On November 1, 2021 Provectus (OTCQB: PVCT) reported that updated response, safety, and immune correlative data from the Company’s ongoing Phase 1b clinical trial of cancer immunotherapy PV-10 (rose bengal disodium), in combination with Keytruda (pembrolizumab), for the treatment of advanced cutaneous melanoma in patients refractory to immune checkpoint blockade (CB) (NCT02557321: first expansion cohort) will be presented at the SMR 2021 Virtual Congress (the Society for Melanoma Research annual meeting), which is being held online from October 28th to 31st (Press release, Provectus Biopharmaceuticals, NOV 1, 2021, View Source [SID1234594034]).
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Highlights of the SMR 2021 presentation:
Baseline characteristics
22 patients; 19 evaluable for efficacy
68% male; median age of 72 years (range 28-90); 50% Stage IV M1b-d
CB-refractory status: 9% CTLA-4, 32% PD-1, 59% CTLA-4+PD-1
Safety (22 patients)
Principally grades 1-2 injection-site reactions for PV-10
Principally grades 1-3 immune-mediated reactions for Keytruda
Best overall response (BOR) by RECIST 1.1 (19 patients)
5% complete response (CR), 26% objective response rate (ORR), 53% disease control rate (DCR)
Prior PD-1 (6 patients): 50% ORR, 67% DCR
Prior CTLA-4+PD-1 (12 patients): 8% CR, 17% ORR, 50% DCR
Durability of response
4.9 months median progression-free survival (mPFS)
Survival
34.1 months median overall survival (mOS)
Immune correlative assessment (6 patients)
Increases in damage-associated molecular pattern (DAMP) high mobility group box protein 1 (HMGB1) were consistent with the HMGB1 pattern of PV-10-treated CB-naïve melanoma patients
IFNγ expression of peripheral T cells demonstrates the induction of tumor-specific reactivity to HLA-matched cell lines, equivalent to that in CB-naïve melanoma patients
Immune correlative data substantiate the same PV-10 immune-mediated mechanism of action in CB-naïve monotherapy and CB-naïve and -refractory combination therapy melanoma patients
Dominic Rodrigues, Vice Chair of the Company’s Board of Directors, said, "Our melanoma drug development program has consistently and reproducibly shown PV-10’s unique innate and adaptive immune signaling mechanisms in single-agent and checkpoint blockade combination therapy clinical trials. To date, more than 50 patients have been treated with PV-10-Keytruda combination therapy for different melanoma indications. Current data notably demonstrate that cancer immunotherapy PV-10 can restore checkpoint blockade activity in patients who are refractory to this immunotherapy drug class."
Prior study data is also available on Provectus’ website:
Melanoma Bridge 2020, December 3-5: 14 evaluable patients, 7% CR, 29% ORR, 57% DCR,
European Society for Medical Oncology (ESMO) (Free ESMO Whitepaper) Virtual Congress 2020, September 19-21: 11 evaluable patients, 9% CR, 36% ORR, 54% DCR, and
SMR 2019 Congress, November 20-24: 8 evaluable patients, 25% ORR, 50% DCR, 4.9 months estimated mPFS, mOS not reached.
About PV-10
Intralesional (IL) administration of PV-10 for the treatment of solid tumor cancers can yield immunogenic cell death within hours of tumor injection, and induce tumor-specific reactivity in circulating T cells within days. This PV-10-induced functional T cell response may be enhanced and boosted in combination with immune checkpoint blockade (CB). In CB-refractory advanced cutaneous melanoma, PV-10 may restore disease-specific T cell function. IL PV-10 has been administered to over 450 patients with cancers of the skin and of the liver. It is administered under visual, tactile, or ultrasound guidance to superficial malignancies, and under CT or ultrasound guidance to visceral hepatic tumors. IL PV-10 is also undergoing preclinical study for pediatric solid tumor cancers (including neuroblastoma, Ewing sarcoma, rhabdomyosarcoma, and osteosarcoma).
Systemic administration of PV-10 is undergoing preclinical study as prophylactic and therapeutic treatments for high-risk and refractory adult solid tumor cancers, and as a treatment for relapsed and refractory blood cancers.
Different formulations and routes of administration of PV-10 and rose bengal disodium are also undergoing clinical and/or preclinical study in virology, microbiology, ophthalmology, dermatology, and animal health.