Following ASCO data presentations last month, as well as time on the road with management, RBC Capital Markets enters 2H17 with increased conviction in both Phase III asset mirvetuximab for ImmunoGen, Inc. (NASDAQ:IMGN), and ongoing turnaround efforts at the company. The firm has updated its model accordingly, and anticipate shares will continue to move higher over the next 12 months. Upgrading to Outperform with a $12 PT.
The updated mirvetuximab soravtansine data presented at ASCO was positive and well received by KOLs RBC Capital Markets spokes to, which gives it increased confidence in the potential for success of the program. Separately, the recent monetization of noncore assets provides concrete evidence of ongoing turnaround efforts, announced last fall by new CEO Mark Enyedy, which are focused squarely on advancing mirvetuximab across the goal line. So while acknowledging that the firm may be somewhat late to the party, it thinks there remains significant room for upside at current levels, based on its risk-adjusted estimates of the commercial prospects for Phase III asset mirvetuximab, as well as multiple readouts/catalysts that it wants to be in front of.
Updated mirvetuximab single-agent results presented at ASCO 2017 included pooled data from three separate Phase I cohorts, in which 36 platinum-resistant patients met the Phase III FORWARD I enrollment criteria. Notably, among these patients the ORR was 47%, with a median PFS of 6.7 months. This compares favorably to results with paclitaxel, PLD, or topotecan, as well as from Avastin (bevacizumab) in the AURELIA trial (27% ORR; 6.7 month mPFS), which enrolled patients who received fewer prior therapies. RBC Capital Markets views the fact that mirvetuximab has now demonstrated comparable efficacy in three separate Phase I cohorts as supportive of the decision to advance this agent into Phase III, and as providing assurances around its probability of success. Separately, the firm is encouraged by initial results from the Phase I/II FORWARD II trial testing mirvetuximab in combination with other approved agents. Additional positive combo data offers potential to expand the addressable patient population, and could drive upside to RBC Capital Markets' current estimates.
A first look at next-gen ADC IMGN779 was presented at EHA in June. This CD33-targeting ADC is in a Phase I trial in AML, and utilizes a novel DNA-alkylating IGN (indolinobenzodiazepine) payload, which may offer improved tolerability vs. PBD (pyrrolobenzodiazepine), a crosslinking agent.
At ASCO 2016, IMGN reported a confirmed ORR of 26% and a median PFS of 4.8 months in 46 heavily pre-treated, FRalpha positive, platinum-resistant ovarian cancer patients. In a subgroup of 16 patients who met the Phase III FORWARD I enrollment criteria (medium or high FR-alpha expression, ≤ 3 prior lines of therapy), a more robust 44% ORR and 6.7-month PFS were observed. Updated results were recently presented at ASCO 2017, which pooled data from three separate Phase I cohorts and included 36 patients who met the Phase III enrollment criteria. Notably, among these patients the ORR was 47% with a 6.7-month PFS, which RBC Capital Markets views as supportive of the decision to advance this agent into Phase III.