Neuromuscular and cardiac adverse events associated with immune checkpoint inhibitors: pooled analysis of individual cases from multiple institutions and literature

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the management of multiple tumors, due to improved efficacy, quality of life, and safety. While most immune-related adverse events (irAEs) are mild and easily managed, in rare cases such events may be life-threatening, especially those affecting the neuromuscular and cardiac system. The management of neuromuscular/cardiac irAEs is not clear due to the lack of consistent data. Therefore, we carried out a pooled analysis of collected cases from selected Italian centers and individual data from published case reports and case series, in order to improve our understanding of these irAEs.

PATIENTS AND METHODS

We collected retrospective data from patients treated in six Italian centers with ICIs (programmed cell death protein 1 or programmed death-ligand 1 and/or cytotoxic T-lymphocyte antigen 4 inhibitor) for any solid tumor who experienced neuromuscular and/or cardiovascular toxicity. Then, we carried out a search of case reports and series of neuromuscular/cardiac irAEs from ICIs with any solid tumor.

RESULTS

This analysis includes cases from Italian institutions (n = 18) and the case reports identified in our systematic literature search (n = 120), for a total of 138 patients. Among these patients, 50 (36.2%) had complete resolution of their neuromuscular/cardiac irAEs, in 21 (15.2%) cases there was a clinical improvement with mild sequelae, and 53 (38.4%) patients died as a result of the irAEs. Factors significantly associated with worse outcomes were early irAE onset, within the first two cycles of ICI (Fisher P < 0.0001), clinical manifestation of both myositis and myocarditis when compared with patients who developed only myositis or myocarditis (chi-square P = 0.0045), and the development of arrhythmia (Fisher P = 0.0070).

CONCLUSIONS

To the best of our knowledge, this is the largest collection of individual cases of immune-related myocarditis/myositis. Early irAE onset, concurrent development of myositis and myocarditis, as well as occurrence of arrhythmias are associated with worse outcomes and should encourage an aggressive immunomodulatory treatment.

Dexamethazone-induced acute tumor lysis syndrome in a T-cell malignant lymphoma

We report a case of steroid-induced acute tumor lysis syndrome and review the literature. A 60-year-old woman was started on steroid therapy for dyspnea due to bilateral pleural effusion and a large mass involving the anterior mediastinum. The final diagnosis was precursor T-lymphoblastic lymphoma-leukemia. Following steroid therapy, the patient developed acute renal failure and laboratory evidence of metabolic changes induced by massive cytolysis. She received vigorous hydration, diuretic and allopurinol therapy, and haemodialysis. Her diuresis, renal function and laboratory data returned to normal within 2 weeks. A review of the medical literature on T-cell lymphoma revealed only one similar case of steroid-induced acute tumor lysis syndrome, a life-threatening metabolic emergency. This risk should be kept into account in the management of patients with lymphoproliferative disorders.

Effects of retinoic acid and amifostine on in vitro growth of normal hemopoietic progenitor cells

Association of all-trans retinoic acid (ATRA) and amifostine (AMF) might be an alternative in treatment of myelodisplatic syndromes. In this study we undertook a preliminary in vitro research on the effects of a combination of ATRA and AMF on normal hemopoietic progenitors. Mononuclear, non-adherent cells from peripheral blood of normal volunteers, were incubated with AMF, at a the concentration of 500 microM and then cultured for CFU-GM and BFU-E growth adding to culture dishes before gelling ATRA at the concentration 10(-6) and 10(-12)M. Controls were cultures not pre-incubated with AMF, cultures incubated with AMF without addition of ATRA and cultures without addition of any drug. ATRA addition did not have significant effects on hemopoietic progenitors growth. Association of ATRA and AMF do not appear to synergize to stimulate in vitro growth of hemopoietic progenitors.

Advanced colorectal cancer: quality of life and toxicity in patients after weekly 24-hour continuous infusions of biomodulated 5-fluorouracil

It is generally agreed that chemotherapy prolongs survival and relieves symptoms more than the best supportive care in advanced colorectal cancer. Since its introduction over 35 years ago, 5-fluorouracil (5-FU) has been the only effective chemotherapeutic option available for the treatment of advanced colorectal cancer. Efforts have focused on the use of various 5-FU-based regimens. A commonly used regimen, frequently extolled as the "gold standard" for clinical trials in advanced colorectal cancer, is the Mayo Clinic regimen; this option has, however, been associated with considerable dose-limiting toxicity. Another approach has involved 5-FU administration by continuous intravenous infusion. In this paper we present our experience on 10 Dukes D colorectal cancer patients treated with 24-hour continuous infusion of biomodulated 5-FU delivered in an ambulatory setting with an intravenous infusional pump. The number of treated patients was admittedly not sufficient to evaluate the clinical response of this 5-FU chemotherapeutic regimen. This is not the goal of our work; however, other rationale for adopting this approach is justified: the regimen has a favourable toxicity profile and can provide considerable benefit in terms of improved quality of life while at the same time the health care costs are alleviated since hospitalization is generally not required.

Effects of docetaxel on the in vitro growth of human myeloid progenitors

Haemotoxicity is usually the primary and dose-limiting side-effect of docetaxel (TXT) a semysyntetic analogue of paclitaxel which has acquired an important role in anticancer treatment. This research presents the results of an in vitro toxicity study of TXT on myeloid progenitors obtained from healthy volunteers and assayed as CFU-GM. Peripheral blood mononucleated non-adherent cells (MNAC) were incubated for 24 h at standard conditions with increasing concentrations of TXT and then cultured for CFU-GM assay. At every concentration severe CFU-GM growth inhibition was observed. In a second set of experiments MNAC were sequentially exposed to TXT and then to doxorubicin or cisplatin or vinorelbine or etoposide at appropriate concentrations. In a third set the sequence of exposure was reversed. No difference of CFU-GM growth inhibition was observed between the alternate sequences. These findings suggest that the toxicity on CFU-GM in vitro growth of TXT combinations with other anticancer drugs is sequence-independent.

In vitro toxicity of taxol based anticancer drug combinations on human hemopoietic progenitors

The sequence dependency of the interaction of taxol with other anticancer drugs is of clinical importance, and may be due to pharmacokinetic changes and/or to inherent differences in the sensitivity of target normal or cancer cells. This study presents results on the in vitro interaction of taxol with doxorubicin, cisplatin, etoposide and vinorelbine in alternate sequences on human hemopoietic progenitors (CFU-GM). Peripheral blood mononuclear non adherent cells were exposed to IC50 of Taxol for 24 hours and then, for 1 hour to IC50 of each of the other drugs. In a second set of experiments the reverse sequence was applied. The cell suspension was subsequently cultured to assay the growth of CFU-GM. A strong sequence dependency characterizes the combination taxol-vinorelbine, while for the other combinations the order of sequence appears to have little impact on in vitro toxicity on CFU-GM. Comparing results on CFU-GM with that obtained in vitro with the same combination sequences on cancer cell lines some remarkable differences show up. Studies on a normal human myeloid line may therefore have a place in preclinical evaluation of sequence of anticancer drug combinations.

In vitro toxicity of A 3'-azido-3'-deoxythymidine and hydroxyurea combination on normal myeloid progenitors

Hydroxyurea (HU) appears to increase 3'-azido-3'-deoxythymidine (AZT) antiretroviral activity and cytotoxicity by inhibiting thymidilate synthesis. The combination of AZT and HU may therefore be of clinical usefulness. We evaluated the in vitro hemotoxicities of different combinations of AZT and HU in comparison with the hemotoxicities exerted by either of the two drugs alone. Peripheral blood granulocyte macrophage committed progenitors (CFU-GM) of healthy donors were selected as targets of hemotoxicity. Both AZT and HU separately had a dose-dependent inhibitory effect on the in vitro growth of normal circulating CFU-GM. The combination of the two drugs induced a statistically significant synergistic cytotoxicity. In fact, addition of HU induced a remarkable reduction of AZT ID50. Thus, future clinical application of AZT, HU combination should take into account the greater hemosuppressive action of the combination in respect to that observed following administration of either drug alone.

Cisplatin inhibits erythroid committed progenitor (BFU-E) mobilization in peripheral blood

Circulating myeloid (CFU-GM) and erythroid (BFU-E) progenitor levels were evaluated weekly throughout 3 courses of treatment with vinorelbine (VNB) ifosfamide (IFO) and filgrastim (G-CSF) with or without addition of cisplatin (DDP) in 20 stage IIIB or IV non small-cell lung cancer patients. In IFO, VNB, DDP-treated patients, BFU-E mobilization in peripheral blood following chemotherapy and G-CSF was completely lacking, in contrast with the patients treated with IFO, VNB plus G-CSF. CFU-GM release, however, was of the same order in the 2 groups of patients. Further investigations are needed to explain why presence of DDP in this chemotherapeutic protocol hinders erythroid progenitor release in peripheral blood.

Toxicity on human hemopoietic progenitors of 2'-2'-difluoro-2'deoxycytidine (gemcitabine)

This study presents results on 2'-2'-difluoro-2'deoxycytidine's (dFdC: gemcitabine) in vitro toxicity on peripheral blood CFU-GM and BFU-E obtained from healthy volunteers. Peripheral blood mononucleated non-adherent cells were cultured according to standard methods with continuous exposure (13 days) to dFdC (4,40 and 400 pmol/L) or following 1 hour's, incubation with increasing drug concentrations (1, 10, 100 mumol/L). The results indicate that dFdC has a marked dose-dependent inhibitory effect on the in vitro growth of peripheral blood hemopoietic progenitors., No significant differences were observed for the growth inhibition induced on CFU-GM and BFU-E. Continuous exposure to dFdC gave an IC50 of 4 pmol/L for both CFU-GM and BFU-E. In four chemotherapy naive patients affected by tumors of different type treated with three standard courses of dFdC the variations in the peripheral blood of hemopoietic progenitor level were determined. Patterns of changes were different, but a marked and sustained decrease of both CFU-GM and BFU-E was observed in one case only. The contrast between the apparently rather mild clinical hemotoxicity of dFdC and its in vitro dramatically potent inhibitory activity on hemopoietic progenitors is discussed.

Feasibility and toxicity of combination chemotherapy with ifosfamide, vinorelbine, cisplatin versus ifosfamide, vinorelbine in patients with advanced non small cell lung cancer

Vinorelbine (VNB) and Ifosfamide (IFO) have recently been proposed for treatment of non small cell lung cancer (NSCLC). The two drugs separately induce response rates in excess of 20% and, when combined, of 32.56%. Cisplatin (DDP) is considered a standard in chemotherapy of NSCLC affected patients. We report data on the feasibility and the toxicity of an IFO, VNB and DDP combination in comparison with IFO, VNB association. Results obtained show that the IFO, VNB, DDP combination has a more severe toxicity profile than the IFO, VNB combination although not to a degree precluding its feasibility. Responses, however, appear somewhat more favorable than in the group treated with the combination IFO, VNB. It is therefore necessary to ascertain if clinical advantages in survival and symptom palliation offered by IFO, VNB, DDP combination outweigh impairment in quality of life due to its significant toxicity.

In vitro synergistic inhibition of human bone marrow hemopoietic progenitor growth by a 3'-azido-3'-deoxy-thymidine, 2',3'-dideoxycytidine combination

In vitro growth of human normal bone marrow granulocyte-macrophage colony forming units (CFU-GMs) and erythroid burst forming units (BFU-Es) was dose-dependently inhibited by 3'-azido-3'deoxythymidine (AZT) (from 0.1 microM to 4 microM) and 2',3'-dideoxycytidine (ddC) (from 0.01 microM to 1.0 microM). These ranges included minimum in vitro inhibitory concentrations to HIV-1 and concentrations corresponding to plasma level achievable in vivo. A synergistic inhibitory effect, statistically highly significant, was observed when combinations of the two drugs were added to cultures. This severe in vitro toxicity of ddC and the synergistic toxicity of AZT-ddC combinations on hemopoietic progenitor cells should be considered when the two drugs are administered in concurrent or alternating regimens.

Interferon-alpha inhibits CFU-GM mobilization following chemotherapy and G-CSF administration

Changes in routine hematologic data and in circulating granulocyte-macrophage colony-forming units (CFU-GM) during granulocyte colony-stimulating factor (G-CSF) administration were evaluated in non-small cell lung carcinoma (NSCLC) patients treated with a combination of 5-fluorouracil (5-FU) and cisplatin (DDP) with and without the addition of interferon-alpha (IFN-alpha). The patterns of leukocyte changes following chemotherapy plus G-CSF were similar in both the IFN-alpha-inclusive and the IFN-alpha-devoid courses. However, the twofold increase in CFU-GM observed in patients receiving chemotherapy plus G-CSF was completely absent following the course including IFN-alpha. The activity of G-CSF on the hematologic pattern is seemingly affected by its combination with IFN-alpha treatment. Mechanisms of the possible in vivo interaction among IFNs and hematopoietic growth factors remain to be elucidated.