)), there was a trend toward better survival with the higher dose (eg, a 2-year survival rate of 36% vs. 22% for 10 mg/kg vs. 3 mg/kg).

[Table: see text]

[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 .

Effect of ipilimumab treatment on 18-month survival: Update of patients (pts) with advanced melanoma treated with 10 mg/kg ipilimumab in three phase II clinical trials

9033

Background: The monoclonal antibody ipilimumab targets cytotoxic T lymphocyte antigen-4. Updated survival data (≤32.5 months follow-up) from 3 Phase II trials of ipilimumab in pts with mostly pretreated advanced melanoma are reported. Methods: Study CA184008 was an open-label, single-arm study of ipilimumab 10 mg/kg. Study CA184022 was a randomized, dose-ranging study of ipilimumab 0.3, 3, or 10 mg/kg. Study CA184007 was a randomized, placebo-controlled study of the effect of budesonide on gastrointestinal immune-related adverse events in pts receiving ipilimumab 10 mg/kg. In all studies, ipilimumab was given every 3 weeks (Q3W) × 4 (induction); eligible pts could continue to receive maintenance ipilimumab Q12W from week 24. Pts continue to be followed-up to determine long-term survival. Results: With a median follow-up ranging from 10.1 to 16.3 months and reaching up to 32.5+ months, pts receiving 10 mg/kg ipilimumab showed durable survival; 12- and 18-month survival rates are presented [ Table ]. The tail of the Kaplan-Meier curve flattened at 18 months, indicating that a substantial proportion of patients continued to survive beyond the updated follow-up period in all three studies. Long-term survivors include pts with disease progression (PD) per modified World Health Organization (mWHO) criteria. Conclusions: Ipilimumab may result in a long-term survival benefit in pts with advanced melanoma, where 18-month survival rates across 3 Phase II studies range from 34.5% to 39.4% for previously treated pts. These results indicate that more than 1/3 of ipilimumab-treated pts with advanced melanoma experience a long-term survival benefit, including some pts characterized as PD by mWHO. The survival data continue to mature, and follow-up is ongoing.

[Table: see text]

[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]

Randomized phase II study of the safety and efficacy of a human anti-αv integrin monoclonal antibody (CNTO 95) alone and in combination with dacarbazine in patients with stage IV metastatic melanoma: 12-month results

9029

Objectives: Evaluate the safety and efficacy of CNTO 95, a human anti-αv integrin monoclonal antibody, when administered alone or in combination with dacarbazine (DTIC). Methods: Patients with Stage IV metastatic melanoma were randomized 1:1:1:1 to receive 5 or 10mg/kg CNTO 95 alone, or DTIC (1000mg/m2) + either 10mg/kg CNTO 95 or placebo administered intravenously once every 3 weeks for 8 cycles in the absence of disease progression or unacceptable toxicity. DTIC arms were blinded; single-agent arms were open-label. The primary endpoint was progression free survival (PFS); secondary endpoints included partial response (PR), complete response (CR), stable disease (SD) and overall survival (OS). Major safety endpoints included the incidence of adverse events (AEs) and serious AEs (SAEs). Results: Patients were randomized to receive 5mg/kg CNTO 95 (n=32), 10mg/kg CNTO 95 (n=33), CNTO 95+DTIC (n=32), or placebo+DTIC (n=32). Baseline demographics were similar across groups. The median PFS for CNTO 95+DTIC was 75 days, placebo+DTIC was 54 days and both CNTO 95 alone arms were 42 days. Six patients achieved PR (2–10mg/kg CNTO 95, 1-CNTO 95+DTIC, 3-placebo+DTIC); one patient achieved CR (CNTO 95+DTIC). A higher proportion (43.3%) of patients achieved SD ≥ 12 wks in the CNTO 95+DTIC group compared with the other 3 groups (<20.0%). The median survival was 11.0 months for the patients in the CNTO 95+DTIC arm, 9.8 months and 14.9 months for the 5mg/kg and 10mg/kg arms, and 8.0 months for those in the DTIC control arm. The most common AEs were headache, nausea, fatigue, pyrexia, vomiting and transient uveitic reactions. Three patients (1–5mg/kg, 2-CNTO 95+DTIC) discontinued treatment due to AEs. A higher proportion of patients experienced SAEs in the placebo+DTIC group (29.0%) than in the 5mg/kg (12.9%), 10mg/kg (16.2%) or CNTO 95+DTIC (18.8%) groups. Conclusions: CNTO 95 alone or combined with DTIC was generally well tolerated. In patients with Stage IV metastatic melanoma, a trend toward improvement in PFS, OS and disease control was demonstrated with CNTO 95+DTIC.

Centocor, Centocor Research and Development, Inc.

Centocor Research and Development, Inc.

Johnson & Johnson

Centocor Research and Development, Inc.

No significant financial relationships to disclose.

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]

Prognostic factors in metastatic melanoma patients treated with biochemotherapy and maintenance immunotherapy

9051

Background: Patients with stage IV metastatic melanoma are usually felt to be incurable with a median survival of 6.4 months and a 5-year survival of only 2%. Biochemotherapy has shown promise with long-term survival in selected patients. We felt the study of prognostic factors would determine which patients might benefit the most from this intensive therapy. Methods: 135 consecutive patients with stage IV melanoma treated with decrescendo biochemotherapy followed by maintenance immunotherapy at one melanoma treatment center were studied to determine the most important prognostic factors; these factors were then validated by analysis of 133 patients treated in a multi-center trial at other institutions. Patients were treated using the inpatient regimen of O'Day (JCO23:710s,2005 abstract). Results: Median overall survival (OS) was 16.6 months with 1-year survival of 70% and 5-year survival of 28%. Median progression-free survival (PFS) was 7.6 months with 15% progression-free at 5 years. PFS curves showed no relapses after 30 months, so remissions were durable. For OS performance status 0, normal LDH, stage M1a, and non-visceral sites of metastases were favorable prognostic factors. For PFS performance status 0, normal LDH, female sex, age <50 and stage M1a were favorable prognostic factors Multivariate analysis demonstrated two important prognostic factors for survival: normal serum LDH and the presence of either skin or nodes as one of the sites of metastatic disease. The group with normal LDH and skin or node metastases had a relatively good prognosis with median survival of 44 months and a 5-year survival of 38%. Conversely patients with elevated LDH without any skin or nodal metastases had a poor prognosis, with no long-term survivors. Conclusions: Metastatic melanoma patients treated with biochemotherapy and maintenance immunotherapy that have either a normal LDH or skin or nodes as one of their metastatic sites may have durable remissions of their disease, and this therapy should be studied further in these groups.

[Table: see text]

Association of peripheral blood absolute lymphocyte count (ALC) and clinical activity in patients (pts) with advanced melanoma treated with ipilimumab

3020

Background: Ipilimumab, an anti-CTLA-4 monoclonal antibody, induces durable survival benefits in advanced melanoma pts. Peripheral ALC from routine safety labs were collected from 533 pts with unresectable stage III/IV malignant melanoma treated with ipilimumab 0.3, 3, or 10 mg/kg (recommended dose) in 4 Phase II studies. Methods: Ipilimumab was given every 3 weeks (Q3W) x 4; eligible pts could then continue to receive ipilimumab Q12W starting at Week 24. ALC was analyzed first in studies CA184007, 008, and 022 combined (ipilimumab 0.3, 3, or 10 mg/kg), and then prospectively analyzed for confirmation in study CA184004 (ipilimumab 3 or 10 mg/kg). Using the modified World Health Organization criteria, Response-evaluable pts (n = 444) were classified by clinical activity (complete or partial response, or stable disease ≥ 24 wks) or without clinical activity. Results: Across studies 007, 008, and 022, pts with clinical activity had a greater mean rate of ALC change (slope) than did pts without clinical activity (P = 0.0013); no pt with a negative ALC slope over the induction period had clinical activity (P = 0.0013) (Table). These associations were confirmed in 004; pts with benefit had a greater mean slope (P = 0.00042), and only 1 pt with a (slightly) negative ALC slope had clinical activity (Table). Over all pts (n = 533), the rate of ALC change was significantly associated with dose (007, 008, 022: P < 0.0001; 004: P = 0.0015). Conclusions: A higher rate of ALC change was associated with clinical activity in a pooled analysis of studies 007, 008, and 022 (n = 379). This was confirmed in study 004 (n = 65). A negative ALC slope was associated with a lack of clinical activity. In both analyses, the rate of change in ALC was dose-dependent, favoring 10 mg/kg.

[Table: see text]

[Table: see text]

Subgroup analysis of efficacy and safety analysis of a randomized, double-blinded controlled phase II study of STA-4783 in combination with paclitaxel in patients with metastatic melanoma

8528

Background: STA-4783 (S), an inducer of heat shock protein 70 (hsp70) is a bis-thiobenzoylhydrazide compound. S leads to up-regulation of hsp70 in tumor cell lines. Xenograft models of solid tumors showed synergistic anti-tumor activity in combination with paclitaxel (P). The combination P + S, in phase I and II studies, showed dose-related hsp70 induction (evidence of biological activity) and tolerability. Methods: Eligibility was based on a diagnosis of metastatic cutaneous melanoma, ECOG <=2, and prior treatment with 1 or no chemotherapy regimens. A total of 81 patients (pts) were randomized 2:1 (P 80 mg/m2 + S 213 mg/m2:P 80 mg/m2) 3 weeks out of 4 at 21 US clinical sites. The primary endpoint was progression free survival (PFS); secondary endpoints were response rate (RR), and adverse events (AEs). Results: Based on intent-to-treat analysis, the median PFS was 3.68 months (m) for P + S vs. 1.84 m in the P only arm (p=.035). RR was 15.1% in the P + S arm and 3.6% in the P arm. Subgroup analysis showed chemo- naive pts (n=23) with P + S showed a median PFS of 8.28 m vs. 2.40 in the P arm (n=9). For pts with 1 prior chemotherapy, (n=29), PFS on P + S was 3.12 m vs. 1.77 m on P (n=19). Of 19 pts who crossed over at progression, data are available for 14. PFS ranged from 0.72 to 5.5 m. Three of the 14 evaluable pts treated with P alone had rapid progression (0.95, 1.6, and 1.7 m) then significant inversion of the time to progression with the addition of S to P (2.3, 5.5, and 4.2 m) suggesting study drug effect. Scans were done at identical intervals (8 weeks). The proportion of pts with AEs of grade 3 or higher was 54% (n=52) in the P + S group and 57% in the P group (n=28); pts on P received a median of 2 cycles, while pts in the P + S group received a median of 4. Adverse events leading to discontinuation were low in both groups: 10% for the P + S, and 14% for P. Conclusions: The addition of S to P showed an increase in PFS vs. P alone particularly in chemo-naïve pts. A few pts failing single agent P appeared to benefit from P + S. Despite the additional treatment duration in the P + S group the drugs were well- tolerated, and showed mainly P related adverse events. A phase III study is planned to confirm a role for P + S in metastatic melanoma.

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Kinetics of response to ipilimumab (MDX-010) in patients with stage III/IV melanoma

8525

Background: Ipilimumab, a fully human monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4 (CTLA-4), enhances immune responses to tumor-associated antigens resulting in durable objective responses (OR). This abstract describes the kinetics of response after ipilimumab treatment. Methods: 5 studies (2 complete; 3 ongoing) in 269 treated patients with stage III/IV melanoma were reviewed and analyzed to determine the kinetics and duration of response after ipilimumab. Patients received ipilimumab alone or with dacarbazine, IL-2 or gp100 peptide vaccine. Ipilimumab doses ranged from 0.3–10mg/kg/dose (single or multiple). Complete and partial response (CR, PR), stable and progressive disease (SD, PD) were evaluated. Results: 41 patients (15%) had a confirmed OR at analysis. CR and PR was of late onset in some patients and occurred from ∼10–106 and ∼5–62 weeks (w) post-treatment initiation, respectively. In 28 patients onset of CR or PR occurred after >∼12w of treatment. PD preceded OR (without additional therapy) in 4 patients. In 2 patients, PD measured at ∼6w post-treatment initiation was followed by a PR at ∼12w. In 1 patient the PR changed to a CR at ∼24w and lasted for ∼188w+; the other patient maintained a PR for ∼17w. In the other 2 patients, PD at ∼12w was followed by SD at ∼17–20w and a PR after ∼30 and 62w; PRs in both patients lasted for ∼17 and 40w+, respectively. Duration of OR ranged from ∼6–187w+; ORs are ongoing in 25 patients. Late onset occurred irrespective of dose, regimen and therapeutic partner. Conclusions: Preliminary results suggest that ORs with ipilimumab may be later in onset and more durable than with traditional chemotherapy and may occur after progression. This late onset of effect likely reflects the immune-related mechanism of action of ipilimumab, and suggests that continued treatment/observation may be beneficial despite initial PD or SD. Acknowledgement: Dr. S. Rosenberg

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Interleukin-2 binds to ganglioside GD(1b)

We have developed a solid matrix immunoassay to determine the binding of interleukin-2 (IL-2) to specific gangliosides. The assay establishes that recombinant human IL-2 binds to ganglioside GD(1b) but not to any other gangliosides (GM(1), GM(2), GM(3), GD(1a), GD(2), GD(3), and GT(1b)). The binding varies with the ratio of GD1b and IL-2. This assay enables distinguishing the nature of the sugar moiety of the ganglioside recognized by IL-2 and establishes the dosimetry of the ganglioside-IL-2 interaction. Since rIL-2 is administered systematically into stage IV melanoma patients, we have examined 45 tumor biopsies for GD(1b) content. The incidence of GD(1b) in tumor biopsies is 51%. We postulate that GD(1b) associated on the tumor or in the circulation of cancer patients may bind to rIL-2 and prevent the availability of rIL-2 to augment antitumor-immune response.

Stereotactic radiosurgery in the treatment of metastatic disease to the brain

We review 190 consecutive patients with 434 metastatic tumors treated by gamma knife stereotactic radiosurgery, from August 1994 to February 1999. Median actuarial survival for all patients was 34 weeks. Factors correlated with significantly improved survival included controlled systemic disease and nonmelanoma histology. We found that no significant survival benefit could be discerned from adjuvant whole brain radiotherapy in this patient group. Survival was not statistically different for patients initially presenting with 1-4 metastases at initial treatment.

Stereotactic radiosurgery in the treatment of metastatic disease to the brain

OBJECTIVE

In recent years, stereotactic radiosurgery has been growing in popularity as a treatment modality for metastatic disease to the brain. The technique has advantages of reduced cost and low morbidity compared with open surgical treatment. Furthermore, it avoids the potential cognitive side effects of fractionated whole-brain radiotherapy. We undertook this study to determine the usefulness of adjuvant radiation therapy and to determine prognostic factors in patients treated with stereotactic radiosurgery.

METHODS

We reviewed our series of patients with metastatic tumors treated using gamma knife stereotactic radiosurgery from August 1994 to February 1999. Nonparametric methods were used to compare treatment subgroups by demographic features including age, Karnofsky Performance Scale score, diagnosis, and systemic disease status. Univariate and multivariate analyses of survival and freedom from progression were performed using Kaplan-Meier and Cox proportional hazards regression techniques.

RESULTS

This study included 190 patients harboring 431 lesions who were treated in 263 treatment sessions. The median follow-up after radiosurgery was 36 weeks for all patients. The median actuarial survival from the time of radiosurgery in all patients was 34 weeks. When patients were stratified according to tumor histology, those without melanoma had a median survival of 39 weeks, and those with melanoma had a median survival of 28 weeks. The cause of death could be determined in 122 (92%) of the patients known to have died during the data capture period. For patients harboring melanoma, death was attributable to systemic disease in 31 (47%), to central nervous system-related processes in 29 (44%), and to unknown causes in 6 (9%). For non-melanoma patients, death was attributable to systemic disease in 45 (68%), to central nervous system-related processes in 17 (26%), and to unknown causes in 4 (6%). Significantly improved survival (P = 0.002) was observed in patients with controlled systemic disease. No significant difference in survival could be ascertained for patients presenting with up to four lesions, although patients with a total tumor volume greater than 9 cc had shortened survival. No survival benefit could be demonstrated for whole-brain radiotherapy administered either concomitantly or after radiosurgery.

CONCLUSION

Factors correlated with significantly improved survival included controlled systemic disease and non-melanoma histology. We found no significant survival benefit that could be discerned from adjuvant whole-brain radiotherapy in this patient group.

A Phase II study of adjuvant therapy with anti-B4-blocked ricin after autologous bone marrow transplantation for patients with relapsed B-cell non-Hodgkin's lymphoma

This Phase II trial was undertaken to determine the safety, toxicity, and potential efficacy of the B-cell restricted immunotoxin anti-B4-blocked ricin (Anti-B4-bR) when administered as adjuvant therapy to patients in complete remission (CR) after autologous bone marrow transplantation (ABMT) for B-cell non-Hodgkin's lymphoma (NHL). Forty-nine patients with B-cell NHL in CR 46-202 days (median, 112 days) post-ABMT received Anti-B4-bR at a dose of 30 microg/kg lean body weight/day for 7 days by continuous i.v. infusion. Patients were eligible for up to two additional courses of therapy at 14-day intervals. A total of 83 courses of Anti-B4-bR were administered, with 31 patients receiving two or more courses of therapy. The mean serum level on day 7 of the first course was 0.77+/-0.41 nM. Reversible toxicities included hepatic transaminase elevations, thrombocytopenia, myalgias, fatigue, nausea, hypoalbuminemia, and dyspnea. Human antimouse antibody (HAMA) and/or human antiricin antibody (HARA) responses occurred in 23 patients at a median of 22 days from the initiation of Anti-B4-bR therapy (range, 11-100 days). The 4-year disease-free survival and overall survival are estimated at 56 and 72%, respectively. Twenty-six patients remain in CR after a median follow-up of 54.5 months. This study demonstrates that Anti-B4-bR can be administered safely to patients as adjuvant therapy early after ABMT for B-cell NHL. The toxicities are tolerable and reversible. Although the early estimate of disease-free survival was very encouraging in this single-armed trial, the 4-year follow-up data demonstrate continued relapse.

Phase II clinical trial of bolus infusion anti-B4 blocked ricin immunoconjugate in patients with relapsed B-cell non-Hodgkin's lymphoma

Immunotoxins, composed of a monoclonal antibody conjugated to a protein toxin, mediate cell death through novel cytotoxic mechanisms. Anti-B4-blocked ricin (anti-B4-bR) recognizes CD19-positive cells, which includes most B-cell non-Hodgkin's lymphomas (NHLs). Previous Phase I clinical studies of anti-B4-bR, using both bolus and continuous dosing regimens, demonstrated no safety or efficacy advantage to the continuous infusion regimen. This Phase II trial in 16 patients with relapsed CD19-positive NHL was conducted to evaluate the efficacy of anti-B4-bR when administered at the previously established maximum tolerated dose using a daily bolus for a 5 consecutive days schedule. Serum pharmacokinetics were measured in selected patients. Tissue samples of involved lymph nodes and bone marrow were also obtained from a portion of patients for determination of anti-B4-bR penetration into tissues. Toxicity was similar to what has been described previously for anti-B4-bR and consisted mainly of reversible elevations of hepatic transaminases and mild to moderate thrombocytopenia. No sustained clinical responses were documented. Pharmacokinetic measurements demonstrated that serum levels compatible with 3 logs of cell kill in vitro could be sustained for several hours in most patients. Immunohistochemical analysis of tissue samples provided some insight into the low efficacy. The immunotoxin could be detected in three of the four bone marrow aspirate samples but in only two of the seven lymph node specimens. Thus, anti-B4-bR, using a single daily bolus for a 5 consecutive day schedule, is not an active agent in relapsed NHL. Poor penetration into certain sites of disease may be one explanation for its lack of efficacy.