Table 2.
Indication | Phase | Treatment regimen | Patients enrolled | Key findings |
---|---|---|---|---|
HCC program | Phase 1 liver tumor | Intratumoral dose escalation 1×108 pfu to 3×109 pfu | 14 | – MTD identified (1×109 pfu) – Pexa-Vec replication and transgene expression confirmed – Antitumor activity observed at all dose levels18 |
Phase II randomized primary liver cancer (HCC) | Intratumoral dose finding 1×108 pfu vs 1×109 pfu | 30 | – Pexa-Vec tolerable at both dose levels in HCC patients – Improved survival at high-dose vs low-dose control (median 14.1 months vs 6.7 months; hazard ratio 0.39; P-value =0.02)26 |
|
Phase IIb second line HCC (sorafenib refractory) | IV + intratumoral Pexa-Vec (1×109 pfu) plus BSC versus BSC | 129 (86 arm A) | – Pexa-Vec plus BSC did not prolong overall survival when compared to BSC alone in advanced, poor-prognosis patient population | |
RCC program | Phase II | Multiple IV infusions 1×109 pfu | 17 | – Study ongoing |
CRC program | Phase 1, Phase II studies | Multiple IV infusions alone or in combination with irinotecan | 60+ patients | – Studies ongoing |
Proof-of-concept studies | Phase 1 IV dose escalation | Single IV Pexa-Vec infusion (1×105 pfu/kg to 3×107 pfu/kg) | 23 | – IV Pexa-Vec well-tolerated (MFD defined) – Dose-dependent intravenous delivery to metastatic tumors demonstrated (biopsy-proven) – Evidence of antitumor activity at high dose17 |
Phase 1 intratumoral dose escalation | Multiple IT Pexa-Vec injections in melanoma patients | 7 | – First-in-man study of Pexa-Vec – Pexa-Vec well-tolerated, MFD defined – Inflammation demonstrated in injected tumors – Evidence of antitumor activity23 |
|
Phase 1 mechanism of action study | Multiple IT Pexa-Vec injections in melanoma patients | 10 | – Pexa-Vec replication confirmed after injection of superficial tumors24 |
Abbreviations: BSC, best supportive care; CRC, colorectal cancer; HCC, hepatocellular carcinoma; IV, intravenous; IT, intratumoral; MFD, maximum feasible dose; MTD, maximum tolerated dose; RCC, renal cell carcinoma; pfu, plaque-forming unit.