Immunogen (IMGN) 8-K Data from Avastin Cohort to be Presented at 2018 ASCO Annual Meeting

Exhibit 99.2

FORWARD PROGRAM NASDAQ: IMGN II UPDATE May 17, 2018

FO RW A RD - L OOKI NGS T A T EMENT S This presentation includes forward-looking statements based on management's current expectations. These statements include, but are not limited to, ImmunoGen's expectations related to: the occurrence, timing and outcome of potential pre-clinical, clinical and regulatory events related to the Company's and its collaboration partners' product programs; the presentation of preclinical and clinical data on the Company’s and its collaboration partners’ product candidates; and the financial guidance provided. For these statements, ImmunoGen claims the protection of the safe harbor for forward-looking statements provided by the Private Securities Litigation Reform Act of 1995. Various factors could cause ImmunoGen's actual results to differ materially from those discussed or implied in the forward-looking statements, and you are cautioned not to place undue reliance on these forward-looking statements, which are current only as of the date of these slides. Factors that could cause future results to differ materially from such expectations include, but are not limited to: the timing and outcome of ImmunoGen's and its collaboration partners' research and clinical development processes; thedifficulties uncertainties as andregulatory inherentinthedevelopmentofnovelpharmaceuticals,including to the timing, expense and results of preclinical studies, clinical trials processes;ImmunoGen'sabilitytofinanciallysupportitsproduct programs; the Company’s dependence on its collaborative partners; industry merger and acquisition activity; and other factors more fully described in ImmunoGen's Annual Report on Form 10-K for the year ended December 31, 2017 and other reports filed with the Securities and Exchange Commission. 2

F O RW A RDI EXECUTING ON OUR HIGHEST STRATEGIC PRIORITY:   Patient enrollment completed ahead of schedule Trial continuing as planned following successful pre-specified interim futility analysis Top-line data on-track to be reported in IH19 MIRVETUXIMAB SORAVTANSINE  FO R WA R D II  Updated data from the Keytruda® cohort at SGO Annual Meeting Data from Avastin® expansion cohort in over 50 patients at ASCO 2018 Updated data from carboplatin escalation cohort Initiated triplet cohort in January    CL INI C A LCO L L A B O R A T IO NS  Co-sponsoring mirvetuximab + Rubraca® combination study in ovarian cancer with Clovis  Multiple studies underway underway with NCCN in FR-positive tumor types 3 Rubraca® is a registered trademark of Clovis

C O M P R E H E N S I V E D E V E L O P M S T R A T E G Y F O R E N T  Establish initial position through single-agent monotherapy in ovarian cancer M I R V E T U X I M A B  Expand benefit through combinations in earlier lines ovarian cancer of  Broaden use into additional FR-positive solid tumors (NSCLC, endometrial and triple-negative breast cancer)

LABEL EXPANSION: MIR V E T U X IMA B BECOME THE COMBINATION AGENT OF CHOICE EN R O LLM EN T: Patients with recurrent platinum-resistant or platinum-sensitive FR-positive ovarian cancer Avastin® is a registered trademark of Genentech Keytruda ® is a registered trademark of Merck 5 C ARB O P L A T I N mirvetuximab+carboplatin+Avastin® triplet expansion cohort ongoing K EY TR U D A ® Keytruda® expansion cohort ongoing AV AS T I N ® Avastin® expansion cohort ongoing

N EED FOR EFFE C TI V E C OM BI N ATI ON S C U RREN T T REA T MEN T S F O R B O T H P L A T I N U M - R E S I S T A N T A N D PL A T INU M - S E N S I T I V E O V A R IA N CA NCE R Regimen Chemo/Avastin Regimen Carbo/Gem Carbo/Tax Median age 61 Median age 61 60 Platinum resist 1-2 priors 60% - 1 prior 40% - 2 prior Patient population plat sensitive, 1 prior plat sensitive, 1 prior Patient population Prior Avastin 0 10% Prior Avastin 7% ORR 57% 56% ORR 27% mPFS (mo) 8.4 (95% 8.3, 9.7) 10.4 (95% 9.7-11) mPFS (mo) 6.7 (95% 5.7, 7.9) 1Pujade-Lauraine, et al., JCO 32:1302 (2014) 2Aghajanian, et al., JCO 30:2039 (2012) 3Coleman, et al., Lancet Oncol 18:779 (2017) 6 PLATINUM-RESISTANT OVARIAN CANCER A U R E L I A 1 PLATINUM-SENSITIVE OVARIAN CANCER O CE A N s 2 GO G 213 3

A VA S T I N EXPANSION COHORT AV AS T I N 1  Mirvetuximab in combination with Avastin shows early evidence of anti-tumor activity with durable responses Greatest benefit seen among the subset of patients with medium or high FR expression levels, which is the population being studied in the FORWARD I Phase 3 trial Encouraging efficacy results support further trials of this novel therapeutic combination Safety profile in line with known profiles of each agent    1ASCO 2018 O’Malley D., et al. Avastin® is a registered trademark of its owner. ORR: objective response rate; mPFS: median progression-free survival; mDOR: median duration of response 7 H E A V I L YP R E - T R E A T E DP L A T I N U M - R E S I S T A N T A L L (n=54) 43% ORR 7.8 months mPFS 10.6 months mDOR M E D+HIG H 1 - 3 P rio rs (n=23) 48% ORR 9.9 months mPFS 10.6 months mDOR M E D+HIG H 1 - 2P ri o rs A v astin-n a ï v e (n=16) 50% ORR 9.9 months mPFS 12.0 months mDOR

C A R B O P L AT I N M A T U R E C O H O R T D O S E - E S C A L A T I O N F I N D I N G S in combination with carboplatin  Mirvetuximab appears well-tolerated and highly active in patients with recurrent, platinum-sensitive ovarian cancer Further evaluation of this combination in a randomized fashion is warranted Recent data support ongoing triplet designed to evaluate mirvetuximab + carboplatin + Avastin in patients with recurrent platinum-sensitive disease   1Company data – manuscript in preparation. ORR: objective response rate; mPFS: median progression-free survival 8 C AR B O P L AT I N 1 P L A T I N U M - S E N S I T I V E A L L (n=17) 71% ORR 15.0 months mPFS mDOR not yet reached M E D + H I G H (n=10) 80% ORR 15.0 months mPFS mDOR not yet reached

K E Y T R U D A DOSE ESCALATION COHORT  Mirvetuximab in combination with Keytruda shows early evidence of anti-tumor activity with durable responses and favorable tolerability profile Greatest benefit seen among the subset of patients with medium or high FR expression levels, which is the population being studied in the FORWARD I Phase 3 trial   Expansion cohort completing enrollment, expect report initial findings later this year to 1SGO 2018 Matulonis U., et al. Keytruda® is a registered trademark of its owner. ORR: objective response rate; mPFS: median progression-free survival; mDOR: median duration of response 9 KEY T RU D A 1 P L A T I N U M - R E S I S T A N T A L L (n=14) 43% ORR 5.2 months mPFS 7.0 months mDOR M E D + H I G H (n=8) 63% ORR 8.6 months mPFS 8.3 months mDOR

MI R V E T U X I M A B C O MB I N A T I O N S O F F E R P O T E N T I A L T O T RE A T M O RE W O M E N W IT H O VA RIA N C A NC E R AV AS T I N 1 P L A T I N U M - R E S I S T A N T (n=10) (95% CI 44,98) mPFS not yet reached 1ASCO 2018 O’Malley D., et al.; 2Company data – manuscript in preparation; 3SGO 2018 Matulonis U., et al. Avastin® and Keytruda® are registered trademarks of their respective owners. ORR: objective response rate; mPFS: median progression-free survival; mDOR: median duration of response 10 C AR B O P L AT I N 2 P L A T I N U M - S E N S I T I V E Med. No. of Prior Therapies (Range): 2.5 (1-6) H E A V I L YP R E - T R E A T E D Med. No. of Prior Therapies (Range): 3 (1-8) A L L (n=54) 43% ORR (95% CI 29,57) 7.8 months mPFS (95% CI 5.6,10.2) 10.6 months mDOR (95% CI 4.9,-) M E D + H I G H (n=23) 48% ORR (95% CI 27,69) 9.9 months mPFS (95% CI 4.6,14.5) 10.6 months mDOR (95% CI 3.3,12.0) A L L (n=17) 71% ORR (95% CI 44,90) 15.0 months mPFS (95% CI 9.9,-) mDOR not yet reached M E D + H I G H 80% ORR 15.0 months (95% CI 9.9,-) mDOR KEY T RU D A 3 P L A T I N U M - R E S I S T A N T Med. No. of Prior Therapies (Range): 4.5 (2-7) A L L (n=14) 43% ORR (95% CI 18,71) 5.2 months mPFS (95% CI 1.6,9.5) 7.0 months mDOR (95% CI 3.4,-) M E D + H I G H (n=8) 63% ORR (95% CI 25,92) 8.6 months mPFS (95% CI 1.6,-) 8.3 months mDOR (95% CI 3.4,-)

MI R V E T U X I M A B C O MB I N A T I O N S O F F E R P O T E N T I A L T O C A NC E R 1 T RE A T M O RE W O M E N W IT H O VA RIA N  Results have indicated a favorable safety profile with adverse events in-line with known profiles of each agent – full dose of each agent able to be combined  Encouraged by early evidence of anti-tumor activity with durable responses CONSISTENCY OF FINDINGS UNDERSCORE POTENTIAL OF MIRVETUXIMAB TO TREAT PATIENTS WITH PLATINUM-RESISTANT AND PLATINUM-SENSITIVE OVARIAN CANCER  Recent data support ongoing triplet designed to evaluate a mirvetuximab + carboplatin + Avastin in patients with recurrent platinum-sensitive disease  Totality of data will guide next stages of development support path to registration for combination regimens and 1O’Malley et al, abstract 5553, ASCO 2017 11