In clinical trials, Proleukin has demonstrated durable complete responses of over 20 years in some mRCC patients and over 15 years in some mM patients. Objective response was seen in 16% of patients with mM (6% had a complete response and 10% had a partial response) and in 15% of patients with mRCC (7% had a complete response and 8% had a partial response).1-4
Early mRCC clinical data methodology2,3:
- 225 mRCC patients were enrolled in 7 clinical trials across 21 institutions
- Proleukin (600,000 or 720,000 IU/kg) was administered in 15-minute infusions every 8 hours for up to 14 consecutive doses over 5 days
- A second, identical cycle was administered, following up to 9 days of rest
Objective response rate (CRa + PRb) 15% (37/255)
Complete responses 7% (17/255)
Partial responses 8% (20/255)
Proleukin demonstrated:
- Both durable complete responses (CRs) and partial responses (PRs)2,3
- > 90% regression or complete disappearance of tumors in over 70% of responders with a baseline tumor of ≥ 50 cm2 5,*
- Responses were evident in metastatic sites (including the lung, liver, lymph node, renal bed, spleen, soft tissue, and bone) regardless of visceral involvement and tumor burden2,3

Long-term progression-free survival
Proleukin demonstrated the potential for some mRCC patients to achieve a durable complete response of over 20 years without needing subsequent systemic therapy.1
Methodology1:
- Eleven treatment centers identified and followed patients (46 with mRCC and 54 with mM) who had survived ≥ 5 years after treatment with Proleukin and had no subsequent systemic therapy
93% (38/46) achieved
a complete response
after treatment
with Proleukin
Follow-up
ranged from
5+ to 30+ yearsd
27 were alive
> 10 years after
Proleukin without
subsequent therapy
Following PD-1 or PD-L1 inhibitors methodology6:
- Retrospective analysis of Proleukin utilizing PROCLAIMSM registry data
- Group 1: 57 patients (17 mRCC, 40 mM) received Proleukin after developing resistance to treatment with PD-1 or PD-L1 inhibitors
- Group 2: 1,122 patients (mRCC and mM) treated with Proleukin only
Results:
Of patients previously treated with, and progressed on, PD-1/PD-L1 inhibitors, the best overall response and stable disease rates reported following treatment with Proleukin were:
Best overall response rate for
mRCC patients (2 CRs, 2 PRs†)
Stable disease rate for
mRCC patients (8/17)
* |
Fourteen of 36 responders had baseline tumor burden ≥ 50 cm2; of these, 8 of 14 had > 90% tumor regression, and 2 of 14 had complete disappearance of tumors after Proleukin treatment.4 |
† |
Neither of the 2 mRCC patients who had a complete response (CR) progressed (during the 2 years of follow-up). Neither of the 2 mRCC patients with a partial response (PR) progressed (during the 2 years of follow-up). |
a |
CR is defined as complete disappearance of tumors. One of the 17 patients with a CR relapsed at 86 months.3,5 |
b |
PR is defined as ≥ 50% reduction in measurable tumor area with no increase in the size of lesions. Two of the 20 patients with a PR remain in continuing remission > 83 and > 126 months.2,4 |
c |
The median CR duration was still not reached at 80+ months (range: 7 to 131+ months).3 |
d |
Median follow-up was 10.5+ years. |
A first- or second-line treatment option for mRCC patients.8,9
References: 1. Clark JI, Curti B, Davis EJ, et al. Long-term progression-free survival of patients with metastatic melanoma or renal cell carcinoma following high-dose interleukin-2. J Investig Med. Published online Feb 4, 2021. doi: 10.1136/jim-2020-001650. 2. Proleukin [package insert]. Yardley, PA: Clinigen, Inc; 2019. 3. Fisher RI, Rosenberg SA, Fyfe G. Long-term survival update for high-dose recombinant interleukin-2 in patients with renal cell carcinoma. Cancer J Sci Am. 2000;6(suppl 1):S55-S57. 4. Atkins MB, Kunkel L, Sznol M, Rosenberg SA. High-dose recombinant interleukin-2 therapy in patients with metastatic melanoma: long-term survival update. Cancer J Sci Am. 2000;6(suppl 1):S11-S14. 5. Fyfe G, Fisher RI, Rosenberg SA, Sznol M, Parkinson DR, Louie AC. Results of treatment of 255 patients with metastatic renal cell carcinoma who received high-dose recombinant interleukin-2 therapy. J Clin Oncol. 1995;13(3):688-696. 6. Buchbinder EI, Dutcher JP, Daniels GA, et al. Therapy with high-dose interleukin-2 (HD IL-2) in metastatic melanoma and renal cell carcinoma following PD1 or PDL1 inhibition. J Immunother Cancer. 2019;7(1):49. 7. Atkins MB, Lotze MT, Dutcher JP, et al. High-dose recombinant interleukin 2 therapy for patients with metastatic melanoma: analysis of 270 patients treated between 1985 and 1993. J Clin Oncol. 1999;17(7):2105-2116. 8. NCCN® Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Kidney cancer. Version 3.2021. March 22, 2021. www.nccn.org. Accessed May 14, 2021. 9. Rini BI, McDermott DF, Hammers H, et al. Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of renal cell carcinoma. J Immunother Cancer. 2016;4:81.
Early mM clinical data methodology2,4:
- 270 mM patients were enrolled in 8 clinical trials across 22 institutions
- Proleukin (600,000 or 720,000 IU/kg) was administered in 15-minute infusions every 8 hours for up to 14 consecutive doses over 5 days
- A second, identical cycle was administered, following up to 9 days of rest
Objective response rate (CRa + PRb) 16% (43/270)
Complete responses 6% (17/270)
Partial responses 10% (26/270)
Proleukin demonstrated:
- Both durable complete responses (CRs) and partial responses (PRs)2,4
- Patients who maintained a response (CRa or PRb) for at least 2.5 years did not relapse4
- Nearly 60% (10/17) of CRs maintained response ranging from 3.5 to 10 years4
- Responses were evident in metastatic sites (including the lung, liver, lymph node, spleen, adrenal glands, soft tissue, bone, and in cutaneous and subcutaneous sites) regardless of visceral involvement and tumor burden2,7,c

Long-term progression-free survival
Proleukin demonstrated the potential for some mM patients to achieve a durable complete response of over 15 years without needing subsequent systemic therapy.1
Methodology1:
- Eleven treatment centers identified and followed patients (54 with mM and 46 with mRCC) who had survived ≥ 5 years after treatment with Proleukin and had no subsequent systemic therapy
96% (43/54) achieved
a complete response
after treatment
with Proleukin
Follow-up
ranged from
5+ to 15+ yearsd
32 were alive
> 10 years after
Proleukin without
subsequent therapy
Following PD-1 or PD-L1 inhibitors methodology6:
- Retrospective analysis of Proleukin utilizing PROCLAIMSM registry data
- Group 1: 57 patients (40 mM, 17 mRCC) received Proleukin after developing resistance to treatment with PD-1 or PD-L1 inhibitors
- Group 2: 1,122 patients (mM and mRCC) treated with Proleukin only
Results:
Of patients previously treated with, and progressed on, PD-1/PD-L1 inhibitors, the best overall response and stable disease rates reported following treatment with Proleukin were:
Best overall response rate for
mM patients (4 CRs, 5 PRs*)
Stable disease rate for
mM patients (15/40)
* |
None of the mM patients who had a CR had progressed at the time of the database lock (1 to 4 years of follow-up). Three of 5 PRs in mM patients were continuing as of the database lock (1 to 2 years of follow-up). |
a |
CR is defined as complete disappearance of tumors. The median CR duration was still not reached at 59+ months (range: 3 to 122+ months).4,7 |
b |
PR is defined as ≥ 50% reduction in measurable tumor area with no increase in the size of lesions.4,7 |
c |
Of 17 patients with a CR, 14 were ECOG PS 0 and 3 were PS 1; of 26 patients with PR, 22 were PS 0, 3 were PS 1, and 1 was PS 2.7 |
d |
Median follow-up was 10+ years. |
References: 1. Clark JI, Curti B, Davis EJ, et al. Long-term progression-free survival of patients with metastatic melanoma or renal cell carcinoma following high-dose interleukin-2. J Investig Med. Published online Feb 4, 2021. doi: 10.1136/jim-2020-001650. 2. Proleukin [package insert]. Yardley, PA: Clinigen, Inc; 2019. 3. Fisher RI, Rosenberg SA, Fyfe G. Long-term survival update for high-dose recombinant interleukin-2 in patients with renal cell carcinoma. Cancer J Sci Am. 2000;6(suppl 1):S55-S57. 4. Atkins MB, Kunkel L, Sznol M, Rosenberg SA. High-dose recombinant interleukin-2 therapy in patients with metastatic melanoma: long-term survival update. Cancer J Sci Am. 2000;6(suppl 1):S11-S14. 5. Fyfe G, Fisher RI, Rosenberg SA, Sznol M, Parkinson DR, Louie AC. Results of treatment of 255 patients with metastatic renal cell carcinoma who received high-dose recombinant interleukin-2 therapy. J Clin Oncol. 1995;13(3):688-696. 6. . Buchbinder EI, Dutcher JP, Daniels GA, et al. Therapy with high-dose interleukin-2 (HD IL-2) in metastatic melanoma and renal cell carcinoma following PD1 or PDL1 inhibition. J Immunother Cancer. 2019;7(1):49. 7. Atkins MB, Lotze MT, Dutcher JP, et al. High-dose recombinant interleukin 2 therapy for patients with metastatic melanoma: analysis of 270 patients treated between 1985 and 1993. J Clin Oncol. 1999;17(7):2105-2116. 8. NCCN® Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Kidney cancer. Version 3.2021. March 22, 2021. www.nccn.org. Accessed May 14, 2021. 9. Rini BI, McDermott DF, Hammers H, et al. Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of renal cell carcinoma. J Immunother Cancer. 2016;4:81.