Intralesional PV-10 Research Articles

Metabolic complete responses (mCR) in patients with metastatic uveal melanoma (mUM) treated with image-guided injection (IGI) of PV-10.

9543 Background: Traditional CT imaging can underestimate the degree of anti-cancer treatment effect due to reliance on morphological changes of visualized tumors. In contrast, PET imaging offers information on metabolic activity using a positron emitting radiolabeled agent (e.g. FDG) but is less sensitive to changes in tumor size. FDG-PET images acquired, co-registered, and superimposed on CT images (PET-CT) allow spatial detection of anti-cancer activity. Moreoever, FDG-PET-CT can provide information regarding anti-tumor immune responses in patients receiving immunotherapy. Rose bengal (PV-10) is a small molecule autolytic immunotherapy in development for metastatic disease. When administered by intralesional injection, PV-10 can produce immunogenic cell death and a T-cell mediated immune response against treatment-refractory and immunologically-cold tumors. Herein, we report the FDG-PET-CT imaging responses of 7 metastatic uveal melanoma (mUM) patients who received percutaneous image-guided injection (IGI) of PV-10 into hepatic tumors. Methods: The Phase 1 study is evaluating safety, tolerability, and efficacy of intralesional PV-10 in hepatic tumors. PV-10 is administered percutaneously via IGI into designated tumors ≤4.9 cm in diameter. Response is assessed at Day 28, then every 3 months, using CT/MRI or PET-CT. Patients with multiple tumors may receive further IGI of PV-10 after Day 28. Results: To date, 25 mUM patients with liver metastases have been treated; 16 patients received standard of care immune checkpoint inhibitor (ICI) during or post PV-10 treatment. Seven subjects had FDG-PET-CT imaging during the study (baseline 1, follow-up 6). Two follow-up FDG-PET-CTs were performed 1 and 3 years after PV-10 injection with intervening ICI, and another was 1.5 years after PV-10, without any follow-on treatment. Four patients experienced mCR in all metastatic sites, including extrahepatic metastasis. Conclusions: FDG-PET-CT shows that PV-10 is capable of inducing mCR in injected (adscopal) and non-injected (abscopal) lesions. This pattern of response is suggestive of immunogenic cell death in mUM patients with liver metastases. Clinical trial information: NCT00986661.

Intralesional injection of rose bengal augments the efficacy of gemcitabine chemotherapy against pancreatic tumors

BackgroundChemotherapy regimens that include the utilization of gemcitabine are the standard of care in pancreatic cancer patients. However, most patients with advanced pancreatic cancer die within the first 2 years after diagnosis, even when treated with standard of care chemotherapy. This study aims to explore combination therapies that could boost the efficacy of standard of care regimens in pancreatic cancer patients.MethodsIn this study, we used PV-10, a 10% solution of rose bengal, to induce the death of human pancreatic tumor cells in vitro. Murine in vivo studies were carried out to examine the effectiveness of the direct injection of PV-10 into syngeneic pancreatic tumors in causing lesion-specific ablation. Intralesional PV-10 treatment was combined with systemic gemcitabine treatment in tumor-bearing mice to investigate the control of growth among treated tumors and distal uninjected tumors. The involvement of the immune-mediated clearance of tumors was examined in immunogenic tumor models that express ovalbumin (OVA).ResultsIn this study, we demonstrate that the injection of PV-10 into mouse pancreatic tumors caused lesion-specific ablation. We show that the combination of intralesional PV-10 with the systemic administration of gemcitabine caused lesion-specific ablation and delayed the growth of distal uninjected tumors. We observed that this treatment strategy was markedly more successful in immunogenic tumors that express the neoantigen OVA, suggesting that the combination therapy enhanced the immune clearance of tumors. Moreover, the regression of tumors in mice that received PV-10 in combination with gemcitabine was associated with the depletion of splenic CD11b+Gr-1+ cells and increases in damage associated molecular patterns HMGB1, S100A8, and IL-1α.ConclusionsThese results demonstrate that intralesional therapy with PV-10 in combination with gemcitabine can enhance anti-tumor activity against pancreatic tumors and raises the potential for this strategy to be used for the treatment of patients with pancreatic cancer.

Phase I study of autolytic immunotherapy of metastatic neuroendocrine tumors using intralesional rose bengal disodium.

4115 Background: Metastatic neuroendocrine neoplasms (mNEN) originating in the gastrointestinal tract are frequently slow growing yet both symptom and disease control remain important. Treatment options include resection, systemic somatostatin analogues (SSA), and systemic peptide receptor radionuclide therapy (PRRT). Additional options are needed; we have explored intralesional (IL) rose bengal disodium (PV-10), an investigational autolytic immunotherapy that can yield immunogenic cell death and disease-specific functional adaptive immunity. Methods: This phase 1 study evaluated safety, tolerability and impact on symptoms and biochemical markers resulting from IL PV-10 administered percutaneously to hepatic lesions in patients (pts) with progressive mNEN not amenable to resection or other potentially curative therapy. Eligible lesion(s) were 1.0 - 3.9 cm in longest diameter with amount of PV-10 administered proportional to size. Cohort 1 (n = 6 pts) received PV-10 to a single lesion per treatment cycle; Cohort 2 (n = 6) could receive injection to multiple lesions per treatment cycle. Pts could receive further PV-10 ≥6 weeks after prior injection. The primary endpoint was safety. Secondary endpoints included objective response rate (ORR) assessed by contrast enhanced CT (RECIST 1.1) and 68Ga-DOTATATE PET, biochemical response (CgA) and patient-reported outcome (EORTC QLQ-C30 and GI.NET21 QOL instruments). Results: Twelve pts were enrolled, 50% male, median age 66 yrs (range 47-79). Primary sites: 7 small bowel, 2 pancreas, 1 caecal, 2 unknown; grade: Gd1 = 5, Gd2 = 7. All pts had received SSA and PRRT as part of previous therapy and all had symptomatic, progressive disease. Median CgA was 1585 (range 35-10370). One lesion was injected per cycle for all 12 pts; none were suitable for multiple injections. One pt received 4 sequential PV-10 treatment cycles, 3 received 2 cycles, and 8 received 1 cycle. Toxicity was consistent with experience in other hepatic malignancies: post-procedure pain was reported by most pts; grade 3 photosensitivity reaction occurred in 1 pt; and grade 1 elevation of hepatic enzymes attributed to PV-10 occurred in 2 pts, resolving by day 7. Additionally, carcinoid flare occurred in 1 pt. ORR of injected lesions was 42%; patient-level disease control was 84%. Estimated PFS was 9.2 months; median OS was 22.5 months. CgA remained stable in 10 pts and upregulation of NK and activated CD4+ T lymphocytes was observed post-injection. QOL data at months 1 and 3 showed stable or improved carcinoid symptoms and global health status in 9 pts. Conclusions: PV-10 elicited no safety concerns with encouraging evidence of both local and systemic disease and symptom control in a heavily pre-treated population. Multiple cycles were delivered safely in suitable patients. Adaptive immune upregulation is consistent with other solid tumors and supports potential systemic benefit. Clinical trial information: NCT02693067.

Treatment of in-transit melanoma metastases using intralesional PV-10

Melanoma in-transit metastases (ITMs) can sometimes be difficult to manage by surgical excision due to their number, size or location. Treatment by intralesional injection of PV-10, a 10% solution of rose bengal, has been reported to be a simple, safe and effective alternative, but more outcome data are required to confirm its value in the management of ITMs. Two hundred and twenty-six melanoma ITMs in 48 patients were treated with intralesional PV-10 supplied under a special-access scheme. By 8 weeks a complete response in all injected ITMs was achieved in 22 patients (46%) and a partial response in 19 patients (40%). Of 19 patients who had uninjected metastases, 3 (16%) had a response in these. The most common adverse event was transient localised pain in injected tumours. New ITMs developed in 25 patients within 8 weeks, and later in another 8 patients. Repeat injection cycles were given to 21 patients: 13 of these received repeat injection into partially responding or nonresponding tumours, 5 had new ITMs, as well as partially-responding lesions injected, and 3 received injection into new ITMs only. Twenty-two patients received subsequent systemic therapy. At 1 year 37 of the 48 patients were alive, 28 with melanoma, and at 2 years 27 were alive, and 19 with melanoma. Injection of PV-10 was simple and safe and resulted in tumour involution in most patients and sometimes in noninjected tumours. However, many patients developed new lesions; these were treated by further PV-10 injections or with alternative therapies.

Percutaneous hepatic injection of rose bengal disodium (PV-10) in metastatic uveal melanoma.

3143 Background: PV-10 is a small molecule autolytic immunotherapy in clinical development for treatment of solid tumors. When administered by intralesional (IL) injection, PV-10 can produce immunogenic cell death that may induce a T cell-mediated immune response against treatment refractory and immunologically cold tumors. Given this mechanism of action and clinical data that metastatic uveal melanoma (MUM) generates low response rates to immune checkpoint blockade (CB), we investigated treatment of MUM with percutaneously-delivered PV-10. Methods: This open-label Phase 1 basket study (NCT00986661) is evaluating the safety, tolerability, and preliminary efficacy of intralesional PV-10 in patients (pts) with solid tumors of the liver. PV-10 is injected into one or more designated hepatic tumor(s) with a maximum sum of diameters ≤4.9 cm. Response assessments using 2D EASL criteria are performed at Day 28, then every 3 months. Pts with additional injectable tumors are eligible to receive further PV-10 after Day 28. Pts can receive standard of care CB immunotherapy during treatment with PV-10. Results: As of February 1, 2020, the initial cohort of 15 pts with MUM to the liver was fully enrolled. Pts had received at least 1 IL injection of PV-10, with an average of 2 hepatic lesions injected per pt (range 1-4). Of these, 4 pts were refractory to prior CB. Three pts received PV-10 alone, 3 received PV-10 + anti-PD-1 and 9 received PV-10 + anti-PD-1 + anti-CTLA-4. Adverse events (AEs) were consistent with established patterns for PV-10 and CB: AEs attributed to PV-10 were transient and included 3 cases of Grade 3/4 transaminitis that resolved within 72 hrs, injection site pain, photosensitivity, and pink discoloration of skin, urine or feces; AEs attributed to CB included nausea, decreased WBC, and fatigue. Response assessments on 24 injected tumors were: 2 complete response (8%), 7 partial response (29%) and 11 stable disease (46%), per 2D EASL. Among the 4 CB-refractory pts, median overall survival (OS) was 9.2 months (range 5.3 - 11.4 months, with 2 pts alive at 5.3 months each), while among the 11 CB-naïve pts OS was undefined (range 0.5 - 21.9+ months, with 1 death at 7.9 months). Pts receiving PV-10 alone (1 CB-refractory, 2 naïve) achieved a median OS of 7.9 months with one CB-naïve pt alive with partial overall response at 21.9 months. Conclusions: Response indicative of regression or stabilization in a majority (83%) of injected lesions is encouraging in a disease of major unmet need. Enrollment and follow-up for safety, duration of response and survival are ongoing. Clinical trial information: NCT00986661 .

Cohort 1 results of a phase I study of autolytic immunotherapy of metastatic neuroendocrine neoplasms using intralesional rose bengal disodium.

e16694 Background: Metastatic neuroendocrine neoplasms (mNEN’s) originating in the gastrointestinal tract are frequently slow growing yet both symptom and disease control remain important. Treatment options include resection, chemoablation, systemic somatostatin analogues (SSA) or peptide receptor radionuclide therapy (PRRT), but additional options are needed, especially when available options have been exhausted. Intralesional (IL) rose bengal disodium (PV-10), an autolytic immunotherapy under development for solid tumors, is being investigated as a potential option for treatment-refractory patients (pts) with hepatic metastases. Methods: This phase 1 study is evaluating the safety, tolerability and objective response resulting from percutaneous administration of PV-10 in 12 pts with progressive mNEN refractory to SSA and PPRT; pts must have at least one injectable hepatic lesion (1.0-3.9 cm in longest diameter) not amenable to resection or other potentially curative therapy. In Cohort 1 (n = 6) pts received PV-10 to a single hepatic lesion per treatment cycle, and could receive PV-10 to additional uninjected hepatic lesions ≥6 weeks after prior injection. The primary endpoint is safety. Secondary endpoints include objective response rate assessed by independent review of contrast enhanced CT and by 68Ga-DOTATATE PET. Results: Cohort 1 has fully enrolled, with 4 of 6 pts male, median age 65 yrs, range 47-72. Primary sites were: small bowel 3, pancreas 2, caecal 1. NET grade: Gd1 = 5, Gd2 = 1. All pts had progressed on prior SSA and PRRT. Median baseline CgA was 645 (range 30-2819). One pt received 4 PV-10 treatment cycles, 1 received 2 cycles, and 4 received a single cycle. Toxicity was acceptable, including transient pain post procedure, carcinoid flare and nausea. A partial response of injected lesions was observed in 50% of pts (injected lesion progression in 1 pt), with an overall response of stable disease achieved in 84% of pts by RECIST 1.1 (progressive disease in 1 pt). Progression free survival (PFS) was not reached by CT (range 2.4-25.3+ months), and was 6.1 months by PET. Median overall survival (OS) was ≥22.5 months, with three subjects alive at the data cut-off of Jan 2020 (range 18.1-33.8 months). Conclusions: Hepatic IL PV-10 elicited no safety concerns with encouraging evidence of both local response of injected tumors and prolonged systemic disease control in some pts. Enrolment to Cohort 2 is nearing completion where an additional 6 pts may receive injection of multiple lesions per treatment cycle. Clinical trial information: NCT00986661 .

A Phase I Study of Percutaneous Oncolytic Rose Bengal Disodium for Metastatic Uveal Melanoma Patients with Hepatic Metastases: A Single-Center Cohort Summary

Abstract Background Rose bengal disodium (PV-10) is a small molecule oncolytic immunotherapy in clinical development for treatment of solid tumors. When administered by intralesional injection, PV-10 can produce an immunogenic cell death that may induce a T-cell mediated immune response against treatment-refractory and immunologically-cold tumors. Given this mechanism of action, we investigated treatment of metastatic uveal melanoma with percutaneous hepatic PV-10. Methods PV-10-LC-01 (NCT00986661) is an open-label phase I basket study evaluating the safety, tolerability, and preliminary efficacy of intralesional PV-10 in patients with solid tumors metastatic to the liver. Percutaneous injections of PV-10 are administered to one or more designated hepatic tumor(s) with a maximum sum of diameters £4.9 cm. Response assessments using 2D EASL criteria are performed at Day 28, then every 3 months. Patients with additional injectable tumors may receive further PV-10 after Day 28. Eligible patients may receive standard of care checkpoint blockade immunotherapy during treatment with PV-10. Results In a single-center cohort of uveal melanoma patients with hepatic metastases, to date, the study has screened 15 patients with metastatic uveal melanoma; eleven patients have been consented, enrolled, and received at least one PV-10 treatment cycle; five have received a second treatment with intralesional PV-10 for a total of 18 injected hepatic tumors. Three patients have received PV-10 with initiation of standard of care checkpoint blockade. One patient was on immunotherapy prior to PV-10 treatment. In 11 injected tumors with response assessment, the objective response rate has been 36%. Toxicities have been self-limiting and consistent with established patterns, including photosensitivity, pink urine, and transaminitis that resolved in Conclusion Percutaneous PV-10 exhibited acceptable safety and tolerability with encouraging evidence of activity in injected lesions. Updated enrollment as well as safety and efficacy data of the uveal melanoma cohort will be presented at the meeting. Clinical trial identification NCT00986661. Legal entity responsible for the study Provectus. Funding Provectus. Disclosure S. Patel: Research grant / Funding (institution): Bristol-Myers Squibb; Advisory / Consultancy: Cardinal Health; Advisory / Consultancy: Castle Biosciences; Leadership role, Data Safety Monitoring Board Chair: Immunocore; Advisory / Consultancy: Incyte; Honoraria (self): Merck; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): Provectus; Leadership role, Research grant / Funding (institution), Data Safety Monitoring Board chair: Reata. E.A. Wachter: Shareholder / Stockholder / Stock options, Full / Part-time employment: Provectus. All other authors have declared no conflicts of interest.

A phase I study of oncolytic immunotherapy of metastatic neuroendocrine tumors using intralesional rose bengal disodium: Cohort 1 results.

4102 Background: Metastatic neuroendocrine neoplasms (mNEN’s) originating in the gastrointestinal tract are frequently slow growing yet both symptom and disease control remain important. Treatment options include resection, chemoablation, systemic somatostatin analogues (SSA) or peptide receptor radionuclide therapy (PRRT), but additional options are needed and one such option is hepatic intralesional (IL) rose bengal disodium (PV-10), an oncolytic immunotherapy under development for solid tumours. Methods: This phase 1 study is evaluating the safety, tolerability and reduction of biochemical markers and symptoms resulting from percutaneous administration of PV-10 in 12 subjects with progressive mNEN with hepatic lesions not amenable to resection or other potentially curative therapy. Target lesion(s) must be 1.0 - 3.9 cm in longest diameter. In Cohort 1 (n = 6) subjects receive PV-10 to a single hepatic lesion per treatment cycle, and can receive PV-10 to additional uninjected hepatic lesions ≥6 weeks after prior injection. Cohort 2 (n = 6) subjects may receive injection of multiple lesions per treatment cycle. The primary endpoint is safety. Secondary endpoints include objective response rate (ORR) assessed by contrast enhanced CT and 68Ga-DOTATATE PET, biochemical response (CgA) and patient-reported outcome (EORTC QLQ-C30 and GI.NET21). Results: Cohort 1 has fully enrolled, with 4 of 6 subjects male, median age 65yrs, range 47-72. Primary sites were: small bowel 3, pancreas 2, caecal 1; grade: Gd1 = 5, Gd2 = 1. All patients received prior SSA and PRRT. Median CgA was 645 (range 30-2819). To date 1 subject has received 4 PV-10 treatment cycles, 1 has received 2 cycles, and 4 have received a single cycle. Toxicity has been acceptable, including pain post procedure, carcinoid flare and nausea. LFT’s have remained stable. Overall QOL score was stable for 5 of 6 subjects. ORR in injected lesions is 50% (progression in 1 subject), with overall disease control of 84%. CgA response: 5 stable, 1 progression. One subject with “carcinoid pellagra” had rash resolution. Response follow-up is ongoing and additional efficacy and functional data will be presented. Conclusions: Hepatic IL PV-10 elicited no safety concerns with encouraging evidence of both local and systemic disease control. Enrolment to Cohort 2 is underway. Clinical trial information: NCT02693067.

Patients with in-transit melanoma metastases have comparable survival outcomes following isolated limb infusion or intralesional PV-10-A propensity score matched, single center study.

Isolated limb infusion (ILI) and intralesional PV-10 are well described locoregional therapies for in-transit melanoma. The objective of this study was to assess the effect of these treatments on survival outcomes within a cohort matched for key characteristics. Patients were treated using ILI or intralesional PV-10 at a single institution and the data prospectively recorded. Propensity score matching was performed using key covariates within a logistic regression model. The primary outcome was the melanoma-specific survival. Seventy-two patients nonrandomized were successfully matched. Both treatments produced similar best overall responses. The median melanoma-specific survival (MSS) was 74.4 months from ILI and 36.4 months from PV-10 treatments (P = 0.164). Within the ILI subgroup, the 12-, 24-, 36- and 60-month MSS rates were 85.3%, 75.3%, 60.1%, and 60.1%, respectively. From the time of PV-10 the corresponding 12-, 24-, 36-, and 60-month MSS rates were 82.6%, 70.0%, 53.9%, and 35.9%. On multivariate analysis, there was a significant difference in survival comparing completely with noncomplete responders ( P = 0.031). These findings demonstrate that ILI and PV-10 treatments for in-transit disease produce comparable long-term survival. Both therapies have reproducible response rates and predominantly localized and tolerable side-effects.

T cell mediated immunity after combination therapy with intralesional PV-10 and blockade of the PD-1/PD-L1 pathway in a murine melanoma model.

Intralesional (IL) injection of Rose Bengal (PV-10) induces regression of injected and uninjected lesions in several murine tumor models. In this study, we investigated the anti-tumor response of combining IL PV-10 with blockade of the PD-1 / PD-L1 pathway and the role of immune cell populations in eliciting this response. To investigate the role of T cell subsets in mediating an immune response, B16 or M05 melanoma-bearing mice received combination therapy as well as CD8+, CD4+, or CD25+ depleting antibodies. Tumor growth was measured. T cells were collected from spleens or tumors, and phenotype, activation markers, and reactivity were measured. Splenocytes from mice treated with combination therapy had increased OVA antigen-specific CD8+ T cells in M05-tumor-bearing mice. Depletion of CD4+ T cells or regulatory T cells (Tregs) in combination with IL PV-10 and anti-PD-1 antibody treatment resulted in an enhanced anti-tumor effect. Treatment with CD8+ depleting antibody abrogated anti-tumor immunity. These results support a clinical study for the safety and anti-tumor immune responses with combination therapy of IL PV-10 and PD-1/PD-L1 blockade.

Intralesional PV‐10 for the treatment of in‐transit melanoma metastases—Results of a prospective, non‐randomized, single center study

BackgroundPatients with in‐transit melanoma metastases frequently experience high rates of recurrence, limited overall survival and reduced quality of life. After promising results within a Phase II, multi‐center study, PV‐10 treatment was continued at our institution for patients with in‐transit disease.MethodologyAn open‐label, non‐randomized, prospective study was performed at the Princess Alexandra Hospital, Queensland, Australia. Patients were treated with PV‐10 in accordance with the treatment protocol established during a previous Phase II study. The primary outcome was the complete response of treated lesions.ResultsForty‐five patients were enrolled over a total of 82 treatment episodes from July 2008 to December 2015. With sequential PV‐10 treatments the complete response rate was 42% and overall response rate 87% on an intention to treat analysis. The median follow‐up duration was 22 months and the median overall survival was 25 months from first PV‐10 treatment. Having fewer than 15 metastases at the time of treatment was associated with a complete response (P = 0.03).ConclusionsIntralesional PV‐10 provided rapid lesion‐specific ablation of melanoma metastases with well‐tolerated local effects and minimal systemic adverse events. This therapy should be considered for patients with multiple accessible deposits within the spectrum of low to moderate disease volume.

Abstract 4978: T cell mediated immunity after combination therapy with intralesional PV-10 and co-inhibitory blockade in a melanoma model

Abstract PV-10 is a 10% solution of Rose Bengal, a xanthene dye that was originally developed for ophthalmic use and later used in liver function studies. PV-10 was formulated for intralesional (IL) injection and is currently being investigated as a novel cancer therapeutic. In murine studies, we have previously shown that intralesional (IL) injection of PV-10 leads to a regression of both injected tumors and untreated bystander tumors. We have also shown that combination therapy of IL PV-10 with blockade of PD-1 and PDL-1 leads to increased anti-tumor immunity. In this study, we have examined the role played by specific immune cell populations in eliciting this response in a murine melanoma model. We first investigated the antigen specificity of CD8+ T cells in the spleens of mice treated with the combination therapy of IL PV-10 and systemic co-inhibitory blockade. We found that splenocytes from mice treated with the combination of IL PV-10 and anti PD-1 antibody have an increased mean percentage of OVA antigen-specific CD8+ T cells (5.77%) compared to single treatment with anti PD-1 antibody (3.8%) or IL PV-10 (3.60%) alone in OVA-expressing B16 tumor bearing mice. To investigate the role of T cell subsets in mediating an immune response, OVA-expressing B16 tumor bearing mice were treated with IL PV-10 followed by intraperitoneal injection of anti-PD-1 antibody. In addition, mice were given either 2.43 antibody to deplete CD8+ T cells, GK1.5 antibody to deplete CD4+ T cells, or PC61 to deplete regulatory T cells (Tregs). We found that depletion of CD4+ T cells in combination with IL PV-10 and anti-PD-1 antibody treatment resulted in an enhanced anti-tumor effect, with an average tumor size of 52.8 mm2 on day 25 compared to the control group (173.7 mm2), and depletion of Tregs resulted in an even greater anti-tumor effect, with an average tumor size of 1.2 mm2 on day 25 (p<0.05). In contrast, mice treated with the CD8+ depleting antibody exhibited diminished anti-tumor immunity compared to the control group, with an average tumor size of 200 mm2 on day 25. Together, these studies indicate that the effect of combination therapy with IL PV-10 and co-inhibitory blockade is mediated by CD8+ T cells, and that depletion of both CD4+ T cells and CD25+ Tregs significantly enhances anti-tumor immunity in a melanoma model. Citation Format: Amy M. Weber, Hao Liu, Krithika N. Kodumudi, Amod A. Sarnaik, Shari Pilon-Thomas. T cell mediated immunity after combination therapy with intralesional PV-10 and co-inhibitory blockade in a melanoma model. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4978.

Intralesional PV-10 for in-transit melanoma-A single-center experience.

Patients with in-transit melanoma metastasis have longer median survival than patients with distant metastatic disease. Furthermore, local disease control is an important endpoint for symptom management. The treatment of unresectable loco-regional recurrence or in-transit disease has been historically managed with a combination of treatments including surgery, radiotherapy, isolated limb infusion or perfusion as well as systemic therapies. Intralesional PV-10 has been used at Peter MacCallum Cancer Centre since 2010, and the current report presents a retrospective analysis of patient outcomes, reporting the response rates, durability of responses, and observed toxicities. Records were analyzed retrieving details of 19 patients treated with PV-10 over a 4-year period from 2010 to 2014. Medical records were reviewed for these patients and data extracted. Nineteen patients with in-transit melanoma were treated with intralesional PV-10 between 2010 and 2014. Disease control (complete or partial response or disease stability) was achieved in 68% of patients with 26% having a complete response. This was achieved with minimal associated toxicity. PV-10 is an effective, durable, well-tolerated treatment tool with an acceptable side effect profile for the management of unresectable in-transit melanoma. J. Surg. Oncol. 2016;114:380-384. © 2016 Wiley Periodicals, Inc.

A phase 2 study of intralesional PV-10 followed by radiotherapy for localized in transit or recurrent metastatic melanoma.

e21072Background: Intralesional rose bengal (IL PV-10) can elicit ablation of injected tumors and a T-cell mediated abscopal effect in untreated lesions. Phase 2 testing in patients with Stage III-...

Efficacy of intralesional injection with PV-10 in combination with co-inhibitory blockade in a murine model of melanoma

PV-10 is a 10% solution of Rose Bengal that is currently being examined as a novel cancer therapeutic. We have previously shown that intralesional (IL) injection of PV-10 into a single subcutaneous B16 melanoma tumor led to regression of both the injected tumor and uninjected B16 lung lesions. Tumor regression correlated with the induction of systemic anti-melanoma T cell immunity. In melanoma patients, IL injection of PV-10 has led to regression of treated lesions as well as untreated bystander lesions. In this study, we have examined whether IL PV-10 and co-inhibitory blockade could improve anti-tumor immunity and regression of melanoma. B16 cells were injected into C57BL/6 mice to establish one subcutaneous tumor. Treatment of this lesion with a single IL injection of PV-10 alone led to partial regression of the injected B16 lesion. Systemic administration of anti-CTLA-4 or anti-PD1 antibodies in combination with IL PV-10 resulted in increased tumor regression and improved survival in this model. Treatment with PV-10 also led to the induction of T cells that produced IFN-γ (495 ± 198 pg/ml) in response to B16 cells but not to irrelevant MC-38 cells. Combination therapy with IL PV-10 and anti-CTLA-4 led to increased IFN-γ responses to B16 (1235 ± 191 pg/ml, p < 0.05). In another experiment simulating heavy tumor burden using a bilateral model, systemic administration of anti-PD-L1 antibodies in combination with IL PV-10 led to regression of the injected B16 lesion as well as a bystander subcutaneous lesion on the opposite flank (p < 0.01 compared to mice treated with anti-PD-L1 antibodies or IL PV-10 alone). Together, these studies support the induction of increased tumor-specific immunity after co-inhibitory blockade in combination with IL PV-10 therapy.

Assessment of immune and clinical efficacy after intralesional PV-10 in injected and uninjected metastatic melanoma lesions.

9028 Background: Intralesional (IL) therapy is under investigation to treat dermal and subcutaneous metastatic cancer. In our murine model, IL injection of PV-10 (10% Rose Bengal) induced regressio...

Intralesional Injection of Rose Bengal Induces a Systemic Tumor-Specific Immune Response in Murine Models of Melanoma and Breast Cancer

Intralesional (IL) injection of PV-10 has shown to induce regression of both injected and non-injected lesions in patients with melanoma. To determine an underlying immune mechanism, the murine B16 melanoma model and the MT-901 breast cancer model were utilized. In BALB/c mice bearing MT-901 breast cancer, injection of PV-10 led to regression of injected and untreated contralateral subcutaneous lesions. In a murine model of melanoma, B16 cells were injected into C57BL/6 mice to establish one subcutaneous tumor and multiple lung lesions. Treatment of the subcutaneous lesion with a single injection of IL PV-10 led to regression of the injected lesion as well as the distant B16 melanoma lung metastases. Anti-tumor immune responses were measured in splenocytes collected from mice treated with IL PBS or PV-10. Splenocytes isolated from tumor bearing mice treated with IL PV-10 demonstrated enhanced tumor-specific IFN-gamma production compared to splenocytes from PBS-treated mice in both models. In addition, a significant increase in lysis of B16 cells by T cells isolated after PV-10 treatment was observed. Transfer of T cells isolated from tumor-bearing mice treated with IL PV-10 led to tumor regression in mice bearing B16 melanoma. These studies establish that IL PV-10 therapy induces tumor-specific T cell-mediated immunity in multiple histologic subtypes and support the concept of combining IL PV10 with immunotherapy for advanced malignancies.

Abstract 4755: Combination of PV-10 immuno-chemoablation and systemic anti-CTLA-4 antibody therapy in murine models of melanoma.

Abstract Rose bengal disodium (PV-10) is an investigational small molecule ablative agent currently entering pivotal phase 3 clinical testing as a monotherapy for locoregional control of cutaneous metastatic melanoma. Upon intralesional (IL) administration, PV-10 localizes to the injected tumor tissues while clearing rapidly from healthy tissue. Tumor infiltration with PV-10 leads to rapid necrosis of the injected lesion, with complete resolution common within 2-8 weeks. In phase 2 testing in 80 patients with Stage IIIB-IV(M1c) melanoma, IL PV-10 elicited an objective response in injected tumors in 51% of patients (CR:25%, PR:26%) after 1-4 treatment cycles. In addition to this direct ablative effect on injected tumors, some patients achieved an objective response in their monitored untreated tumors (CR:26%, PR:7% in 42 subjects with monitored untreated lesions) in an apparent immune-mediated bystander response that highly correlated with successful ablation of their injected tumors. Treatment was generally well tolerated, with adverse events confined mainly to the injection site and no grade 4 or 5 adverse events associated with use of PV-10. Recent nonclinical testing in the B16-F10 murine melanoma tumor line has confirmed that PV-10 ablation induces tumor-specific immunity, resulting in marked suppression of synchronous lung metastases upon ablation of a flank tumor and tumor-specific IFN-γ production. In this study we assess potential benefit of combination of PV-10 immuno-chemoablation with the hamster anti-murine CTLA-4 antibody 9H10 in bilateral flank and lung metastasis models (B16-F10 melanoma in C57BL/6 mice). Results from these models will be reported and could support clinical development of combination therapy in advanced melanoma patients, such as stage IV patients with substantial tumor burden in locations inaccessible to PV-10 injection. The rapid reduction in tumor burden and tumor specific immunologic stimulation provided by PV-10 may complement the immune stimulation of anti-CTLA-4 antibodies such as ipilimumab without increased toxicity. Citation Format: Eric A. Wachter, Savannah Blair, Jamie Singer, Craig Dees. Combination of PV-10 immuno-chemoablation and systemic anti-CTLA-4 antibody therapy in murine models of melanoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4755. doi:10.1158/1538-7445.AM2013-4755